The Epidemiological and Clinical Concepts of Viral Hepatitis in Libya ; Part II- Geography, Prevalence, Genotyping and Modeling Mohamed A Daw
LIBYA SERIES ;2-Viral Hepatitis in Libya; Geography and Epidemiology, Tripoli, August 2017
The Epidemiological and Clinical Concepts of Viral Hepatitis in Libya ; Part II- Geography, Prevalence, Genotyping and Modeling
Mohamed A Daw, MPS, PhD, MD, FTCDI Professor of Clinical Epidemiology & Acting Physician of Internal Medicine, Faculty of Medicine, University of Tripoli LIBYA SERIES; 2-Viral Hepatitis in Libya; Geography and Epidemiology, Tripoli, August 2017
CONTENTS 1-Prevalence of hepatitis B and hepatitis C infection in Libya: results from a national population based survey
2-Epidemiological manifestations of hepatitis C virus genotypes and its association with potential risk factors among Libyan patients 3-Geographic distribution of HCV genotypes in Libya and analysis of risk factors involved in their transmission 4-Seroprevalence of HBV, HCV & HIV Co-Infection and Risk Factors Analysis in Tripoli-Libya 5-The role of hepatitis C virus genotyping in evaluating the efficacy of INF-based therapy used in treating hepatitis C infected patients in Libya 6-Modelling the prevalence of hepatitis C virus amongst blood donors in Libya: An investigation of providing a preventive strategy
Daw and El-Bouzedi BMC Infectious Diseases 2014, 14:17 http://www.biomedcentral.com/1471-2334/14/17
RESEARCH ARTICLE
Open Access
Prevalence of hepatitis B and hepatitis C infection in Libya: results from a national population based survey Mohamed A Daw1,3*, Abdallah El-Bouzedi2 and In association with Libyan Study Group of Hepatitis & HIV
Abstract Background: Libya is one of the largest countries in Africa and has the longest coast in the Mediterranean basin facing southern Europe. High rates of prevalence of viral hepatitis have been observed in various regions in Africa, but the prevalence in Libya is not well documented. We report on a large-scale nationwide study that evaluated the epidemiology of hepatitis B and hepatitis C in Libya and assessed the risk factors involved. Methods: A cross-sectional study was carried out in 2008 on 65,761 individuals all over Libya. The country was divided into 12 regions according to the population density and sampling within each region was carried out under the supervision of the National Centre for Prevention of Infectious Diseases. Serum samples were collected from both males and females of all ages in both urban and rural areas and tested for HBsAg for hepatitis B and anti-HCV antibody for hepatitis C. Prevalence rates were determined in regions and in different groups and correlated with different demographic and risk factors involved in the spread of these viruses. Results: The prevalence of hepatitis B and hepatitis C viruses varied regionally across the country. The overall prevalence of hepatitis B was 2.2% (95% CI 2.1%−2.3%) and was higher among males than females (1.4:1.0). Hepatitis C virus (HCV) prevalence was 1.2% (95% CI 1.1−1.3) and it increased gradually after the age of 30 years (0.7−0.9% for < 30 years; 3.6% for ≥ 60 years). Prevalence of HBsAg was 0.8−0.9% below the age of 10 years, and higher but similar in older age groups (2.3−2.7%). There was an association between literacy and prevalence of hepatitis, particularly for HCV. Hospital admission, surgical operation, blood transfusion, and intravenous drug use were the main risk factors, and they were associated independently with a higher prevalence rate of viral hepatitis. Conclusions: Libya may be considered an area of low-intermediate endemicity for hepatitis B virus infection, with lower rates in young age groups, and an area of low endemicity for hepatitis C. The prevalence of hepatitis B and C across Libya is not homogeneous, with indications of the effect of the higher rates in some neighbouring countries. Libya should adopt full coverage national plans and guidelines to face the future consequences of viral hepatitis, particularly hepatitis C virus. Keywords: Hepatitis B virus, Hepatitis C virus, Libya, Prevalence, HBsAg, Anti-HCV-Ab
* Correspondence:
[email protected] 1 Department of Medical Microbiology, Faculty of Medicine, Tripoli, Libya 3 Professor of Clinical Microbiology & Microbial Epidemiology, Acting Physician of Internal Medicine, Scientific Coordinator of Libyan National Surveillance Studies of Viral hepatitis & HIV, Tripoli, Libya Full list of author information is available at the end of the article © 2014 Daw and El-Bouzedi; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Daw and El-Bouzedi BMC Infectious Diseases 2014, 14:17 http://www.biomedcentral.com/1471-2334/14/17
Background Hepatitis B and C viruses (HBV and HCV) are the major causes of liver diseases in the world. The relative importance of HBV and HCV infections varies greatly from one part of the world to another and changes over time [1]. Worldwide, over two billion people are infected by HBV alone, of whom about one million die annually. Hepatitis C virus affects about 200 million people [2]. However, in many countries its prevalence is expected to surpass that of hepatitis B, particularly among certain risk groups that are vulnerable to both hepatitis B and C viruses [3]. The endemicity of HBV infection varies greatly over the world, from highly endemic areas (> 8% infection rate), to intermediate (2−8%) and low endemicity areas (< 2%). Africa is among the highly endemic areas, but some countries in the north fall in the intermediate category, with an average rate of about 7%, whereas most regions of west and east Africa are highly endemic areas with chronic infection rates of 7−10% [4]. In some countries, such as Senegal, a large part of the population will be exposed in the course of their lives to HBV and become infected [5]. All of central and southern Africa is also in the high endemicity category [6]. Few studies evaluated the status of HBV in Libya. In 2000, Daw et al. [7] reported a HBV prevalence of 10% among hospital health-care workers and that infection was associated with certain occupational risk factors. Hepatitis C virus infection is a major public health problem [8,9]. African countries have among the highest prevalence rates of HCV in the world, ranging from 1 to 26% [10,11]. More than 28 million people are chronically infected with HCV in this continent, and it is difficult to speculate about current and future trends [3,12]. In Libya, one study reported that the prevalence of HCV among different populations varied according to the risk factor involved [13]. Recently, a comprehensive study was carried out on HCV genotypes in Libya. Hepatitis C virus genotype 4 was the predominant one, followed by HCV genotype 1 and then other less common genotypes [14]. However, further studies are needed to clarify the magnitude and impact of HCV in Libya. Viral hepatitis has tremendous socioeconomic, healthcare and even political repercussions. A better understanding of the epidemiology of viral hepatitis and the risk factors involved is among the priorities of any nation [15,16]. Reliable epidemiological data on prevalence rates and transmission routes [17,18] of viral hepatitis are essential for designing national control policies. The epidemiological data in Africa are scanty and vary greatly from one region to another [4]. Therefore, each country should adopt its own strategy to combat viral hepatitis. Libya has an area of 1,775,500 km2 and a population reported in mid 2006 as 5,323,991, giving a population density of 2.9 persons per km2. The country boasts the highest literacy and educational enrolment in North
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Africa and among the Arab nations [19,20]. Life expectancy (73 years) and health-adjusted life expectancy (64 years) are among the best in the Middle East and North Africa [19,21]. Nevertheless, Libyan health services have been hampered by bureaucracy and lack of proper long-term planning [20,22]. Both Libyan and international medical experts have voiced concerns about the potential for increases in infection, particularly viral hepatitis and AIDS [23,24]. Recent data on the prevalence of hepatitis B and C viruses and risk factors among the Libyan population are lacking. Such data are important for understanding the burden of viral infection and for predicting future trends. Implementation of surveillance to guide public health policy is needed to efficiently control viral hepatitis spread in this country, and this requires reliable epidemiological data. In this comprehensive nationwide study we determined the prevalence of hepatitis B and C virus infections among the Libyan population and analysed the risk factors.
Methods Study population
We conducted a national cross-sectional study stratified by region and age. The sample size in each region was set ahead of the survey and recruitment continued until the sampling teams fulfilled the required sample size. Those enrolled from each region were selected randomly. Regional representativeness was fulfilled by classifying the country into 12 regions including all administrative divisions and sampling based on population proportions. Sample sizes of males, females and age strata were determined by multi-stage cluster sampling in each region proportional to regional populations according to the latest national census in 2003–2004. Teams of medical doctors and nurses established the sampling frames and collected the information and samples in all the regions as described in Table 1. The following targeted age strata were selected: – < 6 years: Pre-school children (maternal and child care centres); – 7–19 years: School age below university level (primary, preparatory and high schools); – 20–49 years: University graduate and post graduate students (universities and health services centres); – ≥ 50 years: Employed and retired personnel (different community and governmental sectors). Demographic and epidemiological data questionnaire
Sample size calculations were based on the prevalence of HCV and HBV infections in prior studies in Libya. To detect a two-fold increase in prevalence among the lowest prevalence expected for HCV 1/1000 in each age group as compared with the next age, a sample of 25,476 has a power of 80% (beta error 20 years, the unweighted and weighted percentages were not significantly different (1.5% and 1.6%, respectively). The prevalence rate was slightly higher Table 2 Association between hepatitis B and C virus infections and influencing factors among the Libyan population HCV OR
HBsAg
95.0% C.I.
OR
Lower Upper
95.0% C.I. Lower Upper
Age group (years) relative to < 6 6-10
0.74 0.46
1.18
1.21 0.79
1.86
11-20
0.91 0.67
1.24
3.36 2.5
4.52
21-30
0.88 0.63
1.22
3.01 2.21
4.1
31-40
1.41 1.01
1.96
3.14 2.28
4.32
41-50
1.87 1.32
2.64
3.77 2.7
5.26
51-60
2.36 1.65
3.37
3.7
2.59
5.28
61-70
3.27 2.17
4.93
3.34 2.13
5.24
>70
3.32 2.01
5.49
5.69 3.54
9.15
1.51 1.35
1.68
0.85 0.76
0.96
0
-
Males vs females
0.86 0.74
0.99
Hospital admission
1.32 1.09
1.61
Dental procedure
0.84 0.71
0.99
Blood transfusion
1.55 1.22
1.97
Intravenous drug use
6.41 2.27
18.07
Surgery
1.35 1.08
1.67
Family HBV
1.52 1
2.3
Haemodialysis
4.37 1.71
11.2
0
1.97 1.46
2.64
Contact with HBV
1.66 1.23
2.23
Skin piercing
1.36 1
1.83
Daw and El-Bouzedi BMC Infectious Diseases 2014, 14:17 http://www.biomedcentral.com/1471-2334/14/17
among females than males but the difference was not statistically significant. The prevalence rates weighted for other factors (age group, education, marital status, type of dwelling, and risk exposure) are shown in Additional file 2: Table S2. Figure 2 shows the prevalence of HBV and HCV among the Libyan population according to age. The prevalence of anti-HCV was stable at 0.8−0.9% until the age of 30 years, after which it rose steadily, reaching 2.7% in those above the age of 50 years. In contrast, the prevalence of HBsAg was lowest in the youngest age group (0.9%), and in the older groups it fluctuated between 2.0% and 2.9% without any evident temporal trend. However, it rose sharply after the age of 70 years. The overall prevalence rates of HCV in males and females were similar (1.1% and 1.3%, respectively). The mean ages of anti-HCV positive females (31.7 ± 18.4 years) and males (35.6 + 20.9 years) were significantly higher (p < 0.001) than those of HBsAg positive females (26.3 + 16.8 years) and males (30.0 + 17.6 years). The mean age of
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HCV positive individuals was significantly higher than that of anti-HCV negative individuals for both males (almost 10 years difference) and females (7 years difference). The mean age of HBsAg positive individuals was also significantly higher (but to a lesser degree) among females (by < 2 years) and males (by < 4 years). More than 50% of the HBsAg positive individuals and about 40% of HCV positive cases were below 30 years of age. The associations between hepatitis B and C virus infections and various factors are shown in Table 2. Hepatitis B virus was more prevalent among the illiterate group (2.9%) than among the literate groups: 1.6% among postgraduates and 2.3% among preparatory school students. The prevalence of HCV was also higher among the illiterate group (3.1%) whereas in the literate groups it ranged from 0.9% to 1.1%. The influence of marital status and living standard on the prevalence of hepatitis B and C is shown in Figure 3. Hepatitis B was more prevalent among the widowed, whereas HCV was more prevalent among single and younger individuals.
Figure 3 Prevalence of hepatitis B and C infections by demographic and social variables, Libya, 2008. A. Gender B. Education C. Marital Status D. Type of housing.
Daw and El-Bouzedi BMC Infectious Diseases 2014, 14:17 http://www.biomedcentral.com/1471-2334/14/17
We also analysed the influence of risk factors, such as hospital admission, surgical operation, blood transfusion, intravenous drug use, and sexual behaviour, on the prevalence of hepatitis B and hepatitis C (Figure 4). Hepatitis B virus was most prevalent among those with previous surgical operations (2.4%) or history of hospital admission (2.4%), followed by blood transfusion (2.1%) and promiscuous sexual behaviour (1.6%). Hepatitis C was most prevalent among intravenous drug users (7.4%) and less prevalent but still substantial in those undergoing blood transfusion (2.7%), surgical operation (2.3%) or hospital admission (1.9%). Table 3 shows the distribution of the estimated seroprevalence of HBV and HCV according to demographic characteristics. There were minimal differences in the estimated number of cases between males and females for HCV, but more than 60% of the estimated number of HBsAg positive individuals were males. Over 50% of them were below 30 years old, and about 40% of HCV cases were also below that age. In terms of educational level, the highest prevalence rate of infection was among illiterates for both viruses (weighted prevalence 2.6% for HBsAg, representing 12.3% of all estimated cases, and 3.0% for HCV, representing 21.8% of all estimated cases).
Discussion The few studies on the prevalence of hepatitis B and C viruses in Libya examined specific population groups, such as parturient women and their newborns [26], healthcare workers, blood donors, transfusion patients [13] and hemodialysis patients [27], or other issues such
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as prevalence of genotypes [14]. However, none of these studies lend themselves to extrapolation to the general population, and our study, the first of its kind in Libya and the largest in Africa, was done to provide a basis for prioritising public health measures in Libya. In the European Mediterranean countries, the overall prevalence of HBV ranges between 2.5% and 3.5% [28,29]. In contrast, North Africa is overall an area of relatively high HBV endemicity. Tunisia, Algeria and Morocco fall in the intermediate category, with current infection rates of about 7% [30]. But Egypt is classified among the highest endemicity countries, along with Sudan, Chad and Niger, all of which neighbour Libya [31,32]. The lower prevalence rate of HBV we observed (2.2%) classifies Libya in the lower part of the low-intermediate endemicity class (2−7% category). This lower rate could be due to the better socioeconomic conditions and the early efforts by the National Prevention Program of Infectious Diseases in Libya. Vaccination against HBV infection has been strongly encouraged and offered free of charge in Libya since 1989, and in 1991 it became compulsory for infants 3 months of age and children 12 years of age. Hepatitis C is an emerging problem among the Mediterranean countries, where the estimated prevalence ranges from 1.0−2.6%, and isolated areas in Italy and Greece have rates of 7−20% among the general adult population [33,34]. A similar picture was also found in Tunisia and Morocco, where the rates ranged from 1.7 to 2.9%, with higher rates in some regions [35,36]. Hepatitis C virus screening and surveillance is minimal at the national level in these countries. In Libya, a study
Figure 4 Prevalence of hepatitis B and C infections by risk factors, Libya, 2008 *Statistically significant at 0.05.
Daw and El-Bouzedi BMC Infectious Diseases 2014, 14:17 http://www.biomedcentral.com/1471-2334/14/17
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Table 3 Number of persons chronically infected by HBV and of anti-HCV positive individuals in Libya according to age, socio-demographic factors and risk factors Nationwide estimated number of HBsAg positive persons
Nationwide estimated number of anti-HCV positive persons
n
%
n
%
107,848
100
68,275
100.0
Females
42,297
39.2
34,845
51.0
Males
65,551
60.8
33,430
49.0
≤5
4,861
4.5
4,699
6.9
6−10
4,110
3.8
3,881
5.7
Total Gender
Age groups
11−20
26,148
24.2
8,889
13.0
21−30
26,153
24.2
10,147
14.9
31−40
20,139
18.7
13,966
20.5
41−50
11,436
10.6
9,738
14.3
51−60
6,856
6.4
6,633
9.7
61−70
3,613
3.4
6,415
9.4
≥71
4,532
4.2
3,907
5.7
Education Below school age
4,957
4.6
5,235
7.7
Illiterate
13,318
12.3
14,850
21.8
Preparatory
34,927
32.4
20,685
30.3
High school
34,389
31.9
17,214
25.2
University
16,118
14.9
7,544
11.0
Post graduate
1,769
1.6
981
1.4
Unknown
2,370
2.2
1,766
2.6
Married
39,844
36.9
32,605
47.8
Single
42,551
39.5
17,845
26.1
Widowed
1,425
1.3
3,403
5.0
Divorced
913
0.8
470
0.7
Marital status
Below age
21,434
19.9
12,828
18.8
Unknown
1,681
1.6
1,124
1.6
Villa
13,545
12.6
6,944
10.2
Apartment
10,491
9.7
10,480
15.3
Rural house
80,646
74.8
49,398
72.4
Other
118
0.1
104
0.2
Unknown
3,048
2.8
1,349
2.0
Type of dwelling
conducted between 1991 and 2001 indicated that the prevalence of HCV ranged from 1.2% to 1.6% among blood donors and healthy individuals but was much higher (20.5%) among hospital personnel [13]. The 1.2% rate we observed in our country-wide study classifies
Libya as a low endemicity country. Libya has made screening mandatory for all blood donors, pregnant women, and patients at high risk of having surgery, and has introduced a national registry system covering all positive individuals. We were not surprised by the substantial regional variation in prevalence rate in Libya. Such variation has also been reported in other Mediterranean countries, such as Italy, Greece and Spain [37-39]. The variation observed in Libya is probably related to different factors, including socioeconomic conditions, but one particular observation is noteworthy. The prevalence of HCV was highest in the southern region of Fezzan (2.08%) and the eastern region of Albatnan (1.77%). The high prevalence in the southern region could be related to its proximity to subSaharan countries and the hosting of many African immigrants. Likewise, the eastern region of Albatnan borders Egypt, which has the highest prevalence rate of HCV in the world [40,41], and from where many workers, both legitimate and illegal, come to Libya. In Libya, the prevalence of HBV was low in children < 10 years of age (0.8%), and in the other age groups it ranged from 2.0 to 2.9%. In most other African countries the prevalence is high among infants and increases rapidly until the age of 30 years, and it rises even higher among those over forty years old [5,6,42]. The lower rate in the Libyan population could be due to the compulsory children vaccination program, which was introduced earlier in Libya than in other African countries. The overall prevalence of HCV in our study was not significantly different between females and males, and it increased gradually after the age of 30 years. This is in agreement with previous studies carried out in Libya, which showed a peak in the prevalence of HCV among those 46−55 years old [13]. Other studies, particularly from North America, also showed the highest prevalence in the 30−49 year age group in all racial groups [43,44]. We also analysed the risk factors associated with HBV and HCV infections. The influence of risk factors on the prevalence rate was evident for HCV. The prevalence rate among those with risk factors ranged from 1.9 to 7.4%, whereas among those without risk factors it was 1.3% (p < 0.025). The most prominent risk factor was intravenous drug use, with 7.4% of intravenous drug users testing positive for HCV. In this context, it is important to note that active drug users are less likely to participate in health surveys, and the actual overall prevalence rate is likely higher than the observed rate [45,46]. A recent study on ~1200 Libyan patients chronically infected with HCV correlated genotypes with risk factors. That study indicated that recent drug use was significantly linked to emergence of new genotypes, lending further credence to the role of intravenous drug use in HCV transmission in Libya [13]. Accordingly, we expect that
Daw and El-Bouzedi BMC Infectious Diseases 2014, 14:17 http://www.biomedcentral.com/1471-2334/14/17
the prevalence of HCV may increase in Libya because there is consensus that HCV-infected populations are heavily weighted towards intravenous drug use worldwide [47-49]. Our findings show that the prevalence rates of HBV and HCV in Libya are relatively low, and this could be an indicator of the success of the national efforts to control these infections. However, we only assessed a marker of the prevalence of HBV chronic infection (HBsAg), which represents the reservoir of infection and of future complications (cirrhosis and liver cancer). We did not estimate the proportion of those who had ever been infected in Libya, which can be estimated by testing for serum anti-HBc antibodies. Moreover, the higher rates in regions bordering high endemicity countries and the poorly controlled state of these borders can lead to an increase in prevalence, especially during this time when the country as whole is experiencing many difficulties. Continuous surveillance and maintenance of the national program for combating hepatitis are essential, and further studies are needed, particularly on co-infection with HIV, which is a problem in this region. Our findings would be useful for making estimates and projections about the overall disease burden, including the complications of hepatitis infection, such as cirrhosis, liver failure, and hepatocellular carcinoma [50]. Recently, El-Bouzedi [51] constructed a mathematical model using published epidemiological data on viral hepatitis to estimate the future consequences of hepatitis infection in Libya. Such modelling will inform health policy, resource allocation and healthcare delivery and may improve the management of patients with viral hepatitis.
Additional files Additional file 1: Table S1. HBV, HCV and HIV questionnaire form used to collect the data from Libyan populations. Additional file 2: Table S2. Sero-prevalence of HBsAg and anti-HCV antibodies among Libyans according to demographic characteristics and risk exposures. Competing interests The authors state that they have no competing interests. Authors’ contributions MD designed the study, extracted the data, and drafted and finalised the manuscript. AE analyzed the data and contributed to the drafting of the data. Both authors read and approved the final manuscript. Acknowledgement We are deeply grateful to the Libyan Study Group of Hepatitis & HIV and the National Centre for Disease Prevention for their advice and help in this survey. Special thanks go to Dr. Amin Bredan, Inflammation Research Centre, VIB & Ghent University, Belgium, for his professional contribution in reading, correcting and editing the manuscript. Author details 1 Department of Medical Microbiology, Faculty of Medicine, Tripoli, Libya. 2 Department of Laboratory Medicine, Faculty of Biotechnology, Tripoli, Libya. 3 Professor of Clinical Microbiology & Microbial Epidemiology, Acting
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Elasifer et al. Virology Journal 2010, 7:317 http://www.virologyj.com/content/7/1/317
RESEARCH
Open Access
Epidemiological manifestations of hepatitis C virus genotypes and its association with potential risk factors among Libyan patients Hana A Elasifer, Yossif M Agnnyia, Basher A Al-Alagi, Mohamed A Daw*
Abstract Background: The information on hepatitis C virus genotypes and subtypes among Libyan population and its association with various risk factors is not known. The objectives of this study were to determine the epidemiological manifestations of HCV genotypes among Libyan patients and their association with certain potential risk factors. Methods: A total of 1240 of HCV infected patients registered at Tripoli Medical Centre were studied in five years period from January 2005 to October 2009. The information were reviewed and the data were collected. A sample from each patient (785 male; 455 female) was analysed for genotyping and sub-typing using specific genotyping assay. The information was correlated with the risk factors studied and the statistical data were analyzed using SPSS version 11.5. Results: Off the total patients studied, four different genotypes were reported, including genotypes 1, 2, 3, and 4. Genotype4 was the commonest (35.7%), followed by genotype1 (32.6%). According to subtypes 28% were unclassified genotype 4, 14.6% were genotype 1b and some patients infected with more than one subtype (2.3% genotype 4c/d, 1% genotype 2a/c). Genotypes 1 was the commonest among males, while genotype 4 among females. According to the risk factors studied, Genotype1 and genotype 4 were found with most of the risk factors. Though they were particularly evident surgical intervention, dental procedures and blood transfusion while genotype 1 was only followed by genotype 3 mainly which mainly associated with certain risk groups such as intravenous drug abusers. Conclusion: Here in we report on a detailed description of HCV genotype among Libyans. The most common genotype was type 4 followed by genotype 1, other genotypes were also reported at a low rate. The distribution of such genotypes were also variable according to gender and age. The commonly prevalent genotypes found to be attributable to the medical -related transmission of HCV, such as blood, surgery and dental procedures when compared with other risk factors. This however, raises an alarming signal on the major steps to be taken to reduce such infection in Libya
Background Hepatitis C virus (HCV) is the major public health problem and it is one of the most important causes of chronic liver diseases all over the world. Studying the epidemiology of such problematic virus plays an important role on the methods of its prevention [1-4]. Such epidemiology varies geographically and temporally due * Correspondence:
[email protected] Department of Medical Microbiology & Immunology, Faculty of Medicine and Department of Infectious Diseases Tripoli Medical Centre, Tripoli-Libya
to distribution and evolution of risk factors. In Europe and North America the prevalence of HCV is about 1% [5,6]. Though it was higher among southern Italy and Southern Spain as it varied between 8.4%-22.4%. In North Africa and Arabian countries such prevalence was between 1.4% and 2.1% in certain countries such Libya, Tunis and Saudi Arabia, though it was the highest in Egypt as it reached up to 19.3% [7,8]. Furthermore the epidemiology of HCV was highly associated with a certain risk groups such as: blood and blood products, Intravenous drug abusers (IVDA), sexual transmission,
© 2010 Elasifer et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Elasifer et al. Virology Journal 2010, 7:317 http://www.virologyj.com/content/7/1/317
inadequate sterilizing medical equipment, body piercing and sharing razors and other personal items which contaminated with HCV [9]. Hepatitis C virus has been characterized by having a higher rate of spontaneous mutation that leads to a marked degree of heterogeneity among its genotypes [10]. The genus hepacivirus consists of six phylogentically distinct clades (genotypes) from1 to 6 and more than 70 subtypes (termed a, b, c, d,.etc...) of HCV [10,11]. The epidemiology of such genotypes has been to be variable among different geographical regions worldwide. However HCV genotypes 1,2 and 3 are commonly distributed all over the world though 4,5, and 6 were mainly found in a certain areas. HCV genotype 4 particularly prevalent in Northern and Central African counties particularly Egypt, whereas HCV genotype 2 is frequent in West Africans countries. Where genotypes (5) and (6) are common in South Africa and Asia respectively [12]. The heterogeneity of HCV genotypes also plays a role in understanding the epidemiology among different risk population. HCV genotype 3a was found to be associated with drug addicts and genotype 1b in blood transfusion. Furthermore a single subtype was found to be associated with certain areas such as genotype 4a in Egypt and genotype 5a in South Africa [13]. A few studies on the epidemiology of HCV among Libyans were reported. These include the seroprevalence HCV among different risk groups including health care workers, blood donors, renal dialysis patients and multi blood transfused patients [14], but the HCV genotype distribution remains to be determined. Hence then epidemiological studies of HCV genotypes among Libyans may provide a good understanding on the nature of HCV infection and its spread. The objectives of this study were to determine the epidemiology of HCV genotypes among different Libyan patients and its association with the risk factors involved and how this could be reflected on the prevention of such virus among the Libyan society.
Methods Patient population
A total of 1240 patients with hepatitis C virus were Studied. They were recruited from the Department of Infectious Diseases at Tripoli Medical Centre, Tripoli. The participation was voluntary in accordance of with the guidelines for observational and interventional studies from ethical committees of our National ethical Standards as the research was conducted according to Helsinki Declaration (2000) [15]. The patients were registered and followed up at Out Patient Department from January 2005 to October 2009. Seven hundred and eighty five patients studied were male and 455 patients were female. Their age ranged
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from16 to 84 years with an average age of 45 years. The study was designed to collect the data and extract information from each patient including age, gender, year of diagnosis and risk factors for HCV such as history of blood transfusion, intravenous drug abuse (IVDA), history of surgical intervention, family history of HCV positive and history of promiscuity and dental procedure. Those patients who denied any risk factors were assigned to be as an; unknown group. Patient Selection Criterion
The study was designed to investigate the impact of HCV genotypes on the epidemiological manifestations of HCV infection among Libyan patients. Each patient has to fulfil the following criteria; no co-infection with human immune-deficiency syndrome (AIDS) virus or with hepatitis B virus and Hepatitis D Viruses, and non of them had liver cirrhosis, or undergo haemodialysis.; and no concomitant metabolic or autoimmune disorder or underlying systemic diseases all patients enrolled in this study were restrictedly chosen to fulfil the criteria mentioned. Laboratory and Clinical Evaluation of HCV Infection
A serum specimen was collected from each patient and was tested positive for HCV antibody (Anti-HCV) using and 3rd generation commercial Enzyme Linked Immunosorbant Assays (ELISA)[The INNO-LIA™ HCV Ab III update (Belgium) is 3ed generation line immunoassay which incorporates HCV antigens derived from the core region, the E2 hypervariable region, the NS3 helicase region, the NS4A, and NS5A regions. The antigens were coated as 6 discrete lines on a nylon strip with plastic backing. In addition, four control lines are coated in each strip: strepavidin control, 3+ Positive Control (antihuman Ig), 1+ Positive Control (human IgG) and ± cutoff line (human IgG). The stirp incubated with test sample then we add purified alkaline phosphatase labelled goat anti -human IgG last we add conjugate]. Such immunoassay was known to have a high specificity and sensitivity (over 99%), with minimal or no limitation of detecting HCV antibody. Determination of HC Viral Genotypes
HCV genotyping was performed by gene amplification using COBAS-Amblicor HCV test { this test detected by reverse-transcribing HCV RNA into cDNA by PCR, hybridizing amplified cDNA with an oligonucleotid probe that binds enzyme, and catalyzing conversion of substrate to a colored product that is recognized by COBAS AMBLICOR Analyzer (Roche, Diagnostic, Basal, Switzerland). Such analysis is in worldwide use and it covers all the six internationally recognized HCV genotypes.
Elasifer et al. Virology Journal 2010, 7:317 http://www.virologyj.com/content/7/1/317
Page 3 of 7
Statistical Analysis
Quantitative variables were expressed as mean ± standard deviation (X ± SD)and were compared by Student’s test (t-test). Differences in proportion of qualitative variables were tested with non-parametric tests (X2) Yates correlation. Fisher exact test and a p value < 0.05 were considered significant. A multivariate analysis was conducted using logistic regression in order to verify which variables statistically had an influence on HCV infection. such as gender (male vs. female), IV drug abuser (yes or no), blood transfusion (yes or no) surgical Intervention and blood transfusion (yes or no), dental care (yes or no); promiscuity (yes or no). The data were analyzed using SPSS version 11.5 to identify the distribution of different genotypes and its association with gender, age, year of diagnosis and risk factors.
Results Prevalence of HCV genotypes among the populations studied
A total of 1240 patients were studied during a five year period from 2005to 2009 as shown in Table 1. Off these patients, 785 (63.3%) were predominantly males and 455 (36.7%) patients were females with a male; female ratio (1.7:1). The age was ranged from 16 to 84 years with a predominantly larger proportion of younger patients with an average of 40 years or less with no significant
Table 1 Prevalence of HCV genotypes among the patient studied Gender
gender variation (P > 0, 05). The prevalence of HCV in this study was calculated, per year and expressed as a percentage. Different HCV genotypes were found among the Patients studied as shown in Table 1. These include genotypes, 1,2,3 and 4 while HCV genotype 5 & 6 were not reported among these patients. The prevalence of such genotypes was variable among the patients, Genotype 4 was the most frequent one detected in 443 (35.7%)patients followed by genotype 1 in 404 (32.6%) patients, and then genotypes 3 and 2 accounted for 207 (16.7%) and 186 (15%) patients respectively. The year by year distribution has been stable since 2005; the beginning of the study including the high percentage of type 4 and 1. The prevalence of gender associated HCV genotypes was analysed among the patients. The most frequent genotype reported among females was genotype 4 as it was accounted for 207(45.5%) patients, followed by genotype 1 accounted for 134 (29.5%), G2 accounted 78 (17.1%) and then genotype 3 accounted for 36 (7.9%). The most frequent HCV genotype among male populations was genotype 1 as it was detected in 270(34.3%) cases, followed by genotype 4 detected in 236 (30%) cases, genotype 3 detected in 171 (21.8%) and less frequent one was HCV genotype 2 detected in 108 (13.9%). The relationship between HCV genotype and gender was statistically significant (P value = 0.00). Different sub-genotypes were reported among the patients studied. Genotype 1 b was among the frequent as it accounted for 181(14.6%) without no gender variation, followed by genotype 4a 68(5.4%) most predominantly among females 34 (7.4%). Then genotype 1a accounted for 60 (4.9%) patients in 42 (5.3%) males and 18(3.9%) females. HCV genotype 3a accounted for 29 (2.3%) patients male 24(3%) female 5(1.1%). Genotype 2 was The most heterogenic genotype as four different subtypes were reported which include genotype 2a, 2b, 2c & 2a/c.
Genotype/subtype
Male (%)
Female (%)
Total (%)
Genotype 1
270(34.3)
134(29.5)
404(32.6)
1a
42 (5.3)
18 (3.9)
60 (4.9)
1b
114 (14.5)
67 (14.8)
181 (14.6)
1(UC*)
114 (14.5)
49 (10.8)
163 (13.2)
Genotype 2
108(13.9)
78(17.1)
163 (13.2)
2a
2(0.3)
3 (0.6)
5(0.4)
2b
2 (0.3)
3 (0.6)
5 (0.4)
Distribution of HCV genotypes according to age
2c
2 (0.3)
8 (1.7)
10 (0.8)
2a/c
5 (0.6)
8 (1.7)
13 (1)
2(UC*)
97 (12.2)
56 (12.5)
153 (12.3)
Genotype 3
171(21.8)
36(7.9)
207(16.7)
3a
24 (3)
5(1.1)
29 (2.3)
3(UC*)
147 (18.8)
31 (6.8)
178 (14.4)
Genotype 4
207(30)
236(45.5)
443(35.7)
The prevalence of HCV genotypes among Libyan population is shown in Table 2. There was a variable distribution of the genotype according to the age group. Genotype 1 was associated with a younger age group between 15-34, decreased in a middle-aged group 35-44 and was less at age more than 55 years (45.1%, 33.2%, 8.9%, 12.8%). Conversely, HCV genotype 2 was higher among older age above 55 years, less at age group 4554, and 35-44 and lesser at a younger age 15-34 years (13.4%, 18.3%, 22.6%, 45.7%). Genotypes 3 & 4 were most associated with patients aged less than 45 years genotype 3; 88.4% where it was 11.6% for patients aged more than 44 years, and genotype 4; 69.8%in patient
4a
34 (4.3)
34 (7.4)
68 (5.4)
4c/d
23 (2.9)
5 (1.1)
28 (2.3)
4(UC*)
179 (22.8)
168 (37)
347 (28)
Total (%)
785 (100)
455 (100)
1240 (100)
*UC; unclassified viral genotype.
Elasifer et al. Virology Journal 2010, 7:317 http://www.virologyj.com/content/7/1/317
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Table 2 Prevalence of HCV genotypes among different age groups Age (Years) Genotype/subtype(%)
15-34
35-44
45-54
55-85
Genotype 1a
34(56.7)
10(16.7)
5(8.3)
11(18.3)
1b
65(35.7)
67(37.2)
21(11.4)
28(15.7)
1 (UC*)
83(50.8)
57(34.9)
10(6.4)
13(7.9)
Genotype 2a
0
0
0
5(100)
2b
0
0
0
5(100)
2(20)
6(60)
0
2(20)
2a/c
2c
2(15.4)
0
3(23.1)
8(61.5)
2 (UC*)
21(13.6)
28(18.6)
39(25.4)
65(42.4)
Genotype 3a 3 (UC*) Genotype 4a 4c/d 4 (UC*) Total(%)
21(72.7)
8(27.3)
0
0
90(50.7)
64(36.2)
13(7.3)
11(5.8)
21(30.8)
18(27)
13(19.2)
16(23)
12(45.4)
10(36.4)
3(9.1)
3(9.1)
121(35)
127(36.6)
36(10.4)
63(18)
472(38.1)
395(31.9)
143(11.5)
230(18.5)
*UC; unclassified viral genotype.
less than 45 years old and it counted 30.2% for patients aged more than 44 years (P = 0.00). Association of the genotypes with the risk factors
The risk factors associated with the transmission of HCV were determined in all patients studied as shown in Table 3. The most frequently reported risk factor was a history of surgical procedure accounted for 300 patients (24.2%), (176 (58.6%) males and 124 (41.4%)
females. Followed by patients with history of blood transfusion 212 (17.1%), (109(51.2%) males and 103 (48.8%) females. Intravenous drug abuser ‘IVDA’ reported 85 (6.9%) patients (all males). Patients who had history of dental procedures were 225 (18.2%) patients, 142 (63.2%) males, 83 (36.8%) females. Family history of HCV infection was recorded in 80(6.5%), patients 64 (80%) males and 16(20%) were females. History of promiscuity were recorded in 27(2.1%), patients all of them were males. The patients denied any history of risk factors were recorded in 311 (25.1%), 181 (58.3%) males and 130 (41.7%) females. The relationship between HCV risk factor for infection and gender was statistically significant ‘P value = 0.000’. Genotype1 and genotype 4 were predominantly associated with most of the risk factors studied, particularly those of previous surgical or dental procedures, blood transfusion and family history. Though, genotype 1 was only followed by genotype 3 in patients with IVDA. The association of between the risk factors and HCV genotypes was found to be statistically insignificant (P value = 0.180).
Discussion The epidemiological studies on Hepatitis C Virus genotypes have gained major attention all over the world as they appear to play an important role in elucidating the clinical status of such infection. They have shown to be of great benefit in guiding therapeutic decision and implementing proper preventive strategies. The epidemiological patterns of HCV vary greatly among the
Table 3 Prevalence of genotypes according to risk factors studied Risk factors (No Patients) Genotype/ subtype
Blood Transfusion
IVDA Surgical procedure
History of promiscuity
Family history of HCV
Dental procedure
Unknown
Genotype 1a
18
13
5
0
1b
36
13
39
10
3
10
11
10
34
1(UC*)
16
13
41
39
3
15
31
44
Genotype 2a
0
0
2b
0
0
2
0
3
0
0
5
0
0
0
2c
5
0
0
3
0
0
2
0
2a/c
0
0
8
0
0
3
2
2(UC*)
23
0
52
3
8
34
33
Genotype 3a
8
2
3
3
0
8
5
3 (UC*)
21
23
44
0
10
28
52
Genotype 4a
18
0
16
0
5
8
21
4c/d
10
0
2
0
3
5
8
4 (UC*)
57
21
80
8
23
62
96
Total
212
85
300
27
80
225
311
*UC; unclassified viral genotype.
Elasifer et al. Virology Journal 2010, 7:317 http://www.virologyj.com/content/7/1/317
different countries and even among the regions of the same country. However, little is known about the epidemiology of HCV genotypes in Libya. Hence then carrying such study will provide great understanding on the prevalence of various genotypes among the Libyans which should guide the therapeutic and prognostic implications in HCV infection. In this study the patterns of HCV genotypes and various risk factors for possible route of transmission in Libya were studied. The serum samples collected from different patients registered at Tripoli Medical centre were found to be positive for HCV and could thus be genotyped. Four different genotypes were reported in this study including genotypes, 1,2,3 and 4. The distribution of these genotypes were variable among the patients studied. The most prevalent genotype was genotype 4 and then genotype 2, though genotypes 3&2 were less accounted. Different subtypes were found among HCV genotypes studied. These include nine HCV subtypes as genotype 1 subtype (1a & 1b), 2(2a,2b,2c&2a/c), 3(3a), 4(4a&4c/d) the most frequent of these subtypes were 4a and 1b. The data of the present study is in concordance with previous studies reported from different regions of the world particularly in North African countries. Previous study conducted in Tunisia reported that genotype 1b was the most prevalent genotype [16] and in Egypt genotype 4a was predominant [17], genotypes 1a and 1b were common in the United State and Europe [18,19]. In Pakistan and Japan Genotypes 3a and 1b were common respectively where as genotype 5a were common in South Africa [9]. The distribution such HCV genotypes among Libyan patients remain invariable during the five years study period including the high rate of genotype 4 and 1. This concise with Henquell, etal. who found that there was no year to year variation of HCV genotypes in Central France in six years prospectively conducted study [20]. It is apparent that further studies are needed to clarify such evident prevalence as longer time may be needed to observe such changes. In Pakistan it seems that 15-20 years needed as the genotype 3 a to be replaced by genotype 1(a or b) [9], while in Venezuela that took only 10 years time for displacement of genotype 1 b by type 2 [21]. Studies on the association of gender with specific HCV genotypes were found to be equivocal. In Luxembourg the prevalence of HCV genotype 3 was found to be a significantly associated with males while genotype 2 and 5 more frequent in females [22]. In Pakistan such association was lacking as the distribution of HCV genotypes were similar in both male and female patients [23,24]. In this study there was a variation of HCV genotypes among male and female patients. Genotype 4 was significantly more frequent in female while genotype 1 more frequent in males though the frequency of
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genotypes 3 and 4 were independent of gender. However, such association merits, further investigation. The distribution of HCV genotypes may be variable according to the age of the population. In Italy, the prevalence of genotypes 1b and 2 decreased significantly among younger children compared with the older ones who have an increased rate of genotypes 3 and 4 [25,26]. In France type 5 was more frequent in patients older than 50 than those younger than 49 [27,28]. Studies carried by Roman etal., showed that genotype 3 was associated with patients aged less than 40 years, while genotype 2 was significantly prevalent with those over 40 years of age [22]. In this study, genotype 1 was associated with a younger age group less than 34 years, decreased in a middle- and older age groups. Conversely, HCV genotype 2 was higher among elderly patient above 55 years, lesser at age group of 45-54, and even after. These finding however, do need further investigations, as such epidemiological variation may be associated with the mode of transmission of HCV and thus they may have clinical and therapeutic implications. Different studies have shown the dynamicity of HCV genotypes, which lead to the emergence of different types and subtypes over time. Such phenomenon is obvious in certain European counties such as in Germany and Greece, where the prevalence of HCV genotypes 1b and 2 have decreased and genotypes 1a, 3a, and 4 increased. Such changes were not noticeable in Luxembourg where genotypes 1 and 3 were the most prevalent [22]. Here in we did not notice any significant changes in the emergence of HCV genotypes among the Libyans during the period of this study. Such results were in agreement with the data reported in Tunis and Egypt [16,17] as HCV genotypes proportion has been relatively constant overtime. The association of HCV genotypes variation with demographic data may be related to the immigration flow which obvious among the European countries and rarely seen in the Arab and African countries. Many studies have been suggesting that HCV genotypes are associated with certain risk factors and different modes of transmission. The genotypes reported in this study were isolated from all the patients with the risk factors stated. Such, relationship between HCV genotypes and risk factors was statistically significant. High prevalence of HCV genotype 4 in our study is particularly attributable to previous history of surgical operation followed by dental intervention and blood transfusion respectively. The same is applicable for genotype 1. While genotype 3 and 1 were common inpatient with IVDA. Configuration of HCV subtypes and its association with the risk factors was also obvious in this study. HCV genotype 1b is more common in patients who had history of blood transfusion and surgical procedures.
Elasifer et al. Virology Journal 2010, 7:317 http://www.virologyj.com/content/7/1/317
The association of HCV genotypes with the risk factor varies from one country to another. The high prevalence of HCV genotype 3 among Europeans is attributed to IVDA and incarcerated population [28]. In this study only 6.9% of individuals admitted they have a history of IVDA which was associated with genotype3. The high prevalence of genotype 4 and 1 among Libyans which is uncommon in Europe and North America is particularly attributable to medical-related transmission such as blood transfusion, surgery and dental procedures. This is an agreement with studies from Pakistan and Hungry where the majority of cases of genotypes 1 and 4 have history of hospitalization for surgery, dental procedure and blood transfusion [9,23,29]. This raises an important question regarding the prevention methods of to be established among Libyan hospitals to prevent the spread of HCV and other blood born viruses [30,31]. This study showed a detailed estimation on the epidemiology of HCV genotypes in Libya. The commonly prevalent genotypes 4 and 1 are more likely attributable to the medical-related transmission such as blood, surgery and dental procedures despite that blood banks in Libya do screen routinely for HCV in all blood products. This however raises an alarming signal on the major steps to be taken to reduce such infection. Therefore, a national strategy should be implemented and specific prevention guide lines have to be followed to reduce such risks. As Libya being a third largest country in Africa with a variable race populations further studies are needed in different regional parts of the country to estimate the diversity of HCV genotypes in each region and assess the risk factors involved with specific emphases on the genetic sequences of un-typable HCV genotypes and multivariate analysis on such risk factors [32].
Conclusion The predominantly isolated HCV genotype from Libyans were genotype 4 followed by genotype 1. Other genotypes and subtypes such as 1(a,b,c),2(a,b,c),3a, and 4(a,c/ d) were also reported in this study. Such genotypes were variable according to the age and gender of the patients studied. The mostly associated risk factors with these genotypes were medical-related route of transmission including blood transfusion, surgical operation and dental procedures, other risk factors such as family history and IVDA were also reported. Acknowledgements We deeply appreciate the great help from the Nursing and medical staff at the Department of Infectious Diseases, Tripoli Medical Centre, and all the Staff at the Department of Medical Microbiology and Immunology, Faculty of Medicine, Tripoli-Libya; http://www.dmi.ly
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Authors’ contributions All authors have read and approved the final manuscript and contributed immensely in the study. HAE; Conceived the study, collected the epidemiological data and analyzed data statistically and helped in writing and revising the manuscript. YMA; Helped in the study, analysing and revising the data. BAA; Treating and following up patients, helped in designing and writing the manuscript. MAD; Designed and supervised the study, writing and revising the manuscript; a leading expert in Nosocomial infections and Microbial Epidemiology Competing interests The authors declare that they have no competing interests. Received: 12 September 2010 Accepted: 13 November 2010 Published: 13 November 2010 References 1. Starader DB, Wright T, David L, et al: Diagnosis, Management, and Treatment of Hepatitis C. Hepatology 2004, 39:1147-1171. 2. BrachoM A, Martró E, et al: Complete genome of a European hepatitis C virus subtype 1g isolate: phylogenetic and genetic analyses. Virol J 2008, 5:72. 3. Gismondi MI, Becker PD, Valva P, et al: Phylogenetic Analysis of Previously Nontypeable Hepatitis C Virus Isolates from Argentina. J Clin Microbiol 2006, 44:2229-2232. 4. Verbeeck J, Maes P, Lemey P, et al: Investigating the Origin and Spread of Hepatitis C Virus Genotype 5a. J Virol 2006, 80:4220-4226. 5. Sherman M, Shafran S, Burak K, et al: Management of chronic hepatitis C: Consensus guidelines. Can J Gastroentrol 2007, 21:25C-34C. 6. Sy T, Jamal MM: Epidemiology of Hepatitis C Virus (HCV) Infection. Int J Med Sci 2006, 3:41-46. 7. Pybus OG, Drummond AJ, Nakano T, et al: The epidemiology and iatrogenic transmission of hepatitis C virus in Egypt: A Bayesian Coalescent Approach. Mol Biol Evol 2003, 20:381-387. 8. Daw MA, Elkaber MA, Drah AM, Werfalli MM, et al: Prevalence of hepatitis C virus antibodies among different populations of relative and attributable risk. Saudi Med J 2002, 23:1356-60. 9. Idrees M, Riazuddin S: Frequency distribution of hepatitis C virus genotypes in different geographical regions of Pakistan and their possible routes of transmission. BMC Infect Dis 2008, 8:69. 10. Simmonds P, Bukh J, Combet C, et al: Consensus proposals for a unified system of nomenclature of hepatitis C virus genotypes. Hematology 2005, 42:962-973. 11. Guobuz A, Chokshi S, Blaciuniene L, et al: Viral clearance or persistence after acute hepatitis C infection: interim results from a prospective study. Medicina (Kaunas) 2008, 44:510-520. 12. Simmonds P: Genetic diversity and evolution of hepatitis C virus-15 years on. J Gen Virol 2004, 85:3173-3188. 13. Cantaloube JF, Gallian P, Attoui H, et al: Genotype Distribution and Molecular Epidemiology of Hepatitis C Virus in Blood Donors from Southeast France. J Clin Microbiol 2005, 43:3624-3629. 14. Daw MA: Viral hepatitis: an overview: Viral Hepatitis in Libya: Biotechnology centre, Tripoli. 2002, 9-16. 15. The World Medical Association Ethics Unit. Declaration of Helsinki. [7 Jun 2009]. [http://www.wma.net]. 16. Djebbi A, Bahri O, et al: Genotypes of hepatitis C virus circulating in Tunisia. Epidemiol Infect 2003, 130:501-505. 17. Genovese D, Dettori S, Argentini C, et al: Molecular Epidemiology of Hepatitis C Virus Genotype 4 Isolates in Egypt and Analysis of the Variability of Envelope Proteins E1 and E2 in Patients with Chronic Hepatitis. J Clin Microbiol 2005, 43:1902-1909. 18. Bracho MA, Saludes V, Martró E, et al: Complete genome of a European hepatitis C virus subtype 1g isolate: phylogenetic and genetic analyses. Virol J 2008, 5:72. 19. Zein N: Clinical significance of hepatitis C virus genotypes. Clin Microbiol Rev 2000, 13:223-235. 20. Henquell C, Cartau C, Abergel A, et al: High prevalence of hepatitis C virus type 5 in central France evidenced by a prospective study from1996 to 2002. J Clinical Microbiol 2004, 42:3030-3035.
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21. Flor PH, Loureiro , Carmen LLic: Replacement of of Hepatits C virus genotype 1b by genotype 2 over a 10 year period in Venezuela. J Clin Gastroenterl 2007, 4:518-520. 22. Roman F, Hawotte K, Struck D, et al: Hepatitis C virus genotypes distribution and transmission risk factors in Luxembourg from 1991 to 2006. World J Gastroenterol 2008, 14:1237-1243. 23. Idrees M, Rafique S, Rehman I, et al: Hepatitis C virus genotype 3a infection and hepatocellular carcinoma; Pakistan experience. World J Gastroenterol 2009, 15:5080-5085. 24. Waheed Y, Shafi T, Safi SZ, Qadri I: hepatitis C virus in pakastain; A systemic review of prevalence, genotypes and risk factors. World J Gastroenterol 2009, 15:5647-5653. 25. Bartolotti F, Resti M, Marcellini M, et al: Hepatits C virus genotypes in 373 italian children with HCV infection; changing distribution and correlation with clinical features and outcome. Gut 2005, 54:852-857. 26. La Torre G, Miele M, Mannocci A, et al: Correlates of HCV seropositivity among familial contacts of HCV positive patients. BMC Public Health 2006, 6:237[http://www.biomedcentral.com/1471-2458/6/237]. 27. Qu D, Hantz O, Gouy M, et al: Heterogenicity of hepatitis C virus genotype in France. J Gen Virol 1994, 75:1063-1070. 28. Maritinot-Peignoux M, Roudot-Thoraval F, Mendel I, et al: Hepatitis C virus genotypes in France: relationship with epidemiology, pathogenicity and response to interferon therapy. The GEMEP. J Viral Hepat 1999, 6:435-43. 29. Salim FB, Keyvani H, Amiri A, et al: Distribution of hepatitis C virus genotypes in patients with hepatitis C virus. World J Gastroenterol 2010, 16:2005-2009. 30. Shabash A, Habas M, Fara A, Daw M: Epidemiological analysis of potential risk factors contributes to infection of HBV, HCV and HIV among the population in Tripoli Area, Libya. Clinical Microbiol Infection 2010, 16(S2):120. 31. Elasifer H, Elagy B, Eltaghdy M, Draah A, Daw M: The influence of HCV genotypes and other predicting factors in virological response in patients treated with INF alpha or PEG INF alpha 2a in combination with ribavirin’. Clinical Microbiol Infection 2010, 16(S2):121. 32. Shabash A, Habas M, Alhajrasi A, Furarah A, Bouzedi A, Daw M: Forecast modeling for prediction of hepatitis B and Hepatitis C seropositivity among Libyan population. Clinical Microbiol Infection 2010, 16(S2):120. doi:10.1186/1743-422X-7-317 Cite this article as: Elasifer et al.: Epidemiological manifestations of hepatitis C virus genotypes and its association with potential risk factors among Libyan patients. Virology Journal 2010 7:317.
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Daw et al. BMC Res Notes (2015) 8:367 DOI 10.1186/s13104-015-1310-x
Open Access
RESEARCH ARTICLE
Geographic distribution of HCV genotypes in Libya and analysis of risk factors involved in their transmission Mohamed A Daw1,2*, Abdallah El‑Bouzedi3 and Aghnaya A Dau4
Abstract Background: Hepatitis C virus (HCV) genotypes have been shown to be differently distributed between distinct geographical areas. Libya is a large country has the longest coast in the Mediterranean basin. Information regard‑ ing hepatitis C genotypes and subtypes circulating in Libya are not well known. The objectives of this study were to determine the frequency of various HCV genotypes cross Libya and the demographic and attributable risk factors associated with HCV transmission among Libyan population. Methods: A cross‑sectional study was carried out on patients with recently confirmed HCV infection. A total of 3,227 serum samples enrolled at 19 collection center cross Libya. 1,756 belonged to Tripoli region, 452 to West region 355 to North region, 181 South regions and 483 East region. The samples were tested by type specific genotyping assay and correlated with demographic and potential risk factors within the studied populations. Results: A total of 20 discrete genotypes and subtypes were identified among the Libyan population ranging from 11.5 to 0.3 % cross the country. Genotype 1 was the most frequent among all regions (19.7–40.5 %), reaching the highest value in Tripoli region, followed by genotype 4 which was more prevalent in the South (49.3 %) and West (40.0 %) regions. Genotype 3, was higher in Tripoli (21.3 %) and East (15.9 %) regions while genotype 2, common in North (23.6 %) and South (22.5 %) regions. However, we found evidence that there is a changing relative prevalence of HCV genotypes in relation to age, gender and the mode of transmission which is reflected in the predominance of certain genotypes among Libyan population. Conclusions: Different HCV genotypes were isolated form Libyan population including newly emerged ones. The prevalence of the genotypes varied by geographic region and influenced by demographic and risk factors. Knowing the frequency and distribution of the genotypes would provide key information on understanding the spread of HCV in Libya and this could be greatly reflected on national plans and future strategies for infection prevention. Keywords: Libya, Hepatitis C virus, HCV subtypes, Genotypic variability, Africa Background Hepatitis C virus (HCV) is a leading cause of chronic viral hepatitis, liver cirrhosis and hepatocellular carcinoma. Such implications have great, clinical, epidemiological and economic burdens worldwide particularly among developing countries [1, 2]. Relative risk factors as well as intervention and preventions programs are greatly *Correspondence:
[email protected] 1 Department of Medical Microbiology, Faculty of Medicine, Tripoli University, 82668 Tripoli, Libya Full list of author information is available at the end of the article
influenced by regional variation of the HCV genotypes [3]. Genotyping plays an important role in the pathogenicity and hepatocarcinogenic potential of hepatitis C infection. Indeed pathological consequences and therapeutic responses has been greatly influenced by the HCV genotypes [4]. Different studies have shown that HCV genotype 1 has been associated with lower rates of response to peginterferon-based regimens compared with genotypes 2 and 3. Furthermore, infections with genotype 1a responds less than genotype 1b to treatment with peginterferon/
© 2015 Daw et al. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Daw et al. BMC Res Notes (2015) 8:367
ribavirin and to triple regimens that include telaprevir or boceprevir [5, 6]. Differences in pathogenicity and hepatocarcinogenic potential of the various genotypes of HCV were also reported. Raimondi et al. found that there was an increased risk of HCC in patients infected with genotype 1b, with or without the presence of cirrhosis [7]. Other studies also found both subtypes within genotype 1 to confer heightened risk of histopathological damage, concomitant progression to HCC, and to a lesser extent, persistence of infection [8, 9]. Many of these studies are from geographical regions where such genotypes predominate, hence then, further studies from different regions are needed. The relative prevalence of HCV genotyping varies geographically and demographically worldwide. HCV genotypes 1a and 1b, are the most frequent genotypes in the North American and Europe [10, 11], and genotypes 5 and 6 seem to be confined to South Africa and Hong Kong [12, 13], respectively. HCV genotypes 7, 8, and 9 have been identified only in Vietnamese patients [14, 15] and genotypes 10 and 11 were identified in patients from Indonesia [16]. HCV genotypes and subtypes within the country also vary according to ethnicity and age. However, world integration and recent massive population displacement has lead to introduction of HCV genotype among a certain areas that not commonly known. HCV genotype distribution has been used for the identification of populations’ origin of HCV infection, examination of historical trends in characteristics of HCV infection and making inferences regarding routes of HCV transmission [17]. Hepatitis C virus infection is a major public health concern among African countries, they have the highest prevalence rates of HCV in the world, ranging from 1 to 26 % [2, 18]. Over 28 million people are chronically infected with HCV in this continent, and it is difficult to speculate about current and future trends [19]. HCV genotyping rarely studied in Africa, however, few studies were carried on a restricted populations in North Africa have shown diversity of HCV genotyping among these countries [20]. Therefore, population based studies are needed in order to plan for future prevention and intervention programs. Libya is the second largest country in Africa, with the longest coast facing the Southern European Union [21]. Bordering six different countries, where HCV has been considered to be endemic [22, 23]. In recent years the country has attracted worldwide attention because many Africans transit through it to enter Southern Europe illegally, with the possibility of transmitting infection in transit, or at the destination. Hence then a wide variation in the frequencies of HCV genotypes would be expected among Libyan territory.
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In Libya HCV has been well studied, recently a comprehensive study including 1 % of the total population was carried. HCV prevalence ranged from 0.9 to 1.2 %. It was most prevalent among intravenous drug users (7.4 %) and less prevalent but still substantial in those undergoing blood transfusion (2.7 %), surgical operation (2.3 %) or hospital admission (1.9 %) [24]. However, few studies had lend themselves studying HCV genotype frequencies in small cohorts or restricted populations, but information concerning the distribution of viral genotypes and demographic and risk factors that influence HCV infection are limited [20]. The objectives of this study were aimed to determine the distribution of various HCV genotypes and subtypes present in different geo-graphical regions of Libya and the association with various risk factors involved in the transmission HCV infection among Libyan population.
Methods Study population
Serum samples were collected from different patients with chronic HCV from all Libyan provinces based on the population proportion. Libya is a large country with a total geographic area; 1,775,500 km2 (square kilometers). The estimated Libyan population based on the consensus of 2006 was found to be 6,154,623 million. More than half of population were located in Tripoli region and less than a million in the Eastern region, the others are scattered over the vast areas of the country. A total of 3,227 different sera samples were collected from each of the five regions as following: • Tripoli Region (TR) represented by five districts [number of isolates (n) = 1,756] including: Tajoura, Old City, Zwara, Alzawia, and Tarhona. • West Region (WR) represented by three districts (n) = 452 including: Navosa Mountains, Garian and Ghadams. • North Region (NR) represented by four districts (n) = 355 including: Sert, Musrata, Alkoms and Baniwaled. • South Region (SR) represented by four districts (n) = 181 including: Aljofra, Ashati, Murzak and Sebha. • East Region (ER) represented by three districts (n) = 483 including: Benghazi, Albtnan and Alkufra. Laboratory tests and HCV genotyping
All the serum samples were received along with specifically designed data sheets at Department of Medical Microbiology, Faculty of Medicine, Tripoli from 19 tertiary collection of the 5 regions involved. A written informed consent was taken from each patient and the
Daw et al. BMC Res Notes (2015) 8:367
data sheet contained demographic information including age, gender, year of diagnosis and risk factors for HCV such as history of blood transfusion, intravenous drug abuse (IVDA), history of surgical intervention, family history of HCV positive and history of promiscuity and dental procedure. Those patients who denied any risk factors were assigned to be as an; unknown group. Each serum specimen was re-tested positive for HCV antibody (antiHCV) using 3rd generation commercial Enzyme Linked Immunosorbent Assays as previously described by Daw and El-Bouzedi [24]. HCV genotyping was carried out using type-specific HCV genotyping method [20]. All the different genotypes of HCV were tested and primers for genotypes 1a, 1b, 1c, 3a, 3c and 4 and 2a, 2c, 3b, 5a, and 6a primers were incorporated. Hence then HCV genotype for each sample was determined by identifying the HCV genotype-specific PCR band [20]. Statistical analysis
Data were coded and entered into a data base, which was then cleaned and verified. Data were analysed by using the Chi square test with Yates’ correction or Student’s t-test for univariate analysis. The results for all variables were given in the form of rates (%). A multivariate analysis was conducted using logistic regression in order to verify which variables statistically had an influence on HCV infection such as gender (male vs. female), IV drug abuser (yes or no), blood transfusion (yes o r no) surgical Intervention and blood transfusion (yes or no), dental care (yes or no); promiscuity (yes or no). The data were analyzed using SPSS version 11.5 to identify the distribution of different genotypes and it s association with gender, age, year of diagnosis and risk factors [20].
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an average age of 37.8 ± 13.4 years. Total of 817 (54.4 %) belongs to Tripoli region, 161 (10.7 %) to North region, 210 (13.9 %) West region, 71 (4.7 %) South region, 242 (15.1 %) East region. The distribution of HCV genotypes was shown in Table 1; a total of 20 different HCV genotypes and subtypes were found among the Libyan population. The distribution of such types was found to be as follows: 371 (11.5 %) were genotype 4; 219 (6.7 %) genotype 1; 205 (6.35 %) genotype 1b; 199 (6.17 %) genotype 3a; 135 (4.18 %) genotype 1a; 118 (3.66 %) genotype 2; (82 %) genotype 2a/c; 68 (2.11) genotype 4c/d; 40 (1.24 %) genotype 3;19 (0.59 %) genotype 4h; 15 (0.46 %) genotype 2b; 10 (0.31 %) genotype 2a; 7 (0.22 %) genotype 4e; and 4 (0.12 %) genotype 4a. Few stains were isolated at a low count (0.3 %) these include genotype 4b, 4f, 4h, 4d, 4a/c and HCV genotype 5 though genotype 6 was not reported. HCV genotype 1, 2, 3 and 4 were isolated from all over Libya, Fig. 1 shows the distribution of such genotypes according to the patients residential regions. Genotype 1 is the most common genotype isolated from Tripoli (40.5 %) and East regions (38.4 %), followed by the West (35.2 %) and North (31.1 %) regions and less reported in the South region (19.7 %); Genotype 4, South (49.3 %) and West region (40.0 %), followed by both East and North Table 1 Distribution of HCV genotypes and subtypes among Libyan populations Type/subtype Total no of isolates (%)
Distribution among (%) Male
Female
1
219 (6.79)
160 (7.26)
59 (5.77)
1a
135 (4.18)
103 (4.67)
32 (3.13)
Ethical approval
1b
205 (6.35)
110 (4.99)
95 (9.29)
The study was approved by the Libyan National Ethical Committee (Approval No. LY NS; HCV-G-399773). It was conducted in accordance with the Helsinki Declaration [25] and under the supervision of the Faculty of Medicine, Tripoli, Libya. All participants signed an informed consent form witnessed by the local health office before collection of data and blood samples. The questionnaire used to collect demographic and epidemiological data was anonymous and linked to the blood sample tube only by a code.
1a/b
3 (0.09)
2 (0.09)
1 (0.10)
2
118 (3.66)
72 (3.27)
46 (4.50)
2a
10 (0.31)
4 (0.18)
6 (0.59)
2b
15 (0.46)
8 (0.36)
7 (0.68)
2a/c
83 (2.57)
49 (2.22)
34 (3.32)
Results A total of 3,227 anti-HCV positive sera were received from all the five regions of the country. Out of these 1,501 (46 %) samples were found positive by HCV qualitative PCR with viral load >500 IU/ml were tested by type-specific genotyping assay. Out of 1,501 patients, 976 (65 %) were males and 525 (35 %) were females with
3
40 (1.24)
33 (1.50)
7 (0.68)
3a
199 (6.17)
170 (7.71)
29 (2.83)
4
371 (11.50)
216 (9.80)
155 (15.15)
4b
4 (0.12)
1 (0.14)
0 (0.10)
4e
1 (0.03)
6 (0.05)
1 (0.00)
4F
7 (0.22)
1 (0.27)
0 (0.10)
4h
19 (0.59)
8 (0.36)
11 (1.08)
4a/c
1 (0.03)
0 (0.00)
1 (0.10)
4c/d
68 (2.11)
29 (1.32)
39 (3.81)
4d
1 (0.03)
1 (0.05)
0 (0.00)
5
1 (0.03)
1 (0.05)
0 (0.00)
Unknown
1,726 (53)
1,227 (55.67)
499 (48.78)
Total
3,227 (100.00)
2,204 (100.00)
1,023 (100.00)
Daw et al. BMC Res Notes (2015) 8:367
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Fig. 1 Geographical distribution of HCV genotypes according to the Libyan regions (color‑coded). Data indicate percentage of patients infected by genotype in each region.
(35.5 %) and less among Tripoli region (25.9); Genotype 3, Tripoli (21.3 %) and East (15.9 %) and varied from 7.1 to 11.6 % among other regions; Genotype 2, North (23.6 %) and South (22.5 %) and from 12.2 to 14.5 % among other regions. HCV genotypes were found to be variables among the Libyan region involved (P