Tropical Biomedicine 31(4): 777–784 (2014)
Seroprevalence of IgG and IgM antibodies and associated risk factors for toxoplasmosis in cats and dogs from subtropical arid parts of Pakistan Ahmad, N.1*, Ahmed, H.2, Irum, S.2 and Qayyum, M.1 1Department 2Department
of Zoology, Pir Mehr Ali Shah, Arid Agriculture University, Rawalpindi, Pakistan of Biosciences, COMSATS Institute of Information Technology (CIIT), Park Road, Chakhshazad,
Islamabad *Corresponding
author email:
[email protected] Received 12 December 2013; received in revised form 30 March 2014; accepted 20 May 2014
Abstract. Pet cats and dogs are an important source of human toxoplasmosis because of their intimate relationship with humans. Present study was designed to determine the prevalence and risk factors of toxoplasmosis in cats and dogs in northern sub-tropical arid region of Pakistan where no such work has been previously conducted. For this study 420 cats and 408 dogs visiting different pet clinics and veterinary hospitals were screened for the presence of anti-Toxoplasma IgG and IgM antibodies using ELISA technique. Epidemiological information regarding age, sex, area, outdoor access and hunting practice was obtained from the owners by questionnaire interview. Overall seroprevalence in cats and dogs was 26.43% (111/420) and 28.43% (116/408) respectively. IgG antibodies were found in 23.33% (98) cats and 25.49% (104) dogs while IgM antibodies were found in 3.57% (15) cats and 3.92% (16) dogs. Seroprevalence was significantly high in cats and dogs older than one year. No significant difference was recorded between males and females. Cats and dogs from rural areas showed higher prevalence. Dogs which had access to outside also showed high seroprevalence. The present study indicates that Toxoplasma gondii is widespread in pet animals in Pakistan which may have important implication for public health.
maintained in the environment in the absence of cats (Dubey et al., 1997). Seroprevalence of T. gondii in humans has been associated with close contact with cats and having pet cats at home (Pereira et al., 1992). Serological survey of T. gondii antibodies in cats is very much needed as it also assess the degree of oocysts contamination of the environment (Miro et al., 2004). Pet dogs are often regarded as closest faithful and intimate friends of humans. There are also some reports of T. gondii oocysts shedding by dogs because oocysts ingested via food and water in dogs can pass through intestinal tract and are excreted in the feces (Lindsay et al., 1997). The presence of pet dog in household has been found to be a risk factor for T. gondii infection in humans (Sroka et al., 2010). Dogs may facilitate the
INTRODUCTION The role of felids including domestic cat in the spread of toxoplasmosis is very critical as they serve as definitive hosts of the parasite where oocysts are produced. All other mammals including human beings and birds serve as intermediate hosts (Dubey, 2004). Millions of oocysts are shed by cats after getting infected (Dabritz et al., 2007). These oocysts when ingested along with food and water can affect humans and livestock animals resulting in abortions, neonatal deaths and other complications in both humans and animals (Afonso et al., 2008). Although the infection can also be transmitted congenitally or by eating meat of T. gondii infected animals, it has been reported by many studies that T. gondii infection is not 777
transmission of the disease to humans by facilitating human exposure to oocysts present in the environment by rolling in contaminated cat faeces or excreting oocysts after ingesting oocyst infected food (Frenkel et al., 1995). Presence of dogs in household indicates a potential risk of toxoplasmosis to humans. Keeping in view the importance of the infection in cats and dogs, the present study was designed to workout the prevalence and associated risk factors in cats and dogs in sub-tropical arid parts of northeastern Pakistan.
area of 23,160 square kilometers. The area is usually arid and agriculture mainly depends upon rainfall which varies between 350 mm to 500 mm annually. Average temperature is around 7.9°C in winter and 30.6°C in summers. Study Animals and Sampling Present study included pet cats and dogs visiting different pet clinics and veterinary hospitals in the study area. A total of 420 cats and 408 dogs were tested for the presence or absence of T. gondii infection from January to December 2012. The blood samples were collected from jugular or sephanous vein and were quickly transported to laboratory where they were centrifuged at 3000 rpm for 15 minutes to obtain serum.
MATERIALS AND METHODS Study Area Present study was conducted in four districts of Potohar plateau region namely Rawalpindi, Jhelum, Chakwal and Attock. Potohar plateau is located between 32°–30' to 34° northern latitudes and 71°–45' to 73°–45' eastern latitudes in northern parts of Punjab province and has a distinct arid sub-tropical climate as compared to other parts of the country (Fig. 1). Consisting of a population of 7.5 million individuals, the plateau covers an
Epidemiological Information Additional epidemiological information regarding age, access to outside, area and hunting practice was obtained on questionnaire by interview to the owner. Climatic Data In order to workout the seasonal distribution of toxoplasmosis, the positive result from
Figure 1. Map of Pakistan showing study area (shaded)
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acute disease phase (IgM positive cases) were compared with climatic data. Daily climatic data (maximum temperature, minimum temperature, rainfall and relative humidity) was collected from the meteorological department of Pakistan.
28.43% in cats and dogs respectively. Prevalence of IgG antibodies in cats was 23.33% as 98 cats were found positive for Toxoplasma-specific IgG antibodies while prevalence of IgM antibodies was 3.57% as 15 cats were found positive for IgM antibodies. Two cats were found positive for both IgG and IgM antibodies. Similarly IgG antibodies were found in 104 dogs giving IgG prevalence of 25.49% while IgM antibodies were found in 16 dogs giving IgM prevalence of 3.92%. Four dogs had both IgG and IgM antibodies (Table 1). Despite dogs showing a little higher seroprevalence as compared to cats, there was no significant difference in seroprevalence in both species (P>0.05, χ 2 =0.4). No significant difference was observed in prevalence in cats (P>0.05, χ2=3.8) and dogs (P>0.05, χ2=3.0) from four districts. Seroprevalence was higher in older cats as compared to younger ones. No sex specific difference of seroprevalence was observed in cats. Prevalence was little high in female cats as compared to males but the difference was statistically non-significant (P>0.05, χ2=0.1). Access to outside also did not contribute in disease prevalence in cats (P>0.05, χ2=0.4). Similarly hunting practice was also a non-significant factor in the spread of the disease in cats (P>0.05, χ 2=0.7). However, prevalence varied highly significantly in cats with respect to urban and rural areas. Infection in cats belonging to rural areas was significantly high as compared to urban cats (P
