jHASE
oa
special issue article
open access
freely available online
Issue Theme: New Strategies and Methods for HIV/AIDS Surveillance in Low and Middle Income Countries - 2009
How can PMTCT Program Data be Used for the Purposes of HIV Surveillance? Kimberly A. Marsh1*, Omotayo Bolu 2, Stephane Bodika3, Khumo Seipone4, Suriya Wonkongkathep5, Fulgentius Baryarama6 , Aisha Yansaneh2, Chineta Eure-Miller2, Jesus M Garcia-Calleja7 Author affiliations: 1Division of Epidemiology, Public Health and Primary Care, Faculty of Medicine, Imperial College London, UK; 2Global AIDS Program, National Centre for HIV, Viral Hepatitis, STD and TB Prevention (NCHHSTP), CDC, Atlanta, USA; 3Global AIDS Program, NCHHSTP, CDC, Gaborone, Botswana; 4Ministry of Health, National AIDS and STI Control Program (NASCOP), Botswana; 5 Ministry of Public Health (MOPH), Bangkok, Thailand; 6 Global AIDS Program, NCHHSTP, CDC, Entebbe, Uganda; 7 HIV Department, World Health Organization, Geneva, Switzerland. Email: KAM(*Corresponding author):
[email protected]; OB:
[email protected]; SB:
[email protected]; KS:
[email protected]; SW:
[email protected]; FB:
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[email protected] Citation: Marsh KA, Bolu O, Bodika S, Seipone K, Wonkongkathep S, Baryarama F, Yansaneh A, Eure-Miller C, GarciaCalleja JM. How can PMTCT program data be used for the purposes of HIV surveillance? jHASE 2010, 2(1):5. Freely available from: http://www.ieph.org/ojs/index.php/jHASE/issue/archive [DOI: pending | predoi ver.04.09.2010] Summary of prepublication history: Submitted: 15 October 2009; Accepted: 30 April 2010; Publication date: 4 September 2010 Copyright: © 2010 Marsh et al., licensee jHASE at IEPH, Inc. This open access article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (http://creativecommons.org/licenses/by/2.0).
Abstract Background: In countries with severe HIV epidemics, including most in sub-Saharan Africa (SSA), monitoring of trends in HIV prevalence is primarily accomplished through annual or biannual ANC-based HIV surveillance using unlinked anonymous testing (UAT) methods. In recent years, the availability of effective measures for the prevention of mother-to-child transmission (PMTCT) has led to increased coverage of HIV testing among pregnant women at antenatal care (ANC) clinics. As a result, the use of routinely-available HIV testing data from rapidly expanding PMTCT programmes has been proposed for monitoring population-level HIV prevalence trends, possibly either as a complement to or a replacement for UAT-based ANC HIV surveillance. Methods: We identified and reviewed 9 studies from 7 countries in SSA and proceedings from consultative meetings assessing the usefulness of PMTCT data for surveillance purposes to adapt PMTCT programme activities to meet surveillance needs. Results: Evidence to date for the use of PMTCT data for surveillance purposes from the literature and presented in consultative meetings was mixed, although all of the studies except in Botswana occurred at a time when PMTCT services were characterized by low uptake and limited human and financial resources to appropriately monitor programme activities. In two studies in Uganda and one in Burkina Faso, associations between characteristics of women accepting testing and their serostatus varied, leading in some cases to biases in PMTCT-based estimates of HIV prevalence. Direct comparisons of PMTCT and UAT-based ANC prevalence from Botswana, Cameroon and rural Uganda demonstrated that PMTCT data could be used for surveillance purposes, whereas at multiple clinics in Kenya, Uganda, and Zimbabwe, problems with the quality of PMTCT data and differences in clinic-level estimates made it difficult to use. We take into account the recent improvements in the quality and availability of PMTCT data when making recommendations for how countries might better begin to use these data for monitoring HIV prevalence trends. Conclusion: Using PMTCT-based data is desirable and feasible for surveillance purposes, however, additional efforts will be required to ensure that HIV testing uptake is such that it does not bias prevalence estimates and that operational challenges to their collection, availability and interpretation are overcome.
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BACKGROUND In resource-limited countries with severe HIV epidemics such as those in sub-Saharan Africa (SSA), trends in HIV prevalence are typically monitored through annual or biannual HIV surveillance among pregnant women routinely seeking antenatal care (ANC) [1]. The primary strategy used to collect ANC surveillance data is unlinked anonymous testing (UAT), in which leftover blood is tested for HIV antibodies and women are not typically asked for their consent to participate. Because HIV prevalence estimates from UAT ANC surveillance (hereafter referred to as ANC surveillance) conducted on an annual or biannual basis are generally considered representative of prevalence in the surrounding community [2], data from participating clinics are used to produce country-specific and global HIV/AIDS epidemic trends [3] and to monitor an UNGASS target to reduce by 50% globally by 2010 the number of newly infected youth aged 15-24 years [4]. In recent years, availability of effective measures for the prevention of mother-tochild transmission (PMTCT) has led to substantial increases in access to and uptake of HIV testing and counselling among pregnant women attending ANC clinics [5]. In terms of access, by 2008, more than 75% of ANC clinics in 25 of 46 SSA countries offered HIV testing and counselling [5]. In terms of uptake, WHO-published guidance encouraging provider-initiated testing and counselling (PITC) or “opt-out” -- rather than client-initiated testing and counselling or “opt-in” -- has substantially increased HIV testing at ANC, in many clinics and some countries exceeding 90% uptake [6-10]. Given these advances, the extent to which HIV testing data from PMTCT services could complement, or even replace, ANC HIV surveillance in the future is being debated. Using PMTCT data for surveillance purposes offers certain advantages over ANC surveillance in that more ANC clinics can participate, ethical concerns of testing women without consent are avoided, and data on the number of women testing and
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their HIV status are routinely available as part of programme monitoring activities. However, possible disadvantages have also been raised. Of greatest concern has been that women refusing or, conversely, preferentially seeking out HIV testing could bias PMTCT-based estimates [11, 12]. The impact of this bias on prevalence estimates could also vary in magnitude and direction with time as uptake levels or approaches to delivering HIV testing and counselling services change [13]. Finally, whether PMTCT data are sufficiently standardized across clinics, detailed enough for surveillance purposes, and accessible in their current form has also been debatable [14-18]. In this paper, we examine previous literature on this topic to understand advantages and disadvantages to using PMTCT data for surveillance purposes. To identify relevant published studies, we conducted a comprehensive online literature review in April 2009 using Google Scholar and PubMed. Key words included: Antenatal Care, HIV prevalence, HIV testing determinants, HIV risk factors, pregnant women, prevention of mother-to-child transmission, sentinel surveillance, seroprevalence, and voluntary counselling and testing. To identify unpublished studies, we reviewed proceedings from international meetings on these subjects and we contacted HIV surveillance and PMTCT experts. The 9 studies included in the final review representing 7 countries (See Table 1) assessed either: 1) the extent to which accepting HIV testing is associated with HIV serostatus (which can be used in turn to measure the impact of non-participation bias on PMTCT-based estimates) [11, 12, 19]; or 2) whether PMTCT-based data from clinics were as accurate and of sufficient quality as ANC surveillance data to monitor HIV prevalence [11, 13-16, 18, 20]. Based on the these studies and consultative reports [17, 21], we collaboratively developed recommendations on measures to adapt PMTCT programme activities to meet
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Table 1a continued in Table 1b
* Refers to Unlinked Anonymous Testing ANC-based HIV surveillance ** PITC – Provider-initiated testing and counselling.
Table 1a: Review of 9 published and unpublished literature from 7 sub-Saharan African countries on the use of PMTCT data for HIV surveillance purposes
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* Refers to Unlinked Anonymous Testing ANC-based HIV surveillance ** PITC – Provider-initiated testing and counselling
Table 1b (continuation of Table 1a): Review of 9 published and unpublished literature from 7 sub-Saharan African countries on the use of PMTCT data for HIV surveillance purposes
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surveillance needs. We conclude suggesting areas for further research.
Marsh et al. How can PMTCT Program Data be Used …
by
STUDIES OF THE ASSOCIATION BETWEEN ACCEPTING HIV TESTING AND HIV SEROSTATUS Bias in HIV prevalence estimates from PMTCT data can occur if women preferentially are offered or accept HIV testing according to their suspected (or known) serostatus. In situations where stigma prevents women with a suspected HIV positive status from getting tested or attending a particular clinic, PMTCT estimates might underestimate true community HIV prevalence. Alternatively, if women most at risk of infection seek testing, PMTCT-based estimates could overstate community HIV prevalence. The extent to which these biases change with time could impede interpretation of trends arising from PMTCT data. While many studies have considered determinants of testing among pregnant women with the goal of increasing uptake, only three have directly linked these determinants to HIV serostatus in order to assess bias [11, 12, 19]. In a first study at a rural North Uganda hospital from 2001 to 2003, 48% of women (6,785/14,040) accepted ‘opt-in’ HIV testing when initially offered at their second prenatal visit. Thirty nine percent (5,414/14,040) did not[11]. Furthermore, 13% (1,841/14,040) of women failed to return for a second visit and therefore were not offered testing. Compared to those who did not agree to test, accepting and testing positive was weakly associated with having lived at a current address for two years or less, cohabitating but not being married, and having a partner with a nonagricultural occupation. Given the weakness of the associations, however, PMTCT-based and ANC surveillance estimates were judged similar (10.9% and 11.1% respectively). Also, because those women offered and not offered testing had similar demographic characteristics, the authors hypothesised that this type of non-participation bias would have had minimal impact on PMTCT-based estimates. In a second study, also in Uganda, Mpairwe et al., [12] followed 4,867 women from May www.ieph.org/hase/jhase.htm
2002 to April 2003 at an urban Entebbe ANC clinic providing ‘opt-in’ PMTCT services. Similar to the rural Northern Uganda site, 25% (1,239/4,867) of the women were not offered testing, resulting in an overall uptake of 54% (2,635/4,867). The 20% who refused (993/4,867) were tested anonymously. Results showed most importantly that women who perceived themselves to be at risk for HIV were more likely to accept testing and to test positive. Also, women with no education or only primary education, those who had an HIV infected partner and those who believed themselves exposed to HIV also accepted testing and tested positive more often than others without these characteristics. Despite these associations, no differences in prevalence levels were observed between individuals accepting (14%) or refusing (12%) testing (pvalue=0.26) during the study. Differences in estimates were observed, however, in the month following introduction of PMTCT services (20% among accepters vs. 11% among non-acceptors; p-value=0.05) and in months with testing uptake below 70%, (17% in accepters vs. 8% among nonacceptors; p-value
