In 2015, the World Health Organization (WHO) issued guidance on HIV testing that brought together the existing guidance relevant to the provision of HIV testing services (HTS) and addressed issues and elements for effective delivery of HTS that are common in a variety of settings, contexts and diverse populations (1,2). At the core of these guidelines was the emphasis on targeted testing, a departure from testing for coverage. Consequently, various nations adopted and adapted the guidelines with varied interpretations and implementation modalities.
Targeted testing entails offering HIV testing to individuals who are likely to provide a positive diagnosis, determined by their risk profile and influenced by their preferred sexual practices (3,4). To operationalize the concept of targeted testing, guiding apparatuses such as screening tools are used to determine eligibility for an HIV test at the point of contact with a health worker. The result is reduced testing volumes and increased positivity yield (5–7). Further, initiatives such as index contact tracing and testing and offering HIV testing to high-risk groups are also employed in the veil of targeting HIV testing (8).
Targeted testing is particularly important for Southern Africa, which, until this day, bears a disproportionate burden of HIV. In Southern Africa, HIV/AIDS caused 336,175 deaths and more than 20 million Disability Adjusted Life Years (DALYs) in 2017 alone (9,10). Southern Africa remain the epicentre of the HIV/AIDS with the top 10 high burdened countries all being within the Southern Africa Development Community (SADC). Swaziland is the global number 1 country with a prevalence of 27.2% in 2021 (11). This is followed by Lesotho at 25%, Botswana 21.9%, South Africa 18.9%, Namibia 13.8 % and Zimbabwe at 13.5%, to name the top 6 countries (11).
It has been observed that varied performances on similar models of targeted testing are being documented in southern Africa. Further, varied models are also being used under the targeted testing mantra creating fundamental challenges in deriving a common understanding of what targeted testing entails in southern Africa. The objective of this study is to provide an overview of the different methodologies and yields of targeted testing models utilized in southern Africa in response to the recommendation to target HIV testing services. This information will inform what should constitute an effective targeted testing model to expedite epidemic control through enhancing positivity yield.
Literature review
Introduction
Globally, as countries around the world are making progress to reach the global goal of 95% of people with HIV knowing their status by 2025, as a critical milestone to ending AIDS by 2030, disparities remain in progress among specific sub-groups of the population with low utilization of HIV testing services (HTS) (12). These sub-groups include men, adolescents and young people, as well as key populations (13). For example, in sub-Saharan Africa, 73% of men with HIV aged 15 years and above are aware of their HIV status compared to 83% in women of the same age. Across all age bands, men have lower knowledge of HIV status than women owing to low testing levels (14). Overall knowledge of status is lowest among men aged 15-24 years in sub-Saharan Africa, however, men aged 25 years and above account for a greater number of undiagnosed HIV infections.
Global Milestones on HTS
The global scale-up of HIV testing has been substantial over the past decade. Between 2005 and 2015, globally the proportion of people living with HIV who were able to test rose from 12% to 60% (15). However, HIV testing levels are the poorest in the Middle East and North Africa, and West and Central Africa. This is contributed by a cocktail of reasons that include weak health systems, socio-cultural barriers and poor application of global guidelines on HTS associated with low coverage of services (16). In both these regions, respectively, just 50% and 48% of people living with HIV were aware of their status in 2017 (17). The situation is only varied in Western, Central Europe and North America which traditionally take a leading role in achieving critical milestones. For example, in 2017, Latin America had already achieved the first 90%, whilst Asia and the Pacific (74% in 2017), the Caribbean (73% in 2017) and Eastern and Central Europe (73% in 2017) were lagging (18).
Data taken from East and Southern Africa show that knowledge of status increased two-fold between 2012 and 2016 compared to between 2007 and 2011, and fourfold in West and Central Africa over the same period.
As a gateway to HIV prevention, treatment, care and other support services, people's knowledge of their HIV status through HTS is crucial to the success of the HIV response (19). The Joint United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) have endorsed global goals to achieve “zero new HIV infections, zero discrimination and zero AIDS-related deaths”. Owing to the potentially serious medical, social and psychological consequences of misdiagnosis of HIV (either false-positive or false-negative), all programmes and people providing HIV testing must strive also for zero misdiagnoses (20).
Guidelines for HIV testing continue to evolve with changes in testing technology and methods to reach persons who can benefit from these services. The overarching goals of HIV testing services are to identify people with HIV through the provision of quality services for individuals, couples and families. Further, effectively link individuals and their families to appropriate HIV treatment, care and support, as well as HIV prevention services, based upon their status; and support the scale-up of high impact interventions to reduce HIV transmission and HIV-related morbidity and mortality. This can be achieved through treatment and prevention packages, that is, antiretroviral therapy (ART), voluntary medical male circumcision (VMMC), prevention of mother-to-child transmission (PMTCT), pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP).
Provider Initiated Testing and Counselling (PITC), often referred to as routine HIV testing, can be expanded in more settings and regions. According to Global AIDS Response Progress Reporting (WHO, UNICEF, UNAIDS), at the end of 2014, 76% of 117 reporting low- and middle-income countries had a policy of recommending PITC during all client encounters, and 90% of 39 reporting countries in the WHO African region recommended PITC in ANC settings (21). However, in other African countries and Asia, HIV testing coverage of pregnant women is less than 40% (22).
Available data on HIV testing trends strongly suggest the need to consider a strategic mix of approaches to deliver HTS (23). The mix should facilitate the diagnosis of as many people with HIV as early as possible, at the same time maximizing yield, efficiency, cost-effectiveness and equity. Equity does not mean that HTS should be provided equally across a country or population; rather it should focus HTS on populations at greatest risk for HIV and who are underserved (23). Further, the mix should support timely and complete linkage to prevention, treatment, care and support services for those testing HIV-positive.
Among those who test HIV-negative, particularly those at ongoing risk, there is a need to facilitate their linkage to prevention services as well as to learn where and when to retest (23). The organization of the health system, local context, epidemiology, current testing coverage and available financial and human resources and what the intended clients want, are important determinants informing the appropriate mix of HTS approaches to reach populations at high risk and geographic areas with largely undiagnosed HIV infection (15).
WHO Guidelines on HIV Testing
In June 2019, WHO released a policy update of the existing 2016 Consolidated guidelines on HIV testing services which had effectively replaced the previous 2015 document (23). The new guidelines synthesise new evidence to inform an enhanced approach to HTS that aim to make it accessible, acceptable, cost-effective and minimize misclassification errors (24).
As part of the deliberate strategies to respond to changing HIV epidemics with high proportions of people already tested and treated, WHO encourage all countries to adopt a standard HIV testing strategy that uses three consecutive reactive tests to provide an HIV positive diagnosis. Previously, most high burden countries were using two consecutive tests. The new approach can help countries achieve maximum accuracy in HIV testing.
WHO recommends countries use HIV self-testing as a gateway to diagnosis based on new evidence that people who are at higher HIV risk and not testing in clinical settings are more likely to be tested if they can access HIV self-tests (25).
The WHO further recommends social network-based HIV testing to reach key populations, who are at high risk but have less access to services. These include men who have sex with men, people who inject drugs, sex workers, the transgender population and people in prisons. These “key populations” and their partners account for over 50% of new HIV infections. For example, when testing 99 contacts from social networks of 143 HIV-positive people in the Democratic Republic of Congo, 48% tested positive for HIV (26).
The use of peer-led, innovative digital communications such as short messages and videos can build demand- and increase uptake of HIV testing. Evidence from Viet Nam shows that online outreach workers counselled around 6 500 people from at-risk key population groups, of which 80% were referred to HIV testing and 95% took the tests. The majority (75%) of people who received counselling had never been in contact before with peer or outreach services for HIV (27).
WHO recommends focused community efforts to deliver rapid testing through lay providers for relevant countries in the European, South-East Asian, Western Pacific and Eastern Mediterranean regions where a longstanding laboratory-based method called “western blotting” is still in use (28). Evidence from Kyrgyzstan shows that HIV diagnosis which took 4-6 weeks with the “western blotting” method now takes only 1-2 weeks and is much more affordable resulting from the policy change.
Using HIV/syphilis dual rapid tests in antenatal care as the first HIV test can help countries eliminate mother-to-child transmission of both infections. The move can help close the testing and treatment gap and combat the second leading cause of stillbirths globally. More integrated approaches for HIV, syphilis and hepatitis B testing is also encouraged (29).
To further support countries, programme managers, health workers and other stakeholders seeking to achieve national and international HIV goals, this 2016 update issues new recommendations and additional guidance on HIV self-testing (HIVST) and assisted HIV partner notification services (23).
Key elements further highlighted within the new guidelines include:
Support targeted HIV testing through the implementation and scale-up of ethical, effective, acceptable and evidence-based approaches to HIVST and assisted HIV partner notification; Support the routine offer of voluntary assisted HIV partner notification services as part of a public health approach to delivering HTS; Guide how HIVST and assisted HIV partner notification services could be integrated into both community-based and facility-based HTS approaches and be tailored to specific population groups; Support the introduction of HIVST as a formal HTS intervention using quality-assured products that are approved by WHO and official local and international bodies and Position HIVST and assisted HIV partner notification services as HTS approaches that will contribute to closing the testing gap and achieving the UN’s 90 –90 –90 and 2030 global goals (23).
Research Question
Which targeted HIV testing model/combination of models has demonstrated improved positivity yield among adults (>/=18years) in Southern Africa?
Objectives
This review will address the following objectives:
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To provide an overview of the different methodologies of targeted HIV testing models utilized in southern Africa
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To identify the targeted HIV testing model that provided the highest positivity yield
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To assess adherence of targeted HIV testing methodologies with the WHO recommendation
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To recommend an effective targeted testing model for HIV