Modeling and Gaps Define HIV Surveillance in Sub-Saharan Africa

Over the past two decades, significant global progress has been documented in the fight against HIV, marked by substantial declines in both new HIV infections and AIDS-related deaths, primarily driven by expanded access to HIV testing, treatment, and prevention services. This progress has necessitated robust data collection to monitor epidemic trends and evaluate the impact of public health programs across various regions. To address this, a comprehensive narrative review was conducted to examine the specific HIV surveillance indicators and methodologies employed by selected African nations to track the evolution of the HIV epidemic and assess the effectiveness of implemented health strategies. The study focused on five specific African countries: Ghana, Kenya, Lesotho, Malawi, and Zimbabwe, analyzing their national and global surveillance guidelines to understand the complexities of modern HIV monitoring.

The methodology involved a meticulous review of global and national HIV surveillance guidelines, specifically extracting information pertaining to two core areas: first, the specific indicators utilized to monitor changes within the HIV epidemic; and second, the concrete activities that these countries undertake to measure those indicators. The review process involved an in-depth document analysis of the selected nations’ strategic plans and related health documents. This systematic approach allowed researchers to compare the documented surveillance frameworks against the actual implementation status of these critical public health activities, providing a detailed snapshot of the current state of HIV data collection across these diverse sub-Saharan contexts.

The analysis of the available documentation revealed that a total of 66 documents were identified that inform HIV surveillance plans, whether at the national or global level. When focusing specifically on the five selected countries, the documented HIV surveillance frameworks reflected a range of 80 to 103 unique HIV indicators per country. This number contrasts with a consolidated list of indicators found in global guidance documents, which contained 128 indicators. A notable finding of this review was the varying emphasis placed on different types of indicators within the national strategies. The largest proportion of reported national indicators across these countries were classified as pertaining to integrated services and non-biomedical measures. These non-biomedical measures included crucial aspects such as HIV stigma and knowledge, accounting for a range of 22.8% of indicators in Ghana (21 out of 92) to a substantial 64.1% in Lesotho (66 out of 103).

Regarding the specific methods used to quantify the epidemic, the reliance on mathematical modeling was overwhelmingly dominant for estimating both HIV incidence and mortality across the five focus countries. While strategic plans detailed various surveillance activities—such as community and facility-based mortality surveillance, HIV drug resistance surveys, and bio-behavioral surveys—the evidence indicated that these activities were either only partially implemented or were not documented in the available strategic plans. This suggests a significant gap between the theoretical surveillance frameworks laid out in policy documents and the practical, consistent execution of those plans on the ground, posing challenges to the timeliness and accuracy of the data available for national health planning.

The conclusion drawn from this review highlights a critical reliance on specific data types within the selected African nations. HIV surveillance among Ghana, Kenya, Lesotho, Malawi, and Zimbabwe primarily utilizes mathematical models to generate estimates for HIV incidence and mortality. Furthermore, there is a heavy dependence on infrequent household surveys to quantify the overall epidemic burden and track behavioral risk indicators. The review observed that while national strategy documents successfully named numerous HIV indicators and listed various surveillance activities, the actual implementation of these activities was consistently inconsistent across the five countries examined. This inconsistency underscores the necessity for countries to undertake a thorough reassessment of the suitability of their current indicators and activities, with the goal of streamlining these processes for a more efficient and reliable estimation of the true HIV burden.

The challenges in measurement are further complicated by the difficulty in tracking mortality, which remains a major hurdle in these selected African countries. HIV mortality estimates are predominantly derived from mathematical modeling, a necessity given the widespread lack of reliable vital registration systems, particularly concerning the mortality of People Living with HIV. Despite this, some innovative approaches were noted, such as in Malawi, where in-hospital admissions and deaths of people living with HIV were analyzed relative to the general population size to determine changes in the rates of HIV-positive admissions over time. Kenya also demonstrated some evidence of improving its mortality surveillance within specific pockets of high HIV burden, while all five focus countries had integrated the measurement of key behavioral factors affecting HIV risk into their population-based household surveys.

A significant discrepancy was identified between the surveillance activities detailed in the national HIV strategic plans and the actual implementation evidence found. For instance, in Malawi, the national strategic plan mentioned the use of various methods for HIV mortality measurement, including vital registration and community- and facility-based mortality surveillance, but no documented evidence of implementation at the national level was present. Moreover, the review found that none of the five focus countries had successfully conducted drug resistance surveys within the last five years, despite these being specified in their surveillance plans. Similarly, bio-behavioral surveys (BBSSs) targeting key populations had only been conducted in Malawi and Kenya within the last five years, illustrating the uneven application of planned strategies across the region.

The review also highlighted a potential disconnect between international public health requirements and the prioritization processes occurring at the national level. While researchers found that countries linked to major international agencies were likely measuring certain indicators, these specific metrics had not been formally included in the national strategy documents as key performance indicators. This suggests that the sophisticated monitoring and evaluation frameworks provided by global bodies, such as UNAIDS, the Global Fund, and PEPFAR, may not be fully integrated into the core planning and indicator selection processes of individual African nations. This divergence is a critical factor in understanding why national surveillance efforts might appear incomplete when measured against global benchmarks.

Moving forward, the findings suggest a need for substantial methodological innovation and strategic refinement. The current reliance on quinquennial population-based surveys, which are subsequently interpreted through mathematical modeling, limits the availability of timely data regarding national HIV trends necessary for accurately estimating incidence. Furthermore, this infrequent data collection leaves a critical gap in understanding subnational incidence, which is essential for monitoring the precise trajectory of the epidemic. There is a clear call for developing mathematical models that can effectively incorporate routine data, such as information gathered from health facilities, while simultaneously accounting for potential biases inherent in health care access and coverage. Programs should consider utilizing sentinel sites equipped with high-quality routine facility-based data to strengthen surveillance during periods of overall health data system strengthening.

In summary, the HIV surveillance landscape in selected sub-Saharan African countries is characterized by a complex mix of advanced modeling techniques and foundational data gaps. While the commitment to tracking key indicators like incidence, prevalence, and mortality remains paramount for achieving the goal of ending AIDS as a public health threat, the sustainability and efficiency of these methods require urgent attention. Countries must prioritize fewer, but more frequent, decision-relevant indicators, coupled with a concerted effort to improve the quality of routine data and strengthen civil registration and vital statistics systems to enhance mortality surveillance capabilities. The consistent reassessment and streamlining of these surveillance activities are essential steps toward achieving more accurate and actionable insights into the evolving HIV epidemic.

Subject of Research: HIV surveillance strategies and implementation challenges in selected African countries.

Article Title: A narrative review of HIV surveillance strategies used in selected sub-Saharan African countries

Article References: Nliwasa, M., Tippett Barr, B. A., Chigawa, F., Chipeta, M. G., Khundi, M., Mzembe, T., Moyo, B., Mafaiti, C., Msosa, T., Imai-Eaton, J. W., & Mwapasa, V. (2026). A narrative review of HIV surveillance strategies used in selected sub-Saharan African countries. Frontiers in Public Health, 14, 1887244. https://doi.org/10.3389/fpubh.2026.1887244

Image Credits: AI Generated

DOI: 10.3389/fpubh.2026.1887244

Keywords: HIV, Surveillance, Sub-Saharan Africa, Public Health, Epidemiology, Mathematical Modeling, Health Policy, narrative, review, strategies, used, selected