Mapping HIV prevalence in Nigeria using small area estimates to develop a targeted HIV intervention strategy

Abstract

Objective Although geographically specific data can help target HIV prevention and treatment strategies, Nigeria relies on national- and state-level estimates for policymaking and intervention planning. We calculated sub-state estimates along the HIV continuum of care in Nigeria. Design Using data from the Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS) (July–December 2018), we conducted a geospatial analysis estimating three key programmatic indicators: prevalence of HIV infection among adults (aged 15–64 years); antiretroviral therapy (ART) coverage among adults living with HIV; and viral load suppression (VLS) rate among adults living with HIV. Methods We used an ensemble modeling method called stacked generalization to analyze available covariates and a geostatistical model to incorporate the output from stacking as well as spatial autocorrelation in the modeled outcomes. Separate models were fitted for each indicator. Finally, we produced raster estimates of each indicator on an approximately 5×5-km grid and estimates at the sub-state/local government area (LGA) and state level. Results Estimates for all three indicators varied both within and between states. While state-level HIV prevalence ranged from 0.3% (95% uncertainty interval [UI]: 0.3%–0.5%]) to 4.3% (95% UI: 3.7%–4.9%), LGA prevalence ranged from 0.2% (95% UI: 0.1%–0.5%) to 8.5% (95% UI: 5.8%–12.2%). Although the range in ART coverage did not substantially differ at state level (25.6%–76.9%) and LGA level (21.9%–81.9%), the mean absolute difference in ART coverage between LGAs within states was 16.7 percentage points (range, 3.5–38.5 percentage points). States with large differences in ART coverage between LGAs also showed large differences in VLS—regardless of level of effective treatment coverage—indicating that state-level geographic targeting may be insufficient to address coverage gaps. Conclusion Geospatial analysis across the HIV continuum of care can effectively highlight sub-state variation and identify areas that require further attention in order to achieve epidemic control. By generating local estimates, governments, donors, and other implementing partners will be better positioned to conduct targeted interventions and prioritize resource distribution.

Cervical Epithelial Abnormalities and Associated Factors among HIV-Infected Women in Lagos, Nigeria: A Cytology-Based Study

“…The relatively lower prevalence of cervical epithelial abnormalities in our study may reflect the population of women enrolled as the study site is an HIV treatment centre where almost all clinic attendees are already on ART. Furthermore, the prevalence of cervical cytological abnormalities closely reflects the burden of HIV reported in the geographical settings of these respective studies [21,22]. The higher prevalence rates of cervical epithelial abnormalities in this study and others [16,19,23] compared to the figures reported in the general women population (3.5-4.1%) [24][25][26] comprising predominantly HIV seronegative women are not unexpected as HIV-infected women are more likely to have persistent oncogenic HPV infections which predispose them to cervical precancers and cancer [2,4].…”

Areas with high HIV prevalence: A spatial analysis of nationwide claims data in Germany

“…Internationally, previous research on small-area variations in the prevalence of HIV have used small-area estimation techniques. Most of these studies were conducted in African countries [8][9][10][11]. One study from the USA estimated the number of people with HIV in 677 counties where HIV case numbers were not previously available [12].…”

Does adherence to antiretroviral therapy differ by place of residence in Nigeria? A systematic review and meta-analysis protocol

“…[14][15][16] There is evidence of geographic variation in coverage and viral suppression, 17 18 including Nigeria, with local government variation in ART coverage and viral suppression. 19 Nigeria is the most populous country in Africa, 20 has an HIV prevalence of 1.4%, 21 with a state-level prevalence of 0.3%-4.8%, and more prevalent in the rural areas than the urban area. 22 Like many other Sub-Saharan African countries, many people in Nigeria reside in rural areas, with up to 47.3% of Nigerians living in rural areas in 2021.…”