Background: Malawi has been monitoring their HIV epidemic by combining antenatal clinic surveys among pregnant women with population demographic and HIV program data in a Spectrum mathematical model to produce population level estimates, with national household surveys incorporated into the model since 2006. This abstract seeks to determine whether indicators from Spectrum modelling are reproducible by another population-based survey, the 2015-2016 Malawi Population-Based HIV Impact Assessment (MPHIA).
Methods: MPHIA, a cross sectional household survey, was conducted for the first time between November 2015 and August 2016 in all districts in Malawi. The survey assessed HIV incidence, prevalence and viral load suppression and targeted both adults and children. Home-based HIV testing using the national rapid test algorithm with Geenius confirmation at satellite labs was conducted. HIV positive samples were centrally tested for viral load suppression and recency of infection using Lag_Avidity EIA. In 2015, antenatal clinic sentinel surveillance, MDHS, and national program data were entered into Spectrum software, which incorporated evidence-based assumptions about HIV program effectiveness and patterns of HIV transmission and disease progression to estimate HIV prevalence, incidence, and mortality in 2015, as well as future projections (unpublished).
Results: Spectrum estimated HIV incidence in 2015 to be 0.38% (95%CI:0.27-0.52%) among adults aged 15-49 years. This same model projected HIV incidence for 2016 at 0.34% (0.40% in females, 0.29% in males). The MPHIA survey estimate for HIV incidence was 0.32% (95%CI:0.16-0.48%). MPHIA found that HIV incidence was higher in females (0.39%, 95%CI:0.15-0.63%) than men (0.24%, 95%CI:0.03-0.46%).
Spectrum projected 2016 HIV prevalence for adults aged 15-49 as 9.2% (11.3% females, 7.2% males). The MPHIA estimate for HIV prevalence was 10.0% (95%CI:9.4-10.7%), with higher prevalence among women (12.4%, 95%CI:11.4-13.4%) than men (7.5%, 95%CI:6.8-8.3%)). In children aged 0-14 years, Spectrum projected 2016 HIV prevalence at 1.03%. MPHIA survey results were 1.6% (95%CI:1.2-2.0).
Conclusions: The HIV incidence and prevalence results from the 2015/2016 population-based survey in Malawi are consistent with the 2015/2016 estimates generated by Spectrum modelling, except for children. This supports the reliability of Spectrum model in estimating adult indicators and its use to inform HIV programming in Malawi.