Overview of the first national population-based HIV testing survey in Nigeria

Background: The introduction of rapid HIV testing, and the use of dried blood spot samples for laboratory testing has made the collection and testing of blood for biomarkers feasible in large scale surveys in developing countries with poor infrastructural facilities. This paper describes Nigeria's first national population-based biomarker survey.

Methodology: The Federal Ministry of Health in Nigeria in collaboration with the Society for Family Health conducted the first population-based biomarker survey called the NARHS-Plus in 2007. Prior to its implementation, HIV prevalence in Nigeria was based on estimates from sentinel studies among pregnant women attending antenatal clinics. The NARHS-Plus used a multi-stage sampling procedure for selecting eligible respondents; males: 15-64years and females: 15-49years. Testing procedures were reviewed for ethical appropriateness. Procedures on safety in the collection and handling of biological specimens and disposal of biohazards were ensured. Testing followed WHO laboratory algorithm designed to maximize sensitivity and specificity of results. Data were analyzed with SPSS 16.0.

Results: The response rate; oral interviewing: 97.5%, HIV testing: 78.6%. Non response to HIV testing was significantly higher in urban compared to rural areas (24% vs. 20%, p<0.0001). Substantial geographical variations in response rates at geopolitical zonal level exist. The national estimated HIV prevalence in the survey was 3.6% (females 4.0% vs. males 3.2%, p<0.0001; and urban 3.8% vs. rural 3.5%, p=0.0047), compared to the 2005 sentinel survey figure of 4.4%.

Conclusions: Population-based biomarker surveys should be encouraged as estimates from ANC sentinel survey may not be a true representation of HIV prevalence rates.