South Africa implements variations of second generation surveillance surveys to monitor human immunodeficiency virus (HIV) epidemic. This paper compares HIV estimates from two design variations: take all approach and sub-sampling approach to ascertain if any changes in HIV epidemic are due to methodological changes or inherent evolution of the epidemic. HIV estimates were comparable with no systematic pattern. Prevalence estimates were slightly higher 12.2% in the take all compared to 11.6% in the sub-sampling approach. Estimates from sub-sampling approach were more variable. The design effects in the take all In conclusion, as the household size increases the number of people living with HIV in each household increases thus increasing intra-class correlation. Similarity of resulting HIV estimates is re-assuring. However, the take all approach is more preferable than sub-sampling approach as it allows for detailed analyses of HIV data such as estimating discordance between sexual partners and parent-child pair.
Human Sciences Research Council (Sat,) studied this question.