Modelling trends in hiv/aids prevalence and incidence in Kenya

Abstract

The trends in the evolution of HIV/AIDS epidemic in Kenya has been tracked through annual sentinel surveillance in antenatal clinics since 1990. Behaviors have been measured through national Demographic and Health Surveys in 1993, 1998, and 2003. The surveillance data indicates that prevalence has declined substantially starting in 1998. Nationally, adult prevalence has declined from 10% in the late 1990s to under 7% today. In the analysis, the 2009 Estimation Projection Package (EPP) and Spectrum Packages customized using Kenya’s data from VCT, ART, and PMTCT programmes were entered into the EPP. Next entered into the EPP/Spectrum were birth rate, survival rate, adult mortality and population growth rate. EPP was used to fit epidemic model to the data yielding trend curves for the two sub groups: males and females. Next, the prevalence and incidence projections produced by EPP were imported into Spectrum which generated final trends and calculated the number of people living with HIV, new HIV infections, and AIDS related deaths. From the results, the number of people living with HIV was increasing. This is due to the positive growth rate in the population. The prevalence trends increased to a pick value before decreasing steadily to the current values. The new infections of adults aged 15-49 constantly increased. This too is due to the ever increasing overall population in Kenya. The incidence rates decreased due to the interplay between several factors including the effects of ART and PMTCT. In conclusion, there is need to scale up the roll out of the PMTCT and sensitization programmes on awareness as there is evidence that these would greatly serve to bring down the prevalence and incidence rates to the desired zero rates.