A Markov chain Analysis of HIV Progression in Key Populations; A case Study of HIV in Homa Bay County

Abstract

Key populations account for the highest number of individuals with HIV infections. Theyincludefemalesexworkers,menwhohavesexwithmenandpeoplewhoinjectdrugs. While many studies have been done regarding HIV/AIDS and its spread, the disease continue to affect newer populations and remain prevalent among those who have already experienced it. Our study focused on HIV progression in key populations in Homabay county.The overall objective of this study was to apply Markov chains in analyzing HIV progression in the key populations. We drew the following specific objectives: 1. To estimate the probability of moving from susceptible state to infected HIV state in the key populations; 2. To estimate the expected time to absorption. We also estimated the probability of absorption of a patient and the probability of moving from one state to the other. This study utilized secondary data from Key Population size Estimates 2019 and primary data from HIV care and treatment register from Homabay county referral hospital.The data was for the whole population in the category.The population mean estimatesperspotwereasfollows: Femalesexworkers(FSW)8.1,menwhohavesexwith men(MSM) 6.1 and People who Inject drugs (PWID) 7.6.We estimated parameters using MaximumLikelihoodEstimatorandcalculated99%confidenceintervaloftheparameters. A Discreet Time Markov chain analysis was used to model the progression of the disease among key populations in the county.The data was then simulated in R markdown to estimate the number of individual in each state at time t. Findings from the study show thatthemeantimetoabsorptionofsusceptibleindividualsis264months,66monthsafter confirmedinfectionwithHIVand63monthswheninfectedwithAIDS.Thesefindingswill be informative to the ministry of health and donor partners in the managing HIV/AIDS in the key populations.