The transition of HIV within and between affected populations in Poland

SummaryBackgroundThe aim of this paper is the estimation of the probabilities that describe the transition of HIV within and between the following three populations: homosexual and bisexual men, injecting drug users and heterosexual persons in Poland in the years 1995–2006.Material and methodsThe data on the routes of HIV infections come from “HIV/AIDS Surveillance in Europe”. The restricted maximum likelihood method is applied for the estimation of underlying Markov chain.ResultsHIV infections are more probable within analysed populations than between them. The scale of HIV mobility is small. The estimated Markov chain predicts radical changes of the routes of HIV infection in the future. However, the evolution of the HIV epidemic in Poland is still far from equilibrium.