Time trends in HIV-1 diversity in Croatia: a follow up on HIV-1 subtype distribution

The geographical distribution and prevalence of HIV-1 subtypes in Europe are highly heterogeneous. Subtype B is predominant in Western and Central Europe but non-B subtypes, introduced mainly via migration, are also present in the region. Croatia is a small Central European country with distribution of HIV-1 subtypes similar to that of other European countries dominated by subtype B. Several studies on HIV-1 subtype distribution have been published in Croatia so far that show that the most common HIV-1 subtype is subtype B. Molecular analysis of HIV subtypes in period 2001-2003 showed a high prevalence of subtype B (>74%) with non-B subtypes found only in heterosexuals. A study on transmitted-drug resistance (TDR) in newly diagnosed HIV-infected patients conducted in the period 2006-2008 showed a high prevalence of subtype B among MSM population with only 11 % of patients infected with non-B subtypes. Subtype B was also confirmed as predominant in respond-driven sampling (RDS) study among MSMconducted in 2006 and 2010. The aim of this study is to show a more recent data on of HIV-1 subtype distribution in newly diagnosed patients in Croatia and compare it with previous years.