Research Themes

In Estonia concentrated HIV epidemic started in 2000 mainly among people who inject drugs. Lead by professor Irja Lutsar, the HIV research group began its work in 2005 in the Department of Microbiology of University of Tartu, with the main research focus on the molecular and epidemiological factors of the HIV epidemic. First studies confirmed that the Estonian HIV epidemic was caused by the rare recombinant form CRF06_cpx. Drug resistance analysis of the same strains showed that viruses were susceptible to all antiretroviral drugs available at the time (Avi et al 2009). In 2005, we initiated drug resistance testing service based on Sanger sequencing for Estonian hospitals.

Our research group focuses mainly on the following three research areas.

First research area evaluates factors that protect some people from acquiring HIV infection or reduce the risk of the infection. These studies are carried out among Estonian injecting drug users, who despite being repeatedly exposed to the virus still remain HIV negative. Thus far, we have found several human gene polymorphisms (CCL3L1, CCR5 and IL-10) that influence the acquisition HIV and its associated co-infections (HCV, HBV, GBV-C) (Huik et al., 2010; Huik et al.,  2013; Kallas et al.,  2015). In addition, associations between T cell subpopulations, immune activation, other blood borne viruses (GBV-C) and HIV infection in people who inject drugs have been studied (Jõgeda et al., 2013, Kallas et al., 2014; Kallas et al., 2015). These studies have been carried out in collaboration with professor Anneli Uusaküla from the Department of Public Health University of Tartu, professor Sunil K. Ahuja from Texas University in San Antonio, and professor Don Des Jarlais from the Beth Isreal Mecial Center in New York.

Second research area focuses on HIV-1 drug resistance in Estonia. We have carried out several descriptive studies of Estonian CRF06_cpx drug resistance mutations against common antiretroviral treatment regimens (Avi et al 2015). We have evaluated transmitted drug resistance in newly diagnosed HIV positive patients through the years. The data is clinically significant as it directly affects the treatment success in patients starting the therapy. Unlike in Western European countries, in Estonia the transmitted drug resistance has increased over the last ten years (Avi et al.,  2010, Avi et al.,  2014, unpublished data). We have also participated in international consortiums that have analysed the transmitted drug resistance dynamics in the whole world (Rhee et al., 2015).