TRANSLATIONAL AND CLINICAL MEDICINE - Georgian Medical Journal

Background: HIV epidemic continues to grow in the Eastern European country of Georgia. It is well documented that people unaware of their HIV status are major contributors to the spread of the virus.

Aim: The aim of this study was to estimate number of new infections in 2015-2016 and to define gap between new infections and diagnoses.

Methods: The number of new HIV infections was estimated with two methods: recent infection testing algorithm (RITA) and Spectrum software modeling. RITA was conducted using limited antigen avidity (LAg) enzyme immunoassay (EIA) and incidence was estimated using McWalter/Welte formula. LAg EIA was performed according to manufacturer’s instructions on frozen remnant specimens initially used for HIV diagnosis. HIV infection was defined as recent if individual did not have evidence of longstanding infection and had recent infection on LAg EIA. Study covered two-year period of 2015-2016.

Results: Of 1421 (711 in 2015 and 710 in 2016) adults newly diagnosed with HIV, 1132 (80%) had complete data and quality blood specimens available and were included in RITA estimation. Among 1132 infections included 136 (12%) were classified as recent (13% in 2015 and 11% in 2016, p=0.33). Estimated 1300 persons were newly infected in 2015 and 1100 – in 2016 based on RITA-derived approach. Spectrum modeling showed that estimated 1100 persons were newly infected annually in 2015 and 2016. If all 1421 persons diagnosed during study period were newly infected, then detection rate would be 59-65%. However, after adjusting for 55% of late diagnoses reported during 2015-2016, detection rate dropped to 26-29%.

Conclusion: Study demonstrates that there is significant gap in diagnosis regardless of estimation method used. Substantial number of HIV positive persons unaware of their status is likely to contribute to the growing HIV epidemic in the country. Increased efforts are needed to reduce the number of people living with undiagnosed HIV.

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