Seroprevalence of hepatitis B, hepatitis C, human immunodeficiency virus, Treponema pallidum, and co-infections among blood donors in Kyrgyzstan: a retrospective analysis (2013–2015)

BACKGROUND: Post-Soviet Kyrgyzstan has experienced a major surge in blood-borne infections, but data from adequately powered, up-to-date studies are lacking. We thus examined a) the seroprevalences of hepatitis B virus surface antigen (HBsAg), HIV-1 p24 antigen and antibodies against hepatitis C virus (anti-HCV), human immunodeficiency viruses (anti-HIV-1/2, HIV-1 group O), and Treponema pallidum among blood donors in Kyrgyzstan and assess their distribution according to sex, age, and provinces of residence; b) trends in the respective seroprevalences; and c) co-infection rates among the pathogens studied. METHODS: Serological screening was performed on 37 165 blood donors at the Republican Blood Centre in Bishkek, Kyrgyzstan, between January 2013 and December 2015. We applied poststratification weights to control for sampling bias and used logistic regression analyses to examine the association of seropositivity and co-infections with sex, age, provinces of residence, and year of blood donation. RESULTS: Twenty nine thousand and one hundred forty-five (78%) donors were males and 8 020 (22%) were females. The median age was 27 years (range: 18 – 64). The prevalences of HBsAg, anti-HCV, HIV (p24 Ag and anti-HIV), and anti-T. pallidum were 3.6% (95%CI: 3.4 – 3.8%), 3.1% (3.0 – 3.3%), 0.78% (0.69 – 0.87%), and 3.3% (3.1 – 3.5%), respectively. Males were more likely to be seropositive for HBsAg than females (OR: 1.63; 95%CI: 1.40 – 1.90), but less likely to be seropositive for anti-HCV (0.85; 0.74 – 0.98) and HIV (0.65; 0.49 – 0.85). Prevalences were lower in the capital than in the other provinces. There was a decreasing trend in the seroprevalences of HBsAg, anti-HCV, and anti-T. pallidum from 2012 to 2015 (P-value for trend, P = 0.01, P < 0.0001, P < 0.0001, respectively), while the seroprevalence of HIV increased (P = 0.049). One hundred eighty donors (0.48%) were seropositive for multiple infections. The highest co-infection rate was observed between anti-T. pallidum and HBsAg (6.0%), followed by anti-HCV and anti-T. pallidum (5.2%), and HIV and anti-HCV (4.9%). CONCLUSIONS: The data suggest that Kyrgyzstan can be reclassified from high to lower-intermediate HBsAg endemicity, whereas the high HIV prevalence with a rising trend is an alarming finding that needs to be urgently addressed by public health authorities. The observed co-infections suggest common risk factors but also common preventive interventions. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40249-017-0255-9) contains supplementary material, which is available to authorized users.