Epidemiology of human herpesvirus type 8 and parvovirus B19 infections and their association with HIV-1 among men who have sex with men and injection drug users in Taiwan

Background/Purpose: Human herpesvirus 8 (HHV-8), the causal agent of Kaposi's sarcoma (KS), is transmitted sexually among men who have sex with men (MSM), but little is known of its transmission among injection drug users (IDUs). By contrast, human parvovirus B19 (B19), a causative agent for anemia, is most frequently detected in IDUs. The aim of this study was to investigate the associations between HHV-8 infection and human immunodeficiency virus type 1 (HIV-1), and between B-19 and HIV-1 among MSM and IDUs patients. Methods: Serum samples from 553 IDUs and 231 MSM were analyzed for anti-HHV-8 lytic and anti-B19 viral structural capsid protein 2 (VP-2) antibodies using enzyme immunoassay, indirect immunofluorescence, and immunoblot assays. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the associations between different viral infections. Results: HIV-1-seropositive MSM had significantly higher rates of HHV-8 infection than seronegative MSM (32.3% and 15.4%, respectively; OR = 2.62, 95% CI = 1.37-5.02). Among HIV-1/AIDS patient groups, MSM had significantly higher HHV-8 seropositive rates (32.3% vs. 6.6%, p < 0.0001) and lower B19 infection rates (35.4% vs. 78.8%, p < 0.001) than IDUs. In addition, HIV-1-infected MSM were 5.95 times (95% CI = 3.38-10.46) more likely to be infected with HHV-8 than male HIV-1-infected IDUs. By contrast, male IDUs were 6.74 times odds (95% CI = 4.28-10.61) more likely to contract B19 infection than MSM. Conclusion: In Taiwan, MSM have a significantly higher prevalence for HHV-8 than IDUs. The contrasting risks of HHV-8 and B19 infections between different HIV-1/AIDS groups suggest that the efficiency of viral infection is affected by their distinct transmission routes.