Epidemiology and risk factors for hepatitis C virus infection in a high-prevalence population.

To understand increasing rates of hepatitis C virus (HCV) infection in Tennessee, we conducted testing, risk factor analysis and a nested case-control study among persons who use drugs. During June-October 2016, HCV testing with risk factor assessment was conducted in sexually transmitted disease clinics, family planning clinics and an addiction treatment facility in eastern Tennessee; data were analysed by using multivariable logistic regression. A nested case-control study was conducted to assess drug-using risks and behaviours among persons who reported intranasal or injection drug use (IDU). Of 4753 persons tested, 397 (8.4%) were HCV-antibody positive. HCV infection was significantly associated with a history of both intranasal and IDU (adjusted odds ratio (aOR) 35.4, 95% confidence interval (CI) 24.1-51.9), IDU alone (aOR 52.7, CI 25.3-109.9), intranasal drug use alone (aOR 2.6, CI 1.8-3.9) and incarceration (aOR 2.7, CI 2.0-3.8). By 4 October 2016, 574 persons with a reported history of drug use; 63 (11%) were interviewed further. Of 31 persons who used both intranasal and injection drugs, 26 (84%) reported previous intranasal drug use, occurring 1-18 years (median 5.5 years) before their first IDU. Our findings provide evidence that reported IDU, intranasal drug use and incarceration are independent indicators of risk for past or present HCV infection in the study population.

Impact of universal infant hepatitis B vaccination in the US-affiliated Pacific Islands, 1985-2015.

The US-affiliated Pacific Island countries (USAPI) is an endemic region for hepatitis B virus (HBV) infection. Universal infant hepatitis B vaccination was introduced in the USAPI in the mid-1980s to mitigate the HBV burden. We assessed the impact of universal infant vaccination on the HBV infection prevalence over time among children born in the 1980s, 1990s, and 2000s in the USAPI. Demographic and serologic data from serial sero-surveys conducted between 1985 and 2015 were obtained. Descriptive statistics and analysis of variance were performed. From data obtained from 4827 children (2-11years), HBV prevalence decreased markedly: 8.4% in the 1980s; 2.5% in the 1990s; and 0.2% in the 2000s (P<0.0001) as vaccination coverage increased: 76.4% in the 1980s; 87.3% in the 1990s; and 97.5% in the 2000s (P<0.0001). These findings underscore the protective effect of universal infant hepatitis B vaccination over time on the HBV burden in an HBV endemic region.