Absence of Hepatitis Delta Infection in a Large Rural HIV Cohort in Tanzania

OBJECTIVES The epidemiological and clinical determinants of hepatitis delta virus (HDV) infection in sub-Saharan Africa are ill-defined. We determined the prevalence of HDV infection in HIV/hepatitis B virus (HBV)-co-infected individuals in rural Tanzania. DESIGN AND METHODS We screened all hepatitis B virus (HBV)-infected adults under active follow-up in the Kilombero and Ulanga Antiretroviral Cohort (KIULARCO) for anti-HDV antibodies. In positive samples, we performed a second serological test and nucleic acid amplification. Demographic and clinical characteristics at initiation of antiretroviral therapy (ART) were compared between anti-HDV-negative and positive patients. RESULTS Among 222 HIV/HBV-coinfected patients on ART, 219 (98.6%) had a stored serum sample available and were included. Median age was 37 years, 55% were female, 46% had WHO stage III/IV HIV disease and median CD4 count was 179 cells/μL. The prevalence of anti-HDV positivity was 5.0% (95% confidence interval 2.8%-8.9%). There was no significant predictor of anti-HDV positivity. HDV could not be amplified in any of the anti-HDV-positive patients and the second serological test was negative in all of them. CONCLUSIONS We found no confirmed case of HDV infection among over 200 HIV/HBV-co-infected patients in Tanzania. As false-positive serology results are common, screening results should be confirmed with a second test.

Molecular epidemiology of hepatitis B virus infection in Switzerland: a retrospective cohort study.

BACKGROUND Chronic hepatitis B virus (HBV) infection affects up to 7 % of the European population. Specific HBV genotypes are associated with rapid progression to end-stage liver disease and sub-optimal interferon treatment responses. Although the geographic distribution of HBV genotypes differs between regions, it has not been studied in Switzerland, which lies at the crossroads of Europe. METHODS In a retrospective analysis of 465 HBV samples collected between 2002 and 2013, we evaluated the HBV genotype distribution and phylogenetic determinants, as well as the prevalence of serological evidence of hepatitis delta, hepatitis C and HIV infections in Switzerland. Baseline characteristics of patients were compared across their region of origin using Fisher's exact test and ANOVA, and risk factors for HBeAg positivity were assessed using logistic regression. RESULTS The Swiss native population represented 15.7 % of HBV-infected patients living in Switzerland. In the overall population, genotype D was most prevalent (58.3 %), whereas genotype A (58.9 %) was the predominant genotype among the Swiss native population. The prevalence of patients with anti-HDV antibodies was 4.4 %. Patients of Swiss origin were most likely to be HBeAg-positive (38.1 %). HBV genotypes of patients living in Switzerland but sharing the same original region of origin were consistent with their place of birth. CONCLUSIONS The molecular epidemiology of HBV infection in Switzerland is driven by migration patterns and not by the genotype distribution of the native population. The prevalence of positive anti-HDV antibodies in our cohort was very low.