Outbreak of acute hepatitis B virus infections associated with podiatric care at a psychiatric long-term care facility

Background Effective measures exist to prevent health care–associated hepatitis B virus (HBV) transmission, yet outbreaks continue to occur. In 2008, the Los Angeles County Department of Public Health identified an outbreak of HBV infections among psychiatric long-term care facility residents. Methods Residents underwent HBV serologic testing and were classified as acutely infected, chronically infected, susceptible, or immune. Persons residing in the facility during 2008 were enrolled in a retrospective cohort study to identify risk factors for acute HBV infection. We assessed infection control practices at the facility. Results Nine of 81 residents (11%) enrolled in the cohort study had acute HBV infection. Five of 15 residents (33%) undergoing podiatric care on a single day subsequently developed acute infection (rate ratio, 4.33; 95% confidence interval, 1.18-15.92). Infection control observations of the consulting podiatrist revealed opportunities for cross-contamination of instruments with blood. Other potential health care and behavioral modes of transmission were identified as well. Residents were offered HBV vaccination, and infection control recommendations were implemented by the podiatrist and facility. Conclusions Of the multiple potential transmission modes identified, exposure to HBV during podiatry was likely the dominant mode in this outbreak. Long-term care facilities should ensure compliance with infection control standards among staff and consulting health care providers.