Hepatitis B outbreak in a nursing home associated with reusable lancet devices for blood glucose monitoring, Northern Germany 2010

In September 2010, an outbreak of acute hepatitis B virus (HBV) infections in a nursing home was notified to public health authorities in Northern Germany. To identify the route of transmission and prevent further cases a retrospective cohort study was conducted. Blood samples of residents were tested for serologic markers of HBV infection and HBV subgenotypes and sequences were analyzed. Outbreak-related cases were defined as residents of the nursing home with detection of hepatitis B surface antigen (HBsAg) and the HBV DNA sequence of the outbreak strain in 2010. Information on possible risk factors as patient care, invasive diagnostic, and therapeutical procedures was collected using a standardized questionnaire. Risk ratios (RR) and 95% confidence intervals (CI) were estimated with exact Poisson regression and binomial regression. Sixty-four residents were included in the study, 5 of them were outbreak-related cases, 12 had a past HBV infection. The outbreak strain belonged to HBV genotype D2 (HBsAg subtype ayw3, Ala118) which is not prevalent in Germany but in Eastern Europe. All cases (median age 81) were female, had diabetes, blood glucose monitoring, and chiropody. In multivariable analysis only blood glucose monitoring was associated with HBV infection (RR = 22, 95%CI 3.0-∞). Blood glucose monitoring was reported to be done by nursing home staff with patient-based reusable lancet devices. In nursing home settings the use of single use lancets for blood glucose monitoring is recommended strongly to prevent transmission. National guidelines on the handling of point-of-care devices and reusable equipment in long-term care facilities should be developed.