NEW YORK, July 31 (Praxis Press) Blood screening, immunization, and infection control policies have made hospital outbreaks of hepatitis B virus (HBV) infection rare; in contrast, community outbreaks of HBV remain problematic. Using molecular epidemiology, Webster and colleagues traced the origin and spread of HBV infection acquired by a woman who attended a London clinic for autohemotherapy. Sixteen percent of the 352 clinic patients 4 staff members tested had serologic evidence of HBV infection. Ninety-one percent of 33 patients and staff members who were positive for hepatitis B surface antigen had matching nucleotide sequences for the surface and core genes. Analysis identified a patient as the likely source of the outbreak and contaminated saline as the probable vehicle. Despite heightened regulations and licensing requirements, patients attending alternative-medicine clinics are still at risk of bloodborne infections.