Investigation of hepatitis B virus and human immunodeficiency virus transmission among severely mentally ill residents at a long term care facility.

BACKGROUND: A high prevalence of hepatitis B virus (HBV) and human immunodeficiency virus (HIV) infections have been reported among persons with severe mental illness. In October, 2009, the Cook County Department of Public Health (CCDPH) initiated an investigation following notification of a cluster of HBV infections among mentally ill residents at a long term care facility (LTCF). METHODS: LTCF staff were interviewed and resident medical records were reviewed. Residents were offered testing for HBV, HCV, and HIV. Serum specimens from residents diagnosed with HBV or HIV infection were sent to the Centers for Disease Control and Prevention (CDC) for analysis. RESULTS: Eleven newly diagnosed HBV infections were identified among mentally ill residents at the LTCF. Of these 11 infections, 4 serum specimens were available for complete HBV genome sequencing; all 4 genomes were found to be closely related. Four newly diagnosed HIV infections were identified within this same population. Upon molecular analysis, 2 of 4 HIV sequences from these new infections were found to be nearly identical and formed a tight phylogenetic cluster. CONCLUSIONS: HBV and HIV transmission was identified among mentally ill residents of this LTCF. Continued efforts are needed to prevent bloodborne pathogen transmission among mentally ill residents in LTCFs.