Notes from the field: lymphocytic choriomeningitis virus infections in employees of a rodent breeding facility--Indiana, May-June 2012.

In late April 2012, an infectious disease physician contacted CDC regarding a patient with aseptic meningitis who worked at a rodent breeding facility in Indiana. Lymphocytic choriomeningitis virus (LCMV) infection was suspected, and LCMV-specific antibody was detected in blood and cerebrospinal fluid from the patient, confirming the diagnosis. LCMV is an arenavirus carried by the common house mouse. Persons become infected through close contact with infected rodents, through infected organ transplantation, or from mother to fetus. In immunocompetent adults, symptoms can range from mild febrile illness to meningeal symptoms (e.g., headache, stiff neck, or sensitivity to light). Congenitally infected infants can have a range of severe birth defects including hydrocephalus, chorioretinitis, blindness, and mental retardation (1). Infections in organ recipients, who are immunosuppressed, can have a case-fatality rate approaching 90% (2).