Laboratory-acquired Brucellosis—Indiana and Minnesota, 2006

Abstract

In November 2006, two cases of brucellosis in microbiologists at two clinical laboratories were reported to state health departments in Indiana and Minnesota. The Minnesota Department of Health (MDH) contacted CDC regarding this suspected multistate cluster of laboratory-acquired brucellosis. MDH and the Indiana State Department of Health (ISDH) asked CDC to conduct further testing on Brucella isolates suspected of causing the infections and to provide recommendations for appropriate response by the laboratories. This report summarizes the investigation conducted jointly by MDH, ISDH, and CDC, provides guidance on safe laboratory handling of Brucella spp., and makes recommendations for responding to Brucella laboratory exposures. The results of that investigation determined that 146 workers at the two laboratories had been exposed to Brucella and that, although two Brucella isolates had been handled by both laboratories, infections in the two microbiologists were caused by two unrelated isolates. Because Brucella spp. pose a risk for aerosol-transmitted infection, CDC recommended risk assessment for all Brucella-exposed laboratory workers, postexposure prophylaxis (PEP) for those at high risk, surveillance for symptoms of disease, and serologic follow-up with workers. The events in Indiana and Minnesota emphasize the importance of adhering to recommended biosafety practices, timely sharing of information regarding laboratory exposures, and rapid implementation of response protocols.