Outbreak of Francisella novicida Bacteremia among Inmates at a Louisiana Correctional Facility.
Clin Infect Dis. 2014 Jun 18;
Authors: Brett ME, Respicio-Kingry LB, Yendell S, Ratard R, Hand J, Balsamo G, Scott-Waldron C, O'Neal C, Kidwell D, Yockey B, Singh P, Carpenter J, Hill V, Petersen JM, Mead P
BACKGROUND: Francisella novicida is a rare cause of human illness despite its close genetic relationship to F. tularensis, the agent of tularemia. During April-July 2011, three inmates at a Louisiana correctional facility developed F. novicida bacteremia; one died acutely.
METHODS: We interviewed surviving inmates; reviewed laboratory, medical, and housing records; and conducted an environmental investigation. Clinical and environmental samples were tested by culture, real-time PCR and multi-gene sequencing. Isolates were typed by pulsed-field gel electrophoresis (PFGE).
RESULTS: Clinical isolates were identified as F. novicida based on sequence analyses of the 16S rRNA, pgm and pdpD genes. PmeI PFGE patterns for the clinical isolates were indistinguishable. Source patients were aged 40-56 years, male, African American, and all were immunocompromised. Two patients presented with signs of bacterial peritonitis; the third had pyomyositis of the thigh. The three inmates had no contact with one another; their only shared exposures were consumption of municipal water and of ice mass produced at the prison in an unenclosed building. Swabs from one set of ice machines and associated ice scoops yielded evidence of F. novicida by PCR and sequencing. All other environmental specimens tested negative.
CONCLUSIONS: To our knowledge, this is the first reported common-source outbreak of F. novicida infections in humans. Epidemiological and laboratory evidence implicate contaminated ice as the likely vehicle of transmission; liver disease may be a predisposing factor. Clinicians, laboratorians and public health officials should be aware of the potential for misidentification of F. novicida as F. tularenis.
PMID: 24944231 [PubMed - as supplied by publisher]