Outbreak of Francisella novicida Bacteremia Among Inmates at a Louisiana Correctional Facility

• Published in: Clinical infectious diseases 2014-09, Vol.59 (6), p.826-833
• Main Authors: Brett, Meghan E., Respicio-Kingry, Laurel B., Yendell, Stephanie, Ratard, Raoult, Hand, Julie, Balsamo, Gary, Scott-Waldron, Christine, O'Neal, Catherine, Kidwell, Donna, Yockey, Brook, Singh, Preety, Carpenter, Joseph, Hill, Vincent, Petersen, Jeannine M., Mead, Paul
• Format: Article
• Language: English
• Subjects: Adult; Anti-Bacterial Agents - therapeutic use; ARTICLES AND COMMENTARIES; Bacteremia; Bacteria; Bacterial diseases; Bacterial sepsis; Biological and medical sciences; Blood culture; Comorbidity; Cross Infection; Disease Outbreaks; Disease transmission; DNA, Bacterial; Environmental Microbiology; Epidemiology; Fatal Outcome; Francisella; Francisella - classification; Francisella - genetics; Francisella tularensis; Gram-Negative Bacterial Infections - diagnosis; Gram-Negative Bacterial Infections - drug therapy; Gram-Negative Bacterial Infections - epidemiology; Gram-Negative Bacterial Infections - microbiology; Health Facilities; Human bacterial diseases; Humans; Ice; Infections; Infectious diseases; Louisiana - epidemiology; Male; Medical sciences; Middle Aged; Phylogeny; Polymerase chain reaction; Prisoners; Prisons; Public health; Ribonucleic acid; RNA; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Treatment Outcome; Water samples
• ISSN: 1058-4838; 1537-6591
• DOI: 10.1093/cid/ciu430

Background. Francisella novicida is a rare cause of human illness despite its close genetic relationship to Francisella tularensis, the agent of tularemia. During April–July 2011, 3 inmates at a Louisiana correctional facility developed F. novicida bacteremia; 1 inmate 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 polymerase chain reaction (PCR), and multigene 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 ribosomal RNA, pgm, and pdpD genes. PmeI PFGE patterns for the clinical isolates were indistinguishable. Source patients were aged 40–56 years, male, and African American, and all were immunocompromised. Two patients presented with signs of bacterial peritonitis; the third had pyomyositis of the thigh. The 3 inmates had no contact with one another; their only shared exposures were consumption of municipal water and of ice that was 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. tularensis.