Listeria monocytogenes outbreak in a comprehensive cancer and transplantation centre

Abstract number: O44

Lingaas E., Johnsen B.O., Torfoss D., Dorenberg D.H., Andersen C.T., Müller F., Ingebretsen A., Gaustad P., Leegaard T.M., Nordoey I.

Objective:Listeria monocytogenes infection is rare in man, but known to occur in the immunocompromised host with high fatality rates. L. monocytogenes is widely distributed in the environment, has the ability to multiply even at low temperatures and is a feared food-borne pathogen. We describe an outbreak in a university hospital in Oslo, Norway. The hospital is primarily a cancer and transplantation centre.

Methods: Identification of L. monocytogenes was based on Gram stain, beta-haemolysis, catalase, VITEK 2 identification and CAMP-test. Resistance pattern, serotyping and MLVA were performed to confirm an outbreak.

Results: From the 1st until the 30th of October, L. monocytogenes was isolated from blood cultures (N = 13), pus (N = 1) or faeces (N = 1) from 10 women and 5 men with a median age of 65 years (range 37–84).

Fourteen of the patients had predisposing underlying disease, 13 had received immuno-modulating therapy and 7 had received antacids. Thirteen patients had fever, 6 patients had diarrhoea, none had classical symptoms of meningitis, but 6 were somnolent and/or had a headache.

Three patients (20%) died before the diagnosis was confirmed. The remaining patients received appropriate treatment after L. monocytogenes was isolated, and have recovered. Eight patients received empirical monotherapy with cephalosporins after onset of fever – 2 of these patients died.

All blood cultures were positive within 2 days. Further identification confirmed that the isolates from our 15 patients were of serotype 1 and had identical MLVA profiles (7–7–9–10–6) and patterns of resistance. A pasteurised camembert cheese was the source of the outbreak.

Conclusions: We report a L. monocytogenes outbreak with a mortality of 20% in a setting of predominately immunocompromised patients. The use of empirical cephalosporins as monotherapy in a setting with immunocompromised patients may be hazardous as L. monocytogenes is resistant to these antibiotics. Food-regulations in hospitals seem warranted.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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