2010-01-30 05:39:02 - Epidemic Hazard - Germany EDIS CODE: EH-20100130-24736-DEU
Date & Time: 2010-01-30 05:39:02 [UTC]
Area: Germany, Baden-Württemberg, Ulm, Neu-Ulm, Number of death person(s): 5
Number of Infected person(s): 65
Confirmed Information! Description: Currently an investigation is ongoing to explore and control an outbreak of Legionnaires' disease affecting 65 people as of 22 Jan 2010, in the cities of Ulm and Neu-Ulm, southwest Germany. A hitherto unidentified wet cooling system in these twin cities is considered as the most likely source of infection. On 5 Jan 2010, Ulm University Hospital informed the local health office of a cluster of hospitalisations due to community-acquired pneumonia caused by Legionella pneumophila serogroup (sg) 1. As of Fri 22 Jan 2010, 65 cases including 5 deaths were under investigation by the local and regional health authorities. With only a few exceptions all cases were living or working in Ulm or Neu-Ulm in southwest Germany. All cases are German residents aged between 27 and 96 years (median age 67 years). The majority of patients identified as of 22 Jan 2010 had to be hospitalised, n=61. All patients and, if the clinical condition of the patient made an interview impossible, their family members, were interviewed using a standardised questionnaire to investigate potential sources of exposition, personal risk factors and the onset of symptoms. For 40 cases the onset of symptoms was during the last week of December 2009. All but 2 patients who were admitted to our hospital had underlying diseases.
Clinical findings
In 41 of the patients who had been admitted to the University Hospital the following clinical symptoms were observed: fever in 35 of 41 patients, cough in 30 of 41 patients, abdominal pain and/or diarrhea in 11 of 41 patients, and symptoms relating to the central nervous system (confusion, somnolence or loss of consciousness, fainting) in 27 of 41 patients. In all patients' chest radiographs showed an infiltrate. All patients were treated with standard antibiotic treatment consisting of a macrolide (clarithromycin), or preferably a fluoroquinolone (levofloxacin) for at least 14 days (1). 4 patients required mechanical ventilation. 4 patients, 2 of whom had received mechanical ventilation and who had been treated in the University Hospital, died between several hours and 8 days after admission. The other patients responded well to treatment and the majority recovered promptly. The median length of hospital stay of the patients who were discharged as of 22 Jan 2010 was 9.9 days (range 4-16 days).
Laboratory investigations
For the investigation of the outbreak, the case definitions of the European Working Group on _Legionella_ Infection were applied (2).
Results
All patients with a microbiological workup in our laboratory had a positive urinary antigen test. PCR for _L. pneumophila_ was positive in the respiratory material of 10 patients. Four clinical isolates belonging to sg1 were further subtyped by using monoclonal antibodies (MAb). All these isolates were identified as monoclonal subtype Knoxville (carrying the virulence associated epitope recognised by MAb 3-1 monoclonal antibody) (3). Molecular identification of cultured legionellae was achieved by 16S rRNA gene sequencing that showed a 99 percent homology to _L. pneumophila_ in 3 isolates. So far, one isolate was genotyped and belongs to sequence type (ST) 62 (4).
Epidemiological investigations and findings
Epidemiological and environmental investigations are coordinated by the local authorities in Ulm and Neu-Ulm, with support of the state health offices in Baden-Wuerttemberg and Bavaria. Investigations are in progress to identify the potential source of this outbreak by comparing environmental isolates from the patients' [homes] and wet cooling systems from the areas of both cities with the clinical [isolates]. According to the patient interviews, the cases had no common exposure to water supplies in public buildings, hotels, sport facilities, or similar sources. Only living in, working in, or visiting Ulm or Neu-Ulm appeared as a common characteristic of the affected persons. Further epidemiological investigations are planned.
Conclusions
This is the largest community-associated outbreak of Legionnaires' disease recognised in Germany so far. In dealing with the event several important steps in outbreak detection and management were confirmed: the importance of a rapid clinical diagnosis and thorough microbiological confirmation and the immediate involvement of the health authorities. The latter is necessary to initiate investigations to detect the source of the outbreak, to raise awareness of the problem in the community and to optimise communication of all involved parties. Furthermore we realised that an outbreak of Legionnaires' disease most likely related to wet cooling systems is not restricted to the warm seasons. Hospitals, general practitioners and the public have been informed of the situation by the local authorities on a regular basis, starting on 5 Jan 2010. As of 23 Jan 2010, health authorities have no indication that persons from other countries have been affected. The last clinical case was hospitalised on 13 Jan 2010. We would be grateful for any reports of cases from other countries that could potentially be linked to this outbreak.
The name of Hazard: Legionnaires\' disease
Species: Human
Status: Confirmed
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