The Human Services Department, Public Health Division of the Government of Victoria, Australia has confirmed sixty-six cases of Legionnaires' disease,
including 2 deaths. The patients, with one exception, had visited the Melbourne Aquarium after 11 April 2000.
Laboratory results for all the cases showed evidence of Legionnella pneumophila - serogroup 1. Test results are pending on a further number of patients who had been to the aquarium and had developed respiratory illness symptoms.
Laboratory test results have also confirmed the presence of legionella bacteria in the cooling towers of the Melbourne Aquarium, which were immediately disinfected.
The outbreak is under investigation. In the meantime, authorities have issued the following information for Australian health care providers:
In the presence
of a cluster/outbreak of Legionnaires Disease, if a patient presents
with a history of exposure to an implicated source such as a building cooling
tower, it is important that you consider this diagnosis, particularly when
the following features are present:
but in the absence of significant cough
- upper lobe
- renal impairment
- liver function
often report diarrhea.
(within 24 hours) of the diagnosis of Legionnaires Disease can be
obtained through urinary antigen testing. However, sputum for culture must
be sought in all cases. A four fold rise in titre between acute and convalescent
sera, or a single high titre of 512 in a convalescent serum sample is also
diagnostic. However, a rise in titre may take 2 to 4 weeks to develop.
of choice is IV erythromycin; rifampicin may be a useful adjunct but should
not be used alone.
disease is a notifiable conditionin Australia and must be reported to authorities
within 24 hours of diagnosis. The Communicable Diseases Section should be alerted on clinical
suspicion of Legionnaires disease, particularly if the case has been
exposed to an implicated source during an outbreak.
For Further information, visit the TARGET="_blank">Government of Victoria, Australia Web site, where you'll find information for practitioners, patients and cooling system owner/operators.