VICTORIA, AUSTRALIA-The Legionnaires' Disease outbreak in Victoria, Australia has infected a total of 81 people to date. All of the people infected had been at or near the Melbourne Aquarium between April 11 and 25, 2000. Health officials believe the Aquarium's air conditioning unit was the source of the legionella bacteria. Legionnaires' Disease is contracted by breathing very fine droplets of water contaminated by the bacteria. In this case, spray drifts vented off from the towers infected not only visitors, but also at least one person who walked close to the Aquarium. Symptoms of the disease include headache, fever, chills, muscle aches, and pains followed by respiratory problems and pneumonia developed over three or four days.
The Aquarium's cooling towers were disinfected on April 27 and test results for legionella bacteria have returned with a zero count. Victoria's Deputy Chief Health Officer, Professor William Hart, said people who visited the Aquarium before the cooling towers were disinfected are no longer in danger of developing the disease since the incubation period is two to ten days.
Regulations require that cooling towers, warm water systems, and public spas be maintained and disinfected regularly. Dr. John Carnie, the Communicable Diseases Manager of the Human Services Department, said he was satisfied that the required maintenance and sampling of the cooling towers had been done. Records show a total bacteria sample taken on March 15 returned a very low count of bacteria.
Of the 81 confirmed cases, two people have died, seven are still in critical condition, 11 have been treated as outpatients, and 23 have been discharged from the hospital. The number of cases may rise as the Human Services Department still awaits test results on 19 people who visited the Aquarium and were hospitalized with respiratory illness symptoms.