One person is known to have died and fifty five have been hospitalised in an outbreak of Legionnaires' Disease that has infected at least 95 people in North Carolina in September 2019. Thirty four of the known cases, including the fatality, were reported in Buncombe County, with twenty one cases in Henderson County. Eleven other counties in North Carolina have reported known infections with the disease, and five cases in other states have been linked to North Carolina. The precise cause of infection is yet to be determined, but the North Carolina Department of Health and Human Services has determined that all of those infected had visited the Mountain State Fair in Fletcher, Buncombe County, between 6 and 15 September, and the possibility that the disease has been spread in water droplets from one of the rides at the fair is being investigated.
A microbiologist pours water samples from a building experiencing a Legionnaires' Disease outbreak into a filtration system to test for Legionella. Centers for Disease Control and Prevention.
Legionnaire's Disease is caused by Bacteria of the genus Legionella. Symptoms typically include shortness of breath, muscle pains, headaches, fever, nausea, vomiting, and diarrhoea. It can also lead to pneumonia, which is the main cause of fatalities. The Bacteria are naturally occurring in soil and freshwater systems, but infection in humans generally comes from standing water within plumbing systems, such as water storage systems, air conditioning units, or pipes to taps which have been disconnected or are seldom used and which remain attached to the main water system, which provide an ideal breeding ground for the Bacteria. Since gestation of the disease is typically between 10 and 20 days, and most victims only suffer mild flu-like symptoms, tracing the cause of infection can be notoriously difficult.
Colony of Legionella pneumophila, one of the main causes of Legionnaire's Disease. Centers for Disease Control and Prevention/Wikipedia.
Legionella Bacteria are Gram-negative, aerobic, flagellated Gammaproteobacteria, related to other pathogenic Bacteria such as Yersina pestis (Bubonic Plague), Vibrio cholerae (Cholera), and Esherchia coli (food poisoning). They naturally occur within biofilms made by freshwater Amoeba, particularly at warmer temperatures (above about 25°C) rather than by being obligate pathogens, but can become problematic when these films form within Human-made water systems. Since the first known outbreak of Legionnaire's Disease occurred in 1976, and the disease was not understood for some time after this, many older buildings have plumbing systems that were not designed with this problem in mind.
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