legionnaires disease

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A severe lung infection by Legionella pneumophila which may occur sporadically or in an epidemic with a mortality of up to 15%; depending on the population, Legionella spp cause 1–27% of community-acquired pneumonias; male:female ratio, 3:1
Epidemiology Most L pneumophila infections are associated with water supplies and ventilation systems; most epidemics occur during the summer with 0.5–5% attack rates; the only documented mode of spead is aerosol
Sources Plumbing, shower heads, water-storage tanks, evaporative condensors, cooling towers
Risk factors Cigarettes, alcohol, renal transplant, elderly
DiffDx Sporadic LD mimics myoplasma pneumonia, Q fever, tularemia, plague, psittacosis, influenza and other viral pneumonias
Lab Decreased Na+, decreased PO4-, increased liver enzymes, proteinuria, microscopic hematuria, relative leukocytosis, increased ESR, hyponatremia, increased ALT, increased AST, increased BR, azotemia
Complications Empyema, shock, DIC, renal failure, neurologic sequelae, peripheral neuropathy
Management Erythromycin, T-S, penicillin
Prognosis 15–20% mortality w/o therapy; up to 50% of immunocompromised patients die
Poor prognostic features Tachycardia, tachypnea, WBCs 14,000/mm3, increased BUN, increased creatinine, hyponatremia, hypoxia, leukopenia, bilateral infiltrates on chest films
Prevention Chlorination of water supply for showers and ventilation systems; UV irradiation of water supplies

legionnaires’ disease

a rare human pneumonial condition, caused by the bacterium Legionella pneumophila, that can lead to death. The disease was named after an outbreak occurring at an American Legion convention in a Philadelphia hotel in 1976, the bacteria eventually being traced to the air-conditioning plant of the hotel. Since then a number of cases have been reported in connection with recirculated hot water systems such as cooling towers. There is no evidence of person-to-person transmission.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

References in periodicals archive ?

She said: "The Trust would like to reassure members of the local community that the recent outbreak of Legionnaires Disease in Dudley is in no way related to Russells Hall Hospital.

Hospital in bug pledge

A case of Legionnaires disease was defined as pneumonia in an area resident with onset of illness during September 1-November 12 with Lp1 identified by culture of sputum, antigen assay of urine, or fourfold rise in serum antibody titers.

However, all of these cases, except the case not related to the outbreak, occurred within the normal incubation period for Legionnaires disease (i.e., 2-10 days) following removal of the source.

Legionnaires disease associated with a whirlpool spa display - Virginia, September-October, 1996

Legionella causes Legionnaires Disease, and there are three patients have been diagnosed with the disease so far.

Legionella found in Sacred Heart Medical Center water supply

A north East health club hit by Legionnaires Disease has been forced to close down.

Bug-hit club has closed

A case of the potentially fatal Legionnaires Disease has been confirmed in the North East.