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1 Legionnaires’ Disease.
2 “Pontiac fever is a self-limited short-duration febrile illness, usually diagnosed only during an outbreak of
the disease. The usual story is onset of symptoms 12 to 36 hours after exposure to a bacterial-contaminated
aerosol, either in a workplace or in some other group setting. Attack rates are very high, withmore than 80%
to 90% of such exposed people becoming ill. The sources of contaminated aerosol have included industrial
processes using sprayed water (lathes, artificial fiber plants, building humidification), recreational spas,
decorative water fountains, and cooling towers. Fever, myalgia, headache, and asthenia are the dominant
symptoms. Cough, dyspnea, anorexia, arthralgia, and abdominal pain occur less frequently. Most patients
are not ill enough to seek medical attention, recovering without specific therapy 3 to 5 days after disease
onset. There is little information about physical examination findings in the first day of illness; examination
2 to 5 days after onset may show fever and tachypnea but little else. Pneumonia does not occur. Fatigue
and nonfocal neurologic complaints have been reported to persist for up to several months in a minority
of affected patients. Because the clinical findings are nonspecific, it is very difficult, if not impossible, to
accurately diagnose this disease in the absence of similar illnesses in co-workers or others with a common
source exposure. Inquires regarding the health to co-workers and acquaintances, and a history of known
water exposure may help to confirm the diagnosis, but even these findings may be nonspecific and lack
sensitivity.” Gerald L. Mandell, John E. Bennett, Raphael Dolin, Principles and practice of Infectious
Diseases, p. 2717.
3 Guidelines for investigating single cases of Legionnaires’ disease, J. V. Lee, p. 157.
4 Also called as Legion Fever.
5 Gram-negative bacillus.
6 Donald Armstrong, Jonathan Cohen (org), Infectious Disease, p. 11.1.
7 Donald Armstrong, Jonathan Cohen (org), Idem, p. 20.13.
8 The fever is an increase of temperature in which the person’s oral temperature is at about 37.8 degrees
Celsius.
9 Janet E. Stout; Vicot L. Yu, Legionellosis, p. 683.
10 I Oren et al, Nosocomial outbreak of
Legionella
pneumophila serogroup 3 pneumonia in a new marrow
transplant unit: evaluation, treatment and control, p. 175.
11 “Legionnaires’ disease is transmitted from the environment to man by inhalation of an infectious
aerosol. In an unknown fraction of cases, microaspiration of contaminated water into the lungs is the
mode of transmission, rather than inhalation of an aerosol. Finally, massive aspiration of contaminated
water into the lungs during near-drownings is a very unusual but reported mode of transmission of the
disease. Multiple examples of exclusive aerosol transmission of Legionnaires’ disease exist, especially in
epidemics having a cooling tower, water spa, water fountain, or water mister as the source of disease. In
these cases, proximity to the aerosol generator, duration of exposure, and presence in an area downstream
of the contaminated device have all been found to be risk factors for disease acquisition. Of note, when
reported, either consumption of water at the epidemic site has not occurred in the majority of disease
victims, or the drinking water of the outbreak site has been culture negative for L. pneumophila.” Gerald L.
Mandell, John E. Bennett, Raphael Dolin, Principles and practice of Infectious Diseases, p. 2716.
