Pontiac fever is an acute, nonfatal respiratory disease caused by various species of

Gram-negative bacteria Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...

in the genus ''

Legionella ''Legionella'' is a genus of pathogenic gram-negative bacteria that includes the species '' L. pneumophila'', causing legionellosis (all illnesses caused by ''Legionella'') including a pneumonia-type illness called Legionnaires' disease and a mi ...

''. It causes a mild upper respiratory infection that resembles acute influenza. Pontiac fever resolves spontaneously and often goes undiagnosed. Both Pontiac fever and the more severe

Legionnaire's disease Legionnaires' disease is a form of atypical pneumonia caused by any species of ''Legionella'' bacteria, quite often '' Legionella pneumophila''. Signs and symptoms include cough, shortness of breath, high fever, muscle pains, and headaches. Naus ...

may be caused by the same bacteria, but Pontiac fever does not include pneumonia.

Cause

Species of ''Legionella'' known to cause Pontiac fever include ''

Legionella pneumophila ''Legionella pneumophila'' is a thin, aerobic, pleomorphic, flagellated, non-spore-forming, Gram-negative bacterium of the genus ''Legionella''. ''L. pneumophila'' is the primary human pathogenic bacterium in this group and is the causative age ...

'', '' Legionella longbeachae'', ''

Legionella feeleii ''Legionella feeleii'' is a Gram-negative, rod-shaped bacterium from the genus ''Legionella ''Legionella'' is a genus of pathogenic gram-negative bacteria that includes the species '' L. pneumophila'', causing legionellosis (all illnesses caus ...

'', ''

Legionella micdadei ''Legionella micdadei'' is a Gram-negative bacterium from the genus ''Legionella'', which stains acid-fast Acid-fastness is a physical property of certain bacterial and eukaryotic cells, as well as some sub-cellular structures, specifically th ...

'', and '' Legionella anisa''. Sources of the causative agents are aquatic systems and potting soil. The first outbreak caused by inhalation of

aerosolized Aerosolization is the process or act of converting some physical substance into the form of particles small and light enough to be carried on the air i.e. into an aerosol. Aerosolization refers to a process of intentionally oxidatively converting a ...

potting soil was discovered in New Zealand in January 2007. A total of 10 workers at a nursery came down with Pontiac fever. It was the first identification of ''L. longbeachae''. Pontiac fever does not spread from person to person. It is acquired through aerosolization of water droplets and/or potting soil containing ''Legionella'' bacteria.

Diagnosis

Epidemiology

Pontiac fever is known to have a short incubation period of 1 to 3 days. No fatalities have been reported and cases resolve spontaneously without treatment. It is often not reported. Age, gender, and smoking do not seem to be risk factors. Pontiac fever seems to affect young people in the age medians of 29, 30, and 32. Pathogenesis of the Pontiac fever is poorly known.

History

Pontiac fever was named for

Pontiac, Michigan Pontiac ( ') is a city in and the county seat of Oakland County in the U.S. state of Michigan. As of the 2020 census, the city had a total population of 61,606. A northern suburb of Metro Detroit, Pontiac is about northwest of Detroit. Founde ...

, where the first case was recognized. In 1968, several workers at the county's department of health came down with a fever and mild flu symptoms, but not pneumonia. After the 1976 Legionnaires' outbreak in Philadelphia, the Michigan health department re-examined blood samples and discovered the workers had been infected with the newly identified ''

''. An outbreak caused by'' Legionella micdadei'' in early 1988 in the UK became known as

Lochgoilhead Lochgoilhead ( gd, Ceann Loch Goibhle, IPA: �kʰʲaun̴̪ˈɫ̪ɔxˈkɤilə is a village on the Cowal peninsula, in Argyll and Bute, Scottish Highlands. It is located within the Loch Lomond and The Trossachs National Park and is widely consider ...

fever. Since that time, other species of ''Legionella'' that cause Pontiac fever have been identified, most notably in New Zealand, in 2007 where '' Legionella longbeachae'' was discovered. The New Zealand outbreak also marked the first time Pontiac fever had been traced to potting soil.

References

External links

* American Legion Building biology Gram-negative bacteria Industrial hygiene Legionellosis Pathogenic bacteria Pontiac, Michigan Legionellales {{portal bar, Biology