Pontiac fever

Pontiac fever is an acute, nonfatal respiratory disease caused by various species of Gram-negative bacteria in the genus Legionella. 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 are caused by the same bacteria, but Pontiac fever does not include pneumonia.

Pontiac fever was named for Pontiac, Michigan, 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 Legionella pneumophila. An outbreak caused by Legionella micdadei in early 1988 in the UK became known as Lochgoilhead 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.