Pontiac fever

The characteristics, diagnosis and treatment of pontiac fever.

Pontiac fever is a mild flu-like illness caused by Legionella bacteria, often affecting previously healthy and young individuals. Symptoms can include fever, headaches and muscle aches but unlike Legionnaires’ disease Pontiac fever does not cause pneumonia.

Pontiac fever is a milder infection than Legionnaire’s disease and both diseases are caused by the same types of Legionella bacteria.


The illness is self-limiting and symptoms can include:

  • fever
  • shivers
  • headache
  • muscle aches
  • tiredness
  • dry cough

It is not clear why some people get Legionnaires’ disease (with pneumonia) and some people get the milder Pontiac fever when infected with legionella bacteria. It is also thought that some people who are infected with legionella bacteria do not become ill at all.

The incubation period is short and varies from a few hours to 12 to 48 hours.


Legionellas are widely distributed in the environment. They have been found in ponds, hot and cold water systems, and water in air conditioning cooling systems.

The disease is spread through the air from a water source. Person to person spread does not occur. Breathing in aerosols from a contaminated water system such as spa pools is the most likely route of transmission.


Pontiac fever is diagnosed through a blood test to show evidence of infection.

Food, water and environmental (FWE) laboratories carry out a range of specialist microbiology tests on food, water and environmental samples, and provide support required in the investigation of water-borne outbreaks.


There is no specific treatment for Pontiac fever but symptoms should be treated appropriately depending on severity. For flu like symptoms, analgesics should help but antibiotics may be recommended for more severe symptoms.

Published 22 November 2007