About Pontiac Fever

Key points

  • Pontiac fever is a mild respiratory disease that gets better without treatment.
  • People can get Pontiac fever by breathing in mist containing Legionella bacteria.
  • To prevent Pontiac fever, reduce the risk of Legionella growth and spread.
An older woman relaxing in a hot tub

What it is

Pontiac fever is a mild respiratory disease caused by a type of bacteria called Legionella.


Legionella most commonly causes one of two lung diseases:

  • Legionnaires' disease is a type of severe pneumonia
  • Pontiac fever is mild respiratory disease

Rarely, Legionella can cause infections outside of the lungs, such as heart or wound infections.


It usually takes between a few hours to 3 days after being exposed to Legionella bacteria to develop Pontiac fever symptoms. This illness is generally milder than Legionnaires' disease. Someone with Pontiac fever doesn't have pneumonia.

Symptoms usually last less than 1 week and mostly include:

  • Fever
  • Muscle aches

Complications are not expected with Pontiac fever.

Risk factors

Most healthy people exposed to Legionella don't get sick. However, older adults and people with certain conditions are at increased risk of getting sick.

Keep Reading: Risk Factors


A type of bacteria called Legionella causes Pontiac fever. People can get Pontiac fever when they breathe in mist that contains the bacteria.

Keep Reading: Causes and Spread


The key to preventing Pontiac fever is to reduce the risk of Legionella growth and spread.

Keep Reading: Prevention

Testing and diagnosis

To diagnose Pontiac fever, healthcare providers can use a

  • Urine test
  • Blood test

A negative test doesn't rule out that someone may have Pontiac fever. It's most often diagnosed when there's other cases of Legionnaires' disease or Pontiac fever that are confirmed by lab tests. Patients with a confirmed illness may've been exposed to Legionella at the same time or place as others with suspected illnesses.

Treatment and recovery

Pontiac fever goes away on its own without requiring treatment.


The first identified cases of Pontiac fever occurred in 1968 in Pontiac, Michigan. Those affected included people who worked at and visited the city's health department.

Legionella wasn't discovered until after the 1976 Legionnaires' disease outbreak in Philadelphia. Then public health officials were able to show these bacteria cause both diseases.