Pontiac fever
Pontiac fever is an infectious respiratory illness caused by the bacterium Legionella, specifically L. pneumophila, which is also responsible for the more severe Legionnaires' disease. Unlike Legionnaires' disease, Pontiac fever presents with milder, flu-like symptoms such as low fever, muscle aches, coughing, runny nose, and sore throat, without the pneumonia characteristic of Legionnaires'. The bacteria are typically contracted by inhaling mist from contaminated water sources, and there is no evidence of person-to-person transmission.
Risk factors for developing Pontiac fever include exposure to contaminated water, particularly in environments like hot tubs, showers, and air conditioning systems, as well as factors such as older age, compromised immune systems, and chronic health conditions. Diagnosis is based on medical history and symptom assessment, with laboratory tests confirming the presence of the bacteria. Treatment may not always be necessary, as symptoms can resolve on their own; however, antibiotics can be prescribed when required. Prevention focuses on maintaining clean water systems and regulating water quality to minimize the risk of bacterial growth.
Pontiac fever
ANATOMY OR SYSTEM AFFECTED: Lungs, respiratory system
ALSO KNOWN AS: Legionellosis
Definition
Pontiac fever, an infectious disease produced by the bacterial genus Legionella, is a milder form of Legionnaires’ disease (or Legion fever). Pontiac fever is a respiratory illness with flu-like symptoms, but without the pneumonia that develops with Legionnaires’ disease. Pontiac fever and Legionnaires’ disease are referred to separately or collectively as legionellosis.
Causes
More than 90 percent of all cases of legionellosis are caused by the bacterium L. pneumophila. The bacteria are contracted by breathing mist that comes from a contaminated water source. It is not known to be transmitted from person to person.
Risk Factors
Contaminated water supplies constitute the primary risk factor for legionellosis. The Legionella species of bacteria can survive in warm water and moist air, such as that associated with hot tubs, showers, humidifiers, hot water tanks, and the air conditioning systems of large buildings, including hospitals.
Most infections occur in middle-aged or older people. The disease is typically less severe in children. Other risk factors include the use of medications that suppress the immune system, such as chemotherapy and steroids, and alcoholism, cigarette smoking, chronic lung disease, cancer, kidney failure, and diabetes.
Symptoms
Typical symptoms associated with Pontiac fever are mild fever, muscle aches, coughing, runny nose, and sore throat, without pneumonia. For more severe infections, known as Legionnaires’ disease, which produce pneumonia, the symptoms are high fever, chest pains, chills, coughing, penetrating muscle aches, headaches, tiredness, loss of appetite, coughing up blood, loss of coordination, and, sometimes, nausea and diarrhea.
Screening and Diagnosis
A medical history is taken to characterize the symptoms. Chest X-rays are examined for lung inflammation. Blood samples determine complete blood count. As necessary, sputum samples are examined for Legionella bacteria, urine samples for L. pneumophila antigens, and blood samples (taken about three weeks apart) to be contrasted for Legionella antibody levels. Doctors may also carry out a urine test.
Treatment and Therapy
Symptoms of Pontiac fever typically disappear in a few hours to five days, often without the need for any treatment.
Prevention and Outcomes
Water supply regulations and ordinances must be in place and enforced. Water delivery systems should be periodically tested and treated for Legionella bacteria. The removal of any slime in these water systems is a necessary control process.
Bibliography
"About Pontiac Fever." Centers for Disease Control, 29 Jan. 2024, www.cdc.gov/legionella/about/about-pontiac-fever.html. Accessed 4 Feb. 2025.
Frazier, Margaret Schell, and Jeanette Wist Drzymkowski. Essentials of Human Diseases and Conditions. 4th ed. St. Louis, Mo.: Saunders/Elsevier, 2009.
Mason, Robert J., et al., eds. Murray and Nadel’s Textbook of Respiratory Medicine. 5th ed. Philadelphia: Saunders/Elsevier, 2010.
Neil, K., et al. “Increasing Incidence of Legionellosis in the United States, 1990-2005: Changing Epidemiologic Trends.” Clinical Infectious Diseases 47 (2008): 591.
Shader, Laurel. Legionnaires’ Disease: Deadly Diseases and Epidemics. New York: Chelsea House, 2006.
Uzel, Atac, and E. Esin Hames-Kocabas. “Legionella pneumophila”: From Environment to Disease. Commack, N.Y.: Nova Science, 2010.