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Pontiac fever: an operational definition for epidemiological studies
Paul Tossa1, Magali Deloge-Abarkan, Denis Zmirou-Navier
1Département Environnement et Santé Publique, INSERM ERI 11, Henri Poincaré University, BP 184-54 505 Vandoeuvre lès Nancy, France. Paul.Tossa@nancy.inserm.fr
BMC Public Health
|May 2, 2006
Summary
A new operational definition for Pontiac fever was developed for non-epidemic settings. This definition aids in identifying environmental Legionella contamination and preventing Legionnaires' disease outbreaks.
Area of Science:
- Environmental microbiology
- Public health
- Infectious disease epidemiology
Background:
- Pontiac fever typically occurs in outbreaks, signaling Legionella contamination.
- Early detection is crucial for preventing Legionnaires' disease.
- A non-epidemic definition is needed for surveillance.
Purpose of the Study:
- To propose an operational definition for Pontiac fever.
- To enable epidemiological surveillance in non-epidemic settings.
- To link Pontiac fever incidence to environmental Legionella exposure.
Main Methods:
- Studied 560 elderly residents in 25 nursing homes over 4 months.
- Assessed daily incidence of Pontiac fever symptoms.
- Analyzed water/aerosol Legionella using bacterial culture and FISH.
- Developed a definition based on symptoms and exposure timing.
Main Results:
- Defined Pontiac fever by symptoms (headache, myalgia, fever, chills) within 3 days of Legionella-contaminated shower exposure.
- Observed an incidence rate of 0.125 cases per person-year.
- Legionella concentration ≥10(4).L⁻¹ (FISH) significantly increased Pontiac fever incidence (p=0.04).
Conclusions:
- The proposed definition may facilitate epidemiological surveillance for Pontiac fever.
- It can help identify environmental Legionella sources.
- Validation in other settings is recommended.
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