Case Management

Clinical DescriptionLegionellosis is associated with two clinically and epidemiologically distinct illnesses: Legionnaires’ disease, which is characterized by fever, myalgia (muscle pain), cough and pneumonia, and Pontiac fever, a milder illness that presents in the patients without the pneumonia.
Case Classification The following has been established as the case classification system for Legionnaires’ disease:
1. Single case: A case of Legionnaires’ disease associated with a permitted facility that has not been linked with any other cases of Legionnaires’ disease for at least the previous two years.
2. Cluster: Two or more cases of Legionnaires’ disease associated with the same permitted facility where the patients’ symptom onset occurred within the same two-year period.
3. Outbreak: Two or more cases of Legionnaires’ disease associated with the same permitted facility where the patients’ symptom onset occurred within the same 12 month period and where environmental investigations provide additional evidence suggesting a common source of infection.
4. Confirmed case: A case with the patient showing the signs and symptoms listed in section IV, paragraph A, that is also confirmed by laboratory results.
5. Suspected case: A person, based on clinical signs, symptoms, laboratory evidence or history of exposure, who is considered by a health care provider or the health authority to have, or possibly have, legionellosis (Legionnaires’ disease or Pontiac fever).
Initiate Epidemiological Investigation
1. The OOE is responsible for case identification, classification and management.
2. The OOE investigates every report of a case of legionellosis.
3. Upon notification of a case, a DIIS investigates to confirm the case status.
4. The DIIS determines if the affected person was present at any public facility which falls within the health district’s jurisdiction that may have been a source of exposure to Legionella. Public facilities include, but are not limited to, public accommodation facilities or public bathing places regulated and routinely inspected by the health district.
Response Coordination and Information Sharing
1. If a case had one or more potential Legionella exposures in the two to 15 days before symptom onset, the OOE coordinates with EH in conducting an onsite joint epidemiological and environmental investigation.
2. Certain information is required to plan a thorough and complete investigation. Specific details needed to clearly identify a location are shared between the OOE and EH.
3. For each potential public accommodation facility exposure, the following information is provided:
  1. The name and address of the public accommodation facility.
  2. The room number and/or floor number.
  3. The reported dates of exposure.
  4. Specific amenities used in a public accommodation facility that may be considered an avenue of exposure (i.e., wet bar, in-room whirlpool bathtub, shower, spa, swimming pool, hot tub, misters, etc.)
4. For each public bathing place (permitted body of water), pool, spa or water feature exposure, the following information is provided:
  1. The name and address of the body of water.
  2. Specific details identifying body of water to which the case was exposed, if a location has more than one.
  3. The condition of the body of water (cloudy, green, clear, etc.).
  4. Anything abnormal about the body of water (strong smell of chlorine, improper temperature, slimy steps, etc.).
Entering and Evaluating Exposure Data
1. Once it has been established that the case(s) had one or more exposures, the DIIS enters the information into the electronic surveillance system and reviews it for any other cases with the same exposure(s) in the past 12 months.
2. If a Legionnaires’ disease cluster or outbreak is identified, an Epi-X posting will be drafted and submitted by the OOE.

Contact Information

Phone: (702) 759-1000

Email: snhdlegionellateam@snhd.org

Updated on: July 23, 2021