Content Information
A. Isolation and Quarantine Requirements
None.
B. Protection of Contacts of a Case
None.
C. Managing Special Situations
Response to a Single Case of Community-Acquired Legionellosis
One case of legionellosis does not require any further investigation other than completing the IDSS investigation. See Section 2) C, Case Investigation. Some people report that they must have gotten the infection from a particular place such as work or their places of worship or recreation. Since Legionella can be found in a wide variety of water sources at low levels, unless several cases occur that implicate a “source”, it is difficult to prove a particular source was the cause of illness. It is not recommended that a water source be tested or decontaminated based on one community-acquired case.
Response to Healthcare Associated Legionellosis
A laboratory-confirmed case of legionellosis occurring in a patient hospitalized continuously for greater than 10 days before the onset of illness is considered a case of healthcare associated legionellosis. When a case of healthcare associated legionellosis occurs in a hospital or long-term care facility, the infection preventionist at the facility should enhance surveillance efforts for additional cases. If more cases are identified, measures should be taken to identify the source and eliminate the contamination. See Section 3) D below. Additionally, refer to the CDC Guidelines for Preventing Healthcare Associated Pneumonia, which are listed in the references section.
Reported Incidence Is Higher than Usual/Outbreak Suspected
If the number of reported cases in a particular city/town is higher than usual, or if an outbreak is suspected, investigate clustered cases in the area or institution to determine possible sources of infection. A source of infection could be a cooling tower, decorative fountain, whirlpool spa, grocery store mister, etc. If the investigation indicates a common source, testing of water samples should be done and applicable preventive or control measures should be instituted. Testing water sources is a specialized procedure and will require the assistance of environmental professionals. A confirmed source should be cleaned and decontaminated according to established protocols and a schedule of continued testing must be put in place for a period of time determined on a case-by-case basis. Consult with a CADE epidemiologist at (800) 362-2736 for assistance in investigating, testing, and implementing control measures. CADE can also perform surveillance for cases regionally that may be difficult to identify at a local level.
D. Preventive Measures/Education
To avoid future exposures:
Cooling towers should be drained when not in use and mechanically cleaned and maintained according to the manufacturer’s recommendations.
Tap water should not be used in respiratory therapy devices.
Hotels, cruise ships and other owners of whirlpool spas and decorative fountains should maintain them according to the manufacturer’s recommendations, have adequate levels of chlorine or other disinfectant at all times, and keep current on protocols for public health safety.
After outbreaks, vigilant monitoring of proven sources should be maintained.
Iowa Dept. of Public Health, Reviewed 7/15