SNHD Investigation Process

Legionnaires’ disease is a reportable disease in Nevada. The Centers for Disease Control and Prevention (CDC) require healthcare providers and laboratories to report diagnosed cases to public health authorities so that they conduct investigations to identify potential sources of exposure and help prevent additional illnesses.

Once a case is reported, SNHD disease investigators review the case information and determine whether an environmental assessment is needed.

Residential Investigations

If a patient’s residence is identified as a potential source of exposure to the bacteria, SNHD may conduct a residential environmental assessment at the patient’s home.

The investigation may include:

• Evaluating the home’s water system
• Collecting water samples from possible exposure sites throughout the home
• Providing the homeowner with sampling results
• Educating the homeowner on water system flushing and Legionella-prevention recommendations

The purpose of the investigation is to determine whether Legionella bacteria may be present in the home’s water system and to provide guidance on reducing future risk.

Travel-Associated Investigations

If a patient stayed at a hotel, resort, healthcare facility, or other lodging in the timeframe they could have gotten ill, SNHD may conduct a travel-associated investigation.

After confirming the patient’s stay at the facility, SNHD staff perform an environmental assessment of the facility. This service generally includes:

• Reviewing the water system and the LEAF
• Reviewing the water management program
• Providing recommendations as necessary
• Collecting environmental samples for testing

Samples are collected from exposure site locations, which may include:

• The patient’s room(s)
• Nearby (distal) rooms
• Hot water return lines
• Decorative fountains and water features
• Health spas and outdoor aquatic venues
• Cooling towers (when applicable)
• Other potential exposure sites identified during the investigation

After sampling is complete, SNHD reviews the laboratory results and shares findings and recommendations with the facility.

Positive Results

If Legionella is detected in the water system, SNHD works with the facility to reduce the risk of future exposure.

This often includes:

• Remediation of the affected water system.
  • SNHD does not dictate which remediation method to use. Some common remediation methods include flushing, hyperchlorination, and/or replacing fixtures and equipment.
• Follow-up environmental sampling to ensure the remediation was effective.

• Continued monitoring through a post-remediation sampling schedule until the water system demonstrates acceptable results.

Non-Detect Results

If Legionella is not detected in the collected samples, no additional environmental action is generally required, and the investigation is closed.

SNHD_EHoutbreaksupport@snhd.org
(702) 759-1504

Nevada Relay “Dial 711” (TTY)
After Hours & Public Health Emergencies
(702) 759-1000