Is Legionella Pneumonia Reportable to the Department of Health?
Yes, Legionella pneumonia (Legionnaires' disease) is reportable to state or local health departments in most states, and you should report cases immediately upon identification. 1
Reporting Requirements and Rationale
When to Report
Report all laboratory-confirmed cases of Legionnaires' disease immediately to your state or local health department, even before completing a full investigation. 1
The Infectious Diseases Society of America/American Thoracic Society guidelines provide a strong recommendation (level III evidence) that cases of pneumonia of public health concern, including Legionnaires' disease, should be reported immediately. 1
Most states require reporting for Legionnaires' disease specifically to enable public health investigation of potential common-source outbreaks and environmental contamination. 1
Why Reporting Matters for Patient Outcomes
Reporting enables identification of common-source outbreaks caused by environmental contamination, which can prevent additional cases and deaths. 1
Health care-associated Legionnaires' disease has a case fatality rate of 25% for definite cases and 10% for possible cases, making rapid public health response critical for preventing additional exposures. 2
The overall mortality rate for severe Legionella pneumonia requiring ICU admission is approximately 30%, with no significant difference between nosocomial (27%) and community-acquired (31%) cases. 3
Healthcare-Associated Cases Require Special Attention
Contact the local or state health department or CDC immediately when even a single laboratory-confirmed healthcare-associated case is identified. 1
In facilities with transplant programs, report when one inpatient develops healthcare-associated Legionnaires' disease after >10 days of continuous stay, or when two or more patients develop laboratory-confirmed disease within 6 months. 1
In facilities without severely immunocompromised patients, report when a single definite healthcare-associated case is identified, or when two or more possible cases occur within 6 months. 1
Important Caveats
Reporting requirements vary by state, so verify your specific state's regulations, though most states do require Legionnaires' disease reporting. 1
Report suspected cases even before definitive diagnosis when considering potential bioterrorism agents or unusual epidemiologic patterns. 1
Detection of a single case should not be considered isolated—it likely indicates unrecognized additional cases, as only 2-10% of estimated cases are actually reported. 4
The concentration of Legionella in environmental samples does not reliably predict disease risk, as transmission depends on multiple factors including aerosolization, proximity, host susceptibility, and strain virulence. 5