Legionellosis
Investigation of an Outbreak of Legionellosis in Western North Carolina
Outbreak Summary
- On September 23, 2019, the NC Division of Public Health was notified about an increase in the number of Legionnaire’s disease cases in Buncombe and Henderson counties.
- 136 cases of Legionnaires’ disease or Pontiac Fever were identified in residents of multiple states and North Carolina counties who attended the NC Mountain State Fair, held September 6-15, 2019 at the Western North Carolina Agricultural Center in Fletcher, NC.
- The Division of Public health has released a Final Outbreak Report (PDF) with findings from the investigation.
- If you have questions about Legionnaires’ disease or the outbreak, you can find more information in our FAQ (PDF).
- Final case count:
| County of Residence |
Confirmed Cases* |
| Buncombe County |
49 |
| Burke County |
1 |
| Caswell County |
1 |
| Cherokee County |
1 |
| Gaston County |
1 |
| Granville County |
1 |
| Haywood County |
11 |
| Henderson County |
33 |
| Jackson County |
3 |
| Madison County |
6 |
| McDowell County |
5 |
| Mecklenburg County |
5 |
| Mitchell County |
2 |
| Polk County |
1 |
| Rutherford County |
1 |
| Transylvania County |
3 |
| Yancey County |
1 |
| Out of State |
11 |
| TOTAL |
136 |
*No new cases linked to the outbreak have been identified since the end of October. Some previously reported cases did not meet the case definition for this outbreak once a full clinical and risk history were assessed.
| Case Characteristics |
|
| Male |
77 (57%)* |
| Female |
58 (43%)* |
| Median age in years (range) |
61 (24-91) |
| Hospitalizations |
96 (71%)* |
| Deaths |
4 |
| Legionnaires' Disease |
135 (99%) |
| Pontiac Fever |
1 (1%) |
*some cases were reported with unknown gender or hospitalization status
Outbreak Case Definition
Clinical Criteria
- A. Legionnaire’s Disease
Pneumonia (clinical or radiologically confirmed) in an individual who attended or worked at the 2019 NC Mountain State Fair, with symptom onset within 2 – 14 days after fair attendance
Or
- B. Pontiac Fever
Fever, myalgia, headache, chills, nausea, vomiting or diarrhea within 3 days of attending or working at the 2019 NC Mountain State Fair.
Laboratory Criteria
Laboratory confirmed Legionella
- By culture: isolation of any Legionella organism from respiratory secretions, lung tissue, pleural fluid, or other normally sterile site
or
- By detection of Legionella pneumophila serogroup 1 antigen in urine using validated reagents
or
- By seroconversion: fourfold or greater rise in specific serum antibody titer to L. pneumophila serogroup 1 using validated reagents on specimens collected 3–6 weeks apart
Confirmed Case: Patient meets clinical criteria A or B AND laboratory criteria
Sources and for more information:
