1. Legionnaire’s Disease
Emerging Diseases
Lecture 11:
Legionnaire’s Disease
11.1: Overview
11.2: Outbreak in 1976
11.3: Legionella is Common
11.4: Biofilms

2. 11.1: Overview
Our Commonwealth’s contribution to the array of emerging diseases
An “old” disease with a new name
Remains a serious problem to the present day

3. 11.2: 1976 Outbreak American Legion Convention July, 1976
Bicentennial convention
July 27, 1976-first cases
Flu-like symptoms
Can progress to more serious
221 cases, 34 deaths
72 non-convention but in hotel

4. August 1976

5. CDC Identifies pathogen
McDade asked to lead team
Difficult to track down causative agent
Does not grow on standard medium
Months of effort
Identification of “new” pathogen
Legionella pneumophila
(Legionella
micdadei)

6. Linked to earlier outbreaks through “retrospective” analysis or analysis of old samples stored in freezer
Mystery outbreak in 1968-Pontiac, Michigan “Pontiac Fever”-also caused by Legionella Mild disease compared to LD

7. 11.3: Legionella is Common
Legionella present in almost every body of water
Prefers warm to hot water
Enclosed space
Enters host via mist or aerosol
Or drinking water
1000s of cases
Many nosocomial

8. Ice machines were source of Legionnaires' May 2, :35 PM By Sean D. Hamill / Pittsburgh Post-Gazette
After one patient died and two were sickened by Legionnaires' disease in November and December at UPMC Presbyterian, where they contracted the disease, UPMC has a message for hospitals nationwide.
“Hospitals in the U.S.: If you have not been looking in ice machines for Legionella, please look," Tami Minnier, UPMC's chief quality control officer, said Friday. "That's the message."

9. L.A. NOW
Southern California -- this just in
Playboy Mansion bacteria points to Legionnaires’ disease outbreak
March 1, 2011 |  6:31 am

10. Legionella
lives in
biofilms with
other organisms
11.4: Biofilm a group of microbes growing together in a large group-protecting and shielding each other

11. Biofilms can form almost anywhere Water systems and plumbing Surgical equipment such as catheters Contact lenses Natural bodies of water

12. Biofilms