ASSE 12080- Legionella pneumophila-
Infectious Disease-Practice Questions
Fully Solved.
Legionella Disease Host/ Reservoir - Answer Waterborne disease, aerosolized water
Legionella Geographic Locations - Answer Global prevalence
- Anywhere with fresh water
Legionella Seasonal Patterns of occurrence - Answer More cases generally during summer or
autumn
Legionella Disease Agent - Answer Legionellae, Gram Negative Bacteria
Legionella Disease Environment - Answer freshwater environments, like lakes and streams. It
can become a health concern when it grows and spreads in human-made water systems like
Showers and faucets
Cooling towers (air-conditioning units for large buildings)
Hot tubs that aren't drained after each use
Decorative fountains and water features
Hot water tanks and heaters
Legionella Mode of Transmission - Answer Aerosol Transmission-
contaminated water then has to spread in droplets small enough for people to breathe in.
People can get Legionnaires' disease when they breathe in small droplets of water in the air that
contain the bacteria.
Person-person Transmission: RARE
Legionnaires Incubation Period - Answer 2-10 days
Generally 5-6
Pontiac fever Incubation Period - Answer 5-72 hours
Generally 24-48 hours
, Legionella period of Communicability - Answer
Legionella Host Susceptibility/ Resistance factors - Answer Most healthy people exposed to
Legionella do not get sick. People at increased risk of getting sick are:
People 50 years or older
Current or former smokers
People with a chronic lung disease (like chronic obstructive pulmonary disease or emphysema)
Immunocompromised
Legionella Preventive/Control measures - Answer maintain and disinfect potable water source
- water should be higher than 50 celicius
Legionella Clinical Manifestiations - Answer
Legionella Main Diseases - Answer Legionnaires Disease - Severe Disease
Pontiac Fever - Temporary Fever
Legionnaires disease clinical symptoms - Answer Pneumonia and non-productive cough
Can lead to respiratory failure
Pontiac fever clinical symptoms - Answer self-limited febrile illness, accompanied with cough
Does not progress to pneumonia or death
-more of clinical reaction than bacterial invasion
Legionnaires Treatment - Answer fluoroquinolone - antibioticsLegionella: Taxonomy - Answer
-L. pneumophilia: 14 serogroups. Group 1 most clinically important.
-Many other smaller ones that make up many nosocomial infections.
Legionella: Virulence factors - Answer -Gram (-), stain poorly with gram stain.
-Do not grow on routine media (require Fe and L-cysteine)
-Grow intercellularly in protozoa and in macrophages in humans.
Legionella: Habitat - Answer -Usually reside in water sources on surface biofilms.
-Gain access and reek havoc in water systems (cooling towers, hottubs, fountains, humidifiers,
flower water.
Infectious Disease-Practice Questions
Fully Solved.
Legionella Disease Host/ Reservoir - Answer Waterborne disease, aerosolized water
Legionella Geographic Locations - Answer Global prevalence
- Anywhere with fresh water
Legionella Seasonal Patterns of occurrence - Answer More cases generally during summer or
autumn
Legionella Disease Agent - Answer Legionellae, Gram Negative Bacteria
Legionella Disease Environment - Answer freshwater environments, like lakes and streams. It
can become a health concern when it grows and spreads in human-made water systems like
Showers and faucets
Cooling towers (air-conditioning units for large buildings)
Hot tubs that aren't drained after each use
Decorative fountains and water features
Hot water tanks and heaters
Legionella Mode of Transmission - Answer Aerosol Transmission-
contaminated water then has to spread in droplets small enough for people to breathe in.
People can get Legionnaires' disease when they breathe in small droplets of water in the air that
contain the bacteria.
Person-person Transmission: RARE
Legionnaires Incubation Period - Answer 2-10 days
Generally 5-6
Pontiac fever Incubation Period - Answer 5-72 hours
Generally 24-48 hours
, Legionella period of Communicability - Answer
Legionella Host Susceptibility/ Resistance factors - Answer Most healthy people exposed to
Legionella do not get sick. People at increased risk of getting sick are:
People 50 years or older
Current or former smokers
People with a chronic lung disease (like chronic obstructive pulmonary disease or emphysema)
Immunocompromised
Legionella Preventive/Control measures - Answer maintain and disinfect potable water source
- water should be higher than 50 celicius
Legionella Clinical Manifestiations - Answer
Legionella Main Diseases - Answer Legionnaires Disease - Severe Disease
Pontiac Fever - Temporary Fever
Legionnaires disease clinical symptoms - Answer Pneumonia and non-productive cough
Can lead to respiratory failure
Pontiac fever clinical symptoms - Answer self-limited febrile illness, accompanied with cough
Does not progress to pneumonia or death
-more of clinical reaction than bacterial invasion
Legionnaires Treatment - Answer fluoroquinolone - antibioticsLegionella: Taxonomy - Answer
-L. pneumophilia: 14 serogroups. Group 1 most clinically important.
-Many other smaller ones that make up many nosocomial infections.
Legionella: Virulence factors - Answer -Gram (-), stain poorly with gram stain.
-Do not grow on routine media (require Fe and L-cysteine)
-Grow intercellularly in protozoa and in macrophages in humans.
Legionella: Habitat - Answer -Usually reside in water sources on surface biofilms.
-Gain access and reek havoc in water systems (cooling towers, hottubs, fountains, humidifiers,
flower water.
