ASSE 12080-Legionnaires Disease-
Questions and Answers All Verified.
Legionnaires disease - Answer serious bacterial pneumonia
Symptoms: pneumonia, cough, shortness of breath, fever, muscle aches, diarrhea, headache,
nausea, confusion
Incubation period: 2-14 days
can cause lung failure resulting in hospitalization and/or death
Case fatality rate of 10% or 15% is healthcare-associated
Less than 5% of exposed will get sick
Modes of transmission - Answer inhalation or aspiration of aerosolized water droplets
containing the bacteria
NOT person-to-person or drinking water
risk factors - Answer 50+ years old, smoking, chronic lung disease, immune system disorder,
systemic malignancy, underlying illness (diabetes, renal failure, hepatic failure), recent travel
with overnight stay, recent healthcare facility visit, hot tubs
disease trends - Answer increased by a factor of 9 in the US since 2000
constantly increasing in IN (drop in 2020, back up in 2021)
peaks in the summer months (June, July)
prevention methods - Answer 1. water management plans- understand plumbing and water
systems, identify risk areas of growth, monitoring, corrective actions
2. proactive risk assessments- temperature, pH, residual disinfectant, sediment/biofilm, water
age
3. be aware of risk factors
History of legionella - Answer Outbreak in July 1976 at the American Legion Convention in
Philadelphia
153 attendees hospitalized, 29 died
legionella isolated by CDC six months later
legionella - Answer gram negative bacteria living in water and soil
19 species known to cause human illness
serogroup 1 of legionella pneumophila causes 84% of LC cases
, legionellosis - Answer infection caused by legionella that is reportable in IN and nationally
Pontiac fever - Answer self-limited, flu-like illness that resolves without treatment
Symptoms: fever, muscle aches, chills, myalgia, malaise, headache, fatigue, nausea, vomiting
Incubation period: 24-72 hours
symptoms lasting days
often undiagnosed with low case fatality rate
90% of exposed will get sick
extrapulmonary infection - Answer infection by legionella outside of the lungs (very rare)
Common sources - Answer *grow in biofilms of freshwater pipes*
shower heads and sink faucets, cooling towers, hot tubs, ornamental ponds, cooling and
vegetable misters, nebulizers, stand-alone humidifiers, spas, birthing baths, ice machines,
decorative water fountains, hot water tanks and heaters
favorable growing conditions - Answer warm water (90-105 F), low disinfectant levels, low
use/ insufficient circulation, nutrients in water and soil, biofilms
diagnostic test - Answer culture of lower respiratory secretion (sputum or BAL); urinary
antigen test (serogroup 1)
why have cases of legionnaires increased? - Answer aging population, increase in
immunocompromised, aging plumbing infrastructure, climate change, increased physician
awareness, better reporting
community-associated outbreak - Answer increase in cases in a certain geographic area
beyond what is expected
Correctional facilities, fairgrounds, and amusement parks
cooling towers, decorative fountains, fan misters, and hot tubs
travel-associated outbreaks - Answer 2+ cases with same travel accommodation in 12-month
period
hotels, motels, resort, cruise ship, casino
whirlpool spas, hot tubs, cooling towers, showers, and decorative fountains
Questions and Answers All Verified.
Legionnaires disease - Answer serious bacterial pneumonia
Symptoms: pneumonia, cough, shortness of breath, fever, muscle aches, diarrhea, headache,
nausea, confusion
Incubation period: 2-14 days
can cause lung failure resulting in hospitalization and/or death
Case fatality rate of 10% or 15% is healthcare-associated
Less than 5% of exposed will get sick
Modes of transmission - Answer inhalation or aspiration of aerosolized water droplets
containing the bacteria
NOT person-to-person or drinking water
risk factors - Answer 50+ years old, smoking, chronic lung disease, immune system disorder,
systemic malignancy, underlying illness (diabetes, renal failure, hepatic failure), recent travel
with overnight stay, recent healthcare facility visit, hot tubs
disease trends - Answer increased by a factor of 9 in the US since 2000
constantly increasing in IN (drop in 2020, back up in 2021)
peaks in the summer months (June, July)
prevention methods - Answer 1. water management plans- understand plumbing and water
systems, identify risk areas of growth, monitoring, corrective actions
2. proactive risk assessments- temperature, pH, residual disinfectant, sediment/biofilm, water
age
3. be aware of risk factors
History of legionella - Answer Outbreak in July 1976 at the American Legion Convention in
Philadelphia
153 attendees hospitalized, 29 died
legionella isolated by CDC six months later
legionella - Answer gram negative bacteria living in water and soil
19 species known to cause human illness
serogroup 1 of legionella pneumophila causes 84% of LC cases
, legionellosis - Answer infection caused by legionella that is reportable in IN and nationally
Pontiac fever - Answer self-limited, flu-like illness that resolves without treatment
Symptoms: fever, muscle aches, chills, myalgia, malaise, headache, fatigue, nausea, vomiting
Incubation period: 24-72 hours
symptoms lasting days
often undiagnosed with low case fatality rate
90% of exposed will get sick
extrapulmonary infection - Answer infection by legionella outside of the lungs (very rare)
Common sources - Answer *grow in biofilms of freshwater pipes*
shower heads and sink faucets, cooling towers, hot tubs, ornamental ponds, cooling and
vegetable misters, nebulizers, stand-alone humidifiers, spas, birthing baths, ice machines,
decorative water fountains, hot water tanks and heaters
favorable growing conditions - Answer warm water (90-105 F), low disinfectant levels, low
use/ insufficient circulation, nutrients in water and soil, biofilms
diagnostic test - Answer culture of lower respiratory secretion (sputum or BAL); urinary
antigen test (serogroup 1)
why have cases of legionnaires increased? - Answer aging population, increase in
immunocompromised, aging plumbing infrastructure, climate change, increased physician
awareness, better reporting
community-associated outbreak - Answer increase in cases in a certain geographic area
beyond what is expected
Correctional facilities, fairgrounds, and amusement parks
cooling towers, decorative fountains, fan misters, and hot tubs
travel-associated outbreaks - Answer 2+ cases with same travel accommodation in 12-month
period
hotels, motels, resort, cruise ship, casino
whirlpool spas, hot tubs, cooling towers, showers, and decorative fountains
