Waterborne Diseases

Question 1

Bacteria
· Vibrio cholerae
· Legionella pneumophila
Protist
· Giardia intestinalis

These are the Major Pathogens of what?

Answer 1

waterborne diseases

Question 2

Pathogen
· Vibrio cholerae
· Gram (–) Bacterium
· Coastal, Marine Habitats

Epidemiology
Vibrio cholerae
· >190,000 cases, >5,100 deaths (worldwide) - 98% of cases in Africa
· Untreated Mortality Rate 25-50%

This describes what?

Answer 2

Cholera

Question 3

Pathogenesis
· Caused by Ingestion of Contaminated Water (or Food)
· V. cholerae Attaches to Wall of the Small Intestine and Produces Cholera Toxin -> causing severe diarrhea and loss of 20L of water per day

Diagnosis
· Presence of V. cholerae Cells in Feces

This describes what?

Answer 3

Cholera

Question 4

Prevention
· Vaccine for Some Strains Available - Only provides short-term immunity
· Maintain Adequate Seawage Treatment and Safe Drinking Water
Treatment
· Fluid and Electrolyte Replacement
· Antibiotics (e.g. Streptomycin)
- Together, Reduce Mortality to <1%

This describes what?

Answer 4

Cholera

Question 5

Pathogen
· Legionella pneumophila
· Gram (–), Obligate Aerobe · Lakes, Stream, Soil
Epidemiology
· 9 Cases per Million (US)
- Increasing Incidence since 1990s
· Mortality (10%) – Severe Cases

This describes what?

Answer 5

Legionellosis

Question 6

Pathogenesis
· Low Concentrations in Nature, High in Air Conditioning
· Travels Via Aerosols, Infection in Lungs
· Mild Infection
- Pontiac Fever · Self-Limiting · Fever and Cough
· Severe Infection
- Pneumonia · Immune Compromised Hosts
Diagnosis
· Cultures from Body Fluids

This describes what?

Answer 6

Legionellosis

Question 7

Prevention
· Improved Maintenance of Heating/Cooling Systems · Killed by Temperatures >63oC and Hyperchlorination · No Vaccine Available
Treatment
· Antibiotics (intravenous erythromycin)

This describes what?

Answer 7

Legionellosis

Question 8

Pathogen
· Giardia intestinalis
- Flagellated Protist
- Trophozoite & Cyst Stages
· Mammalian Parasite
Epidemiology
· 1.2 Million Annually (US) · Mortality (<1%)

This describes what?

Answer 8

Giardiasis

Question 9

Pathogenesis
· Ingestion of Giardia Cysts
- Shed in feces of infected mammals
· Ubiquitous in Natural Waters
Symptoms & Diagnosis
· Diarrhea, Gas (nasty smells) - 1-2 weeks (up to a month)
· Microscopy, Immunoassays

This describes what?

Answer 9

Giardiasis

Question 10

Prevention
· Water Filtration - Cysts resistant to
chlorine treatment
Treatment
· Antibiotics
- Variable effectiveness

This describes what?

Answer 10

Giardiasis