Waterborne Disease Outbreaks

Question 1

Are WBOs nationally notifiable?

Answer 1

No

Question 2

Are WBOs notifiable in Tas?

Answer 2

Outbreaks, no.

But waterborne illness is.

Question 3

What are some common WBDs?

Answer 3

Cryptosporidium
Giardia
Shigella
E. coli
Norovirus

Question 4

What are examples of non-infectious WBDs?

Answer 4

Harmful algal blooms, fish toxins

Question 5

Can Cryptosporidium be easily disinfected?

Answer 5

No, very resistant to chlorine disinfection.

Question 6

Can Giardia be easily disinfected?

Answer 6

No, requires long period of disinfection

Question 7

Which types of water bodies to Shigella and E. coli typically contaminate?

Answer 7

Beach, lakes, inadequately disinfected pools

Question 8

Can Norovirus be easily disinfected?

Answer 8

Killed by chlorine disinfection but lakes/beaches can be contaminated.

Question 9

How are WBDs typically transmitted?

Answer 9

Drinking or recreational water.

Reservoir usually animals or humans.

Ingestion, dermal, mucous membranes, inhalation (Legionella), secondary person-to-person transmission.

Question 10

What are the clinical features of WBDs?

Answer 10

Abdominal pain, N / V / D.

Question 11

Which are high-risk groups for WBDs?

Answer 11

Children, elderly, immunocompromised.

Question 12

What are case definitions for WBOs?

Answer 12

Pathogen-specific.

Outbreak case definition based on T/P/P

Question 13

How are WBDs diagnosed?

Answer 13

Isolation / detection - various methods typically from stool

Question 14

What is the outbreak definition for a WBO?

Answer 14

2 + cases (T/P) of enteric or other symptoms that may have been acquired from contact with contaminated water.

Question 15

How can WBOs be prevented?

Answer 15

• Healthy swimming practices
• Prevention of drinking water and aquatic facility contamination
• No water play at daycares

Question 16

What are some specific management points for WBOs in a drinking water source?

Answer 16

• Engage stakeholders e.g. TasWater
• Understand water system to ID potential contamination sites
• Investigate recent events e.g. damage to infrastructure, weather events
• Physicall inspect drinking water system
• Take samples
• Review recent water quality and operational monitoring data
• Control measures
• Advice on alternative sources, boiling water

Question 17

What are some specific management points for recreational water source contamination?

Answer 17

• Inspect facility (council EHO, Water Unut)
• Review compliance with guidelines
• Treatment - hyperchlorination
• Signage - promote healthy swimming
• Persisitent OB - consider closure, issue improvement notice, engage independent treatment specialist
• Facility to communicate with staff, visitors, other SHs during OB