Cryptosporidium: Public health impacts of a waterborne pathogen Renay Cooke Senior Water Quality Advisor Water Quality Unit, SA Health Public-I1-A1

SA Health Cryptosporidium Protozoan parasite with complex life cycle Oocysts shed in faeces Multiple species identified C. hominis (carried by humans) and C. parvum (carried by livestock) cause disease in humans Public-I1-A1

SA Health Cryptosporidium Highly infectious Single oocyst capable of causing disease Outbreaks generally associated with drinking and recreational water One of the most important waterborne human pathogens in developed countries Public-I1-A1

SA Health Transmission >Transmitted via faecal-oral route: Person-to-person spread Direct spread through drinking or swimming in contaminated water or eating contaminated uncooked foods (e.g. fruits and vegetables) Indirect spread through hands and other objects being contaminated with faeces of infected people or animals Public-I1-A1

SA Health Symptoms >Common: Watery diarrhoea (self-limiting) Stomach cramps Symptoms typically last around 1 week >Less common: Fever, vomiting, loss of appetite Symptoms persist for >30 days Chronic infections which can be life threatening (associated with immunodeficiency conditions) >Infected people continue to shed Cryptosporidium for up to 14 days after symptoms cease >No specific treatment, symptoms can be managed Public-I1-A1

SA Health Detecting an outbreak >Cryptosporidiosis is a notifiable disease >Mandatory reporting to CDCB >Changes in surveillance data trends Increase in cases Unusual clusters (person, place, time) >Reports from cases Links to swimming pools (risk of secondary transmission), child care, petting zoos, etc. Public-I1-A1

SA Health Case studies from SA >2007 outbreak – swimming pools implicated >2014/15 outbreak – swimming pools implicated >2007 cluster of cases – linked to contaminated drinking water Public-I1-A1

SA Health Public-I1-A1 Notified cases of Cryptosporidiosis 1 January 2005 – 15 November 2015, South Australia

SA Health Public-I1-A1 Notified cases of Cryptosporidiosis 1 January 2007 – 1 June 2007, South Australia

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SA Health Public-I1-A1 Notified cases of Cryptosporidiosis 1 November 2014 – 1 September 2015, South Australia

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SA Health 2007 & 2014/15 outbreak summary >Pools implicated in a high number of cases >Spread within families common >Increased cases: young males (0-14 yrs) and females aged ~ yrs >No single source identified >2007 outbreak brief (Jan – April 07) >2014/15 outbreak persistent (Dec 14 – ongoing: increased number of cases still being observed) Public-I1-A1

SA Health Adelaide Hills cluster 2007 >19 cases notified >Links to youth residential facility in the Adelaide Hills >Further investigation undertaken by local Council EHO >Inspection revealed likely contamination between main to septic system and rainwater tank pipework (both in same trench) >Remedial plumbing work undertaken, tank cleaned/disinfected, UV installed Public-I1-A1

SA Health Drinking water outbreaks >Sydney Incident (1998) 3 boil water notices issued following detection of Cryptosporidium & Giardia in drinking water No increase in illness observed Estimated costs:  Sydney Water - $75 million  Overall - $350 million Loss of public confidence in provision of safe drinking water Contributing factors: high rainfall event, changes in raw water quality, poor communication between NSW Health and Sydney Water, poor protocols in place for responding to incidents, questionable laboratory results Public-I1-A1

SA Health Drinking water outbreaks >Milwaukee, USA (1993) > 400,000 infected with Cryptosporidium ~ 50 deaths Estimated cost - $96 million (USD) Contributing factors: changes in plant operation (coagulation), increase in raw water turbidity, wastewater contamination of Lake Michigan, inadequate filtration Inadequate assessment of Crypto risk Most drinking water outbreaks occur following a series of failures/events not a single event Public-I1-A1

SA Health How we respond to Crypto in SA >Increase in numbers of Cryptosporidiosis Cases interviewed by CDCB Linked to swimming pool(s) – referred to Health Protection Programs Linked to drinking water – referred to Water Quality Unit Environmental investigation – referred to local Council EHOs  Checking swimming pool records, assisting with pool closures / decontamination,etc  On-site investigation of private drinking water supplies (as per 2007 cluster) Public-I1-A1

SA Health How we respond to Crypto in SA >Detection of Cryptosporidium in the drinking water supply Immediate notification under Water/Wastewater Incident Notification and Communication Protocol Interagency meeting convened between SA Health, SA Water and contractors Review WTP operation, plant challenges, system specifics (e.g. distribution area, storages, flows) Further speciation / infectivity testing, e.g. if no C. parvum or C. hominis present, no immediate risk to human health Consideration for boil water notice – presence of human infectious species, density, evidence of treatment failure/plant challenge Public-I1-A1

SA Health Preventative mechanisms >Swimming pools Bather education/hygiene (e.g. not using pools for 14 days after diarrhoea, showering before using a pool, use of swimming nappies) Faecal incident response UV disinfection Decontamination/closure >Drinking water Multiple barrier approach (catchment to tap)  Protection of catchments (human & animal waste)  Treatment (filtration, UV disinfection)  Optimum plant operation (e.g. coagulation /flocculation, turbidity, filter performance) Boil water notice Public-I1-A1

SA Health Ongoing measures >Notifiable disease >Enhanced surveillance when cases increase >Good relationships (within SA Health and externally, e.g. local Councils, SA Water) and existing protocols >Enforcing compliance with Public Health (General) Regulations and Safe Drinking Water Act >Research & development, e.g. new single assay for species, density and infectivity >Education / media Public-I1-A1

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