Cryptosporidium monitoring of Ireland's waters- Theo de Waal

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  • Tyzzer described parasite in gastic mucosa of common mice. Named the parasite in 1910 as Cryptosporidium muris. Later in 1912 described C. parvum from small intestine of experimentally infected mouse
  • Cryptosporidium galliChicken (Gallus gallus)Gastric (proventriculus)Cryptosporidium andersoniCattle (Bostaurus)Gastric (Abomasum)Cryptosporidium murisMouse (Musmusculus)Gastric
  • Also airborne route described – importance?
  • Symptomatic treatment of the diarrhea by administering plenty of fluids to prevent dehydration is the primary management. A new drug, Nitazoxanide has been approved for the treatment of cryptosporidiosis.
  • Cryptosporidium ryanae from calves, identified as the Cryptosporidium deer-like genotype
  • Cryptosporidium monitoring of Ireland's waters- Theo de Waal

    1. 1. Cryptosporidium monitoring of Irelands waters Theo de Waal UCD School of Veterinary Medicine Scoil Leighis Tréidliachta UCD 1
    2. 2. Outline • Introduction • What is Cryptosporidium • How is it spread • Cryptosporidium in humans • Cryptosporidium in surface water • National reference laboratory • Survey of Irish water supplies 2
    3. 3. Introduction • Cryptosporidium first described in 1907 Tyzzer – C. muris • Only associated with disease and death in 1955 in Turkeys – C. meleagridis • In early 1970’s first reported of its association with diarrhoea in cattle • In 1976 first two human case described – 3-year-old child – 39-year old immunosuppressed patient • Today Cryptosporidium one of the most commonly identified intestinal pathogens 3
    4. 4. What is Cryptosporidium?• Small single cell eukaryotic organism• Found in GIT• Oocyst  environment – Small • 4-8 µm in size – Smooth, thick outer wall – Contain infective sporozoites 4
    5. 5. Cryptosporidium life cycle• Direct life cycle• Sporulated oocyst ingested• Infect microvillus border of GIT – vertebrates – 3 species : Gastric mucosa – 1 specie: Respiratory system• Complex development – Asexual multiplication – Sexual reproduction• Autoinfection 5
    6. 6. How is it spread? • Transmission: faecal-oral route – Close contact – Waterborne – Foodborne 6 Fayer, R., 1997. Cryptosporidium and Cryptosporidiosis . CRC Press
    7. 7. Cryptosporidium oocyst survival • Very resistant! – Oocysts can remain viable in environment & animal liquid waste ~ 1 year – Resistant to environmental stressors – Resistant to most chemical disinfectantshttp://www.bio-uv.com/fr/site/Piscines-spas-collectifs/Prevention-Cryptosporidium/Prevention-contre-les-pathogenes-parasitaires_129_.html 7
    8. 8. CRYPTOSPORIDIUM INHUMANS 8
    9. 9. Cryptosporidium spp: • More than 22 recognised Cryptosporidium species – 39 Cryptosporidium genotypes • Host specific - C. hominis to broad host range - C. parvum and C. ubiquitum • Only few considered infectious to humans – Human cryptosporidiosis in Ireland1,2 • C. hominis (20%) • C. parvum (80%)1. Zintl, et al, 2009, The prevalence of Cryptosporidium species and subtypes in human faecal samples in Ireland. Epidemiol. Infect. 137, 270-277. 92. Graczyk, et al., 2007. Human enteropathogen load in activated sewage sludge and corresponding sewage sludge end products. Applied and Environmental Microbiology 73 (6):2013-2015.
    10. 10. Cryptosporidium in Ireland: Human • Crude incidence rate Cryptosporidium1 – 6.9 – 13.4/100,000 annually 700 • Strong urban-rural divide 600 • Rural areas reported moreNumber cases 500 cases 400 • Regional as high as 300 – 31.4/100,000 per year 200 100 0 Year 2004 2005 2006 2007 2008 2009 2010 2011 10 1Human cryptosporidiosis became a notifiable disease on January 1st 2004
    11. 11. Ireland: Seasonal distribution in humans 11 http://www.hpsc.ie/hpsc/A-Z/Gastroenteric/Cryptosporidiosis/Publications/EpidemiologyofCryptosporidiosisinIrelandAnnualReports/
    12. 12. CRYPTOSPORIDIUM INSURFACE WATER 12
    13. 13. Cryptosporidium waterborne outbreaks• First waterborne outbreak Braun Station, Texas (1984)• Largest epidemic – Milwaukee, Wisconsin (1993)• To date outbreaks affecting >106 individuals documented Finnegans Lake, County Galway. 13
    14. 14. Cryptosporidium waterborne outbreaks - IrelandArea Year Cases Source & Deficiency SpeciesBelfast 2000 & 2001 246 & 191 Septic tank seepage into reservoir C. bovine strain & C. human strainMullingar 2002 26 Heavy rain, agricultural runoff into C. genotype 2 (=C. lake. No filtration. parvum) in humansEnnis 2003, 2005, 2008 ? Surface water into spring source. ? No filtrationCarlow 2004 31 ? C. parvum, C. andersoni, C. muris in water. C. hominis in humansGalway 2007 240 Agricultural runoff, sewage plant. C. hominis and C. Inadequate filtration parvum in water and humansClonmel 2007 ? Surface water contamination ? following heavy rain 14
    15. 15. Drinking water in Ireland- vulnerable?• Surface water (82% of drinking water)• Climate • High rainfall• Geology – Shallow layer of soil and subsoil Groundwater vulnerability map over karst limestone – Heavy soils  either rapid surface runoff or preferential flow• Unprotected catchments • Septic tanks • Livestock• Inadequate treatment on some supplies Households with septic tanks 15
    16. 16. Cryptosporidium in Ireland: Environment • Several Irish studies have detected Cryptosporidium species in Irish river basins1,2 • 2005 EPA risk assessment - Irish public water supply – 8% high risk – 13% very high risk 161. Graczyk, et al., 2004. Human waterborne parasites in zebra mussels (Dreissena polymorpha) from the Shannon River drainage area, Ireland. Para Research 93: 385-391.2. Lucy, et al., 2008..Biomonitoring of surface and coastal water for Cryptosporidium, Giardia and human virulent microsporidia using molluscan shellfish. Para Research 103:1369-1375
    17. 17. Cryptosporidium in Irish Water • Source of contamination and public health risk – Very limited information – No genotyping facilities in Ireland – Few local authorities get samples genotyped in UK • Survey of Cryptosporidium monitoring in public water supplies – 24.5 % supplies being monitored • >83% high Crypto risk score • Monitoring frequency low 17
    18. 18. Monitoring Reasons given for routine monitoring Reasons why supplies are not routinely 40 monitored 50 30 40responses (%) responses (%) 30 20 20 10 10 0 0 18
    19. 19. Development of a National ReferenceFacility for Cryptosporidium: 2010 • National survey of Irish public water supplies • Adopt best practice procedures – Laboratory accreditation • Pilot study of water supplies • Significance of emerging waterborne contaminants • Strategies for service delivery beyond project
    20. 20. National Reference Facility forCryptosporidium • Detection of Cryptosporidium in water – Based on USEPA 1622 • Filtration • Immuno-magnetic separation • Fluorescent antibody • INAB Accreditation – ISO17025 – April 2012 20
    21. 21. Cryptosporidium Reference Laboratory Genotyping • Source of contamination • Public health risk • Catchment protection FITC stained • Water safety plan development for supply Cryptosporidium oocysts• Frontline help in source contamination events or outbreak investigations without need for samples to be sent overseas• Nurture and provide local knowledge and expertise 21
    22. 22. Pilot Scheme - 2011 • Detection and identification of Cryptosporidium species in supplies on RAL • 5 supplies selected • “Type” supplies established – Groundwater under influence of surface water – Pristine upland lake – Spring/Borehole supply 22
    23. 23. Results to datePilot scheme details No samples %Samples submitted 152Positive USEPA 1622 74 48.6Genotyped 46 62.2 23
    24. 24. Type supply:Groundwater under influence of surface water • No barrier for Cryptosporidium • On boil water notice • Previously had one sample genotyped in Scotland – very mixed results – up to 7 different species implicated • No clear idea of source of contamination/ public health risk 25
    25. 25. Type Supply :Groundwater under influence of surface water Date No of Oocysts/10 L Genotype Possible source Public oocysts Health detected Risk March 15 0.19 C. andersoni Uncertain 6 0.3 April 64 0.45 C. parvum High May 3 0.01 ND June 2 <0.01 C. parvum High July 3 0.01 ND August 4 0.01 C. muris No risk September 24 0.11 C. andersoni Uncertain October 55 0.52 C. parvum/ High C.ubiquitum November 24 0.12 C. bovis/C.ubiquitum Uncertain 26
    26. 26. Type Supply: Upland Lake• Town supply - source water upland lake• No barrier for Cryptosporidium• Cryptosporidium detected in 2007 during intense monitoring period – C. parvum detected once in raw water – C. ubiquitum also detected once• EPA audit conducted in 2009 27
    27. 27. Type supply: Upland lake monitoring results Date No of Oocysts/10 L Genotype Possible Public Health oocysts source Risk detected March 3 0.02 ND April 0 <0.01 N/A May 16 0.14 C. ubiquitum Uncertain June 52 0.33 C.ubiquitum/ C. Uncertain xiaoi August 1 <0.01 N/ASeptember 2 <0.01 no amplification October 2 0.01 C. envir genotype ??? No known riskNovember 3 0.01 C. envir genotype ??? No known risk 28
    28. 28. Type supply: Spring/Borehole supply • Spring & Borehole supply • Spring supply located downstream of lake – concern over influence of lake over spring • No barrier for Cryptosporidium • July 2011 - 5 oocyts detected (0.02/10 L) 29
    29. 29. Type supply: Spring/Borehole supply monitoringresults Date No of Oocysts/10 L Genotype Possible Public oocysts source Health Risk detected August 264 2.4 C. ubiquitum Uncertain 30
    30. 30. SUMMARY 31
    31. 31. Cryptosporidium spp. and genotypes inIrish Drinking Water Supplies Cryptosporidium spp. detected No. Samples Possible source Public Health Risk * C. andersoni 14 adult cattle/yearlings Uncertain risk C. ubiquitum 11 deer/sheep Uncertain risk C. parvum 4 preweaned calves/human High risk C. bovis 4 weaned calves No known risk C. environmental genotype 3 unknown No known risk C. ryanae 1 weaned calves No known risk C. muris 1 mouse Uncertain risk C. andersoni / C. bovis mixed 1 calves/yearlings/adult cattle Uncertain risk C. ubiquitum / C. xaoi mixed 1 wildlife/sheep Uncertain risk C. andersoni / C. canis mixed 1 cattle/dog Uncertain risk C. andersoni / C. muris mixed 1 cattle/mouse Uncertain risk C. parvum / C. ubiquitum mixed 1 wildlife/cattle/sheep High risk C. bovis / C.ubiquitum mixed 3 deer/sheep /cattle Uncertain risk Total 46 As described in the UK Environment agency Microbiology of Drinking Water (2009)- Blue Book High risk: Known human pathogen and causative agent of outbreaks Uncertain risk: Isolated from sporadic human cases but pathogenicity uncertain No known risk: No human isolates reported 32
    32. 32. Summary & Conclusions• Drinking water in Ireland particularly vulnerable to Cryptosporidium contamination• Risk of recreational waters?• Humans incidence – Predominant spring peak • C. parvum, C. hominis• Cryptosporidium reference facility established in Ireland – INAB Accreditation – ISO17025 33
    33. 33. Acknowledgements– Carolyn Read– Jenny Pender– Annetta Zintl– Marzieh Mirhashemi– Frances Lucy– Declan Feeney– Hui-Wen Cheng 34
    34. 34. Original illustrations and photographs of Cryptosporidium parvum - Tyzzer, 1912 35

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