Cyclosporiasis an emerging zoonotic disease
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Cyclosporiasis: An Emerging Zoonotic Disease? . Proposed Life Cycle. Ingested oocysts excyst in GI tract Sporozoites invade small intestinal epithelial cells Asexual forms 2 different sized merozoites type I meronts (8-12 merozoites) type II meronts (4 merozoites) Sexual forms

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Cyclosporiasis an emerging zoonotic disease l.jpg

Cyclosporiasis: An Emerging Zoonotic Disease?


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Proposed Life Cycle

  • Ingested oocysts excyst in GI tract

  • Sporozoites invade small intestinal epithelial cells

  • Asexual forms

    • 2 different sized merozoites

    • type I meronts (8-12 merozoites)

    • type II meronts (4 merozoites)

  • Sexual forms

    • gametocytes

    • zygotes

    • oocysts shed in stools


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Transmission

  • Fecal-oral route

  • Direct transmission from person-to-person UNLIKELY

  • Oocysts need to sporulate before becoming infectious

  • Food or waterborne USUALLY

http://www.dpd.cdc.gov/dpdx/HTML/Cyclosporiasis.htm


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Cyclosporiasis

  • GI illness

    • diarrhea - protracted ~ 6 weeks

    • cramps

    • dehydration

    • bloating

    • Constipation

    • nausea

  • Treatment

    • Trimethoprim-sulfamethozaxole (Bactrim)

  • Complications if untreated

    • Reiter’s

    • Guillain-Barré


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Epidemiology

Previously known as cyanobacterium-like body

1979: 1st probable report

  • undescribed coccidian in humans in PNG

  • (Ashford, L’pool Sch Trop Med, Ann Trop Med Parasitol)

    1989: Expatriates in Nepal

  • (Shlim et al, 1991, Am J Trop Med Hyg)

    1993: Study on Peruvian cases (Ortega et al, NEJM)

    1994: New species designation (Ortega et al, J Parasitol)

  • Reports on travel-related cases

    • Australian traveller to Bali, Indonesia (Butcher et al, 1994)

    • US travellers to Mexico or Thailand (Berlin et al, 1994)

    • Bangladesh cases (Albert et al, 1994)


  • Cyclosporiasis outbreaks waterborne l.jpg
    Cyclosporiasis OutbreaksWaterborne

    • 1990 Chicago hospital

      (Huang et al, 1995, Ann Intern Med)

      • cluster of 21 cases

      • associated with tap water in physicians’ dormitory

    • 1994 British soldiers in Nepal

      (Rabold et al, 1994, Lancet)

      • 12 cases

      • Cyclospora oocysts detected in water specimen from storage tank


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    Cyclosporiasis OutbreaksFoodborne

    • 1996 USA / Canada

      Herwaldt & Ackers 1997 NEJM

      • 1,465 non-travel cases

      • 20 US states + DC

      • 2 Canadian provinces

        • Ontario - 36 cases

        • Quebec - 3 cases

      • 55 event–related clusters

      • Associated with Guatemalan raspberries


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    More Foodborne Outbreaks

    Year & Location Cases Vehicle

    1997 Florida 93 mesclun lettuce

    1997 US/Ontario 1,012 raspberries

    1997 Wash., DC 341 basil

    1997 US bans Guatemalan raspberries

    1998 Ontario 315 raspberries

    1998 Canada bans Guatemalan raspberries

    1999 Florida 94 berries

    1999 Ontario 104 blackberries

    1999 Missouri 64 basil

    Herwaldt 2000 Clin Inf Dis 31:1040-1057


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    Cyclosporiasis outbreaks in British Columbia (BC)

    Location Date Cases Association

    L. Mainland Jul 1999 15 Unknown

    Vancouver May 2001 17 Thai basil

    L. Mainland Jul 2003 11 Cilantro

    L. Mainland Jun 2004 18 Cilantro


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    Cyclosporiasis

    • North American outbreaks associated with the consumption of imported fruits and vegetables

    • A reportable communicable disease

    • 1999 - British Columbia

    • 2000 - Canada


    Cyclosporiasis cases and rates in british columbia and canada l.jpg
    Cyclosporiasis cases and rates in British Columbia and Canada

    Data: Epidemiology Services, BC Centre for Disease Control


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    refractile globules

    MICROSCOPY

    Wet mounts examined using:

    • DIC

    • UV fluorescence microscopy (excitation filter 330-365 nm)

    autofluorescence

    http://www.dpd.cdc.gov/dpdx/HTML/Cyclosporiasis.htm


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    Cyclospora sp. in Animals?

    Reported in:

    • Duck Peru Zerpa et al, 1995

    • Chickens Mexico García-López et al, 1996

    • Dogs Brazil Yai et al, 1997

    Absent in:

    • Domesticated animals, Haiti Eberhard et al, 1999

      • Livestock - pigs, cattle, horses, goats

      • Poultry - chicken, ducks, turkeys

      • pigeons

      • Companion animals - dogs, cats, guinea pigs

    • Dogs Brazil Carollo et al, 2001


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    Cyclospora sp. in Primates

    Reported in:

    • Baboons Tanzania Smith et al, 1996

      Lopez et al, 1999

    • Baboons / Monkeys Eberhard et al, 1999

      Ethiopia

    • Primates Kenya Eberhard et al, 2001


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    CYCF1E1

    CYCF3E1

    18S rRNA

    ITS1

    5.8S rRNA

    CYCR4B1

    CYCR2B1

    MOLECULAR METHODS

    • Nested PCR: conserved 18S rRNA gene

    • Diagnostic marker for Cyclospora cayetanensis

    • Cross-reacts with Eimeria tenella

    1Relman et al. (1996) J.Inf.Dis. 173:440





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    Quartet puzzling maximum likelihood tree

    18S rRNA gene sequences of Cyclospora and Eimeria species

    Outgroup: Toxoplasma gondii

    Eberhard et al (1999) Emerg. Inf. Dis. 5:651


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    Multiplex PCR for the differentiation of Cyclospora spp. and Eimeria spp.

    Specificity Primer Sequence Amplicon size (bp)

    C. cayetanensis5'-GTAGCCTTCCGCGCTTCG-3'298

    C. cercopitheci, 5'-CTGTCGTGGTCATCTGTCCGC-3‘ 361

    C. colobi

    Eimeria spp. 5'-GTTCTATTTTGTTGGTTTCTAGGACCA-3'174

    Common 5'-CGTCTTCAAACCCCCTACTGTCG-3'

    reverse primer

    Orlandi et al, Appl Env Mic (2003), 69(8):4806


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    Multiplex PCR

    Specificity

    Sensitivity

    Orlandi et al, Appl Env Mic (2003), 69(8):4806


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    Cyclosporacayetanesis

    • Absence in Haitian domestic animals

    • Different Cyclospora species in primates

      NOT A ZOONOTIC PATHOGEN!

      REALLY?


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    C. cayetanensis in Nepal

    Monkeys 1/3

    Dogs 2/14

    Chickens 1/3

    Chu et al., Am.J.Trop.Med.Hyg. (2004) 74(4):373-9


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    Animal Reservoirs?

    Can’t confirm

    • Infections?

      OR

    • Human fecal material passing through?

      • Coprophagic feral animals

      • Poor sanitary conditions

      • Contamination of feed


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    Future Work Required

    • Check animal scats for Cyclospora sp. oocysts

    • Confirm by molecular methods that species is C. cayetanensis

    • Perform tissue biopsies in animals shedding C. cayetanensis oocysts to determine if infections are really present


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    Questions?

    Photo: Jean Ryder / DHD Multimedia Gallery

    http://gallery.hd.org