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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proposed life cycle
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
transmission
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

cyclosporiasis
Cyclosporiasis
  • GI illness
    • diarrhea - protracted ~ 6 weeks
    • cramps
    • dehydration
    • bloating
    • Constipation
    • nausea
  • Treatment
    • Trimethoprim-sulfamethozaxole (Bactrim)
  • Complications if untreated
    • Reiter’s
    • Guillain-Barré
epidemiology
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
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
cyclosporiasis outbreaks foodborne
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
more foodborne outbreaks
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

cyclosporiasis outbreaks in british columbia bc
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

cyclosporiasis10
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
Cyclosporiasis cases and rates in British Columbia and Canada

Data: Epidemiology Services, BC Centre for Disease Control

microscopy

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

cyclospora sp in animals
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
cyclospora sp in primates
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
molecular methods

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

slide19
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

multiplex pcr for the differentiation of cyclospora spp and eimeria spp
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

slide21

Multiplex PCR

Specificity

Sensitivity

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

cyclospora cayetanesis
Cyclosporacayetanesis
  • Absence in Haitian domestic animals
  • Different Cyclospora species in primates

NOT A ZOONOTIC PATHOGEN!

REALLY?

c cayetanensis in nepal
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

animal reservoirs
Animal Reservoirs?

Can’t confirm

  • Infections?

OR

  • Human fecal material passing through?
    • Coprophagic feral animals
    • Poor sanitary conditions
    • Contamination of feed
future work required
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
questions

Questions?

Photo: Jean Ryder / DHD Multimedia Gallery

http://gallery.hd.org