Cyclosporiasis: An Emerging Zoonotic Disease

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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.ht
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Cyclosporiasis

• GI illness
• diarrhea - protracted 6 weeks
• cramps
• dehydration
• bloating
• Constipation
• nausea
• Treatment
• Trimethoprim-sulfamethozaxole (Bactrim)
• Complications if untreated
• Reiters
• Guillain-Barré

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Epidemiology

• Previously known as cyanobacterium-like body
• 1979 1st probable report
• undescribed coccidian in humans in PNG
• (Ashford, Lpool 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)

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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 eventrelated 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 311040-1057
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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

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Cyclosporiasis cases and rates in British
Columbia and Canada
Data Epidemiology Services, BC Centre for
Disease Control
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MICROSCOPY

• Wet mounts examined using
• DIC
• UV fluorescence microscopy (excitation filter
  330-365 nm)

autofluorescence
http//www.dpd.cdc.gov/dpdx/HTML/Cyclosporiasis.ht
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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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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. 173440
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Nested PCR Amplification of the 18S rRNA gene
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18S rRNA Gene Sequence
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18S rRNA Gene Sequence
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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. 5651
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Multiplex PCR for the differentiation of
Cyclospora spp. and Eimeria spp.

• Specificity Primer Sequence Amplicon size (bp)
• C. cayetanensis 5'-GTAGCCTTCCGCGCTTCG-3' 298
• C. cercopitheci, 5'-CTGTCGTGGTCATCTGTCCGC-3 361
  
• C. colobi
• Eimeria spp. 5'-GTTCTATTTTGTTGGTTTCTAGGACCA-3' 17
  4
• 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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Cyclospora cayetanesis

• 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?

• Cant 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?
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