Canada and UK reported 176 Cyclospora cases
Cyclospora cayetanensis was identified in people who travelled to the Riviera Maya region of Mexico between 1 June and 22 September 79 in the UK and 97 in Canada.
This is in addition to the 546 cases from 31 states and 21 hospitalizations between May 1 and August 22, reported by the US Centers for Disease Control and Prevention (CDC).
UK patients were interviewed about travel history, food consumption, clinical symptoms and demography.
Infection source
Of 45 cases for whom food histories were available, 43 consumed fruit or berries, 41 ate salad or vegetables and 35 had fresh herbs.
Specific items mentioned included fresh mint in drinks (15), strawberries or raspberries (9) and coriander (6).
Most cases ate from all-inclusive buffets which included meat and fish products, cheese and desserts. Consumption of bottled water and ice was reported by 39 and 38 cases, respectively.
In the US outbreak, some illnesses were linked to fresh cilantro from Puebla, Mexico.
Local investigation in Mexico suggests fresh cilantro from Puebla had been distributed to hotels in the Riviera Maya region, said the report.
Cases occurred over an extended period and in people who stayed at 32 different hotels on the Riviera Maya coast of Mexico, from Cancun to Tulum.
Between 1 June and 22 September, 79 probable or confirmed case-patients were reported in England (55), Scotland (21) and Wales (3).
Symptom onset dates were available for 62 confirmed or probable cases and ranged from 8 June to 19 August.
Only 43 of the 79 cases diagnosed in local laboratories were confirmed by a reference laboratory.
Cyclospora detection
Cyclospora cases were identified in primary clinical diagnostic and commercial laboratories by microscopy or molecular testing.
Cases were confirmed in reference laboratories using microscopic methods (e.g. examination of a wet preparation by bright field microscopy and, if structures resembling Cyclospora were observed, viewing under UV light for autofluorescence).
Smears were permanently stained using modified Ziehl Neelsen and examined.
Canada has no routine travel surveillance but 97 cases in travellers returning from Mexico were reported from May to August with two people hospitalised.
Public Health Agency of Canada (PHAC) closed its investigation in October as the outbreak appeared to be over.
However, weeks later the Canadian Food Inspection Agency (CFIA) informed of a recall of snap peas due to Cyclospora.
Costco Wholesale Canada Inc. recalled Alpine Fresh brand Snap Peas sold in its stores across Ontario.
It was triggered by a CFIA investigation into a foodborne illness outbreak.
Source: Eurosurveillance, Volume 20, Issue 43, 29 October 2015
“Cyclospora infection linked to travel to Mexico, June to September 2015”
Authors: GL Nichols, J Freedman, KG Pollock, C Rumble, RM Chalmers, P Chiodini, G Hawkins, CL Alexander, G Godbole, C Williams, HA Kirkbride, M Hamel, JI Hawker
