UK reports Cyclospora increase for third year in a row
From the beginning of the year to 19 July, 58 cases were reported.
Cases were equally distributed among females and males, mostly between 20 and 50 years old. No children under 15 were reported.
Cyclospora
Cyclospora infection causes watery diarrhoea, nausea, loss of appetite and abdominal cramps, within two to 14 days after the ingestion of sporulated oocysts (the infective form of the parasite).
The parasite is most common in tropical and subtropical regions such as the Caribbean, South and Central America, South and South East Asia, the Middle East and Africa.
In the US, Europe and Australia, outbreaks are usually linked to fresh produce such as raspberries, basil, snow peas/sugar snap peas and salad.
Information on travel history is known for 38 patients: 23 travelled to Mexico, 10 to a range of other overseas destinations and five did not travel abroad.
Mexican history
In 2016, the UK had 440 cases of cyclosporiasis between June and October, 359 of whom travelled to Mexico, mostly the Riviera Maya and Cancun regions.
The year before, 79 UK cases associated with travel to Mexico were reported. Food histories suggested cases had consumed fresh foods including fruits, herbs and salads.
Cyclosporiasis is not a mandatory notifiable disease in most EU/EEA countries.
Belgium reported four cases in 2017, three of whom had a travel history to Mexico.
In August 2016, France had six confirmed and three probable cases in July and August in travellers from Mexico.
The European Centre for Disease Prevention and Control (ECDC) said in previous years, most cases appeared to acquire the infection by eating contaminated food items.
“The considerably lower number of cases reported by other EU countries compared to the UK is likely due to differences in testing and surveillance," said the agency.
“Although readily detectable by microscopy using special staining techniques for coccidia, the possibility of a Cyclospora diagnosis is often neglected and identified only in more severe patients after repeated samples are tested.
“Although Cyclospora oocysts can be detected by examining stool specimens by microscopy using special staining (modified acid-fast or safranin) or fluorescence microscopy, the diagnosis is easily missed when screening algorithms are not followed. Cyclospora oocysts can be distinguished from those of Cryptosporidium based on cellular shape and diameter size.
“The risk from Cyclospora infection amongst travellers to Mexico remains high due to the lack of confirmation of suspected vehicles and related control measures.”
US and Canada infections
Texas authorities reported a spike in illnesses caused by the parasite Cyclospora with 68 cases between June and July this year.
Past US outbreaks have been associated with imported fresh produce, including fresh pre-packaged salad mix, raspberries, basil, snow peas and mesclun greens. Texas has had multiple outbreaks linked to cilantro.
The Texas Department of State Health Services recommends washing fresh produce but warned it might not eliminate risk because Cyclospora can be difficult to wash off. Cooking will kill the parasite.
In 2016, 384 cases were reported in the US and the year before 546 confirmed cases were from 31 states. Most of these did not have a travel history within two weeks before disease onset.
The Public Health Agency of Canada is investigating locally acquired Cyclospora infections in two provinces. The source has not been identified.
A total of 57 cases have been reported in British Columbia (5) and Ontario (52). Individuals became sick between May and June this year.
PHAC said Cyclospora infections can be prevented by ensuring consumption of fresh produce grown in countries where the parasite is not common, such as Canada, the US and European countries.
In 2015, 97 infections were reported in five provinces and last year 87 cases came from four provinces. For both years, the main affected region was Ontario.
