Up to 176 travelers from the UK and Canada contracted the parasitic infection, Cyclosporiasis, while on holiday in the Riviera Maya region of Mexico this summer, according to Eurosurveillance report last week.

Cyclospora/CDC
Cyclospora/CDC

Cyclospora cayetanensis was identified in 176 returned travelers from the Riviera Maya region of Mexico between 1 June and 22 September 2015; 79 in the United Kingdom (England, Scotland, Wales) and 97 in Canada.

In the UK, between 1 June and 22 September 2015, 79 probable or confirmed case-patients (hereafter called cases) were reported in England (n = 55), Scotland (n = 21) and Wales (n = 3).

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. A formal epidemiological study was not therefore possible. Questionnaires were completed for 46 of 79 cases, with 43 reporting all-inclusive catering, of whom 24 (56%) reported also eating outside their hotel.

Of 44 cases with symptom details recorded, all had diarrhea (range: 5–62 days; mean: 16 days) which was rapid onset in 30. Other symptoms included abdominal pain (n = 35), fatigue (n = 31), nausea (n = 27), vomiting (n = 24), fever (n = 19), weight loss (n = 19) and headache (n = 17). There were no hospitalizations or deaths.

Of 45 cases for whom food histories were available, 43 consumed fruit or berries, 41 consumed salad or vegetables and 35 consumed fresh herbs. Specific items mentioned by cases included fresh mint in drinks (n = 15), strawberries or raspberries (n = 9) and coriander (n = 6). Most cases ate from all-inclusive buffets which also included a number of meat and fish products, cheese and desserts.

A similar increase has also been noted in Canada: while Canada has no routine travel surveillance, 97 cases of Cyclospora infection in travelers returning from Mexico were reported from May to August 2015; the cases reporting staying at various resorts in the same geographical area as the UK cases.

Drinking water was an unlikely source as several different water networks supply the resorts (some hotels have their own borehole and treatment). Geographical and temporal associations suggest that the outbreak was related to a consumed product(s) distributed throughout the region rather than hygiene deficiencies in individual hotels.

A multistate outbreak of cyclosporiasis has also occurred in the US, during the same period in which fresh cilantro from Puebla, Mexico has been implicated as the cause of cluster-associated cases in three US states. Local investigation in Mexico suggests fresh cilantro from Puebla had been distributed to hotels in the Riviera Maya region.

Cyclospora cayetanensis is a single celled coccidian parasite that is endemic in the United States and Canada.

The parasite causes watery diarrhea, nausea, anorexia, abdominal cramps and weight loss. Fever is a rare symptom.

People get infected with Cyclospora through foodborne or waterborne means. Swimming in contaminated water is also a way someone can get infected.

Cyclospora has been implicated in numerous outbreaks in North America with contaminated fruits and vegetables being the common culprits (raspberries, basil and lettuce all washed with contaminated water), especially those imported from developing nations.

All fruits and vegetables should be thoroughly washed before eating though this does not guarantee safety. Cyclospora is resistant to chlorination.

Treatment is usually successful after a course of the antibiotic Septra. Patients with HIV or otherwise immunocompromised usually require higher dosages for a longer period of time. Untreated infections can last from a few days to over a month.