The Public Health Agency of Canada (PHAC) said the 51 cases come from British Columbia (1), Alberta (2), Ontario (44), and Quebec (4).
The source has not been identified but imported fresh produce are ‘items of interest’, it added.
Public Health England (PHE) has reported 265 cases in the UK since June 1 and up to 12 August of which 193 (73%) were associated with travel to Mexico (travel history is pending for other cases).
A total of 193 (87 in England, 94 in Scotland and 12 in the rest of the UK) travelled to Mexico.
Cases stayed at 24 different hotels and resorts in Mexico, but predominantly on the Riviera Maya coast between Cancun and Tulum. Females represent 54% of cases and the range of ages affected is 12-76 (although most are adults).
The Texas Department of State Health Services (DSHS) said at least 55 cases had been reported within the last month.
The US Food and Drug Administration (FDA) said it is monitoring the situation.
The Import Alert for fresh cilantro from Puebla, Mexico remains in effect from April 1 through August 31 of every year because the Centers for Disease Control and Prevention (CDC) and state public health officials identified annually recurring outbreaks (in 2012, 2013, and 2014) of cyclosporiasis associated with fresh cilantro from the state of Puebla, Mexico.
The CDC said at this point the Texas investigation is at the local/state level and directed us to the Texas DSHS.
Canadian illnesses
Cyclospora is a microscopic single-celled parasite that is passed in people's feces. If it comes in contact with food or water, it can infect the people who consume it.
The parasite is most common in countries such as Peru, Cuba, India, Nepal, Mexico, Guatemala, Southeast Asia and Dominican Republic.
In Canada, non-travel related illnesses occur more frequently in the spring and summer months.
Individuals became sick between May and July. The majority are male (51%), with an average age of 49 years and one case was hospitalized.
Previous outbreaks in Canada and US have been linked to imported fresh produce, such as pre-packaged salad mix, basil, cilantro, raspberries, blackberries, mesclun lettuce and snow and snap peas.
Washing produce does not always get rid of the Cyclospora parasite that causes the illness.
“You can reduce your risk by cooking produce imported from countries where Cyclospora is found; and consuming fresh produce grown in countries where Cyclospora is not common, such as Canada, the United States, and European countries,” said PHAC.
PHE outbreak investigation
PHE said the infection is diagnosed by testing of stool samples, and although most cases resolve on their own, antibiotics can treat severe or prolonged infections.
Dr Vanessa Field, deputy director of the National Travel Health Network and Centre (NaTHNaC), said travellers to tropical or subtropical countries must follow good food and water hygiene advice at all times, even if staying in high-end, all-inclusive resorts.
“Avoid buffets and choose recently prepared, thoroughly cooked food that is served piping hot. Avoid fresh uncooked berries or unpeeled fruit and any salad items not washed in safe water. Remember that drinks may also contain uncooked herbs, vegetables or fruit.”
Cases were equally distributed between males and females, with the range of ages affected being 12-76. Travellers returning to Scotland accounted for 98 of the cases.
A similar increase in travellers returning from Mexico was detected last year, with 79 cases reported in UK travellers between 1 June and 22 September.
Typically, around 30 cases occur each year in the UK, with various tropical and subtropical countries of travel reported.
In 2015, there was a multistate outbreak in the US in which fresh cilantro (coriander) from Puebla, Mexico, was implicated as the cause of cluster-associated cases in three states, outbreaks in Texas in 2013 and 2014 having also been associated with Mexican salad products.