Mexico Continues to Investigate Cyclosporiasis Cases in Quintana Roo

CANCÚN, Quintana Roo — Federal health investigators have arrived in Quintana Roo after British authorities reported an increase in cyclosporiasis among travelers returning from Mexico, including people who stayed at all-inclusive resorts in Cancún and the Riviera Maya.

Gov. Mara Lezama said personnel from the Federal Commission for Protection against Sanitary Risks (Cofepris) and Mexico’s General Directorate of Epidemiology were sent to determine whether the travelers were exposed while visiting the state.

“We acted immediately; we spoke with the federal government,” Lezama told reporters. “Today, personnel from Cofepris and Epidemiology are arriving to see what happened, or if it didn’t happen.”

British health authorities recorded 67 cases between April 30 and July 15. Of those patients, 48 reported traveling to Mexico, including one who also visited the United States. The cases involved 30 people in England, 27 in Scotland and 10 in Wales.

Many of the travelers reported stays in Cancún or the Riviera Maya, often at all-inclusive hotels. However, the available information does not establish that all 48 infections originated in Quintana Roo or that a particular hotel, restaurant or food supplier caused them.

Mexico’s Health Secretariat said inspectors would visit establishments identified through the British investigation and examine food-handling procedures and supply records. No Mexican authority had announced the closure of a hotel or restaurant in connection with the cases as of Tuesday.

What is Cyclospora?

Cyclosporiasis is an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis. People become infected by consuming food or water contaminated with the parasite, usually through fecal contamination somewhere in the production or handling process.

The illness is frequently associated with raw produce because foods such as lettuce, fresh herbs, berries and other fruits and vegetables are often eaten without cooking.

The most common symptom is prolonged watery diarrhea, sometimes accompanied by stomach cramps, bloating, nausea, loss of appetite, weight loss and fatigue. Some patients also experience vomiting, body aches or a low-grade fever.

Symptoms usually begin about one week after exposure, but the incubation period can range from two days to more than two weeks. Without treatment, symptoms may last for a month or longer and can disappear before returning.

That delay makes tracing the source difficult. A traveler may eat at several restaurants, hotels or destinations during the two weeks before becoming sick. By the time investigators begin their work, the suspected shipment of produce may already have been consumed or discarded.

Fresh produce may also become contaminated before reaching a hotel or restaurant. An infection linked to a meal served in Quintana Roo would not necessarily mean contamination occurred in the establishment where the food was eaten.

Negative samples do not settle the question

Mexican health officials said testing conducted so far had not detected Cyclospora. That is reassuring, but it does not determine where the British travelers were exposed.

A negative sample collected in August cannot rule out contamination in food served weeks earlier. Investigators will therefore need to compare the travelers’ dates, accommodations, meals and other destinations, looking for common suppliers or foods.

Cyclospora can also be difficult to detect in patients. Routine stool testing may miss it, and doctors must sometimes request a specific test or collect samples on several days.

The parasite does not normally spread directly between people. After leaving the human body, it must mature in the environment for at least one to two weeks before becoming infectious. That makes immediate person-to-person transmission unlikely.

Investigation follows a separate U.S. outbreak

The Quintana Roo review comes as Mexico and the United States investigate a much larger increase in domestically acquired cyclosporiasis in several U.S. states.

U.S. investigators initially identified an epidemiological association with shredded iceberg lettuce. Mexican agencies reviewed the supply chain and collected samples, but Mexico later reported that neither country had detected the parasite in the lettuce samples tested.

Cofepris said the suggested lettuce connection was based on interviews with patients and statistical patterns rather than a positive laboratory result from the produce itself.

Mexico’s health secretary, David Kershenobich, said July 21 that only three cases had been recorded in Mexico and that the number remained within the country’s usual epidemiological range. He said authorities had no evidence of a domestic outbreak.

The U.S. and British cases should not be assumed to have the same source. Investigators will have to establish whether the patients shared a food supplier, type of produce or other exposure.

Advice for travelers and residents

British health officials recommend drinking bottled or properly treated water and choosing thoroughly cooked food served hot. Travelers may reduce their risk by avoiding raw salad leaves, uncooked herbs, berries and fruit that cannot be peeled, even at high-end resorts.

Ordinary chemical sanitizers may not reliably eliminate Cyclospora from contaminated produce. Washing fruits and vegetables remains good food-safety practice, but it cannot guarantee removal of the parasite.

Anyone who develops prolonged or recurring watery diarrhea after traveling should seek medical care and mention their recent destinations and food history. Diagnosis requires a stool test, sometimes using a specialized molecular method.

The preferred treatment is the prescription antibiotic combination trimethoprim-sulfamethoxazole. Most healthy people eventually recover, but treatment can shorten the illness. Patients with weakened immune systems may face a greater risk of prolonged or severe symptoms.

Cofepris and epidemiology personnel are expected to compare the British travel information with hotel records, food suppliers and any illnesses reported locally. Authorities had not identified a common establishment or confirmed a Quintana Roo source as of the latest update.