The U.S. Centers for Disease Control and Prevention (CDC), State and Local Health Departments, and the Food and Drug Administration (FDA) are investigating an increase in reported cases of cyclosporiasis. The purpose of this HAN Advisory is to notify public health departments and healthcare facilities and to provide guidance to healthcare providers of the increase in reported cases. Please disseminate this information to healthcare providers in hospitals and emergency rooms, to primary care providers, and to microbiology laboratories.

Healthcare providers should consider a diagnosis of cyclosporiasis in patients with prolonged or remitting-relapsing diarrheal illness. Testing for Cyclospora is not routinely done in most U.S. laboratories, even when stool is tested for parasites. Healthcare providers must specifically order testing for Cyclospora, whether testing is requested by ova and parasite (O&P) examination, by molecular methods, or by a gastrointestinal pathogen panel test. Cyclosporiasis is a nationally notifiable disease; healthcare providers should report suspect and confirmed cases of infection to public health authorities.

As of August 2, 2017, 206 cases of Cyclospora infections have been reported to CDC in persons who became infected in the United States and became ill on or after May 1, 2017. These cases have been reported from 27 states, most of which have reported relatively few cases. Eighteen cases reported hospitalization; no deaths have been reported. At this time, no specific vehicle of interest has been identified, and investigations to identify a potential source of infection are ongoing. It is too early to say whether cases of Cyclospora infection in different states are related to each other and/or to the same food item(s).

The number of cases (206) reported in 2017, is higher than the number of cases reported by this date in 2016. As of August 3, 2016, 88 Cyclospora infections had been reported in persons who became infected in the United States and became ill on or after May 1, 2016.

A case-control study performed in crew members found that illness was associated with eating items of fresh produce served onboard the ship, but the study was unable conclusively to identify the responsible food(s). It is likely that one or more of the fresh produce items taken onboard at a south-east Asian port during the first cruise was contaminated. If fresh produce supplied to cruise ships is sourced from countries or regions where Cyclospora is endemic, robust standards of food production and hygiene should be applied to the supply chain.