Thousands of people across the United States have been infected with Cyclospora cayetanensis, a parasite that can cause prolonged diarrhea, stomach cramps, nausea and fatigue. As health officials investigate the growing outbreak, some experts and members of the public are asking if government cuts to public health have hampered the investigation.
The outbreak is growing rapidly, with Michigan reporting more than 2,600 cases and illnesses reported across over 30 states. Yet investigators have not yet identified a confirmed source, or sources of the contamination.
“The lack of information on possible sources for the outbreak is frustrating,” said Craig Hedberg, PhD, professor of Environmental Health Sciences, School of Public Health at the University of Minnesota. “It is normal for public health and regulatory officials to be somewhat guarded with information about potential sources of contamination while the investigation is ongoing. This may be necessary to provide opportunities to trace possible sources of contamination.”
The difficulty of the investigation has renewed debate over recent cuts to foodborne disease surveillance and public health funding by the current U.S. government on both the state and federal level.
“Have the funding cuts to public health impacted the current activities related to the Cyclospora outbreak? I think they have,” said Barbara Kowalcyk, PhD, director of the Institute for Food Safety and Nutrition Security at George Washington University, quoted in The Guardian.
Kowalcyk explained that staffing limitations can affect the speed of investigations, particularly when investigators need to interview patients about possible exposures. Delays can make it more difficult to identify common exposures because patients may struggle to remember what they ate weeks earlier, and contaminated food may no longer be available for testing.
“It’s like putting a puzzle together. You start taking pieces out of your puzzle – it’s harder to see the whole picture, and that’s what we’ve done. We’ve taken pieces out of the whole puzzle,” Kowalcyk said.
The debate centres in part on cuts to the CDC’s Foodborne Diseases Active Surveillance Network (FoodNet), one of the country’s key systems for monitoring foodborne illness trends. Established in 1996, FoodNet is a collaboration between the CDC, state health departments, the U.S. Department of Agriculture and the Food and Drug Administration. It conducts active surveillance across selected sites to estimate the burden of foodborne infections, track changes over time and provide data that help guide prevention efforts.
In 2025, the CDC announced changes to FoodNet surveillance protocols that narrowed the number of pathogens under active surveillance. While FoodNet continues to monitor some major foodborne pathogens, including Salmonella and Shiga toxin-producing E. coli (STEC), active surveillance requirements for eight other pathogens including Cyclospora were reduced. The changes have prompted concern among some experts that fewer resources dedicated to tracking foodborne diseases could weaken the country’s ability to identify emerging trends and respond quickly to outbreaks. However, others warn that linking the scale of the current outbreak and current unresolved nature to recent changes at the CDC requires caution.
“FoodNet is not intended to detect outbreaks, and many multistate outbreaks, such as the current Cyclospora outbreak, primarily affect states that are not part of FoodNet,” said Hedberg.
Hedberg said that Cyclospora surveillance itself has not been reduced as a result of changes to FoodNet, because the parasite remains a nationally reportable disease.
“That means that as cases are reported to individual state and local health departments, they forward information about the number of cases reported to CDC through the Nationally Notifiable Disease Surveillance System (NNDSS). Surveillance for Cyclospora through NNDSS has not changed as a result of changes to FoodNet surveillance protocols,” said Hedberg.
According to Hedberg, outbreak detection relies on a broader network involving state health departments, laboratories and federal agencies.
“CDC has a team that tracks the number of cases of Cyclospora that are reported, and when they detect an unusual increase in reports, or when a state reports a potential outbreak, they will help coordinate an investigation to determine the source of the outbreak,” he said.
But CDC reporting is not keeping up with the fast-pace of this outbreak, with the most recent published case count at the CDC being 843, last updated on July 10th. Case counts confirmed in Michigan alone are approximately 2,600.
“National counts of cases frequently lag individual counts from states due to delays in confirming, forwarding and processing information. This is not optimal for providing timely updates in the context of an ongoing investigation, and is frustrating for the public health community as well as the public,” said Hedberg.
Despite not being designed to detect outbreaks, Hedberg acknowledged that reductions to FoodNet still have consequences for understanding foodborne disease trends over time.
“FoodNet plays an important role in national foodborne disease surveillance by providing consistent, comprehensive surveillance for a group of important foodborne pathogens. This allows us to monitor long-term trends in the occurrence of these diseases and to estimate the overall burden of illness they cause,” said Hedberg.
Beyond questions about surveillance, investigators face significant scientific challenges in identifying the source of the current Cyclospora outbreak. Unlike some bacterial foodborne illnesses, Cyclospora has a relatively long incubation period, meaning people may become sick days or even weeks after exposure and may not immediately connect their illness with a specific meal.
“Another complicating factor is that many fresh produce items are combined at the restaurant level before being served to customers,” said Hedberg. “Disentangling what ingredient that may appear with several others in multiple food items is challenging. It is also possible that there could be multiple sources of contamination contributing to the number of cases nationwide. It is important to provide as much information as possible to narrow the list of potential fresh produce sources that may be linked to this outbreak.”
The CDC has been contacted and asked for comment on this topic.
