The US is currently battling a growing Cyclospora outbreak in the states. According to researchers, this is the largest outbreak of its kind in the country’s history and health officials have not yet been able to identify the source. Since May 1, 1,645 infections with the parasite have been confirmed in 45 states and more than 5,100 other cases are under investigation.These figures exceed the total number of cases typically seen in a year, according to Joel Barrett, a molecular parasitologist at the Emory School of Medicine in Atlanta, Georgia. More than 100 people with parasitic infections have been hospitalized, but no deaths have been reported.
What is Cyclospora and how does it affect people?
The main symptom is watery diarrhea as the parasite inflames the intestinal lining
According to the journal Nature, Cyclospora cayetanensis is an intracellular parasite, meaning it invades the host’s cells and then hijacks them, specifically in the intestinal lining. Once inside, it starts growing rapidly, which damages the cells. It may take a week or more for the parasite to complete its life cycle and cause enough damage for symptoms to appear.Getting the infection means that someone has consumed food or water contaminated with human feces. Cyclospora cayetanensis reproduces through egg-like structures called oocysts that are shed in human feces. These oocysts are not immediately infectious: they must first germinate or mature in a warm environment at temperatures between 22 °C and 32 °C for a week or two, which is one reason why outbreaks occur during summer.The main symptom is watery diarrhea as the parasite inflames the intestinal lining and disrupts the body’s ability to absorb water and nutrients, causing excess fluid to pass out through the intestine. While the infection runs its course when the immune system expels the parasite from the body, the illness can last for weeks or even months.The main treatment that doctors use to fight the parasite is the combined antibiotic trimethoprim-sulfamethoxazole (sold as Bactrim). Antibiotics are not normally used against parasites, but Bactrim deprives Cyclospora of an essential vitamin it needs to replicate.
How are researchers trying to trace the origins of the outbreak?
Health officials are still working to identify the source, but the state of Michigan, which has reported the most infections at 4,300, has indicated that lettuce or salad greens may be the culprit. On Thursday, the U.S. Food and Drug Administration identified iceberg lettuce harvested from a supplier in Mexico that was shipped to Taco Bell locations in five states as a source of the outbreak, but it’s likely that other food sources are also spreading the disease.Tracking the parasite requires coordination between US state and federal health officials. First, state laboratories collect stool samples from people with symptoms of the disease and send them to federal facilities. If a sample tests positive for Cyclospora, health officials will track when the person started showing symptoms and record what the person had eaten in the weeks beforehand.
How can you survive the infection?
Produce is safest when heated to 158°F degrees or higher, which actually kills Cyclospora.
The best way to prevent illness is to follow standard hygiene and food safety practices. It is important to wash hands with soap and water after using the bathroom and before and after preparing food, as alcohol-based hand sanitizers do not kill Cyclospora; However, soap and water do. Cleaning the product with vinegar has been more effective than running water alone. Produce is safest when heated to 158°F degrees or higher, which actually kills Cyclospora.
Foods to Avoid During Cyclospora Infection
Because Cyclospora is embedded in leafy, delicate, and wet surfaces, previous outbreaks have been linked to:
- Leafy vegetables: Bagged lettuce, spinach, iceberg, and romaine lettuce.
- Fresh Herbs:
Cilantro Parsley, and basil. - Berries: Raspberries, blackberries and strawberries.
- Raw vegetables: snow peas, green onions, carrots, and celery.
According to the CDC, the typical Cyclospora season lasts until the end of August, and cases may continue to rise until then.