Feed the Future
This project is part of the U.S. Government's global hunger and food security initiative.

Parasites: Hazardous for Health and Commerce?

This is the third post in an ongoing series with USAID's Dr. Barakat Mahmoud sharing a few case studies from real life outbreaks and inviting Agrilinks readers to weigh in on a key question related to each. Read the second installment here and post a comment below!

There are thousands of parasites. However, less than a hundred can infect people through contaminated food. According to 2015 World Health Organization estimates, parasites are responsible for approximately 17 percent of all foodborne illnesses worldwide. The most associated parasite hazards with foodborne illnesses are Giardia spp., Entamoeba histolytica, Helminths, Ascaris spp., Taxoplasma gondii and Cryptosporidium spp., causing approximately 28, 28, 13, 12, 10 and 8 million illnesses, respectively. Cyclospora is also an important food safety parasite which has not been included in the WHO’s estimates.


Case Study: Cyclospora Coyetanenis Associated With Guatemalan Raspberries

One of the most unforgettable parasite outbreaks happened in 1996, when more than 1,400 cases of cyclosporiasis were recorded in the United States and Canada. Initially, the outbreak was mistakenly linked to California strawberries, and California strawberry growers lost more than $20 million in 1996 as a result. Later, a traceback investigation conducted by the U.S. Food and Drug Administration (FDA) indicated that the source was contaminated raspberries imported from Guatemala. The Guatemala Berry Growers Organization (GBGO) did not accept the FDA claim because it was based on epidemiology without physical evidence, so they responded slowly to the outbreak.

A year later, another large outbreak in the U.S. and Canada took place linking back to the Guatemalan raspberries. Upon the advice of the FDA, the Centers for Disease Control and Prevention, and Health Canada, the GBGO voluntarily stopped exporting raspberries to the U.S. Later, the GBGO developed a system that only allows low-risk farms to export to the U.S. However, there was no enforcement mechanism or traceability system in place to see this through. Therefore, the FDA issued an import alert, denying all Guatemalan raspberry entries into the U.S.

In response, the Guatemalan government and the GBGO developed a mandatory food safety and traceability program, whereby farmers must pass frequent Guatemalan government inspections and FDA audits. In 1999, the U.S. only allowed entries for raspberries produced under this program. Based on the traceability system, the FDA was able to determine that outbreaks associated with Cyclospora in 1999 were not associated with Guatemalan raspberries.

However, in 2000, two outbreaks were traced back to a farm in Guatemala. This farm was immediately removed from the food safety and traceability program and from exporting to the U.S. The Guatemalan raspberry industry struggled to recover from the negative publicity of all these outbreaks. In 2001, Guatemalan raspberry exports to the U.S. were slashed by more than 80 percent. Export of blackberries was also down by 50 percent that year. As a result, the Guatemalan food industry lost millions of dollars.

What are some of the key takeaways for stakeholders in developing countries from this case study? Do you know of any similar parasite outbreaks associated with food from or within developing countries that you can share with us?