Overview

• A Journal of Infectious Diseases study found that over 90 percent of sampled game fish, including largemouth bass and bluegill, harbored at least one of two trematode flatworms, Haplorchis pumilio or Centrocestus formosanus.
• The parasites likely arrived in the U.S. more than a decade ago via invasive red-rimmed melania snails and can cause gastrointestinal issues, weight loss, lethargy, and, in rare cases, strokes or heart attacks.
• In 2023, researchers dissected 84 fish across seven species from five popular San Diego County fishing locations and discovered some individual fish carried thousands of parasite larvae.
• A survey of 125 social-media videos with nearly 5 million views revealed that 65 percent omitted advice on cooking or freezing freshwater fish, potentially increasing consumers’ risk of infection.
• The authors recommend adding fish-borne trematode infection to the list of diseases doctors must report and sharing findings with local public health officials to improve monitoring and awareness.