Fish Parasites – Will Cold Smoking Kill Them?

September 11, 2014

Question: I recently caught a number of trout that had what I believe to be parasites called “Lernaea” attached to them in various places. I know after reading another posting from this column titled “Parasites and Trout” that these “are killed during cooking, effectively eliminating any possibility of infecting humans eating the fish,” but I am considering smoking them. Would these parasites pose any threat if the trout were cold smoked rather than cooked, or would the curing that takes place eliminate any threat as well? Presumably if they were hot smoked there would be no threat because the fish are then cooked. I appreciate any info you can provide. Thanks. (Keith R.)

Answer: First off, Lernea and other external parasitic copepods of fish are not transmissible to humans.

As far as fish brining and smoking (even hot smoking), according to Dr. William Cox, California Department of Fish and Wildlife (CDFW) Program Manager of Fish Production and Distribution, there are other parasites that warrant more serious consideration, such as anasakine nematodes and human tapeworms. These parasites are not reliably killed by brining, smoking or even freezing. The only way to ensure they are killed is to thoroughly cook your fish. Generally, we are not worried about those parasites in freshwater fish caught in California. But, nematodes are a concern and they are commonly found in saltwater fish of all species.

For any additional questions related to human health issues, please contact the California Department of Public Health www.cdph.ca.gov.

This is why I'm not a fan of eating raw fish!  Thanks for the link Howard.