Tapioca disease in pink salmon

Ocean / Sea

Fish

Safety

Food Security

Deformity / Disease / Injury

One Health

Kelsey Bay

Nearby

White cysts in the muscle of salmon could be caused by Henneguya salminicola also called "tapioca disease". It affects the texture of the meat but is not a health concerns for people. White cysts could also however, be from a tape worm. That is a human health concern. Guidance on how to check the cysts to confirm and how to prepare food so it is safe to eat, is provided.

Observation by Jordan Brubacher:

The first salmon I caught this year had what appears to be tapioca disease. So far it's the only one we've seen this year, and we did not see it at all last year.

LEO Network says:

Thank you for your observation Jordan. LEO Network has forwarded this post for a consult to the Fish Pathology Laboratory at the Alaska Department of Fish and Game and our partners at the First Nations Health Authority for consultation and assistance with identification. White cysts are likely Henneguya, but can also be the white nodules that contain tapeworm cysts.

In a previous post we received a consult from Ted Meyers at ADFG. Ted wrote, "in general (cysts) are better diagnosed by breaking them open--if a white, milky fluid oozes out (parasite spores), then it is likely Henneguya. However, the larger nodules could also be containing tapeworm cysts, instead, a plerocercoid larva that would be visible only if the cysts were opened."

This is the first observation of tapioca disease we have seen this year. That said, we have several observations about this disease in LEO Network, often coupled with questions about the safety of consuming fish that have this infection. Tapioca disease is caused by the parasite Henneguya zschokkei also know as or Henneguya salminicola. You can read more about this interesting endo parasite in the Wikipedia link (attached). According to the reference (attached) Disease of Wild and Cultured Fish in Alaska, "Although the cysts in the flesh are unsightly when present in large numbers, there are no human health concerns associated with Henneguya." We asked Jayde Ferguson at ADFG Fish Pathology Lab about henneguya and tape worms and he provided the following comments:

Comments by Jayde Ferguson:

This could be Henneguya, but as Ted has previously pointed out, one of the cysts should be punctured to determine if it contains a white liquid instead of a worm. The best method (if it is tape worm) is to freeze the fish at -20C (-4F) for 7 days. It could then be thoroughly cooked as an added precaution or prepared other ways. Attached is an older FDA guidance document that lists the control methods for parasites in fish.