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Parasitic Worms

There are many different kinds of parasitic worm infections that can impact human health. The life cycles and transmission of these worms varies greatly, and is often complex. Some kinds of worm infections, such as cysticercosis, are specifically reportable to the Section of Epidemiology, while others are not. Healthcare providers and patients are encouraged to report clusters of parasitic worm infections or unusual infections, regardless of species.

This page is divided into three sections:
More information is provided in each section.

Fish Worms 

There are two important kinds of human infection from worms in fish. One is the fish tapeworm group, Diphyllobothrium species. Diphyllobothrium infections must be reported to the Section of Epidemiology. These infections are acquired by eating raw or undercooked infected fish.

The second kind of worm infection from fish is called anisakiasis, which is caused by fish roundworms from the Anisakis genus. Anisakiasis infections are caused by eating raw or undercooked seafood. It’s not required to report anisakiasis to the Section of Epidemiology, but it can be helpful for us in case of other reports.

Occasionally, people will notice a worm in a meal of fish or seafood. While upsetting, this is only a concern if the fish has not been cooked thoroughly. If you think you may have swallowed a worm and are concerned, consider seeing a healthcare provider. If the meal in question was eaten at a restaurant, you can file a complaint by calling (907) 269-8000 or emailing infdisease@alaska.gov.

Resources for the General Public

Resources for Healthcare Providers

Required Reporting Worms 

In addition to Diphyllobothrium species discussed above, there are three other types of worm infections that must be reported to the Section of Epidemiology. These are echinococcosis, cysticercosis, and trichinellosis.

Echinococcosis is infection with tapeworms from the Echinococcus genus. These worms are found in dogs, as well as other animals. The life cycle of these worms is complex, but infection generally arises from ingesting the eggs of the worm, which are excreted in the feces of infected dogs and other canines.

Cysticercosis is a special type of tapeworm infection where the tapeworm infects tissue outside of the intestines. It is caused by ingesting the eggs of the Taenia solium pork tapeworm, which are excreted in the feces of people who have the tapeworm living in their intestines.

Trichinellosis (also called “trichinosis”) is an infection with a roundworm called Trichinella. Trichinellosis is spread by eating raw or undercooked meat. Game meats, such as bear, and marine mammals like walrus and seals are particularly high-risk for carrying the Trichinella worm and should always be cooked thoroughly.

Resources for the General Public

Resources for Healthcare Providers

Other Parasitic Worms 

There are many common parasitic worm infections that the Section of Epidemiology doesn’t formally track, such as pinworm infections and swimmer’s itch. Most of these conditions can be treated easily at home. However, if there is concern about an outbreak, the Section of Epidemiology is able to investigate and make recommendations to prevent additional illness.

Resources for the General Public

Download a snapshot of five year disease activity for select diseases in Alaska.

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