Trichinosis: Symptoms, Causes & Treatment

Trichinosis is a parasitic infection caused by Trichinella spiralis, a parasite that can be found in raw or undercooked pork or wild game, such as wild boar. It can happen when these meats are eaten raw or not cooked thoroughly.

This infection can first cause gastrointestinal symptoms such as nausea, vomiting, diarrhea, and abdominal pain. If trichinosis is not treated, it can progress and lead to delayed symptoms.

Trichinosis can be cured with proper treatment using antiparasitic medications such as albendazole. Treatment may also include pain relievers to reduce pain and discomfort, as prescribed by a primary care provider or infectious disease specialist.

Trichinosis symptoms

The main symptoms of trichinosis are divided into two stages:

1. Initial symptoms

The first symptoms of trichinosis include:

• Abdominal pain

• Diarrhea

• Nausea and vomiting

• Fatigue

The first symptoms of trichinosis can appear a few days after eating raw or undercooked meat. Symptoms may be mild or severe, depending on the number of parasites ingested.

These symptoms can last up to 8 weeks. When they are mild, they may be mistaken for the flu and go away without treatment.

2. Delayed symptoms

Delayed symptoms of trichinosis can include:

• Muscle pain

• Persistent fever

• Eye pain and sensitivity to light

• Swelling in the face, especially around the eyes

• Excessive tiredness

• Headache

• Skin redness and itching

Delayed symptoms of trichinosis can appear about 2 weeks after infection, when the larvae reach the bloodstream.

In more severe cases, shortness of breath, heart problems, and difficulty walking or coordinating movements may occur.

Delayed symptoms are more likely to occur when treatment is not started early. Therefore, if trichinosis is suspected, medical care should be sought to assess symptoms, confirm the diagnosis, and start the most appropriate treatment.

Confirming a diagnosis

Trichinosis is diagnosed by an infectious disease specialist or primary care provider based on symptoms and health history. This includes eating habits, such as whether the person ate raw or undercooked pork or wild game.

The doctor may also order blood tests, such as a complete blood count (CBC), to check for eosinophilia. This is an increase in eosinophils, a type of white blood cell that can suggest a parasitic infection.

Immunologic tests, known as ELISA tests, may also be done to detect antibodies against the disease. According to the CDC, antibody levels are often not detectable until 3 to 5 weeks after infection, so these tests may not be useful right away.

In some cases, a muscle biopsy followed by microscopic examination may be recommended to identify larvae in the muscles. This method is more invasive and is used less often.

Possible causes

The main causes of trichinosis are:

• Eating pork that is raw or not fully cooked
• Eating meat that was not stored at a safe temperature
• Preparing meat with utensils or surfaces that were not properly cleaned
• Cross-contamination, which can happen when raw pork comes into contact with cooked or ready-to-eat foods

In addition, eating raw or undercooked meat from infected wild animals, such as deer, elk, wild boar, bears, and birds, can also spread the disease.

Life cycle of trichinosis

The life cycle of Trichinella spiralis starts when a person eats raw or undercooked meat, either pork or contaminated wild game, that contains larval cysts of this parasite.

Once in the stomach, gastric juices and digestive enzymes dissolve the cysts and release the larvae. The larvae then move to the small intestine, where they enter the intestinal lining and become adult worms within 1 to 2 days, developing into males and females.

The adult worms mate in the small intestine. After mating, the females produce live larvae, rather than eggs, within a few days.

The newly hatched larvae enter the lymphatic system and then the bloodstream. From there, they spread throughout the host’s body and settle in the muscles, where they become encapsulated.

Inside the muscles, the larvae develop into cysts and become infectious in about 4 to 5 weeks, resulting in symptoms.

Treatment options

Treatment for trichinosis helps relieve pain, swelling, and discomfort. A primary care provider or infectious disease specialist may prescribe medications such as acetaminophen or ibuprofen.

The doctor may also recommend antiparasitic medications. According to the CDC, the recommended treatment for trichinellosis is either mebendazole oralbendazole.

In more severe cases, the doctor may recommend corticosteroids, such as dexamethasone or hydrocortisone, to reduce inflammation and severe allergic reactions related to larval invasion.

During treatment, the person should rest, drink about 2 liters of water per day, eat a balanced diet, and avoid physical exertion.

In some cases, trichinosis goes away on its own and does not require treatment. In other cases, treatment must be started as soon as possible to prevent complications.

Prevention measures

To prevent trichinosis, it is recommended to:

• Wash your hands with soap and water before preparing food and after handling raw meat

• Cook pork and other wild game thoroughly, making sure it reaches an internal temperature of at least 160°F (71°C) to destroy the larvae

• Freeze and store meat properly at temperatures as low as 5°F (-15°C) to inactivate the parasite larvae

• Avoid eating raw or undercooked meat, especially in regions where this parasitic infection is common

In addition, it is important to keep raw meat away from cooked or ready-to-eat foods, and to thoroughly wash all utensils that come into contact with raw meat.

Following these recommendations is essential to prevent infection with Trichinella spiralis and the development of complications.