Overview

Trichinosis is a disease condition which is caused by roundworm parasites (Trichinella). Disease is caused when people eat raw or undercooked infected meat. The infection is caused when people eat raw meat which contains trichinella larvae. It takes several weeks for the larvae to grow into adult worms in the small intestine, and again, the adult worm produces the larvae, which travel through the bloodstream and reach different parts of the body.^1-3

Most of the conditions can be treated with proper medication. This is not a contagious disease. Animals get infected when they feed on garbage containing infected meat.

Trichinosis

Trichinosis is a condition where people are infected when they eat raw or undercooked meat which is infected with the larvae of the trichinella roundworm parasite. The digestive enzymes in the stomach help to digest the food in the stomach, but in the case of larvae, these digestive enzymes break only the hard shell of the larvae. The larva takes several weeks to grow into an adult worm in the small intestine. The adult worm then produces larvae that travel through the bloodstream to reach different parts of the body and infect the muscle tissue.^1-3

Causes

This condition is caused by the infestation of the larvae of the trichinella roundworm parasite. Most commonly, these infections are seen in wild animals, where they feed on other infected animals. Domestic pigs or horses are affected when they feed on the garbage that contains the infected meat. Some of the common ways to get affected by trichinosis are:

• Eating raw or undercooked meat products
• Eating undercooked or raw meat from infected wild animals
• Eating improperly stored meat
• Using unclean kitchen utensils to prepare meat
• Using a meat grinder to grind the meat which was previously been ground for the infected meat

Symptoms

The severity of the infection depends on the number of larvae ingested through the infected meat. The signs and symptoms help in understanding how severe the infection has affected. In mild cases, where the parasite infestation is mild, it may not show any signs and symptoms. Symptoms develop in case of moderate to heavy infestation of the parasite in the body.

Early signs and symptoms

Early symptoms of trichinosis start a few days after the worm enters the person’s body, and they are:^4-7

• Abdominal pain
• Diarrhoea
• Nausea and vomiting
• Severe tiredness and weakness

Later signs and symptoms

The symptoms of trichinosis start 2 weeks after the parasitic infestation and last for several weeks. In certain severe cases, this condition may cause death. These are:^8,9

• Headache
• Fever and chills
• Muscle pain
• Pain in the joints
• Swelling of the eye
• Extreme tiredness
• Diarrhoea or constipation
• Skin irritation or rash
• Cough
• Difficulty in breathing
• Difficulty in movement and coordination
• Inflammation of the heart muscles
• Encephalitis (inflammation of the brain)

Diagnosis

Healthcare providers or doctors may do a physical examination and ask questions regarding the history of any illness and family history. They may also ask about the diet and travel that the person has done in the last few days. 

• Blood tests: To diagnose trichinosis, they may take blood tests for its signs, which may show increased blood count (eosinophils), which form against the parasite¹⁰
• Biopsy: It is a procedure where the healthcare provider removes a sample of tissue or fluid from the area of affected area. Then the sample is examined under a microscope in the laboratory

Management and treatment

Healthcare providers may suggest treatment as soon as possible if the patient shows the symptoms of trichinosis. In most cases, where a small number of parasites are affected, they may not show any signs and symptoms, and they may go away on their own without any treatment. But in severe cases, if the condition is left untreated, it may be fatal. 

Medicines

Anti-parasitic medication like albendazole or mebendazole is given to kill the larvae and worms in the small intestine. These medicines may cause stomach pain, nausea, vomiting or diarrhoea. These medications help in preventing the infection from getting into the muscle.

Pain medications

If the larvae have entered the muscles, the person may feel pain and swelling. Pain medications help in relieving the pain, muscle aches and swelling. 

Steroid medication

Trichinosis may cause allergic reaction, pain and swelling in a person while the parasite enters the muscle tissue, or when the larva dies, it releases chemicals in the muscle tissue. 

Risk factors

Some of the factors that may cause trichinosis are: 

• Rural areas: Trichinosis is more common in rural areas
• Improper food preparation: Trichinosis occurs when people eat infected meat undercooked or raw
• Eating wild meat: Wild animals are a common source of infection; these animals feed on other animals

Prevention

Avoiding these factors helps in preventing trichinosis, and the factors are:

• Maintaining proper hygiene: Washing hands after cleaning or handling the meat prevents the infection from spreading to other food items
• Avoid eating raw or uncooked food: Cook meat thoroughly, as a higher temperature helps kill the parasite
• Freeze the meat: Freezing meat other than wild animal meat helps kill the roundworm parasite. Freezing wild animal meat won’t kill the roundworm parasite
• Cleaning meat grinders: Clean the meat grinders after every use

FAQs

What is trichinosis caused by?

Trichinosis is the condition caused by the parasite Trichinella. People are infected by this parasite by eating raw or undercooked infected meat. Wild animal meat is more prone to parasitic infection. 

Is there a cure for trichinosis?

Mild cases of trichinosis go away on their own, but in severe cases, proper treatment is required, and without proper treatment, this can be fatal.  

Why is trichinosis painful?

The larvae of the trichinella parasite hatch in the intestine and produce more larvae in the bloodstream, and they migrate to other parts of the body and infect the muscle tissue.

How does trichinosis spread? 

The infection is caused when people eat raw or undercooked meat which contains trichinella larvae. Animals get infected when they feed on garbage containing infected meat or when wild animals feed on other animals' meat which are infected.

Summary

Trichinosis is a disease condition which is caused by roundworm parasites (Trichinella). Disease is caused when people eat raw or undercooked infected meat. The digestive enzymes in the stomach help to digest the food in the stomach, but in the case of larvae, these digestive enzymes break only the hard shell of the larvae. The larva takes several weeks to grow into an adult worm in the small intestine. The adult worm then produces larvae that travel through the bloodstream to reach different parts of the body and infect the muscle tissue. This is not a contagious disease. Animals get infected when they feed on garbage containing infected meat. Most common symptoms are nausea, vomiting and diarrhoea.