Trichinosis - Causes, Symptoms, Diagnosis, and Treatment

What Is Trichinosis?

Trichinosis, also known as trichinellosis, is a food-borne infection caused by Trichinella. Humans get infected when they consume raw or undercooked meat that contains the larvae of Trichinella; it is present mainly in wild animals like boars.

What Is the Cause of Trichinosis?

Trichinosis occurs when someone consumes undercooked pork or wild game infected with the Trichinella larvae. Even though domestic pigs are not commonly infected, they may get infected if they are in close contact with other wild animals.

Trichinella species require two hosts to maintain their life cycles. After development in a host, they spread to the next through ingestion of infected flesh, as opposed to the traditional insect host in other parasitic diseases. These have three major life cyclesin nature: pig-to-pig, rat-to-rat, and carnivorous or omnivorous animals in the wild. Rats and pigs are the most common means of the life cycle of Trichinella.

Once the larvae are ingested, the acids in the stomach dissolve the cyst covering the larvae, releasing the larvae into the intestine, which later enter the bloodstream and reach the muscles, where they may stay for a long period.

What Are the Symptoms of Trichinosis?

The signs and symptoms of trichinosis vary from mild to severe depending on the number of larvae and the tissue infected.

Mild Symptoms: In the case of mild trichinosis, the person may develop very few to no signs. This is when the number of invading larvae is less.

Moderate Symptoms: Once the larvae reach the intestine, the digestive juice dissolves the cyst and releases the worms into the intestine, where they proliferate and infect the walls of the small intestine, causing symptoms like:

• Diarrhea.

• Constipation.

• Fatigue.

• Abdominal cramps.

• Nausea and vomiting.

• Mild fever.

These develop one to two days after consuming the contaminated food. About a few weeks after the infection, the worms enter the bloodstream and reach the muscles, where they cause symptoms like:

• Muscle soreness.

• High fever.

• Weakness.

• Swelling in the face.

• Swelling around the eyes (periorbital edema).

• Sensitivity to light.

• Pink eye (conjunctivitis).

• Rashes.

• Headaches.

Severe Symptoms: If the infection is to a greater extent, the patient may experience:

• Heart problems.

• Difficulty in breathing.

• Uncoordinated muscle movements.

In extreme cases, it may lead to death.

When to Consult a Doctor?

The initial mild symptoms may not require medical attention, but it is crucial to consult a doctor in case of gastrointestinal or muscular problems.

Who Is at Risk of Trichinosis?

Risk factors for Trichinosis include:

• Improperly Cooked Food: Trichinosis develops in humans when they consume food (meat) that is undercooked, resulting in the parasite entering the body.

• Improperly Stored Meat: Improperly stored meat can give rise to parasite proliferation and increase the number of invading larvae.

• Consuming Meat of Wild Animals: Wild animals are considered the primary source and reservoir of the Trichinella larvae; consuming non-commercial meat or meat of wild animals may lead to trichinosis.

How Is Trichinosis Diagnosed?

The doctor may take a complete history of the patient to check if the person has eaten any wild meat in the recent past and also a note of all the symptoms that the patient experiences. A blood test may be advised to confirm the presence of trichinella infection, although this could be effective only after a few weeks. Therefore, the blood test is repeated later at weekly intervals to confirm the diagnosis. In some cases, the doctor may advise an additional muscle biopsy as a confirmatory test.

What Is the Treatment for Trichinosis?

The treatment for trichinosis is vital if a person has consumed raw or undercooked meat and develops symptoms. The treatment, however, is symptomatic, based on laboratory tests and the overall health of the person. The doctor may advise an antiparasitic medication (like Albendazole and Mebendazole) to prevent the systemic invasion of the parasite. An analgesic (painkiller) for muscle aches and anti-inflammatory medicine for reducing the inflammation in the body may also be advised.

What Are the Complications of Trichinosis?

Complications due to trichinosis are usually rare and may occur in case of heavy infection or an increased number of invading parasites.

This includes:

• Myocarditis: It is the inflammation of the heart muscles, which may result in irregular heart rhythm or heart failure.

• Encephalitis: It is the inflammation of the brain, which may cause personality changes, seizures, and other serious symptoms depending upon the area of the brain that is affected.

• Meningitis: It is the inflammation of the membranes and the fluid surrounding the brain and spinal cord, which may risk permanent damage to the brain or death.

• Nephritis: It is the inflammation of the kidney, which may have complications of renal failure.

• Pneumonia: It is the infection of the air sacs in the lungs, which may sometimes lead to lung abscesses and respiratory failure.

• Sinusitis: It is the inflammation of the sinus cavities and nasal passage, which may in rare cases lead to meningitis.

How Can I Prevent Trichinosis?

Trichinosis can be prevented by following a few steps:

• Do Not Consume Undercooked Food: Make sure to cook meat well, at an optimum safe temperature (160o F - 165o F) - as mentioned by the centers for disease control and prevention (CDC).

• Clean The Meat Grinder Regularly: The meat grinder should be cleaned regularly to prevent the accumulation of microorganisms.

• Avoid Consuming Non-Commercial Or Wild Meat: Wild animals are more often reservoirs of Trichinella.

• Wash Hands Before Preparing Meat: Wash your hands properly with soap and water before preparing meat.

• Freezing Pork: Freezing pork which is less than six inches thick over a period of three weeks is said to be killing the parasites - as mentioned by the centers for disease control and prevention (CDC).

However, freezing other wild meat apart from pork may not kill the parasite as some species are resistant to freezing temperatures. Also, note that other modes of preservation like salting, smoking, or pickling do not kill Trichinella species. Another measure that can be adopted is to prevent Trichinella infection in animals is by not providing uncooked meat of any animal that may be infected with Trichinella to domesticated and wild animals.

Conclusion:

Trichinosis is a foodborne illness. It is contracted by consuming raw or undercooked meat that may be contaminated by the Trichinella species. Symptoms of the illness may vary from mild to major, depending on the number of infected larvae entering the body. However, it is said to have a good prognosis, and a speedy and complete recovery if prompt treatment measures are taken. So, consult a doctor if there is a development of any symptoms. However, it is best to adopt preventive measures to avoid the occurrence of the disease.