By | June 10, 2022

Trichinellosis or trichinosis is one of the infectious diseases caused by parasites. The notifiable disease is one of the most widespread worm diseases in humans worldwide.

What is trichinellosis?

Trichinellosis is a worm disease caused by the larvae of trichinella. Trichinella can enter the human body by eating raw or undercooked meat. Pork is particularly dangerous, but so is meat from other domestic or wild animals. Pigs or wild animals are the carriers of the parasite, humans are intermediate or final hosts. For lentigo malignant basics, please visit


Trichinella are tiny roundworms. They can be found in raw meat, especially pork, or even wild animal meat.

If a person eats this meat raw or insufficiently roasted or cooked, the larvae of these roundworms get into the person’s stomach. The enzymes in the stomach are ideally suited for the larvae to be able to free themselves from their cocoon. Through the movements of the intestine, the larvae reach the small intestine. There they nest in the intestinal wall and grow into adult worms within 24 to 30 hours. Then mating takes place, after which the males die off quickly.

However, a fertilized female can produce up to 1500 larvae in the intestinal wall. From here they enter the human bloodstream. The females themselves survive up to 8 weeks.

The worms finally reach their full development in the striated muscles, in which the parasites encapsulate and damage the muscles. Muscles with a good blood supply (shoulder girdle and upper arms, neck and chewing muscles) are particularly affected. Eyes, tongue and diaphragm can also be affected.

Symptoms, Ailments & Signs

The course of trichinellosis depends both on the number of larvae ingested and on the immune system. In addition to very severe clinical pictures, some of which are fatal, there are also mild forms of trichinellosis that often go undetected. After an incubation period of five to fourteen days, intestinal problems first appear because the larvae are initially in the intestinal mucosa.

There is a severe feeling of illness with abdominal pain, diarrhea, exhaustion and insomnia. In a second phase, the larvae migrate via the bloodstream into the muscles. This stage is initially characterized by a very high fever up to 41 degrees Celsius, chills, eye inflammation and hoarseness.

Later, muscle pain is added to a variety of muscles. After about three to four weeks, muscle pain and fever subside. Without treatment, however, several symptoms such as muscle pain, muscle and joint stiffness, abnormal sensations, sensory disturbances, conjunctivitis of the eyes or increased sweating can persist for a long time.

However, these symptoms usually disappear completely after a year. Since the larvae can sometimes encapsulate themselves in the central nervous system, neurological symptoms are sometimes also observed. But there are also very severe courses of the disease, which often lead to death. Inflammation of the heart muscle, inflammation of the brain, inflammation of the lungs or even sepsis can occur as dangerous complications.

Diagnosis & History

Initially, a patient with trichinellosis shows symptoms of a gastrointestinal disease. Once the trichinella enter the human gastrointestinal tract, nausea, vomiting and diarrhea occur. Fever is also possible. However, the symptoms do not necessarily occur in all affected patients.

In the second phase, the actual symptoms of the infectious disease appear. The worms have reached the bloodstream and eventually the muscles, causing high fever and muscle pain. The patient often mistakes the muscle pain for joint pain at first.

There are also problems with swallowing and breathing. Edema forms around the eyes. Conjunctivitis and skin rashes are also possible. The symptoms can persist for a year and usually heal without complications.

The doctor confirms the diagnosis with a blood and stool test of the patient. Antibodies in the patient’s blood indicate trichinellosis. At a later stage, a sample of muscle tissue is also indicative.


Infection with nematodes of the genus Trichinella can take very different courses. In mild cases, when only a small number of larvae have been ingested, the infection is often mistaken for an upset stomach and soon heals without complications. Severe forms of the disease, on the other hand, can lead to a whole range of serious complications, including death.

In the case of severe infections, the typical symptoms initially intensify. The often observed muscle hardening as well as the muscle and joint pain no longer only occur when trying to move, but also when you are at rest. The typical hoarseness may worsen to the point that the patient temporarily loses his or her voice, and severe difficulty swallowing may necessitate intravenous feeding.

Breathing problems can lead to an acute suffocation hazard. If the eye muscles are affected, migraine-like headaches and visual disturbances can also occur, and those affected often also perceive double vision. The most dangerous complications include encephalitis and secondary infections such as bronchopneumonia or sepsis.

Myocarditis (inflammation of the heart muscle), which is associated with permanent damage to the organ, cannot be ruled out either. In the worst case, which is rare in industrialized countries, the disease assumes life-threatening proportions and ends in the death of the patient.

When should you go to the doctor?

A decrease in well-being, a persistent feeling of illness and fatigue are causes for concern. If the irregularities persist for a long time or increase in intensity, a doctor is needed. Abdominal pain, chills, increased body temperature and hoarseness should be examined and treated. Pain in the muscular system, sensory disorders and abnormalities in the musculoskeletal system should be presented to a doctor. Sleep disorders, exhaustion and a decrease in the usual resilience are further indications of an illness.

If there are irregularities or functional disorders of the digestive tract, medical attention is required. Since trichinellosis is one of the notifiable diseases, special care must be taken if there are any abnormalities when going to the toilet. If worm movements or other activities are detected in the stool, this should be discussed with a doctor. Sweating, stiffening of the joints or an irregularity in the eye area are other complaints that require action.

Without a doctor’s consultation and medical care, the patient can die if the disease progresses severely. For this reason, a doctor is needed as soon as there are discrepancies in memory, heart rhythm or breathing. In the event of neurological deficits, an emergency service must be alerted. Disorders of consciousness, severe pain, coordination difficulties and a body temperature over 40° must be presented to a doctor immediately.

Treatment & Therapy

If trichinellosis is detected in time, drug treatment is possible. The severity of the infection depends on how many larvae the patient has ingested.

For therapy, the doctor prescribes drugs that kill the worms and larvae in the patient’s body. Starting therapy early means that the worms do not nest in the patient’s muscles.

If the amount of pathogens ingested is very high, complications can occur and trichinellosis can also be fatal. Complications are heart disease ( inflammation of the heart muscle ), pneumonia or blood poisoning. Meningitis and meningitis are also a possible complication.

The doctor reports the trichinella disease to the health department, which then has the task of finding out where the meat comes from and who the meat producer is. In this way, other possible victims can be found.


The most important prevention is not to eat raw or undercooked meat. A cooking temperature of at least 65 degrees Celsius will definitely kill the larvae in the meat. The pathogens also do not survive prolonged deep-freezing (at least 20 days below -15 degrees Celsius). Curing, smoking, salting or drying, on the other hand, does not kill the pathogens.

In Germany, meat is also tested for trichinae by law. Care should be taken when importing meat from non-EU countries or consuming raw or undercooked meat abroad, as there are no laws on testing meat for Trichinella.


In principle, the further course of the trichinellosis will continue to be medically monitored even after the diagnosis and treatment. The aftercare measures usually focus on caring for the damaged muscles and preventing irreversible damage to the muscles. In the case of trichinellosis, however, the extent of the follow-up examinations and treatments depends on the effectiveness of the treatment measures.

Because the disease is regularly treated first with medication (anthelmintic based on benzimidazoles). However, the drug intervention is only effective as long as the trichinella larvae migrate or are in the intestine of the affected person. As soon as the larvae have arrived in the striated muscles, the success of the therapy is no longer guaranteed. The parasite then finally encapsulates itself and damages the muscles.

The parasite capsule only calcifies after a year has passed. Much later, the calcification begins in the parasite itself. The focus of the aftercare measures are now the symptoms that may occur as a late effect. Neurologically focal symptoms (e.g. muscle twitching) are often observed. This is caused by trichinella larvae encapsulated in the central nervous system.

The neurological symptoms are regularly examined during follow-up and alleviated with medication. In individual cases, symptoms can even be life-threatening, so that chemotherapy is necessary as follow-up treatment. Rheumatic pain and chronic conditions (e.g. anemia) are treated with medication for life during follow-up care.

You can do that yourself

In the event of an infection with the trichinellosis pathogen, all possible sources of infection must first be removed. The health authority and, if necessary, various veterinary and food control authorities must be informed. They will take over the backup of the diagnosis and, if necessary, identify other affected persons. In addition, it must be determined where the infected meat comes from. For this purpose, the person concerned must be questioned in detail when the opportunity arises.

After the actual treatment, which is usually mebendazole, the patient needs a lot of bed rest. The immune system is severely weakened, especially after chemotherapy, as is carried out in the case of advanced diseases, and rest is essential. The most important measure is to take the prescribed medication as prescribed. The earlier therapy is initiated, the less aggressive action must be taken against trichinellosis. Nevertheless, the patient usually has to be quarantined to minimize the risk of infection.

If symptoms of the lungs, the cardiovascular system or the brain occur after the initial treatment, the responsible doctor must be informed immediately. The Federal Institute for Risk Assessment provides those affected with further information on the prevention and treatment of trichinellosis.