Trichinosis: symptoms and treatment
Trichinellosis is an acute helminthiasis that occurs in both humans and mammals. The importance of the medical and social significance of this disease is due to the severity in clinical manifestations, which are often expressed in the loss of ability to work, and in some cases — and death.
Trichinosis in its manifestations is characterized by such conditions as fever and face swelling, muscle pain and skin rashes, eosinophilia and, in severe course, lung, myocardium, nervous system. Trichinella are the causative agents of the disease. Localized in the muscles of animals, Trichinella larvae retain their invasiveness (the ability to penetrate into another organism for the subsequent distribution in it) for many years. The entry into the cadaveric material leads to their death when exposed to very high or very low temperatures (+ 80 / -40-50 ° C). Smoking, like salting meat, does not contribute to any effect on the larvae.
As an invasion source for humans, animals (domestic, wild) affected by trichinosis act. Most often such animals include pigs and wild boars, foxes, nutria, badgers, in some nationalities this may be dogs.
As for the mechanism of infection, it is oral, and the susceptibility of a person to this disease is extremely high. So, it is enough to consume about 15 grams of meat affected by trichinosis. It is noteworthy that often infection occurs due to the use of insufficiently boiled or raw meat of the infected animal. Basically, it is meat and lard, as well as ham, brisket, bacon loin, made from infected pork sausage, meat of wild animals. It should also be noted that the incidence of trichinosis is group, respectively, all members of the family participating in the feast with such meat are affected.
Features of Trichinosis
The course of this disease is characterized by its own complexity and represents a whole complex of concomitant pathological reactions for which the causative agent becomes a causative agent.
The following phases are characteristic of the development of the pathological process:
- Enzymatic-toxic phase (first two weeks after infection)
- The allergic phase (the end of the second week after infection — the third and fourth week after it)
- Immunopathological phase.
Let us dwell in more detail at each of these phases.
The enzymatic-toxic phase . The flow of this phase is accompanied by penetration into the intestinal mucosa of Trichinella during subsequent formation of adult helminths. The effect of their metabolites and enzymes leads to the development of an inflammatory reaction in this area.
Phase allergic . For this phase, the formation of a general type of allergic manifestations, which consist in fever and in edema, conjunctivitis and the formation of catarrhal syndrome in the lungs, as well as in other pathologies becomes characteristic. By the end of the first week, adults have formed Trichinella begin to multiply, after which the young larvae through the blood and lymph reach the striated muscle.
The defensive reaction from the human body manifested in a depressed form due to the immunosuppressive effect exerted by adult parasites does not become an obstacle to the activity that arises in the circulation of the larvae. Completion of the second / third week of the disease is characterized by an increase in the level of antibodies of a specific character in the serum of a person infected with trichinella. This in combination provokes a violent allergic reaction. Allergic inflammation, which thus occurs in the intestine, leads to the death of adult Trichinella in it, as well as to the formation around the larvae of Trichinella found in muscles, granulomas. Of these granulomas, fibrous capsules are formed, acting as an obstacle to the entry of parasite antigens into the human body.
The overall degree of expression characteristic of immunological reactions is determined on the basis of the immunoreactivity of the human body and the dose of the antigen, and also from the degree determining adaptation to the human (host) of the parasite. With increasing doses of infection, there is, respectively, an increase in intensive order of muscular and intestinal invasion (invasion of parasites into these areas).
Thus, the severity of the disease also undergoes strengthening, the immunological processes due to this are depressed. It is accompanied by systemic lesions of tissues and organs, which occurs due to sensitization of the body (that is, the acquisition of a specific type of sensitivity of a heightened nature with respect to the effect of trichinella).
At the same time, sensitization occurs not only because of the effects of the products of parasite metabolism, but also due to the effect of the products of decay of tissues damaged or destroyed by the host. Manifestations of this phase are in muscle pain, fever, respiratory disorders, conjunctivitis, edema.
Immunopathological phase . This phase, as a rule, follows an intensive infection. It is characterized by the formation of systemic allergic vasculitis (inflammation arising in the walls of blood vessels), as well as organ damage in their severe manifestation. The brain, myocardium, liver and other organs are characterized by the appearance of nodular infiltrates in them (clusters of cellular elements in tissues with impurities in them in the form of lymph and blood).
The disease is complicated by diffuse-focal allergic myocarditis, focal pneumonia, meningitoencephalitis and other organ lesions of no less severe specificity. In this case, such lesions are often combined with each other, which is accompanied by fever and significant muscle pains, swelling and skin rash.
The fifth-sixth week of the course of the disease from the moment of infection is characterized by a change in the inflammatory process that occurs in the parenchymal organs with dystrophic disorders, the recovery of which subsequently occurs extremely slowly. So, for him it takes about six months or a year.
Characteristic clinical manifestations characteristic of trichinellosis are remittent fever (in which diurnal temperature fluctuations are of the order of 1-1.5 ° C), muscle pains, skin rashes, high eosinophilia (a characteristic manifestation of allergic reactions), facial swelling.
The low intensity of the spread of infection can often be asymptomatic, and the only sign that can result is an eosinophilic reaction from the blood pointing to it.
The clinical severity of the variants of the disease may differ in the severity of its own course, as well as in the duration of the incubation period of the fever and, in fact, the outcome. Based on this, the following forms of infestation (infection) are accepted:
- Wiped invasion
- Invasion is easy;
- Medium-level invasion
- The invasion is heavy.
The course of the spread is determined by the following periods, characterized by their own symptoms:
- Incubation period;
- Period of acute manifestations
- Complication period
- Reconveneence / relapse period
The incubation period of the disease is generally on the order of 10 to 25 days. Meanwhile, infection with natural strains helps increase this period to 45 days. Based on clinical observations, it is determined that the duration of the incubation period is inversely proportional to the severity with which the disease as a whole proceeds. So, the severe course of trichinosis can be accompanied by an incubation period lasting for up to 10 days, and especially malignant course of the disease and may be characterized by an incubation period of 1-3 days.
The erased form of the disease can occur with an incubation period of 4-5 weeks. This form of infection is characterized by a lack of pronounced symptomatology, which determines the complexity of diagnosing trichinosis. Among the main symptoms:
- Subfebrile fever
- Minor muscle pain;
- Swelling of the face in an inconspicuous form of manifestation
Peripheral blood determines the content in it of the order of up to 12% of eosinophilia at normal values in the number of leukocytes. The duration of the disease is up to a week, and any manifestations (with the exception of eosinophilia) disappear during this time.
The mild form of trichinosis is characterized by the duration of the incubation period on the order of up to 5 weeks. The onset of the disease is acute, the temperature rises to a level of 38-39 degrees, there are headaches, malaise. Then there is a rapid decrease in temperature (to subfebrile) with its preservation up to a week. There are pain in the area of chewing, lumbar and gastrocnemius muscles. The face acquires a puffiness, the eyelids swell. Any painful manifestations can disappear on their own within a week or two.
The average severity of trichinosis is characterized by an incubation period within 2-3 weeks. Characterized by a marked symptom characteristic of the syndrome of a general type of allergic reactions. The disease begins sharply, with the temperature rising to 40 °, while maintaining it at a high level for several hours and then falling to 38.5 °. These indicators are held for a week, the second is the transition to subfebrile fever. For this feverish period, the typical manifestations are the pains of the occipital, lumbar, chewing and calf muscles.
Characteristic symptoms are also in the expression of edema of the eyelids, the puffiness of the face, conjunctivitis. Often against the background of febrile conditions, patients develop skin rashes. 1/3 of the cases are marked by the appearance of bronchopulmonary pathology. Symptomatics in this case is manifested in the form of inflammation in the upper respiratory tract, bronchitis, pneumonia, pleurisy.
With fever, there is also an increase in symptoms, indicating a lesion in the cardiovascular system. Such manifestations are tachycardia, deafness in cardiac tones, systolic noises. Palpitation increases, dyspnea occurs.
In some cases, trichinosis is accompanied by a symptom that indicates a lesion of the gastrointestinal tract, which is manifested in pain in the abdomen, nausea and vomiting, diarrhea.
The maximum manifestations in the symptomatology of the average severity of trichinosis occur at the end of the first week, the disease is completed for a period of 3-4 weeks.
Severe form trichinosis is characterized, as we noted earlier, by the shortness of the incubation period (from 1 to 10 days). Quite often, the disease manifests itself in atypical symptoms for him, resembling the flu and ARI, abdominal or typhus fever, food poisoning.
For the first days of the disease, there is a presence of manifestations of intoxication of a general type, as well as CNS lesions. Increasing gradually to 40-41 °, the temperature is subsequently held for 2-3 weeks. There are severe headaches, insomnia, agitation, manifestations of meningism in combination with the growth of muscle pains with marked swelling are the companions of fever. It is noteworthy that muscle pains are characterized by prevalence, affecting the eye, gastrocnemius and chewing muscles, then going over to the muscles of the lumbar and brachial muscles. Due to the intensity of pain sensations, concomitant phenomena are contractures, limitations in mobility, complete immobility.
The spread of edema occurs on the limbs and trunk, as well as loose fiber in the internal organs, the parenchyma and the meninges. This, in turn, provokes the emergence of functional disorders of the central nervous system and other manifestations. Cardiovascular pathologies are frequent, suffering in severe form of trichinosis and respiratory organs, but in a greater intensity of manifestations than with an average form of the disease.
One of the variants of this form of flow is the abdominal syndrome, which, along with other manifestations, is characterized by abdominal pain, a loose stool (with mucus and blood), nausea and vomiting. The cause of death can be ulcerative necrotic lesions, important for the intestines and stomach, in which there are critical manifestations in the form of perforation and bleeding.
Often, symptoms are similar to characteristic lesions of the CNS as meningoencephalitis and encephalomyelitis, manifested as severe headaches and insomnia, and in extreme conditions — in the form of delirium, convulsions, seizures, and mental disorders. Emerging systemic and organ damage are often the cause of death, and the main cause of death in this disease is myocarditis with sudden disturbances in cardiac activity. The second cause of death in the case of trichinosis is pneumonia (in some cases with concomitant asthmatic bronchitis or pleurisy). The third complication that provokes at trichinosis death, is the central nervous system lesions (epileptiform seizures, severe hysteria, paralysis, pointing to deep lesions brain and spinal cord).
Any forms of trichinosis, with the exception of erased forms, require inpatient treatment. The reason for this is the possible progression of the disease along with severe adverse reactions that arise as a response to specific therapy.
When erased and mild forms, as well as in convalescence at the background of moderate forms prescribe anti-inflammatory therapy with nonsteroidal drugs. The medium-heavy and severe form of the disease requires the need for specific therapy. The administration of drugs along with anti-inflammatory drugs is performed taking into account possible side effects in the form of allergy to trichinella already dead in the body. A severe form with actual organ damage requires the treatment of the disease in combination with specific drugs, including glucocorticoid hormones.
If you have these symptoms, you should immediately contact an infectious disease doctor.