Pulmonary flukes are the causative agent of paragonimosis. Paragonymosis in humans: symptoms, treatment, prevention

Infectious diseases are one of the most widespread groups of human pathologies. A separate group among them is parasitic diseases. One such process is the lung paragonymosis.

What it is?

Paragonymosis is an infectious disease caused by a parasite from the group of trematodes - annelids. It affects primarily pulmonary tissue, muscles. The brain is involved in the infectious process quite rarely.

The causative agent of the disease - paragonimus westermani (or its other name - "pulmonary flukes") - has an ovoid shape, a reddish-brown color. His whole body is covered with small spines, which allows stronger fixation in the tissues of the body of the parasite carrier. On the abdomen there is a sucker, which also performs a fixation function.

The disease is characterized by certain zones of infection and endemicity. Refers to zoonoses.

If untimely started treatment can lead to serious complications, some of which are life-threatening.

What is the method of infection and what are the characteristics of this parasite?

Spread of the disease

Pulmonary flukes are widely distributed in the middle lane. Most often, outbreaks of this disease are observed in Russia and Asia.

The intermediate host of the trematode is small crayfish and arthropods. The ultimate host is small rodents, muskrats, beavers, wolves, foxes. To the final owners is also a person.

In the human body, the pulmonary flukes penetrate when eating improperly prepared crayfish and crabs.

Eggs of the parasite are excreted from the body with feces and urine. If they get into the external environment, some of them die, and a part, falling into the water, continues the cycle of the development of the worm.

In the human body, the worm is localized mainly in the lung tissue - its small bronchioles. From there, spreading through the lymphatic vessels, can penetrate into other parts and organs of the human body, which leads to a complicated course of the infectious process.

How is the life cycle of this pathogen carried out?

Development of the parasite

How does the pulmonary fluke develop? Its life cycle consists of three stages:

The first of these forms miracidia (nymph). This stage is the initial one, and the parasite passes it after exiting the egg. In water, miracidium penetrates the body of the first intermediate host, the freshwater mollusk. During the first five months, asexual reproduction occurs in the body of a mollusc, as a result of which it dies, and a large number of cercariae - the second stage of parasite development - enters the water. These larvae have mobility and penetrate into the body of their intermediate hosts invasively, i.e. Through the surface of their body.

The worm penetrates into the body of crabs and crabs at this stage, where it develops to metacercaria - the third stage of development. This form is already pathogenic to humans.

In the human intestine, the metacercaria exits from its membrane and migrates to the lungs, where its fixation and further egg formation takes place.

Clinic of the disease

How can one suspect that paragonimosis has developed? Symptoms of this disease are quite nonspecific, which requires more precise and detailed diagnosis.

The disease can occur in the form of several forms - abdominal and pleuropulmonary.

Abdominal form most often occurs with the clinic of enteritis or hepatitis, can lead to the development of parasitic peritonitis relatively favorable course.

The pleuropulmonary form of the disease is manifested in most cases. There is an increase in temperature to 38 degrees and above, a strong cough with the discharge of purulent bloody sputum with eggs of the parasite. There is also a clinic of pneumonia, pleurisy.

When the parasite is located at the outer edges of the lungs, it is possible to form the parietal cysts with the development of pleural empyema or pleurisy.

With the progression of the disease develops diffuse pneumosclerosis with deterioration of all functions of external respiration.

Possible rupture of lung tissue with the development of pulmonary hemorrhage.

Complications

The disease itself is quite difficult, but there may be various complications. How is the complicated paragonimosis? Symptoms of it are as follows.

With the predominance of the abdominal form, intestinal perforation is possible with the development of the peritonitis clinic and the formation of empyema of the peritoneum and phlegmon.

The pulmonary form is complicated by bleeding, the formation of pleural effusion, and lung infarction. Dangerous development of cysts in the field of diligence of the heart to the left lung.

When the hematogenous or lymphogenous spread of the parasite is possible, it can enter into various organs and tissues. Brain in paragonymosis is rarely affected, but it is possible to develop parasitic meningitis and meningoencephalitis.

Paragonimosis of the lung can lead to the formation of intrapulmonary cysts. This happens when, in case of inadequately conducted anthelmintic therapy, the worm, in order to avoid the effects of drugs, forms around itself a dense calcified capsule, which allows you to wait out unfavorable conditions (in this case, the action of the drugs). Such cysts require surgical intervention.

Diagnosis of the disease

What kind of research will help determine if the pulmonary fluke has entered the body?

First, a general blood test should be performed. In it, the most interesting indicators will be ESR, the number of erythrocytes and eosinophils.

The patient's complaints, as well as carefully collected anamnesis (consumption of cancers or crabs, use of running water from rivers in endemic areas) will also help.

With helminthiasis, eosinophils and ESR will be increased. The level of erythrocytes decreases with a long-term current process.

Of the instrumental methods, the best is fluorography. It allows to determine the presence of cavity formation in the lung tissue, to reveal its localization and dimensions. Based on the data of the picture, the diagnosis is made.

Examination of sputum makes it possible to identify eggs of the worm, as well as blood veins with bleeding that begins.

Treatment

How is this disease treated?

Parasites in the human lungs are quite a serious problem, so treatment should begin as early as possible and pursue the goal of eliminating the helminth.

The main drug used to treat paragonimosis is the "Praziquantel". Its dose is calculated based on the proportion of 60-70 mg of the drug per kilogram of body weight. This remedy for parasites is given in three doses after each meal. The drug is used inside.

In addition, you can use and tools such as "Emetin", "Chloksil", but the effect of their reception is much smaller than that of "Prazikvantel."

When forming massive cysts, surgical removal is required. In some cases, especially if the cysts are large, pneumonectomy may be required - removal of the entire lung.

With lesion of the brain, the treatment is only surgical.

Prevention

What should I do to prevent paragonimosis? Prevention can include several activities:

• First of all, you should carefully observe the rules for preparing freshwater arthropods. The greatest number of paragonimosis infections falls precisely on non-compliance with culinary requirements and norms.
• Part of the spread of the disease can be affected by cleaning rivers and streams from the pathogen. It is rather difficult to do this, because as a result of active actions, the existing flora and fauna of this region may die.

If there is a suspicion of the presence of a disease (the appearance of a cough or other symptoms), for prophylactic purposes it is possible to take Prazikvantel for 4-5 days. However, do not rely on self-medication, because you can only hurt yourself. It is better to ask a qualified specialist for help, so that he can determine what kind of a disease is, and make up a competent treatment plan.

Forecast

In general, if the patient turned early in the onset of symptoms, and the process did not have time to fully activate, the diagnosis was carried out in a timely manner and an adequate treatment plan was assigned, the prognosis is quite favorable. Many people are completely cured of paragonism.

If the process was started, and the cysts were formed in the lungs, the prognosis is somewhat worsened. Small cysts may not have a significant effect on the body; Large ones will require their removal, which, as a result, can lead to disability of the patient. In general, patients after surgery continue normal life with some restrictions on physical activity and work.

The most unfavorable prognosis is when the pathogens get into the brain. If you do not take the necessary measures in time, a fatal outcome is possible.