Toxoplasmosis: Symptoms and Treatment
- Causes of development of toxoplasmosis
- Sources of infection
- Symptoms of toxoplasmosis
- Forms of toxoplasmosis and peculiarities of their course
- Toxoplasmosis, pregnancy and breastfeeding
- Toxoplasmosis in HIV-infected
- Diagnosis of toxoplasmosis
- Treatment of toxoplasmosis
- Prophylaxis of toxoplasmosis
Toxoplasmosis is a congenital or acquired disease of a parasitic nature, affecting the nervous system, the organs of the reticuloendothelial system, the visual apparatus, skeletal muscles and myocardium.
To this day, this parasitic infestation does not lose its relevance and annually, according to WHO, it infects tens of thousands of people. Extremely frequent registration of the disease is associated with the fact that the causative agent of toxoplasmosis is spread almost everywhere, and every year the risk of infection increases by 0.5-1%.
In the case when a small amount of pathogen enters the body of a healthy person, it does not pose a great danger, as it is covered with a dense shell and turns into a cyst. According to experts, about half a billion people on the globe have antibodies to the causative agent of this disease.
Most often, toxoplasmosis is diagnosed in regions with a warm climate, and this ailment is typical for certain professional groups (often people who are infected with raw meat are infected with it). It should also be noted that the infection of women is 2-3 times higher than that of men.
Unfortunately, due to the lack of mandatory registration and difficulties in diagnosis, it is very difficult to judge the actual level of infection, since it occurs almost everywhere in the form of sporadic diseases and asymptomatic parasitosis.
Causes of development of toxoplasmosis
The causative agent of the disease is toxoplasm (Toxoplasma gondi) belonging to the protozoa type (Protozoa), a class of sporoviks, a detachment of coccidia. It was first discovered in Africa in 1908 in mononuclear cells of the spleen and liver of the North African gondy rodent. Under the lens of the microscope, toxoplasm looks like a crescent moon, or an orange segment (toxon in Greek means "arch").
This unicellular parasite has a rather complex development cycle. Its main owner are cats. It is in their body that the agent becomes a sexually mature individual. Infection of the cat occurs when eating raw meat of infected animals, pigeons or rodents. Getting into the intestines of the animal, toxoplasm begins to multiply and be released together with feces into the environment.
A person becomes infected by contact with feces and is considered an intermediate host of the parasite. Penetrating into the human body, toxoplasma can freely circulate in the blood, enter the regional lymph nodes, be deposited in the brain, eyes and muscles, destroy cells and form cavities (cysts and pseudocysts). However, after the death of the parasite in the human body can form calcicates (dead toxoplasma, impregnated with calcium salts).
Several strains of the pathogen are found in nature. The strain RH is highly virulent and very quickly leads to the death of laboratory animals, and avirulent strains, as a rule, do not cause any clinical manifestations of the disease.
Sources of infection
1. The main sources of infection are homemade and homeless cats, since in the organism of these animals the complete path of development of the parasite (tissue and intestinal) takes place. Cat feces can remain very long in the environment, presenting a potential danger to other animals and humans, but more often infection can occur when cleaning a cat's toilet.
2. Sand or earth. Very often toxoplasma penetrates the human body through contaminated sand or earth (in the garden, in the garden, in the park or on the playground equipped with a sandbox).
3. Meat and eggs. Some agricultural animals and birds are considered intermediate hosts of the parasite. It should be noted that they are not a direct source of infection, since toxoplasm does not form cysts in their bodies, but at the same time, the pathogen can be found in meat (most often in lamb and pork), as well as in bird eggs. In this case, infection occurs due to insufficient heat treatment of the food products listed above.
4. Unwashed vegetables and fruits. If food is contaminated with infected land, the risk of infection is simply enormous (from literature sources it is known that a cat can allocate about 2 billion cysts in the environment for 2-3 weeks, which remain contagious up to two years).
5. Transmission of infection from mother to fetus. This way of transmission of toxoplasmosis is the most dangerous. Typically, this infection occurs when the parasite enters the body of a previously uninfected woman, and then, through the placenta, into the fetus. In this case, the consequences for the unborn child can be the most catastrophic, and therefore, toxoplasmosis during pregnancy is often an indication for its artificial interruption.
Зараженный токсоплазмозом человек не опасен для окружающих, то есть, прямого заражения от человека к человеку не происходит ни при каких контактах. Note: A person infected with toxoplasmosis is not dangerous to others, that is, direct infection from person to person does not occur at any contacts. However, transfusion of blood from an infected donor to a recipient or organ transplant poses a certain danger, but in this case, according to experts, the risk of infection is negligible.
- Oral, or alimentary (through the mouth);
- Percutaneous (very rare route of transmission);
Symptoms of toxoplasmosis
In an acute stage, the disease affects almost all the systems and organs of the body. Patients complain of weakness, drowsiness, chills and fever. It can be yellowing of the sclera and skin, enlarged spleen and liver, there is a profuse papular rash. Often, the muscle tone decreases and strabismus appears.
If the inflammatory process develops gradually, there is a less pronounced clinical picture. At the same time, changes are observed on the part of the visual apparatus (clouding of the lens), and, step by step, the dropsy of the brain develops.
Chronic forms of the disease are characterized by irreversible changes in the central nervous system (impaired mental development and complete blindness). Often, when involved in the pathological process of the central nervous system, patients experience emotional lability, irritability and even neurasthenic seizures. Women are disrupted by the menstrual cycle, men may develop erectile dysfunction or complete impotence.
Forms of toxoplasmosis and peculiarities of their course
Acute forms of the disease
Depending on the clinical syndrome, medical practice distinguishes between glandular (lymphogangliary), typhoid-like (exanthematous), visceral, meningoencephalitic (cerebral) and ocular forms of the disease.
For the glandular (lymphoglial) form is characterized by hypertrophy of the lymph nodes (while they remain painless), headache, fever, disruption of the autonomic nervous system, damage to the liver, spleen and bile ducts.
Typhoid-like (exanthematous) form differs acute beginning with fever, chills, headaches, pains in muscles and joints. On the 4th-7th day of the onset of the disease, a profuse maculopapular rash appears on the body. It spreads throughout the body, except for the plantar area and palms. Lymph nodes, liver and spleen are enlarged, eyes and CNS are affected. This form of toxoplasmosis is very difficult and often ends in a fatal outcome.
The visceral form arises from the generalization of parasites by the hematogenous pathway and the destruction of various organs by them. In this case, interstitial pneumonia, hepatitis, myocarditis and other severe heart lesions can be diagnosed in patients.
Cerebrospinal forms are characterized by signs of acute meningoencephalitis, and the symptomatology depends on the prevalence of inflammation in the brain. In this case, too, the temperature rises and sometimes there is a characteristic rash, as well as meningeal symptoms and severe intoxication.
Patients may develop paralysis, paresis, psychosis, loss of hearing and vision, and possible fatal outcomes.
In acute ocular form of toxoplasmosis, lesions of the visual apparatus are manifested in the form of iridocyclitis, choreoretinitis, exudative or serous retinitis and opacity of the vitreous humor.
Characteristics of chronic intoxication are characteristic for this form of the disease. There is a defeat of the reticuloendothelial, nervous and cardiovascular systems, the musculoskeletal system, the digestive tract, and also the organs of vision.
в период обострения патологического процесса наблюдается кратковременная паразитемия (присутствие возбудителя в периферической крови). Note: during the exacerbation of the pathological process, short-term parasitemia is observed (the presence of an agent in the peripheral blood).
This form can be characterized by various clinical manifestations and severity of the course. The disease occurs in both acute and chronic forms with exacerbations and remissions. In this case, various internal organs, organs of vision and hearing and CNS are involved in the inflammatory process.
This form is a consequence of intrauterine infection of the fetus. In the case when transplacental transmission of the causative agent from mother to child occurs in the first trimester of pregnancy, often the fetus dies. If he remains alive, he usually has severe CNS lesions, such as hydrocephalus, acrania, anencephaly, microcephaly, etc.
With a later intrauterine infection, the newborn is diagnosed with signs of hydrocephalus, meningoencephalitis and choreoretinitis.
Toxoplasmosis, pregnancy and breastfeeding
In the event that the infection of the expectant mother occurred more than 6 months before the onset of pregnancy, the infection is not transmitted to the child. With less time, there is a risk of infection of the fetus, although, according to experts, it is insignificant.
About intrauterine infection with toxoplasmosis can be said when the pathogen itself is detected in the blood of a pregnant woman, or antibodies to it, and also when parasites are detected in the internal organs of the mother and amniotic fluid. If suspected of a primary infection with toxoplasmosis, an infectious disease specialist should be consulted and the analysis should be repeated after 2-3 weeks.
Only when the diagnosis is confirmed, specific treatment can be conducted, reducing the risk of congenital infection. However, this type of therapy does not completely rule out negative consequences, and therefore doctors often recommend an artificial termination of pregnancy.
In detecting toxoplasmosis in the II and III trimester of pregnancy, women are prescribed etiotropic therapy and in parallel, the study of amniotic fluid is conducted.
характерно то, что ребенок с врожденным токсоплазмом у одной и той же женщины рождается только один раз, а все её последующие беременности протекают нормально и оканчиваются рождением здорового малыша. Note: it is characteristic that a child with congenital toxoplasm in the same woman is born only once, and all her subsequent pregnancies proceed normally and end with the birth of a healthy baby.
If during the breastfeeding period of a child the active forms of toxoplasmosis are not detected in the nursing mother, infection through breast milk is virtually excluded. However, in the presence of erosions or bleeding cracks in the nipples in the acute (active) stage of the disease, in which the pathogen is in the peripheral blood, the child may become infected. In all other situations, when only signs of a previous illness are detected in the maternal blood, you can breastfeed without any fear.
Toxoplasmosis in HIV-infected
Very often, toxoplasmosis develops against the background of weakened immunity, and therefore it can be found in HIV-infected patients and those on immunosuppressive therapy. Typically, this predisposition is associated with the activation of a latent infection. According to statistics, in 95% of cases the cerebrospinal form of toxoplasmosis is detected in HIV-infected patients.
Symptomatology of acute toxoplasmosis against the background of human immunodeficiency is mainly caused by CNS damage. In most patients, the brain suffers, and both focal and general cerebral signs of the disease can be observed. 75% of patients have mental disorders, 33% have epileptic seizures, and 10-72% have fever and headache.
The causative agent, penetrating the brain, causes necrosis of the brain tissues, and also provokes the development of secondary pathologies such as hemorrhages, edema or vasculitis . Often, the disease is characterized by a gradual onset, when the symptomatology is growing for several weeks. However, there are cases when toxoplasmosis begins sharply, with sudden confusion, local headache and lightning-fast development of focal symptoms (loss of visual fields, hemiparesis, hemiplegia, partial epileptic seizures). In this case, the brain stem, pituitary gland, basal nuclei and the boundary between the white substance and the cortex are most often affected.
Diagnosis of toxoplasmosis
When diagnosing, first of all, the nature of the course of the infection process (carrier or illness) is revealed.
Because of the huge variety of clinical forms of the disease, its differential diagnosis is significantly more complicated. Therefore, in the case of an unclear clinical picture, the patient is obligatorily assigned a study for the presence of an agent in the body.
To do this, in laboratory practice, a serological test method is used, based on the application of the binding reaction of the compliment to the special Sabin-Feldman dye. If a negative result is obtained, toxoplasmosis is excluded, and a positive diagnosis can be confirmed only if there are clinical symptoms.
At the same time, during the diagnosis, an intradermal test with toxoplasmine, an indirect hemagglutination reaction, an immunofluorescence method and a neutrophilic leukocyte damage response can be used.
Absolute confirmation of the diagnosis is an intravital and postmortem parasitological examination. It provides for isolation of the causative agent of toxoplasmosis from various biological fluids of the body.
Treatment of toxoplasmosis
Toxoplasmosis is a parasitic infection that does not always need treatment. Unfortunately, it is not possible to completely destroy the pathogen, so a small amount of the parasite and antibodies to it remain in the human body for the rest of his life.
At the same time in clinical practice there were isolated cases when patients were completely cured of the disease. However, this occurred only when they were given adequate therapy in the very first days after infection.
After a very short period of time after the penetration of the pathogen into the organism of its host, toxoplasm forms cysts that have high resistance, including drugs. That is why when a human is found to have antibodies to a parasite in the absence of clinical signs of the disease, treatment of toxoplasmosis, as a rule, is not carried out. Exception is made by pregnant women, newborns and people with immunodeficiency.
Drug therapy in the acute form of the disease involves the use of antibacterial drugs and pharmaceuticals of chemical origin (chemotherapy). It should be noted that when applied, the patient's immunity decreases, which often leads to an exacerbation of the disease. That is why the treatment of toxoplasmosis should be directed not at the complete destruction of the parasite, but at preventing the development of severe flow accompanied by the defeat of internal organs. As a rule, it is prescribed for a severe clinical picture of the disease, CNS, lung, heart and other vital organs.
It should be emphasized that the treatment of toxoplasmosis is a complex and lengthy process, conducted in several courses using etiotropic drugs and antibiotics.
Patients with a chronic form of toxoplasmosis in the acute stage are assigned a weekly course of chemotherapy, and also desensitization with corticosteroids and antihistamines is performed in parallel. В завершении рекомендован курс иммуномодулирующей терапии, способствующий налаживанию иммунного ответа организма.
Профилактика заболевания заключается в неукоснительном соблюдении правил личной и общественной гигиены. Беременным женщинам не рекомендуется контактировать с кошками, а еще, по возможности не следует допускать животных в песочницы и другие места, где играют дети. Категорически недопустимо дегустировать сырой фарш и употреблять термически необработанное мясо, а также пить сырые яйца и молоко.