Toxoplasmosis( toxoplasm) - Causes, symptoms and treatment. MF.
Mar 25, 2018
Toxoplasmosis is a parasitic disease caused by intracellular parasites of toxoplasma, characterized by chronic course, with the defeat of skeletal muscles, myocardium, eyes, central and peripheral nervous system, as well as development of lymphadenopathy( increase of regional lymph nodes) and hepatosplenomegaly( increase of spleen and liver).
The causative agent was discovered in 1908 at one and the same time by two different scientists who were apart from each other: Splendore and Nicolas. They found in the internal organs of fixed unicellular parasites, an arcuate shape( Toxoplasma - arch, arc) - which explains the origin of the name.1914 - Castellani has established a pathogenic significance for a person, having discovered the same parasites in the deceased soldier.1916 - prof. Fedorovich discovered these parasites in a child when he was examined for malaria.1923 - the German scientist Yanki described in detail the case of death in an 11-month-old child who died from these parasites.1937-1955 - American virologist Sabin described the features of intracellular structure, reproduction and serodiagnosis with respect to these parasites. But despite even such a long and thorough study and knowledge in this area, toxoplasmosis continues to terrify people who hear such a diagnosis, especially for pregnant women.
Pathogen - a parasite Toxoplasma gondii, is a protozoan type. Conducts intracellular parasitization and in the phase of reproduction takes the form of an arc( which was discovered by the discoverers).In a nondividing form, the body is covered with a double sheath( pellicle) - this explains the stable stability in the external environment.
Like any other parasite, toxoplasm has a life cycle with a change of host and the passage of different phases of development. Development of the pathogen is carried out in the epithelial cells of the intestine of cats( cats are the final hosts).Inside these cells, immature cysts( a form of existence covered by a shell) are formed, which are excreted with feces of cats into the external environment and are found in the soil. After 3-7 days, oocysts are formed - fertilized cysts with a stronger shell and ready for self-division, which persist in the soil for 1.5-2 years and can enter the human body in this form( the person is an intermediate host).
In a person, toxoplasm also enters the epithelial cells of the intestine and tissue macrophages and begins to undergo the following stages of the life cycle: trophozoids( multiplying parasites - they fill the affected cells) and after - tissue cysts( this stable form, which remains in the body for a long time;destruction is released toxoplasm and relapses disease).
For each form of development, there is a range of resistance and sensitivity, which is important in the prevention and treatment:
- cysts and oocysts are resistant to chemical preparations and physicochemical factors, persistently stored in the soil( up to 2 years) at high and low temperatures.
- trophozoid is sensitive to pyrimethacin, streptomycin, sulfonamides, tetracyclines;quickly dies under the influence of disinfectants, as well as drying and heating.
Causes of infection with toxoplasmosis
The causative agent is anthropozoonosis( affecting humans and animals).Source - cats, pigs, cows, sheep( in the muscle tissue of the last 3 animals are toxoplasm in the form of cysts).Transmission routes:
- Alimentary( getting oocysts with soil in the human gastrointestinal tract with unwashed vegetables and fruits, eating poorly heat-treated meat);
- Parenteral - ie through the blood( contamination of meat workers, blood transfusion or organ transplantation).This is especially true for highly virulent strains( the types of pathogen most dangerous to humans).
- The vertical path( transplacental) is the primary infection of the fetus during pregnancy due to the penetration of toxoplasma through the placenta.
Symptoms of toxoplasmosis
Symptoms of toxoplasmosis are very diverse and very often take the appearance of other diseases, ranging from inflammation and ending with a tumor, but it can also be completely asymptomatic. All the symptoms will be explained by tropism( directed to defeat) to some organs and the nature of the flow, which depends on the immune status of the infected person. Target organs: lymph nodes, liver, spleen, skeletal muscles, myocardium, CNS and eyes.
The incubation period( from the onset of infection, to the first onset of symptoms) is up to 3 weeks. In this phase, the oocysts enter the enterocytes( intestinal cells) of the lower part of the small intestine → through the lymphatic and blood vessels, reach the lymph nodes and target organs( listed above), where they multiply → further necrotic foci with subsequent calcificationdeposition of Ca2 + salts), and specific granulomas( cell clusters of epithelioid cells, macrophages, plasmocytes, lymphocytes and eosinophils) are formed in the lymph nodes-their detection is diagnostically important when starting from the limvuzloat.
Once the immune system overcomes the disease, all active toxoplasma dies and only tissue cysts remain, which last indefinitely, but eventually they die and dissolve. But with immunodeficiency states, instead of destruction of tissue cysts, their release and the development of recurrence of the disease occur. By the nature of the course of the symptoms can be: acute, chronic, latent.
Forms of acquired toxoplasmosis will depend on which organ is affected:
1. Lymphonodular form - enlarged lymph nodes( more often occipital and cervical, but can be affected by inguinal / axillary / mesenteric( in the gastrointestinal tract)) to 1.5-3.5 cmin diameter, to the touch they are painless, elastic, mobile and not soldered to each other and surrounding tissues. Against this background, hepatosplenomegaly is possible - enlargement of the liver and spleen.
2. Meningoencephalitic - a very diverse neurological symptomatology, therefore only main changes will be listed below.
• cerebral manifestations( encephalitis, meningoencephalitis, vasculitis) - in this case, there is a lesion of the soft meninges with serous inflammation and the development of cerebrospinal hypertension( i.e., an increase in intracranial pressure), this can be accompanied by headaches, more often of a diffuse nature, there are false meningeal symptoms. With these manifestations of toxoplasmosis often think of brain tumors.
• common( meningoencephaloradiculoneuropathy, diencephalitis) - vascular crises and lability of the psyche with personality changes are added to the above symptoms.
• Spinal - damage to the posterior columns of the spinal cord, which is characterized by tension symptoms( pulling along the nerve fibers during passive movement).
• defeat of peripheral nerves - pain and numbness in the limbs along the roots and peripheral nerves, a symptom of tension, disturbance of pain sensitivity, vegetotrophic disorders( violation of vascular innervation, which can lead to vegetovascular dystonia).
3. Ocular - chorioritenitis( inflammation of the vascular and mesh shell of the eyes) and uveitis( defeat of the vascular envelope of the uveal tract).
4. Cardiac form - development of focal or diffuse myocarditis or pericarditis. This form is manifested by weakness, fast fatigue, shortness of breath, palpitations, chest pains.
5. Generalized form - a combination of the above forms, against the background of fever, chills, muscle and joint pain.
6. Congenital toxoplasmosis is isolated in a separate form and has a number of symptoms depending on the gestational age at the time of infection.
• Before 2 weeks of pregnancy - death of the embryo or blastopathy( systemic pathology similar to the genetic one).
• 2 weeks -2 months - interruption or formation of embryopathopathies( malformations at the organ or cellular level).
• 2-6 months - interruption or formation of early fetopathies( generalized inflammation with the outcome of fibrosclerosis of the whole organ or its site).
• 6-7 months - acute or subacute form of the flow passes in utero and ends before the development of the child, after birth, toxoplasmosis proceeds in chronic form: the presence of hydrocephalus, the deposition of intracranial calcifications, chorioretinitis, lag in physical and mental development, spastic paralysis, convulsive syndrome, hepatosplenomegaly, prolonged jaundice, anemia.
• 7-8 months - acute phase ends before birth and, the child is born with a subacute form: CNS and eye lesions, progressive hydrocephalus.
Toxoplasma injury 7-8 months after pregnancy
• 8-9 months - birth with clinic of acute congenital toxoplasmosis - severe condition characterized by severe intoxication, fever, profuse polymorphic rash, hepatosplenomegaly, jaundice, generalized lymphadenopathy, hemorrhagic syndrome, pneumonia, myocarditis, dyspeptic disorders.
As you noticed, the later the infection occurs, the more severe the further symptoms at the time of birth. A number of scientists associate this with the permeability of the placenta( by its "aging"), which increases closer to birth.
After recovery, the current of toxoplasmosis in the child can take a slow form with the following manifestations:
• encephalitis( after 5-7 years)
• hepatolic syndrome( in the form of neuroendocrine disorders in adolescence):
- weight gain of 25-40 kg from the agenorms,
- uniform obesity,
- hypogenitalism in boys and premature maturation in girls,
- impairment in the emotional-volitional sphere, with the full preservation of the intellectual abilities of
• diencephalnepilepsy, is also manifested in adolescence and is characterized by: urinary incontinence, visual hallucinations, night terrors, prolonged fever, lymph node enlargement, intelligence corresponds to age on the background of emotional lability and reduced performance, VSD( in violation of vascular innervation)
Diagnosis of toxoplasmosis
1.In the hemogram: ↓ Lc and Nf, relative lymphocytosis, ↑ E, ESR normal - ie, the blood shows only inflammation and the presence of allergic readiness.
2. In the liquorgram: it is made according to strict indications, in particular with meningeal symptoms, as a result of which yellow color of the liquor, ↑ Lf and protein is detected.
3. On the roentgenogram: strengthening of the vascular pattern, finger impressions, widening of the interosseous sutures, the presence of intracranial calcicates( especially in the occipital region).
4. Laboratory diagnostics:
• Direct detection of toxoplasm, their antigens and DNA:
- culture method( by bacteriological culture of blood smears, cerebrospinal fluid centrifuges, biopsy specimens of lymph nodes and other tissues)
Toxoplasma cells marked red
Toxoplasma in immunofluorescence
- polymerase chain reaction( PCR) - detected toxoplasmal DNA in blood and liquor
These methods can not be used often, because of short-termthe presence of the pathogen in accessible biological tissues.
• Methods for determination of immune readiness: use of ELISA for determination of immunoglobulins class G and M;IgM - appear by 2 weeks from primary infection and their high titer persists up to 3 months, for someone up to 12 months - this makes it difficult to determine the timing of infection. But it is important, that IgM at exacerbations are not infected. IgG begin to be synthesized from 2 weeks after infection, with reactivation and congenital toxoplasmosis, the indicator may increase, but not always, therefore, not only the presence of IgG itself, but also the degree of avidity( the binding strength of Ig to the antigen) - the stronger the bond, the older the infection process(ie occurred a long time ago).
• Determination of the degree of response with a sample with toxoplasmamine( in children of the first 2 years of life it can be false positive), therefore spend more often with divorced. It is considered positive for infiltration more than 10 mm, formed on day 2.
• For testing the congenital toxoplasmosis, examine the Am( antibodies) in the child and compare them with the mother's At titre:
- the absence of At in the mother and the child allows to eliminate the congenital toxoplasmosis
- the presence of IgM and G in a titre exceeding 4 times the mother's At titre,speaks about congenital toxoplasmosis
- at the same indices both for mother and baby - the results should be rechecked in 2-3 weeks
- the decrease in the titre Am in a baby is 2 times compared with the mother's - this means the mother At, the young
• Diagnostic evidence for congenital toxoplasmosis:
- weakened obstetric history( gestosis, infection during pregnancy, threat of interruption)
- contact with cats, inadequate use of thermally processed meat
- prolonged febrile or subfebrile fever with symptoms of intoxication in the child
-CNS and / or eye
- hepatosplenomegaly accompanied by prolonged jaundice
- polymorphic exanthema
- prematurity, lag in physicaldevelopment of
- confirmation of possible infection with laboratory data
Treatment of toxoplasmosis
1. Etiotropic treatment. Only affects trophozoids. Drugs of choice: pyrimethacin, spiramycin, clarithromycin. Some of them are quite toxic, so they should be prescribed only by a doctor, taking into account age-related dosages and strict contraindications.
2. Pathogenetic treatment - toxoplasmotherapy, antihistamines, immunomodulators and immunostimulants under the control of immunograms. Assign probiotics for the prevention of dysbacteriosis, multivitamins and drugs of metabolic therapy - as fortifying, enterosorbents, plant adaptogens.
3. Symptomatic treatment is prescribed depending on the prevailing symptoms in different forms of toxoplasmosis
Treatment duration depends on the severity of the disease and the response to treatment, maybe from 4 weeks to 12 months. When treating infected pregnant women raise the issue of abortion and, with continued pregnancy, prescribe a course of spiromycin with antenatal diagnosis. This issue is very scrupulous and is decided collectively.
Rehabilitation after treatment
The timing, the frequency of follow-up and the amount of examination depend on the severity and form of clinical manifestations. Children who have suffered acute toxoplasmosis are observed by the pediatrician for 10 years, once every 6 months, with a neurologist and ophthalmologist, and carrying out an ELISA.Rehabilitation measures include: protective regime, therapeutic nutrition, immunomodulators and stimulants, multivitamins, plant adaptogenes and metabolic therapy.
Complications of toxoplasmosis:
cerebral dysfunction, cardiovascular failure with the formation of arrhythmias, atrophy of the optic nerve disk with the possibility of complete loss of vision, anemia, dysbacteriosis, etc., but severe flow with poor compensation of organs and systems can lead to deathat an early age and with congenital infection).
Prophylaxis of toxoplasmosis
Specific prophylaxis is not developed, therefore it is necessary to observe personal hygiene rules, conduct heat treatment of food products, limit contact with cats and periodically conduct laboratory tests for toxoplasmosis( after consultation with a doctor).
Doctor therapist Shabanova IE