Shagas's disease – an inoculable protozoan infection which causative agent is pathogenic Trypanosoma cruzi, and a carrier triatomovy bugs. The sharp form of a disease of Shagas is shown by fever, head and muscular pain, hypostases, rash, lymphadenitis, a gepatosplenomegaliya, a kardiomegaliya and myocarditis, an encephalomeningitis; chronic - heart failure, megaezofagusy, megacolon. The diagnosis of a disease of Shagas is based on data of the anamnesis, a clinical picture, microscopic, cultural and serological researches. In treatment of a disease of Shagas anti-parasitic medicines, symptomatic means are applied, at complications - surgery.
Shagas's disease (American ) – , caused by an intracellular elementary parasite of the sort T. cruzi, leading to inflammatory and degenerate changes from heart, nervous system, a GIT. Shagas's disease belongs to natural and focal diseases, is widespread practically in all countries of the American continent: areas, endemic on a tripanosomoza, are Central and South America. In rural areas most of the population catches tripanosomozy at children's age, often the invasion proceeds asymptomatically. Among infected with Shagas's disease males prevail.
Infecting agent of Shagas is zhgutikovy elementary Trypanosoma cruzi which difficult cycle of development includes change of owners - vertebrate animals and the person, and as a specific carrier serve blood-sicking bugs of a subfamily of Triatominae (triatomovy). T. cruzi has the spindle-shaped form, and an undulating membrane. The parasite passes several phases of life cycle: an amastigot, living in fabric cells of the person; the epimastigota growing in intestines of carriers; and the tripomastigota which is in blood of animals and the person. As the main owner of T. cruzi serves the person, additional - battleships, anteaters, monkeys and pets (dogs, cats, pigs). An invasive stage for carriers and owners are tripomastigotny forms.
Infection of bugs occurs in the course of food the blood of the person or animals containing tripomastigota. In a human body the infecting agent of Shagas is brought together with the infected excrements of bugs when combing wounds after their stings on skin and mucous lips, a nose, a conjunctiva. Characteristic of T. cruzi is ability to intracellular parasitism in macrophages of skin and mucous membranes, in cells of a myocardium, an endoteliya of lymph nodes, spleens, a liver, lungs, a neuroglia. After a rupture of the struck cages overflowed with the bred amastigota there is infection of new cages. Parasitizing of trypanosomes leads to inflammatory dystrophic and degenerate damage of internals. The most widespread way of infection with Shagas's disease – inoculable, transfer is possible in the alimentary, sexual, transplacentary, haemo transfusion way and at organ transplantation. The persistention in the owner's organism during all life is characteristic of T. cruzi.
Symptoms of a disease of Shagas
The incubatory period of a disease proceeds 1-3 weeks. Then in the place of penetration of trypanosomes local inflammatory reaction (shagoma) in the form of eritematozny knot with a swelling and reddening or unilateral crimson hypostasis of a century (a symptom of Rominyi) with conjunctivitis, followed by increase in regionarny lymph nodes can develop. Shagas's disease passes in 2 stages: sharp (the first 2 months) with circulation of a large number of parasites in blood and chronic - with concentration of trypanosomes in internals.
In a sharp stage of a disease of Shigas in most cases symptoms are absent, at a part of patients are shown benign. At children up to 5 years the most severe form with system manifestations and a lethality to 10-14% develops. Among the general symptoms of a disease of Shagas the indisposition, constant or remitiruyushchy fever (up to 39-40 °C), head and muscular pain, hypostases standing, puffiness of the person, small makulezny rash can be noted. Cervical, pakhovy and axillary lymphadenitis, a gepatosplenomegaliya is characteristic. There can be secondary shagoma – dense knots in hypodermic cellulose. Primary damage of heart, TsNS and peripheral , bodies of reticuloendothelial system is noted. The acute inflammation and expansion of all cameras of heart (kardiomegaliya), diffusion myocarditis, violation of warm activity develops. Some patients (especially, at children of early age) can have a sharp specific encephalomeningitis, hemorrhage in brain covers. The congenital disease of Shagas can lead to spontaneous abortion or premature birth; at newborns is followed by heavy anemia, a gepatosplenomegaliya, jaundice, spasms, it is frequent - a lethal outcome.
At a chronic form of a disease of Shagas symptoms can long be absent, there will be no irreversible internal injuries yet. Most often the cardiomyopathy which is expressed heart failure, arrhythmia, a thrombembolia develops. From a GIT the pathological expansion of a gullet () which is shown a dysphagy, pain when swallowing and the expansion of a thick gut (megacolon) which is followed by intestinal impassability, a congestion of kalovy stones are characteristic. There are vegetative violations and peripheral neuropathy. Eventually Shagas's disease can lead to sudden death owing to the progressing destruction of a cardiac muscle.
Diagnosis of a disease of Shagas
Diagnosis of a disease of Shagas includes careful collecting the anamnesis (taking into account a sore point, trips to areas, endemic on a disease), the analysis of data of a clinical picture and laboratory researches (microscopic and cultural methods, serological analyses and PTsR).
As the studied material blood, cerebrospinal fluid, punktata from primary places of defeat, lymph nodes, spleens, marrow is used. In a sharp stage of a disease of Shagas (the first 6-12 weeks) of parasites it is possible to find at microscopy of a thick drop of blood or the fixed painted medicines. Bacteriological crops of blood of the patient help to reveal true culture of T. cruzi. At Shagas's disease the ksenodiagnostika including a research of contents of intestines of a neinvazirovanny triatomovy bug after saturation by its blood of the patient is applied. Conducting biological test with introduction of blood of the patient to guinea pigs or white mice and the subsequent studying of samples of fabrics is possible.
At a chronic disease of Shagas the serodiagnosis is more effective: reaction of binding of a complement, reaction of indirect fluorescence, reaction of indirect hemagglutination, IFA. Existence of specific IgM speaks about a sharp stage of a disease of Shagas, at chronic there are only IgG. Some infections, for example, malaria, , can yield false positive results on therefore rekoyomendutsya to apply not less than two nezavisiyomy methods of serodiagnosis. Differential diagnostics of pathogenic trypanosomes from not pathogenic types capable is necessary is in a human body, without causing development of a disease.
Treatment and forecast of a disease of Shagas
Today treatment of a disease of Shagas is ineffective; therapy allows to lower a lethality among patients, but does not give confidence in a full eradikation of the intracellular T. cruzi forms. In treatment of a disease of Shagas two anti-parasitic medicines are applied: and which reception is more effective in a sharp stage of a disease. In a chronic stage of an infection treatment is directed to relief of symptoms of the developed complications of a disease of Shagas. At heart failure and arrhythmia, for prevention of tromboembolichesky states APF inhibitors, warm glycosides, antiarrhytmic means, anticoagulants are appointed, in hard cases aortocoronary shunting, implantation of a pacemaker, transplantation of heart are shown. Treatment of an encephalomeningitis – symptomatic; at damage of a GIT corticosteroids can be used; at megacolon perhaps surgical intervention: imposing of a kolostoma, resection of a thick gut.
The forecast of a disease of Shagas depends on a stage of a disease, sharpness of development and reversibility of inflammatory and degenerate damages of internals, age of the patient. Patients with a late stage of a disease of Shagas often die of an acute heart failure, a heart attack, a stroke, children of early age - of promptly developed sharp encephalomeningitis. Prevention of a disease of Shagas includes insecticidal processing of housing of the person, hen houses, pigsties – the main habitats of bugs - carriers of parasites, improvement of the dwelling; selection and inspection on potential blood donors and bodies, sanitary education of the population.