Amoebiasis - Causes, symptoms and treatment. MF.

Amoebiasis is a protozoal infection with a fecal-oral transmission mechanism, characterized by ulcerative lesions of the colon and extraintestinal lesions in the form of abscesses in other organs and tissues, and a tendency to prolonged and chronic course. Only people are ill. The causative agents are the simplest parasites - amoeba. This is one of the diseases of "dirty hands".

As early as 1875, amoebiasis pathogens were first detected, and in 1891 - this disease was isolated into an independent nosological form, called "Amoebic dysentery."The term "amebiasis" has been used since 1906 to the present day.

Dysenteric amoeba

It is known that a human can parasitize 6 species of amoebae, 5 of them are not pathogenic and feed on intestinal bacteria, and 1 - Entamoeba histolytica - pathogenic, causes severe intestinal symptoms.

Dysenteric amoeba in the intestine

As with any parasite, the dysentery amoeba has 2 life forms - trophozoite( vegetative stage) and cyst( resting stage).Trophozoite also passes several stages and can stay in one of them for a long time:

• tissue form( found only with acute amebiasis in the affected organs and rarely in feces);
• a large vegetative form( this form already inhabits the intestine and is found in the coprogram, it absorbs red blood cells);
• luminal form( found in chronic amoebiasis or in the stage of reconvalescence after taking a laxative);
• pre-form( found under the same conditions as the luminal).

All this matters to determine the source and methods of fighting against its parasites.

Cysts are found in patients with chronic recurrent amebiasis in the remission phase and in amoebasic patients.

The resistance of trophozoite and all its varieties is very low, in the external environment it dies within 30 minutes. Cysts are the most stable, for example:

• at 17-20ºC persist for a month, in darkened and moistened soil - up to 8 days;
• in chilled foods, fruits, vegetables and household items - up to 5 days on average;
• at minus temperatures remain several months.

Drying and heat ruins an amoeba almost instantly. Of the disinfectants, only cresol and emitin have a disastrous effect on them, and even chloramine does not adversely affect them.

Causes of infection with amebiasis

Age groups of both sexes are afflicted with amoebiasis, but mostly pregnant due to physiological suppression of the immune system, namely cellular immunity. The category of high risk of infection can also include people who received immunosuppressant therapy( GCS, cytostatics, etc.).The incidence is recorded year-round, with the maximum rise in hot months. Especially this disease is common in countries with a hot climate, including in the countries of Central Asia, in Transcaucasia. Quite often, the carriage is common, when there are no symptoms, and there is amoeba in the body.

Source - a person who secretes cysts, can be with or without symptoms. Excretion of the pathogen continues for many years, 300 million cysts or more are released per day. With bright symptoms, patients are not dangerous, because they identify vegetative forms that are not stable in the external environment.

Transmission routes - fecal-oral( through contaminated water and products) and contact-household( through "dirty hands" there is contamination of household items, contaminated feces of the patient).

Factors that reduce the body's resistance to the pathogen: dysbacteriosis, protein deficiency, concomitant worm infestations, pregnancy and other conditions, accompanied by a decrease in immunity.

Symptoms of amebiasis

Symptoms will be determined by pathogenesis, i.e. the technique of damaging factors. As soon as the cysts enter the intestine, the incubation period begins and lasts 1-2 weeks, that is, from the beginning of the introduction to the first signs of the disease. During this time, cysts move through the intestine and, with provoking factors, they begin to move further and penetrate the walls of the large intestine. The most commonly affected are the transverse and descending sections of the large intestine.

As the process progresses, the cysts turn into vegetative forms, which contain proteolytic enzymes( trypsin and pepsin), which destroy the intestinal wall and thereby facilitate penetration of the pathogen into the muscular layers of the intestine. This penetration will initiate the onset of clinical symptoms and further complications as the parasite spreads.

Symptoms of "acute" intestinal amebiasis( onset subacute - ie, symptoms are noticeable not on the first day, but with an increase in 2-3 days):

• liquid stool 4-6 times a day, with clear mucus and a pungent odor;
• the frequency of defecations gradually increases to 10-20 times a day and the stool is no longer of a stained nature, but in the form of vitreous mucus;
• after a few days or immediately in feces appears an admixture of blood in the form of "crimson jelly";
• Constant or cramping pain of varying intensity, intensifying during defecation;
• the appearance of tenesmus - a false urge to defecate, they are painful, long and do not lead to results;
• low-grade fever of 37-38ºС, holds for several days;
• swelling and tenderness of the abdomen.

The appearance of blood in the feces suggests that the wall has already been destroyed by intruding parasites, and the appearance of tenesmus is due to the defeat of the nerve endings of the intestinal walls. This symptomatology takes place during 4-6 weeks with the timely start of a specific treatment. If not treated, then there is remission and the disease takes a chronic course, which leads to a more extensive lesion of the intestinal walls, and subsequently to a violation of digestion and absorption.

Chronic course( as a result of untimely started treatment):

• unpleasant taste in the mouth, difficult to characterize;
• the tongue is coated with a white coating;
• the stomach at this stage is drawn, despite possible flatulence, with palpation - soreness;
• asthenic syndrome( weight loss), with a deficiency of proteins and vitamins( pale skin, brittle nails, dull hair, etc., there are a lot of options and they will depend on a certain vitamin deficiency);
• appetite decreased / absent;
• Decompensation is observed on the part of other organs and systems( but these symptoms are unstable and may be absent altogether), especially in the cardiovascular system and liver function: on the side of the heart - tachycardia and subdued cardiac tones, and on the liver side -increase and soreness.

In immunodeficiency, as well as in infants, it is possible for a lightning-fast course of amoebiasis: the disease develops during the first two days, manifests itself as a high fever, marked intoxication, severe pain, frequent stools, and dehydration. The extensive lesion of the intestinal wall quickly comes, which leads first to ulceration, then to paresis, and there is a high risk of perforation of the intestinal wall and the development of peritonitis. With such forms, the is very lethal.

There are also other clinical forms of amoebiasis, but they are better attributed to complications, because they occur more often due to untimely started treatment.

Diagnosis of amebiasis

It is possible to use the method from simple to complex:

1. Pay attention to the dynamics of the disease + stool character + epidemiological data.
2. Microscopic examination of the patient's feces, and in the presence of complications, from abscesses of internal organs, sputum, scrapings from mucous nasopharynx, biopsies of affected areas. Smears are stained to identify cysts and trophozoites. To obtain feces, you can use a provocative method - laxatives, but this is only applicable in case of remission, with acute course - absolutely contraindicated.
3. Endoscopy is performed when it is impossible to obtain feces for one reason or another. With the help of this method, biopsy specimens from the intestinal walls are taken, the condition of the walls is evaluated, namely ulcers formed by amoeba. In tissue cultures, biopsy specimens are found to have a vegetative form with erythrocytes inside, which is why it is called a hemophagus and this partly explains the development of anemia.
4. Serological methods: RIF( immunofluorescence reaction), ELISA( enzyme immunoassay) - methods aimed at detecting antibodies.
5. Additional methods: ultrasound of the abdominal and kidney organs, biochemical analyzes, UAC and OAM - these parameters can be informative if there are suspicions of abscesses, decompensation by organs and systems, etc.

Amoeba in a smear under the microscope

Treatment of amebiasis

There are several groups of drugs that act at different stages of the disease:

1. Direct contact medications( direct amoebicides), which have a disastrous effect on the luminal forms of the pathogen. They are used for sanitation of amoeba carriers and for the treatment of chronic amoebiasis in remission. This is Khiniophon, Diiodohin. Quinophone can be used in the form of enemas.
2. Drugs that act on tissue amoebocytes, ie against tissue and luminal forms in the stage of acute intestinal( and extra-intestinal) amoebiasis: Emetine, Dihydroemitin, Ambilgar, Hinamine( with amoebic liver abscesses).
3. Drugs of universal / combined action, are applicable for all forms of amoebiasis: Metronidozole( Trichopolum), Furamid.
4. Antibiotics are used to change microbial biocenosis in the intestine.
5. Preparations that restore the normal intestinal microflora: prebiotics, probiotics, symbiotics, a complex immunoglobulin preparation( CIP) is possible.
6. Enzyme preparations( digestal, panzinorm) for relief of the colitis syndrome.

Dosages of drugs are not given purposefully, because several drugs are toxic, often used in combination with each other or other groups of drugs( with antibiotics), and are assigned under the control of laboratory diagnostics.

In parallel with drug treatment a protein mechanically chemically sparing diet is used. Vitamin-therapy with oral access, bypassing the intestine, because there is impaired absorption. In the presence of abscesses in certain organs, surgical tactics are used against a background of complex treatment.

Complications of amebiasis

• Appearance of extraintestinal amebiasis( liver abscess, pleuropulmonary amebiasis, brain abscess, skin lesions);
• Perforation of the intestine, leading to peritonitis and high lethality;
• Strictures( constriction of the areas) of the intestine;
• Intestinal bleeding;
• Breakthrough abscesses.

Prevention of amebiasis

Detection and division of cystogenerators and carriers. Compliance with sanitary and hygienic measures. Specific prevention is currently not developed.

Therapist doctor Shabanova I.Е.