Amoebasis of the intestines: diagnosis and treatment

Amoebiasis of the intestine: what is it? This is a fairly common infectious disease, which is accompanied by a primary lesion of the intestinal tube, as well as other organs and systems after the generalization of the process. This is a very dangerous pathological process, the result of which can be fatal.

Definition

Amoebiasis of the intestine is a disease that is caused by pathogenic species of Entamoeba histolytica. This protozoan microorganism is widespread in countries with a humid and hot climate. In addition, in countries located in the tropics and subtropics, an extremely low level of social hygiene, therefore, intestinal infections occur in most of the population. This is an urgent problem for the health of third world countries.

In order to understand how dangerous amoebiasis is for a person, it is important to know that mortality is second only to malaria. Practically half a billion people in the world are carriers of Entamoeba histolytica. Ten percent of them have clinical symptoms, and another twenty percent are death from complications without a preliminary manifestation of the disease.

The constant migration of people from developing countries to more prosperous countries promotes the spread of the pathogen and increases the incidence. In Russia, due to emigration from the countries of the Middle East, the disease is widely spread.

Etiology

Amoebiasis of the intestine is caused by a histolytic or dysenteric amoeba that colonizes the lumen of the large intestine of a person. Amoeba can exist in three forms: cystic, tissue, luminal and pre-cystic.

1. Tissue form is found in patients only in the acute period of the disease and only in the tissues of the intestine, and not in the feces. It is a small amoeba that has soft ectoplasm and endoplasm, which does not contain organelles. It is moved in the body with the help of pseudopods. This form can absorb red blood cells, and also make enzymes that help it get into the mucous and submucosal layer of the gut. This causes necrosis of the tissues and the appearance of ulcers.
2. The enlightened form is found in the lumen of the large intestine. It feeds on bacteria that make up the human normoflora, as well as tissue detritus formed during ulceration. It is often found in people who have suffered an acute form of the disease or are carriers. Its dimensions are smaller, movements are slower than tissue.
3. The preexisting form is transitional and occurs only in this species of amoebae. It is unstable to methods of disinfection and quickly perishes outside the host organism.
4. Cysts are a sleeping form of a dysentery amoeba. So it can exist in the external environment. These are round, colorless cells that have four cores and a vacuole. This form is found in the intestines of convalescents and carriers.

Epidemiology

Amoebiasis of the intestine is anthropogenous infection. That is, the causative agent lives only in man and is transmitted from person to person. The mechanism of transmission is fecal-oral, the transmission routes can be different: through water, food, household items or skin-to-skin contact. A person, who is a carrier, can excrete from the body millions of cysts every day and potentially infect everything around. This form of amoeba can remain viable in the open air for more than a month, and when frozen - up to six months. In tap water, the pathogen lives for more than two months, and on the soil surface - slightly less than two weeks.

Doctors try to diagnose amoebiasis of the intestines as soon as possible. Symptoms in women and children develop rapidly and the disease is difficult. Therefore, taking into account the intensity of allocation of amoebas from the body and their stability in the external environment, it is necessary to follow the rules of personal hygiene and conduct regular wet cleaning of living quarters with disinfectants.

Prevalence

Amebiasis of the intestine is widespread everywhere, regardless of climate or race. In tropical countries, the percentage of cases is higher, but in other areas this infection also occurs quite often. The spread of the disease is facilitated by low sanitary culture of the population and poor hygienic conditions: lack of centralized water supply, untimely garbage collection and cleaning of gutters.

The number of people who are carriers of the pathogen and even do not suspect about their disease, many times exceeds the number of those who have clinical symptoms. In some countries, this figure reaches forty percent of the population. In countries with a temperate climate, sporadic morbidity is recorded. The literature describes outbreaks of amoebiasis in places of imprisonment and in barracks.

In CIS countries, amoebas are usually people with human immunodeficiency virus, injecting drug users and AIDS patients. Transmission of the pathogen occurs in a warm travel time.

Pathogenesis

Amoebiasis of the intestine - what is it? This is a serious intestinal infection that develops when the large intestine is affected. The development of the disease is due to the properties of the pathogen. After swallowing a person cysts, she is exposed to the acidic environment of the stomach and small intestine enzymes and goes into a vegetative form.

From one cyst there are eight amoebas that move into the upper parts of the large intestine. While human immunity suppresses the mass reproduction of amoebas, they do not manifest themselves in any way: they feed on bacteria and chyme. But if circumstances start to favor them, for example, there is a violation of the acidity of the environment, trauma to the bowel wall, disruption of the peristalsis, the appearance of helminths or stress, the pathogen begins to actively multiply and penetrate from the lumen of the intestinal tube into its wall.

The parasite secretes proteases, hemolysin and other enzymes that destroy tissues and help penetrate the pathogen into the body. Neutrophils (tissue macrophages) try to absorb amoebae, but instead they are melted and isolated by mono-oxidants, which increase inflammation and necrosis. In places of ulcers there is a mixture of opportunistic and pathogenic microflora, the causative agent is plunged deeper into tissues and multiplies more intensively. So the primary focus or abscess is formed.

Over time, it is opened and in its place an ulcer with dented edges and necrosis in the center is formed. Mucous tries to close the defect with a new cloth and granulations. In the end, there is fibrosis of the mucosa, the formation of scarring and strictures. Abscesses do not appear simultaneously. On the mucosa of the large intestine, it is possible to detect both fresh and open ulcers and already epithelializing, as well as scars.

Ulcers can be so deep that they penetrate through the entire thickness of the wall, and can cause organ perforation with the development of peritonitis and intestinal bleeding. This contributes to the generalization of the disease and migration of amoebas with blood flow to other organs and tissues.

Symptoms

The World Health Organization identifies several forms by which amoebiasis of the intestine can develop. Symptoms of each of them are pathognomonic enough, therefore diagnostics do not cause the doctor considerable difficulties.

Dysentery colitis. The most common form of the disease. There are both acute and chronic variants of the course. The incubation period is from two weeks to four months. The main symptom is diarrhea. At first about six times a day, but then it becomes more frequent twenty or more times, impurities of blood and mucus appear in the stool. Over time, the stool becomes like a raspberry jelly. Complaints about pain, temperature or fatigue a person does not show. But in severe cases, cramping pain in the right lower abdomen (often confused with an inflammation of the appendix) and high fever are possible.

The acute process lasts no more than six weeks, after which the remission period begins. Sometimes it goes into recovery, but it's rare. As a rule, after a couple of months the disease resumes, but in a chronic form. Without treatment, the process drags on for years. Chronic amebiasis can be conditionally divided into recurrent and continuous forms.

In the recurring course of the disease, periods of exacerbation die remissions, but the symptoms do not completely disappear, but only become less pronounced (at the level of mild disorder of the stool). During an exacerbation of a dysentery the temperature of a body essentially does not change, there are pains in a stomach, visits of a toilet become frequent (in comparison with remission). Continuous flow is manifested by the intensification of all intestinal symptoms, the appearance of blood and mucus in the stool.

Prolonged course of the disease severely depletes patients, they have anemia, weight loss right up to cachexia, asthenovegetative symptoms.

Extraintestinal amebiasis

Penetration of protozoal pathogens into the body can manifest not only as an amoeba of the intestine. Symptoms of the disease may be completely different from the classical disease, but nevertheless they will be caused by the same pathogen. Extra-intestinal forms occur when amoeba enter the systemic circulation. Most often, the target organ is the liver, lungs or brain.

In the above-mentioned organs abscesses develop. Their presence is manifested in an increase in the liver, a rise in temperature to high figures (39 or more), with concomitant chills, sweating (especially at night). If the liver is severely depressed, jaundice may appear. Sometimes abscesses break through the diaphragm or melt it and the contents enter the pleural cavity. This provokes the formation of empyema, lung abscesses and atelectasis.

Amoebasis of the intestine in children

Among the diseased and carriers Entamoeba histolytica many children, as they poorly observe the rules of personal hygiene and often get dirty. In addition, they have weakened immunity. Any person over 5 years of age may experience amebiasis of the intestine. Symptoms, treatment and diagnosis do not differ much from those in adults. Clinical manifestations are moderately expressed, the temperature is more often normal, less often subfebrile. Diarrhea is of a cramping character; veins of blood and mucus appear in the stool. The number of desires can vary from 2 to 15 times a day. Pain in the abdomen may be absent, due to imperfections in the nervous system of a small child.

The pediatrician is difficult to diagnose intestinal amebiasis, the symptoms in children are smeared and masqueraded as other intestinal infections. Therefore, you need to carefully collect anamnesis, specify the time of departure abroad and the presence of symptoms in the parents.

Diagnostics

In adults, too, it is quite labor-consuming to diagnose "intestinal amebiasis". Diagnosis begins with the collection of an epidemiological anamnesis. Living conditions, the presence of sick people in the environment, trips to Southeast Asia in the recent past play an important role in the potential infection of the pathogen and can orient the doctor in the right direction.

Decisive in the diagnosis is a laboratory study of stool and colon tissue, the contents of abscesses in the liver and lungs. The disease of amoebiasis of the intestine is confirmed by the presence in the material of vegetative forms of dysentery amoeba. In order for the diagnosis to be effective, the study is carried out repeatedly, starting from the first day of the illness or from the patient's admission to the hospital. Detection of exclusively luminal forms and cysts does not provide sufficient grounds for diagnosing.

If the results of parasitological studies are negative or ambiguous, the next step is to establish serological responses to identify antigens or antibodies to the pathogen in the patient's blood. Diagnostic criterion is a dynamic increase in antibody titer 4 times or more from the initial level.

From instrumental research is performed ultrasound of the liver, lung radiography, computed tomography or magnetic resonance imaging. This is necessary to identify the extra-intestinal foci of the disease.

Treatment

Usually, doctors do not wait until the diagnosis of "intestinal amebiasis" is diagnosed, treatment begins immediately after the person enters the hospital. In the beginning, it is symptomatic: fluid loss and electrolytes are compensated, intravenously drugs are introduced that support the work of the heart, lungs. If there is a high temperature, then it is lowered to acceptable figures. After clarifying the final diagnosis, specific therapy is included.

If a person is a carrier of amoebas, then prescribe luminal amoebocytes, which promote the removal of parasites from the body and inhibit their reproduction. In addition, this group of drugs is prescribed for patients with other forms of the disease, in order to finally eliminate the pathogen from the body.

For patients with acute amoebic dysentery, there are tissue amoebocytes that act directly on the vegetative forms of the pathogen and eliminate it in organs and tissues. It is important to fully complete the course of treatment, even after the disappearance of clinical symptoms. There are cases of recurrences of the disease decades after the first time.

Prevention

What should I do to prevent intestinal amebiasis? Treatment is aimed at eliminating the parasite from the patient's body, and prevention affects its environment and living conditions. An infectious disease doctor should identify a risk group and conduct a survey of these people, and also recommend that they clean the house.

In the risk group, most people fall into:

• Having pathology of the digestive system;
• Residents of settlements in which there is no centralized water supply;
• Food industry workers;
• Travelers;
• People of non-traditional sexual orientation.

Examination of patients discharged lasts a year. Investigations for the allocation of amoebae are carried out every three months, and out of turn if symptoms of impaired functioning of the gastrointestinal tract appear. To disrupt the mechanism of transfer, disinfection of the objects to which the patient's allocation has been released is carried out. In addition, recommendations are issued for improving the sanitary and epidemiological regime.