Manson's intestinal schistosomiasis: causes, symptoms, diagnosis, treatment

Intestinal schistosomiasis of Manson is a chronic tropical intestinal trematode with a predominant lesion of the digestive system.

[1], [2], [3], [4], [5], [6]

Epidemiology

The cycle of development of intestinal schistosomiasis Manson is similar to the life cycle of S. Haematobium. After the active introduction of cercariae through the skin and the complex migration of schistosomes along the lymphatic and blood vessels, sexually mature helminths are localized in the branches of the portal vein. Most of them migrate to the small branches of the inferior mesenteric vein, where the females begin to lay eggs. With the help of an acute spine and cytolysins, some eggs penetrate through the wall of the vessels and tissues of the mucous membrane into the lumen of the intestine and are excreted with feces. Many eggs of parasites linger in the wall of the intestine. The average lifespan of the female parasite is 3-5 years, but cases of allocation of eggs to intestinal schistosomes have been noted without re-infection for more than 20 years.

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Causes

Manson's intestinal schistosomiasis is caused by Schistosoma mansoni. The size of the male is 6-14 mm, the female is 12-16 mm. Testes in males are small, in number 8-9. The ovary of the female is located in the anterior part of the body. Uterus short, contains 1-4 eggs. Eggs are oval in shape, with a lateral thorn. The size of eggs is 120-160x60-70 microns.

Intestinal schistosomiasis is widespread in African countries (Egypt, Sudan, Zambia, Tanzania, Central African Republic, Congo, Cameroon, Liberia, etc.). In South America, the disease occurs in Venezuela, Guyana, Brazil, the islands of Haiti, Puerto Rico.

[9], [10], [11], [12], [13],

Symptoms of intestinal schistosomiasis Manson

Helminth antigens exert a sensitizing effect on the host's organism.

The acute stage of schistosomiasis proceeds as a consequence of allergic reorganization of the body. Symptoms of intestinal schistosomiasis appear after 2-16 (usually 4-6) weeks after infection. There is a fever of the wrong type, appetite worsens. Patients are disturbed by a frequent liquid stool, sometimes with an admixture of blood and mucus, abdominal pain. Often there are nausea and vomiting. Increase the size of the liver and spleen. There may appear a cough with phlegm, in young children - dyspnea, cyanosis, tachycardia, hypotension. Eosinophilia and leukocytosis are found in the blood. On the skin there is an itchy rash, local swelling of the skin is noted. Defeats of the nervous system (adynamia, agitation, sometimes coma) are rare.

In the chronic phase, the remaining eggs in the tissues of schistosomes cause inflammatory reactions, granulomatous and fibrotic processes. The greatest pathological changes develop in the wall of the colon, in the liver and in the lungs. There are three main forms of the chronic stage of intestinal schistosomiasis: interstitial, hepatosplenomegalic and pulmonary. The interstitial form is associated with the lesion of the thick intestine, especially its distal sections. There is a loose stool, alternating with constipation. Characteristic symptoms of intestinal schistosomiasis Manson: pain in the abdominal stomach, often formed cracks in the anus, develops hemorrhoids. Hepatosplenomegaly with portal hypertension develops 5-15 years after infection, signs of impaired liver and spleen functions appear: patients complain of a feeling of heaviness and pain in the area of the sub-suture, a decrease in appetite, weight loss, development of edema of the lower extremities and ascites. There are esophageal and gastric bleeding. With a prolonged course of the disease, cirrhosis develops. The further development of pathological processes leads to the death of the patient from developed liver failure, thrombosis of the blood vessels of the liver, bleeding or as a result of acute cardiovascular decompensation. In 5-10% of patients develop pulmonary form of intestinal schistosomiasis. In this case, patients complain of shortness of breath, fatigue, tachycardia, dizziness, pain in the chest. The formation of granulomas and the proliferation of fibrous tissue around the eggs of schistosomes that enter the portal system into the liver creates a presynusoidal block leading to the development of portal hypertension. There is varicose veins of the esophagus and stomach, splenomegaly. In conditions of stagnation in the system of the portal vein, the swallowing of eggs with schistosomes into the lungs and other organs is noted. Skidding eggs can cause damage to the appendix, gallbladder, pancreas, genital organs, spinal cord and rarely the brain. As a complication there may be bleeding from the esophagus, gastric bleeding, phlegmon and abscesses of the stomach and intestines, adhesions, polyposis of the rectum and sigmoid colon, development of pulmonary heart syndrome,

Schistosomiasis intestinal intercalary

Chronic intestinal schistosomiasis, common in tropical regions of Africa, is pathogenetically and clinically similar to Manson's intestinal schistosomiasis, but differs from it in a more benign course.

What causes chronic intestinal schistosomiasis?

The causative agent is Schistosoma intercalatum, morphologically similar to S. Haematobium. Eggs are somewhat larger. Their sizes are 140-240 x 50-85 microns. Eggs stand out with feces.

The disease of chronic intestinal schistosomiasis is recorded in Zaire, Gabon, Cameroon, Chad.

Epidemiology, pathogenesis, symptoms, treatment and prevention are the same as in intestinal schizosomiasis of Manson.

Diagnosis of intestinal schistosomiasis Manson

Manson's intestinal schistosomiasis should be differentiated from amoebiasis, bacterial dysentery, balantidiasis.

[14], [15], [16], [17], [18]

Laboratory diagnosis of intestinal schistosomiasis Manson

Parasitological diagnosis of intestinal schistosomiasis Manson is based on the detection of eggs in stool. To detect eggs, you should make large strokes on slides. A sample of feces from the smear should be taken from the surface of the feces, which immediately came into contact with the intestinal mucosa, where the eggs came from. If the results of a co-examination are negative, rectal mucus is examined after defecation. The method of detecting larvae of schistosomes in feces is also used, based on their phototropism. In this case, the patient's feces are kept in a glass flask under special conditions, in which, after 2 hours and at a temperature of 25 ° C, miracidia hatch from the eggs with schistosomes, which, due to positive phototropism, accumulate on the illuminated surface of the bulb and can be detected with a magnifying glass or with the naked eye. In order to identify inactive schistosomiasis, a rectum of a piece of the intestinal mucosa at a distance of 10 cm from the anus is sometimes performed during rectoscopy. In positive cases, eggs of schistosomes are found. In recent years, serological reactions based on ELISA are widely used abroad. As additional methods, you can use laparoscopy, liver biopsy, etc.

Treatment of intestinal schistosomiasis Manson

The drug of choice is prazikvantel or azinoks, which are prescribed in a daily dose of 40 mg / kg in two divided doses during the day (the effectiveness of intestinal schistosomes is 60%). Treatment of intestinal schistosomiasis Manson consists in the appointment of a highly effective drug oksamnihina. Adult drug is administered orally at a daily dose of 15 mg / kg in a single dose. Its efficiency reaches 85-95%. You can also use niridazole in a daily dose of 25 mg / kg treatment course 5-7 days. Symptomatic and pathogenetic treatment of intestinal schistosomiasis of Manson is also used to improve the functions of the affected organs and systems. With secondary infection, antibiotics can be used.

Prevention

Manson's intestinal schistosomiasis is also prevented, as with genitourinary schistosomiasis.