INFECTIOUS DISEASES : AMEBIASIS (AMEBIC DYSENTERY) (Amoebiasis) - etiology, pathogenesis, symptoms and course of, recognition, prediction and prevention
Etiology. The disease is caused by Entamoeba histolytica. First discovered in 1875 F. A. the Goblin in the faeces of the patient in a therapeutic clinic of the Military medical Academy.
Epidemiology. Epidemic disease affecting mainly in southern latitudes. The main reservoir of the virus is man - sick and tectonical. Route of transmission: direct contact, fecal contamination of the environment or patient support, the transmission by flies, contamination of the food product hearth. In ispresented, even dried, viable cysts persist up to 4 weeks in water from 2 to 4 weeks, in the gut of flies - 40 - 50 hours. Water factor is, apparently, a big role. Flies and zastanawiali easily carry contagious beginning on food. Summer heat plays the role of predisposing moment. Among patients with dysentery has up to 10 zastanawiala, among patients with chronic dysentery and 6.5%among healthy to 16%.
The pathogenesis. Swallowed with food cysts develop in the intestine in the vegetative form, actively penetrating into liberkey cancer, and thence into the submucosal tissue of the colon. Around amoebae fabric podvergaetsya coagulation necrosis with abscess formation, the speaker and then exploding into the intestinal lumen. Formed at the break abscess ulcer takes "Spokoiny" character with deep saped edges, under which certain ulcers are interconnected submucosal tunnels. Nests hemorrhagic necrosis separated from healthy tissue area cellular infiltration, which are in a large number of amoebae. Necrosis often grab the muscular layer and reach the subserous and serous membranes. In the latter case are formed of peritoneal adhesions with intestinal loops and adjacent organs or developing acute perforative peritonitis. Ulcers are predominantly in the area of the bends of the colon (hepatic and splenic), the upper and lower bounds of the sigmoid curvature in the region of the caecum. Intestinal ulcers gradually undergo scarring, sometimes with the formation of strictures.
Symptoms. Prodromal effects: weakness, a feeling of pressure and pain in the abdomen, nausea, sometimes vomiting. Typical symptoms: diarrhea, often pasty, mixed with glassy mucus; in the presence of blood in stool latter penetrates the mucus (raspberry jelly). The nature of the chair alternates; the stool, bloody-mucous. Pain in the abdomen. Pain points: on the left papatowai ligament, left at the level of the navel, in the left and right hypochondrium and in the ileocecal region.
Course and complications. The disease begins a short prodromal period with the above symptoms. A typical picture of the disease begins with severe pain in the abdomen along the colon, mainly in the descending part of it. The urge on the bottom of painful, frequent; the chair as described above. Gradually, the stool frequency increases, the pain intensifies, patients strongly lose weight. Thermal response in uncomplicated cases. After 4 to 6 weeks, if not death occurs from the rapid exhaustion, intestinal bleeding or other complications, the effects gradually subside even without treatment, and the disease passes from acute phase to chronic with alternating periods of relative health and acute gastrointestinal effects.
For there may be deviation:
1) absence of acute and chronic diarrhea, alternating with constipation (often in children);
2) cases simulating first acute appendicitis, ulcer of stomach or duodenum;
3) cholerophobia beginning with the transition in a typical week 2 - day 3;
4) gangrenous form with frequent foul-smelling stool color and consistency of spinach or chocolate brown. Complications depend on the depth of the lesions of the intestinal wall or from specific metastases in other organs.
The first group includes:
1) intestinal bleeding with a large number of fresh blood in the stool,
2) pericolic, periphrastic,
3) perforation of the colon; the second - most commonly the liver abscess.
To confirm the clinical diagnosis requires microscopic examination of stools and for postmarketing - study punctate or histological sections of the mesenteric glands. Recommended sigmoidoscopy and x-ray showing through 28 - 30 hours after giving bismuth or barium oatmeal smoothness of the contours of the colon in places of destruction.
Prevention is the same as when bacillary dysentery (see), but more attention is paid to water. The destruction of the reservoirs of the virus is achieved by isolation of patients, a systematic study of patients and convalescents to titanosilicate and routine examination of the persons working in catering. Preventing the transmission of infection, disinfection of drinking water, supply of boiled water, the destruction of the larvae of flies in their places of emergence (chlorination latrines, septic tanks, manure, etc.,), the destruction of winged flies, protection from flies residential premises, products nets, systematic disinfection of faeces of patients. Great value has a correct food regimen, especially in the hot season.
Medicamental treatment and diet. Short fasting, then digestible carbohydrate meals (broths, jellies) with the exception of milk and butter. With the disappearance of the blood, vitamins, cereals, boiled fish, jelly, jelly, ground white meat. Milk and butter are allowed after 4 weeks from the onset of the disease. Surgical treatment is used when the perforation, stenosis and metastatic abscesses.