Mature cysts of amoebae in the lumen of the intestine are converted into vegetative forms, which in a reduction of the local resistance of the mucosa of the colon acquire the ability to penetrate the mucosa and submucosal layer of intestine with the formation of microabscesses in them, and ulcers.
As a result of hematogenous dissemination from the intestinal wall tissue forms of the amoeba may penetrate into all tissues and organs, most commonly to the liver, less often in the lungs and brain, causing the development of these foci of necrosis with subsequent abscess formation.
Lung damage in amoebiasis develops as a result of hematogenous dissemination from other organs, as well as direct distribution process of the liver. In the area of localization of amoebae developed lysis of cells with preservation of collagen structure and small lymphocytic and histiocytic proliferation. At the periphery of the chamber revealed tissue forms an amoeba. Joining pyogenic flora leads to the formation of a purulent abscess. Suppuration is accompanied by severe general intoxication.
Clinic lung amebiasis
The incubation period of the disease varies from a week a few months. According to the WHO classification distinguishes intestinal (acute and chronic with various complications), extraintestinal (with the defeat of the various systems and organs, most commonly the liver), and cutaneous amebiasis.
The disease begins acutely or gradually, usually with the progressive development of ulcerative colitis. Subsequently, it may be an abscess of the liver. With the localization of amebic abscess in the upper regions of the liver in some patients having basal pneumonia, usually right-sided, dry pleurisy, often formed plevrodiafragmalnye seam. Progression of liver abscess in these conditions can lead to a breakthrough in the right lung abscess with the formation of broncho-hepatic fistula. Patients note a fever, pain in the right half of the breast, painful, dry cough, shortness of breath, in the future there is abundant expectoration of dark brown ("chocolate") in color.
Breakthrough of the liver abscess into the pleural cavity is accompanied by the development of pleural empyema with a sharp deterioration of the patients, hectic fever, increasing respiratory distress.
Hematogenous drift of amoebae in the lungs causes the development of amoebic pneumonia manifesting febrile reaction, chest pain, painful cough with scanty expectoration of brownish-gray, which can be detected by tissue forms of amoebae. Joining a secondary infection results in purulent fusion of foci of necrosis and abscess formation of the lung. X-ray study reveals the first infiltrative focus, often in the right lung, resembling tuberculous lesion. In the future, is found round shade with moderate perifocal infiltration, and in case of drainage of abscess cavity in the bronchus revealed a horizontal level.
During a long illness, pulmonary abscess may break through into the pleural cavity with the development of pneumoempyema.
The diagnosis of pulmonary amebiasis is based on the totality of clinical data showing intestinal or hepatic manifestations of amebiasis, the results of X-ray studies confirmed the detection of amoebae in the sputum or pleural fluid, and occasionally in the feces (if the clinic colitis) used serological diagnostic methods, complement fixation (RAC), the method of fluorescent antibody (IFA), the reaction of an enzyme-labeled antibody (Rem). The differential diagnosis is tuberculosis, lung abscesses different origin, tumors of the lung.
Prevention of amebiasis is similar to that of acute intestinal infections, and includes debridement tsistonositeley, a complex of sanitary and hygienic measures.
Treatment of pulmonary amoebiasis
The most effective drugs for the treatment of amoebiasis are universal and tissue amebotsidy amebotsidy.
Forecast amebiasis pulmonary severe, with the development or pneumoempyema bronhopechenochnogo fistula - a bad one.