الفهرس | Only 14 pages are availabe for public view |
Abstract Human fascioliasis is becoming an important public health problem. It has been recently reported in several countries. I t was even considered endemic in some areas. The clinical picture of human fascioliasis is highly variable, although fever, pain in the right hypochondrium and high eosinophilia are very suggestive signs and symptoms. Specific diagnosis is based on recovery of the egg in the patient’s stools. However, eggs do not appear in acute infection. This makes immunodiagnosis an important adjunct desparately needed for the definition of Fasciola infection particularly during the incubating stage. Numerous antigens and tests have been used for the immunodiagnosis of fascioliasis. An antigen system that is receiving increasing attention is the excretory-secretory (ES) products which proved to be of value both in immunodiagnosis and immunoprophylaxis. The aim of the present work was to prepare Fasciola ES adult worm antigen, to fractionate it and to evaluate the different fractions in the diagnosis of acute human fascioliasis by the ELISA technique. For collection of positive sera, a house to house survey was carried out in Abis 13/4 village. The total population amounted to 850 individuals, 455 participated in the study. Stool samples were collected and examined after the Kato/Katz technique. The study on acute infection depended on cases suspected clinically and referred to our department for serological testing. They were from the city of Alexandria, from different Abis villages and from Beheira province. IHA test was performed on all sera and all cases giving positive titres were included. Four groups of sera were collected and studied: 1. Controls (obtained from healthy, parasite-free, members of the parasitology and microbiology departments) (17). 2. Sera from patients with incubating fascioliasis (38). 3. Sera from patients with chronic fascioliasis (14). 4. To test for the presence of cross reactions with other parasites, sera from patients with schistosomiasis (12), toxoplasmosis (9) and hydatidosis (2) were included. To prepare Fasciola ES antigen, adult worms were washed and incubated in 0.01 M phosphate buffered saline (PBS)/0.8 mM phenyl methyl sulfonyl fluoride (PMSF) for 3 hours at 37°C. After incubation, the suspension containing the ES products was centrifuged at 3600 rpm for 1 hr at 4°C.The supernatant was then obtained and fractionated by gel filtration chromatography using Sephadex G 200. A chromatogram of two peaks was obtained. The crude antigen and the two Fasciola antigenic fractions were evaluated by IgM ELISA. A chequerboard titration was carried out and the antigen concentration and serum dilution that gave the best results determined. The test was performed using the three antigens at a protein concentration of 4 ug/ml and serum dilution 1/100. The prevalence of fascfoliasis was 10.3. Cases were grouped in families. Sharing the same food by members of the family may be the factor responsible for this distribution. Females revealed higher prevalence than males, and the age groups (5-10) and (20-30) revealed higher infection rate. Intensity was either .. light (24-96 eggs/gm stool) or moderate (120-480 eggs/gm stool). |