Diagnosis of active urinary schistosomiasis using homologous adult Schistosoma haematobium antigen.

The role of antigen prepared from Schistosoma haematobium adult worm (ShAWA, W.H.O. Geneva) in diagnosis of active urinary schistosomiasis, by counterimmunoelectrophoresis (CIEP), was evaluated by comparison with simpler methods as sedmentation of urinary ova and detection of haematuria by chemical reagent strips. Sixty patients (30 school boys and 30 adults) passing living S. haematobium eggs, as detected, by nucleopore filtration technique (NF), and 30 controls were studied. Results showed statistically significantly higher (P < 0.001) egg counts in school boys than adults. Sensitivities of haematuria detection, ova sedimentation and CIEP were 93.3%, 80%, 50%, 70%, 73.3%, 33.3% in school boys and adults respectively. It was concluded that direct parasitological examination of urine samples is more superior than CIEP using homologous ShAWA to detect active urinary schistosomiasis both qualitatively and quantitatively. Haematuria detected by chemical reagent strips can identify a high proportion of active urinary schistosomiasis in epidemiological surveys in endemic areas. Nucleopore filtration is more superior than ova sedimentation method for detection of active urinary schistosomiasis.

Evaluation of direct and indirect methods in diagnosis of chronic intestinal schistosomiasis in Menoufia Governorate.

A comparative study of Kato thick smear method, modified Ritchie concentration technique (MRCT), rectal snip biopsy and indirect haemagglutination (IHA) test were done on fifty patients with chronic intestinal schistosomiasis from Menoufia governorate, an area of Nile Delta endemic for schistosomiasis. Study revealed that a single kato-preparation was not sufficient to determine correctly the prevalence of Schistosoma mansoni infection particularly in chronic cases (22%), the accuracy was maximized by examining stool samples obtained from the same patient by MRCT (46%). Rectal snip biopsy and IHA test showed high positivity rate of 80% and 74% respectively. It is recommended to combine stool examination by MRCT with either rectal snip or IHA test according to the condition of patient as the former can not be performed on routine basis.

Human cystic echinococcosis: diagnostic value of different antigenic fractions of hydatid cyst fluid with different specific immunoglobulin G subclasses by enzyme linked immunoelectrotransfer blot.

The present study intended to evaluate the usefulness of immunoblot analysis of hydatid cyst fluid (HCF) for diagnostic verification of human cystic echinococcosis (CE). HCF of camel origin was resolved by SDS-PAGE gel electrophoresis and transblotted on nitrocellulose membrane. Immunoglobulin G (IgG) subclass-specific antibody responses in 25 sera from surgically confirmed CE cases, 44 persons with other parasitic infections and 20 normal controls were analyzed. Total IgG and IgG subclass1-4 in CE sera preferentially recognized several polypeptide bands in the range of 14-200 kDa. The most predominant band recognized by total IgG antibodies was at 21 kDa (sensitivity, 96%; specificity, 98.5%; J index, 94.5%), by IgG1 at 38 kDa (sensitivity, 92%; specificity, 100%; J index, 92%) and by IgG3 at 60 kDa (sensitivity, 96%; specificity, 100%; J index 96%). Sera from the normal controls did not recognize any of these polypeptides. These data suggest that detection of any of these polypeptides bands could be used for confirmation of human cystic echinococcosis in Egypt.

An enzyme-linked immunosorbent assay for detection of IgG1 antibodies specific to human cystic echinococcosis in Egypt.

Human cystic hydatidosis (cystic echinococcosis) is a chronic zoonotic disease that results from infection with the dog tapeworm Echinococcus granulosus. In Egypt, cystic echinococcosis (CE) is recognized in slaughtered livestock by veterinarians, however, there is little information about human CE infection rates. We describe an immunological assay useful for the diagnosis of human cystic hydatidosis. Sera were collected from surgically confirmed hydatid cases (34), nonendemic subjects free from parasitic infection (20) and from subjects (109) infected with other helminths (Hymenolepis nana, Schistosoma mansoni, Fasciola hepatica and Ancylostoma duodenale). Hydatid cyst fluid (HCF) of camel origin was used as antigen in an ELISA format to measure total E. granulosus specific IgG antibodies and IgG subclasses. Sensitivity measurements of total IgG, and IgG1-4 were 100, 100, 79.4, 61.8 and 55.9%, respectively, whereas respective specificity reached 65.1, 97.7, 98.4, 96.1 and 83. 7%. The diagnostic value of measuring IgG1 (97.7%), as assessed by a rating index (J) for combined sensitivity and specificity, was superior to total IgG (65.1%) and IgG2-4 (77.8, 57.9 and 39.6%, respectively). These findings set the stage for field evaluation of the IgG1 assay in areas endemic with human cystic hydatidosis.