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.

Interleukin-4, immunoglobulin E and immunoglobulin A and resistance to re-infection with Schistosoma haematobium before and after chemotherapy.

The role of serum IL-4, IgE and IgA in protective immunity had been determined in 88- S. haematobium infected-individuals before and 3, 6, 9 and 12 months after treatment with a single dose of praziquantel. Before treatment, IL-4 level was found to be highly significant in all stages of infection, there was a positive correlation between IL-4 levels and egg count. Whereas serum IgE and IgA levels were significantly high in late infected group showing a negative correlation with egg count. After praziquantel treatment, IL-4 levels decreased gradually while IgE and IgA levels were significantly increased in all patients. At 9 and 12 months, viable ova were detected in 11 cases (12.5%), they were re-infected after treatment showing an increase in IL-4 levels, and a decrease in both serum IgE and IgA. These results indicate that IL-4 plays an important role in suppression of severe inflammatory responses associate with persistence of the parasitic stages. Also, serum IgE and IgA participate in protective immunity against S. haematobium infection. It may be essential to administer a second dose of praziquantel to all persons living in endemic areas who are likely to be in contact with infested water.

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.

Detection of cellular and humoral markers (IL-2, IFN-gamma and IgE) in sera of patients with urinary schistosomiasis.

Schistosomiasis continues to be major health problem throughout the developing world. Infection with Schistosoma haematobium is associated with very high morbidity. The work aimed at the determination of role of cellular immune response (IL-2, and IFN-gamma) and specific humoral IgE in protective immunity in human urinary schistosomiasis, as a function of both age and infection intensity including examination of changes in immunoresponsiveness following curative therapy. The study revealed that IL-2,IFN-gamma level were higher in all patients compared to the normal control group and the levels were higher in lightly infected groups than heavily infected ones with no respect to age. IgE levels showed higher values compared to normal individuals and IgE levels were higher in children groups than in adults regardless of the intensity of infection. IL-2, IFN-gamma and IgE levels were higher in patients with mixed S. mansoni and S. haematobium infections than monoinfected patients. Follow up of patients 2 months, 4 months and 12 months after Praziquantel treatment showed that the level of IL-2 and IgE fell back to normal values after 4 months while IFN-gamma remained high, IL-2, IFN-gamma and IgE were raised once more after 12 months.

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.