Effect of early treatment with praziquantel on serum connective tissue metabolite markers in children and adolescents with intestinal schistosomiasis mansoni.

This work was designed to assess the reflection of early treatment by praziquantel (CAS 55268-74-1, EMBAY 8440, Biltricide) on serum connective tissue metabolite markers (hyaluronic acid and procollagen III peptide) in patients with active intestinal schistosomiasis. Children and adolescent subjects from primary and secondary schools in an endemic area of schistosomiasis mansoni were included. Age-matched subjects from an urban area served as normal controls. All subjects were examined clinically and parasitologically. Detection of hepatitis B seromarkers was also done. The infected subjects were treated with praziquantel at a dose of 60 mg/kg of body weight which was repeated after 4 weeks. Serum hyaluronic acid and procollagen III peptide were measured by radioimmunoassay. High hyaluronic acid was encountered in infected subjects when compared to their respective age-matched controls. Significant decrease of 4 and 8 weeks post-treatment was noted when compared to ist level before treatment. There was no significant change in serum procollagen III peptide on comparing infected subjects to their controls, whereas a significant increase was observed in its level after 4 and 8 weeks post-treatment compared to that before treatment. This work suggests that early treatment of intestinal schistosomiasis with specific chemotherapy (praziquantel) decreases serum hyaluronic acid and increases procollagen III peptide probably via downregulation of granulomatous inflammatory cell reaction and activation of collagenase enzymes, respectively.

Detection of circulating schistosome antigens in serum and urine of schistosomiasis patients and assessment of cure by a monoclonal antibody.

From a panel of monoclonal antibodies (MAb), an IgM monoclonal antibody (7F1/6B) reactive with repetitive epitopes on S. mansoni soluble egg antigen was selected. This MAb was employed both as antigen capture and detection antibody in a sandwich ELISA and had a detection limit < 1 ng S. mansoni SEA/mi. Serum and urine samples were collected from rural students who had S. mansoni (169 subjects) or mixed S. mansoni and S. haematobium (64 subjects) infections. Samples were collected before and at 4, 8 and 12 weeks after praziquantel therapy. Circulating schistosome antigens (CSA) were demonstrated in 90% of sera and 97% of urine samples of S. mansoni group and in 91% of sera and 100% of urine samples of mixed infection group. All sera from 29 uninfected individuals, 30 patients with other parasites and 70% of 55 S. haematobium-infected subjects were negative in this assay. CSA level in serum and urine samples correlated positively with the number of S. mansoni eggs/g stool in both groups. A significant reduction in CSA level was observed in serum and urine samples after praziquantel therapy. By 12 weeks post-treatment, negativity was 98% in sera and 97% in urine of S. mansoni-infected group and 98% in sera and 91% in urine of mixed infection group. The data demonstrate that the use of MAb 7F1/6B for the detection of CSA provides a sensitive method for immunodiagnosis of schistosomiasis and monitoring of cure.

Evaluation of urinalysis reagent strips versus microscopical examination of urine for Schistosoma haematobium.

This study deals with the effectivecess of chemical reagent strips for detection of haematuria and proteinuria in selecting S. haematobium egg positive subjects as compared to microscopical examination of urine. Out of 222 students from primary and secondary rural schools, 191 were S. haematobium and 59 were parasitologically negative. 135 students had a count of less than 50 eggs/10 ml. urine and 56 had more than 50 eggs/10ml. The sensitivity of reagent strips in detecting haematuria was 10% and 36% for the groups with less than and more than 50 eggs/10 ml. of urine respectively. The correspondant microscope figures were 42% and 93% respectively. Proteinuria was detected in 11% and 29% of urines from the groups with less than and more than 50 eggs/10 ml. respectively. The specificity of strips and microscopical examination in detection of haematuria was 100%, while that for proteinuria was 97% as detected by strips. These results show that urinalysis strips cannot be used as an alternative to microscopic examination of urine for the presence of S. haematobium eggs.

Use of Kato and nucleopore techniques for qualitative diagnosis of schistosomiasis.

A comparison on qualitative basis, is attempted between merthiolate-iodine-formaldehyde concentration (MIFC) and Kato thick smear techniques for diagnosis of schistosome eggs in stools. As well, the centrifugation-sedimentation method was compared with the Nucleopore filtration technique for schistosome eggs in urine. Using MIFC and Kato techniques, 149 out of 185 subjects were found to have Schistosoma mansoni infection, 41 of them were diagnosed by Kato alone, while no case was solely MIFC positive. The sensitivity of MIFC compared to kato was 72.3% and both techniques were 100% specific. For diagnosis of S. haematobium infection, 78 out of 103 subjects were positive by centrifugation- sedimentation and/or Nucleopore techniques. 42 of them were diagnosed by Nucleopore alone and none was positive by centrifugation- sedimentation only. The sensitivity of the latter technique was 46.2% and both techniques were 100% specific. The study demonstrates that Kato thick smear and Nucleopore filtration are highly sensitive techniques that can be used for routine qualitative diagnosis of schistosomiasis. Under field conditions, they are qualitatively and quantitatively useful. The Kato technique besides its high sensitivity is very cheap. The only limitation for the Nucleopore technique is its relative high expenses.