The dynamics of a soluble egg antigen of Schistosoma haematobium in relation to egg counts, circulating anodic and cathodic antigens and pathology markers before and after chemotherapy.
A cohort of Schistosoma haematobium infected schoolchildren from Cameroon (n = 146) was studied for urine circulating soluble egg antigen (SEA), in comparison to other urine infection parameters: the circulating adult worm-derived antigens, circulating anodic and cathodic antigens (CAA and CCA), egg counts and the reagent strip index (RSI). Before treatment, SEA prevalence was 90%, while 89% and 65% of the children were positive for CCA and CAA respectively. The children were treated with 2 doses of praziquantel (2 x 40 mg/kg bodyweight) at an interval of 10 days and followed-up at 1, 2, 3, 5 and 12 months after treatment. Urine SEA correlated significantly with egg counts and RSI; levels of CAA and CCA were also significantly correlated with those of SEA. The levels of SEA showed a better correlation to both egg counts and RSI than did the levels of CAA and CCA. SEA levels dropped sharply 1 month after treatment, with few children excreting any SEA whereas egg counts decreased less rapidly. The prevalence and levels of SEA remained low during the whole post-treatment period whereas egg counts, RSI and CCA in urine rose progressively in the post-treatment period with a final egg count prevalence of 78%. The results of the present study indicate that for S. haematobium infections, measurement of SEA in urine is a valuable additional diagnostic parameter.
D000293:Adolescent; D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use; D000947:Antigens, Helminth / Q000652:urine*; D015415:Biomarkers / Q000652:urine; D002163:Cameroon / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D010270:Parasite Egg Count / Q000379:methods; D011223:Praziquantel / Q000627:therapeutic use; D011934:Reagent Strips; D012548:Schistosoma haematobium / Q000302:isolation & purification*; D012552:Schistosomiasis / Q000188:drug therapy* / Q000453:epidemiology / Q000652:urine