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

• Published in: Transactions of the Royal Society of Tropical Medicine and Hygiene 1998-11, Vol.92 (6), p.629-633
• Main Authors: Kahama, A.I., Kremsner, P.G., van Dam, G.J., Deelder, A.M.
• Format: Article
• Language: English
• Subjects: Adolescent; Animals; Anthelmintics - therapeutic use; Antigens, Helminth - urine; Biological and medical sciences; Biomarkers - urine; Cameroon; Cameroon - epidemiology; chemotherapy; Child; Child, Preschool; circulating anodic antigen; circulating cathodic antigen; Diseases caused by trematodes; Enzyme-Linked Immunosorbent Assay - methods; Female; Helminthic diseases; Humans; Infectious diseases; Male; Medical sciences; Parasite Egg Count - methods; Parasitic diseases; praziquantel; Praziquantel - therapeutic use; Reagent Strips; Schistosoma haematobium; Schistosoma haematobium - isolation & purification; Schistosomiases; schistosomiasis; Schistosomiasis - drug therapy; Schistosomiasis - epidemiology; Schistosomiasis - urine; soluble egg antigen; Tropical medicine
• ISSN: 0035-9203; 1878-3503
• DOI: 10.1016/S0035-9203(98)90789-1

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 × 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.