Pre and post treatment patterns of serodiagnostic parameters (antibody and immune complexes) in schistosomiasis haematobium patients

Abstract

56 school children from Tiwi Primary school located in Kwale district, Coast province, Kenya, found to have s. haematobium infection parasitologically, had their sera obtained and assayed for circulating antischistosome antibodies and specific immune complexes. Praziquantel, 40 mg/kg body weight was given as a stat dose. Follow up was performed at two weeks (50 pupils), five weeks (49 pupils) and sixteen weeks (45 pupils). At each follow up period, urine was collected for egg output estimation and serum samples were obtained for assay of circulating anti-schistosome antibodies and specific immune complexes. Circulating immune complexes identified correctly all (100%) the pupils shown to have S. haematobium infection parasitologically. Circulating antibodies identified correctly 93% of these. The mean egg output was 84.5 per 10 mls of urine before treatment, falling to 1.24 per 10 mls of urine at the end of sixteen weeks follow up. This drop was apparent as early as two weeks after treatment; There was no correlation between the egg output, circulating anti-schistosome antibodies and immune complexes at the start of the study (p>0.05). Statistically significant reductions in circulating antibodies and immune complexes following treatment,were recorded (p < 0.001). Circulating antibody was detected in 93% of the pupils -at an intensity of 96.2% at the pre-treatment period and rose to an intensity of 140.0% in 92% of the pupils at two weeks follow up.

With time, the level of circulating antibodies decreased and though still positive in 62.2% of the pupils, at sixteen weeks the intensity was only 31.3%. Circulating immune complexes, detectable in all the pupils at pre-treatment and two weeks follow up at an intensity of 111.2% and 112.6% respectively, decreased more dramatically to an intensity of 21.9% in 28.2% of the pupils at sixteen weeks.