Schistosoma mansoni low infection: evaluation of serologic assays - Lima, D M C; Abrantes-Lemos, Clarice Pires; Valle, L C P; Hoshino-Shimizu, Sumie; Velloso, S A G; Kanamura, Hermínia Yohko; Silva, L. C. (International Symposium on Schistosomiasis, 1993)