Sensitive enzyme-linked immunosorbent assay with urine samples: a tool for surveillance of schistosomiasis japonica

An enzyme-linked immunosorbent assay (ELISA) to detect antibodies to Schistosoma japonicum soluble egg antigens (SEA) in un-concentrated urine was developed. The urine ELISA was applied to samples collected in a schistosomiasis-endemic village in China. The levels of anti-SEA antibodies detected in urine correlated well with those obtained with paired serum samples (r = 0.694, p<0.0001). Among 129 serum ELISA positives, 112 (86.8%) were positive by urine ELISA, while all 40 serum ELISA negatives from a non-endemic area were negative. The levels of anti-SEA in urine samples were stable up to 8 weeks of storage at 37 degrees C, with sodium azide as a preservative. Therefore, ELISA with urine samples can be used for the surveillance of schistosomiasis.