Diagnostic tools for Schistosoma japonicum in control programmes.

Parasitological diagnostic techniques for control programmes should be inexpensive, quantitative and highly reliable. For parasitological diagnosis of Schistosoma japonicum infection in the field, the merthiolate-iodine-formaldehyde concentration (MIFC) technique has been widely used. This technique requires expensive laboratory equipment, including a centrifuge, its sensitivity is limited and the results are not reproducible quantitatively. The cellophane smear technique (Kato) is simple, reproducible and has been adapted as a quantitative measure of S. japonicum infection. The miracidial hatching technique is simple and highly sensitive but has not been well standardized for quantitative measurements. Ideally, immunodiagnostic tests for use in control programmes should be at least as sensitive and slightly less specific than the current parasitological techniques to assure detection of most infected persons. Recent evaluations of S. japonicum egg and adult antigens in various immunoassay systems indicate that immunodiagnosis may play an important role in the monitoring and surveillance phase of schistosomiasis control.