Egg viability in urinary schistosomiasis. III. Repeatability and reproducibility of new methods.

Two new field methods for the detection and quantification of egg viability/hatchability in urinary schistosomiasis due to Schistosoma haematobium have been described recently, and compared with reference methods; the new methods are cheap and simple to use, and may be used singly or together. Before recommending their widespread use in control programmes, repeatability (r) and reproducibility (R) were studied using the guide for determination prepared by the British Standards Institution. Both parameters were found to be low in relation to the mean proportions of eggs viable/hatchable except at very low egg counts, and the new methods can safely be used in PHC-based control programmes.