Development of a simple and rapid latex test for rotavirus in stool samples

In the fields of infectious diseases, a variety of immunoassay methods has been reported. More simple, rapid and cost-effective manual tests for infectious diseases are needed. For the purpose of simple diagnosis of rotavirus infection, a rapid test against human rotavirus was developed. As for the preparation of the reagent, clinically isolated human rotavirus was cultured using MA-104 cells. Then, the cultured virus was purified by an ultracentrifugation method. The purified virus was inactivated with formaldehyde for use as antigen for immunization of rabbits. The antibody was purified and applied to sensitize the surface of latex particles to react with rotavirus in diarrheal stools. The latex agglutination test showed that the sensitivity was 98.2% and the specificity was 94.8%, in comparison with electron microscopy as the gold standard. Furthermore, to measure the virus concentration in stool samples, an automated latex photometric immunoassay system (LPIA) was used, which has been developed for quantitative measurement of agglutination. The range of the reactive viruses detected by the LPIA system was 3 x 10(7)-10(9) virions/mL. The rotavirus-positive and rotavirus-negative subjects were clearly discriminated. The results were in good accordance with electron microscope results. Those results showed that the latex agglutination test is a good tool for the simple and rapid detection of rotavirus in stool samples.