Comparison of the Quantity and Antigenicity of Schistosoma japonicum Eggs Derived from Mice Liver and Intestine for the Circumoval Precipitin Test (COPT)

Abstract

The parasitic disease schistosomiasis has been present in the country for over a century due to difficulties in controlling and eradicating the disease. However, since patients are asymptomatic during the early stages of infection, the diagnosis of schistosomiasis is challenging. The widely-used stool exam, unfortunately, has low sensitivity to provide accurate prevalence data. The circumoval precipitin test (COPT) is a highly specific and sensitive test has high diagnostic potential. However, modifications must be made to further raise the sensitivity of the test. It was the aim of this study to compare the quantity and antigenicity of Schistosoma japonicum eggs from mice liver and intestine for the improvement of COPT to further enhance the test. Murine infection was done to obtain antigen and sera for COPT. Results showed that there is a significant difference in the antigenicity of S. japonicum eggs between the liver and intestine (p =0.015). However, there is no significant difference in the egg yield between the two organs (p = 0.359) though the egg counts were consistently higher in the liver than the intestine. Due to the higher percentage of eggs that exhibit positive COP reactions, the use of liver-derived eggs for COPT is recommended.