The intradermal test in the diagnosis of human intestinal capillariasis

ABSTRACT

Capillaria adult worms amounting to 4 ml were collected from the contents of the small intestines of a case who died and was autopsied and the material was made into a crude antigen for the intradermal test. This was tried on human intestinal capillariasis cases confined in 2 hospitals as well as among non-cases. Male subjects were found to be more reactive to the intradermal test than females, a finding similar to schistosomiasis intradermal test. Hence, it is suggested that a set of limits for positive and negative be prepared separately for the two sexes. The capillaria antigen employed in the test did not show any cross-reaction with trichuris, hookworm, schistosoma and trichinella. The test appeared to be highly sensitive and species specific, hence we recommend its use not only for epidemiological surveys but also for diagnosis of individual cases. It is felt that the test could pick up more cases in a shorter period than stool examination would, particularly among asymptomatic cases. The practicability of the test will become even more evident the moment the life cycle and biology of the parasite have neem elucidated, because transfer of the parasite into experimental animals would serve as sources of antigen. In the event that the parasite can not be transferred to animals the use of heterologous antigens such as animal capillaria might have to be resorted to. This method has been used in filariasis and schistosomiasis intradermal tests. (Summary and conclusion)