Abstract
On the occasion of the mass anthelmintic treatment for hook worm carriers, we conducted a statistical study of the incidence of so-called “Koekase” which was prevalent in the rural part of lchihara-gun, Chiba Prefecture.Data for this study were obtained through direct interviews with the ova positive cases.
1. 35% of all the 240 ova positive cases had had the local dermatitis: 32.3% of 136 male cases and 38.4% of 104 female cases.
2. Sites affected were: hands & arms (46%) and feet & legs (54%). Same persons had had the disease more than once. It usually healed within one or two weeks, but 6.3% of the cases were long in recovery and received medical treatment.
3. Incidence was about the same with the group infected with Anchylostoma duodenale only and that infected with Necator americanus only. It was about 18% with both groups comparatively low ratio. With the group of mixed infection, ratio was as high as 43%. Incidence was about the same for male and female in the mixed infection group, while in both of the two groups infected with single species incidence in women was twice as high as that in men. The avarage number of worms discharged was larger for the cases who had had the dermatitis, and those of Necator americanus were discharged in larger amount.
