Abstract
In cases of family infection of leprosy, the disease is usually infected from diseased parents to healthy children or from elder diseased brothers or sisters to younger healthy ones. But in rare occasious, the infection takes place in reverse direction. Descrip- tions of such cases of leprosy infection in reverse direction seemed to be useful from the epidemiological point of view.
Out of 4528 leprosy patients admitted to the Tama Zensho-en Leprosarium dur-ing 34 years (from 1927 to 1961), 15 cases of infections from diseased children to healthy parents were observed.
The results of observations are summarized as follows:
1) As regards the sex ratio of the diseased children who were the source of in- fection, there were 3 the diseased children who were the source of infection, there were 3 cases of female children against 12 cases -4 times as many-of male children.
2) The type of the disease of children who were the source of infection showed the predominance of "lepromatous type"; 14 cases of "lepromatous" against 1 case of "tuberculoid".
3) Mothers were more frequently infected than fathers; 4 fathers against 11 mothers.
4) As to the types of the disease of the infected parents, 3 cases were "lepromatous" and 1 case "tuberculoid" in father-group, whereas 4 cases were "lepromatous" (36.4%) and 7 cases "tuberculoid macula" (63.6%) in mother-group.
5) The onsets of the disease were in average about 10 years later than those of the disease of children, and the average age of the parents when they showed the symptoms of leprosy was about 56.2 years of age.
6) The fact that mothers show higher incidence than fathers is generally due to the greater opportunity of close contact with diseased childre.
7) Tne predominance of "tuberculoid macula" type among infected mothers seems to suggest that female sex is less susceptible to leprosy than male is.
