“…Daniels and MacMurray (1954) mentioned 12 household epidemics, involving 26 patients, mainly children (no other details are given). Clement et al (1951) report the disease in a child aged 13 and in his mother; Blinski and Kaye (1955) found it in a child of 16 months and his mother; and Philpott et al (1955) describe the cases of twins aged 5 who suffered from it. But in all these examples the household illnesses were roughly concurrent, so that one animal was responsible for all the cases in each outbreak.…”