INCIDENCE ON MILK-DRINKERS 



26: 



Mr Power was also able to furnish returns throwing light upon 

 the same point in the diphtheria epidemic which he investigated in 

 York Town and Camberley in 1 886. He divided the cases into those 

 belonging to the better class and those of cottagers, small trades- 

 folk and the like, with the following very interesting results : — 



The same incidence was also illustrated in the milk-borne epi- 

 demic of typhoid fever investigated by Dr Davies at Bristol in 1897. 



(c) Incidence on milk-drinkers.— A third characteristic is the 

 obvious one that milk-borne disease affects in highest degree those 

 individuals who drink most milk. With almost incredible accuracy 

 the disease attacks persons in a family who are the chief milk- 

 drinkers. When this occurs it is one of the surest signs of milk- 

 infection. In 1893 there was an outbreak in a school at Hastings. 

 There were twenty boys, only two of whom took the implicated 

 milk — they alone were attacked. In the same outbreak a man 

 isolated for twelve days on account of influenza drank the milk 

 and was attacked. In Canterbury in 1886 diphtheria picked out 

 one member from a family, and it turned out that he was the only 

 one who had consumed the infected milk in his tea at a friend's 

 house. In 1882, out of fifteen persons in a family only one con- 

 sumed the suspected milk raw. He was attacked. There are 

 several instances on record of how a casual glass of milk at the 

 farm gave rise to disease in persons not residing in the infected 

 locality. In one of the typhoid outbreaks recorded, only one 

 person was affected in a certain house. He was the butler who 

 *' saved his beer money," and contracted enteric fever. In an 

 epidemic at the Iowa State College the attack rate was 8-8 per 

 cent., except among the football players, who were served with a 

 double allowance of milk, and amongst them the attack rate was 

 over 50 per cent. In the Clifton typhoid epidemic in 1897 in one 

 of the College Houses containing fifty-five persons, thirty-nine 

 were attacked. In the scarlet fever outbreak in North London in 



