56 



Protozoal Infections found in Family I. 



[+ denotes that an infection -was found, ... that it was not found during the single 



examination made.] 



Matthews and Smith conclude, from all their observations, 

 'that within certain families infections are much more common 

 than in the general population of children. This is strikingly 

 seen in Family I, where, in one family only, there are almost as 

 many E. histolytica infections as we have found in the 548 cases 

 taken from single members of different families. This applies 

 also to the other infections, particularly to E. coli and E. nana.' 



These authors have remarked further that ' there are at least 

 two possible ways in which this state of affairs may have been 

 brought about. (1) A single member (or some small number of 

 members) of the family has become infected in a way at present 

 unknown and from this source the infection has spread to other 

 members of the family. ... (2) The whole family, or those mem- 

 bers of it who have similar infections, may have been infected 

 simultaneously, for instance by all eating food from the same 

 contaminated source.' Matthews and Smith ' think the former 

 method the more probable ' : and with reference to the particular 

 families in question they add the following information. ' With 

 regard to the possible source of these protozoal infections it may 

 be recorded that in each of the families investigated, one member 

 — in six of the families the father, in the seventh a brother — had 

 been abroad and had visited the home after going abroad. In five 

 cases this member of the family was a soldier and in two cases a 

 sailor. It is therefore possible that all the infections had their 

 origin abroad. It is not at all necessary to make this supposition 

 however, for protozoal infections, as we have shown (Matthews 

 and Smith, 1919), are sufficiently common in all sections of the 

 population to warrant the belief that they may have existed in 

 this country before the war.' 



Attempts were made to determine, by measurements of the 

 cysts, how many races of E. histolytica and E. coli were present 

 in the members of two families. From the few observations 

 which they were able to make Matthews and Smith concluded 

 that ' the evidence does not go far, but such as it is, it points to 

 one race, and therefore presumably one source of infection, for the 

 E. histolytica infection in the two members examined of Family II, 

 and to two sources of infection in the four members of Family I '. 



There is but little that can profitably be added to the foregoing 

 observations at the present moment. In this connexion, however. 



