23.5 Leach et al.: Hookworm Infestation 501 



mains, however, that only 30 per cent of the worms expelled 

 after the first day were Ancylostoma. In our judgment, it is 

 not likely that any difference in response would be notice- 

 able in the doses we administered, which are proportionately 

 larger than those given by other investigators. Whether or not 

 the high efficiency of the drug which led to the expulsion of 97 

 per cent of the total number of worms within the first twenty- 

 four hours can be turned to account in the saving of time and 

 labor in future surveys remains to be determined. 



Carbon tetrachloride, as has been said, is not nearly so effi- 

 cient a vermicide against Ascaris and Trichuris as it is against 

 hookworm. Based on stool examination, not of itself entirely 

 conclusive, we succeeded in clearing only five Ascaris and three 

 Trichuris infestations. At the same time, we regard our results 

 in the treatment of Trichuris infestation as somewhat encourag- 

 ing, for it will be seen on scanning Table 19 that in several in- 

 stances the drug brought about the expulsion of numerous worms, 

 even though ova were found at a subsequent microscopical exam- 

 ination. In the treatment of subjects infested with Ascaris 

 and Trichuris, we failed to recover Ascaris in eleven cases and 

 Trichuris in sixty-three. In six instances we recovered Ascaris 

 on screening the stools, only to find the ova on reexamination. 

 We likewise recovered Trichuris in eighteen cases, the ova being 

 recovered on reexamination. 



This performance seemed to bear no relation whatever to the 

 quantity of drug administered, as will be seen by inspection 

 of Table 18, which sets forth the doses administered to eleven 

 Asmm-infected subjects from whom no adult worms were reco- 

 vered after treatment. 



> eleven subjects 



19366 

 14709 

 14722 

 14724 

 14726 

 14731 

 14682 

 14704 

 57342 

 13112 

 14641 



