The medical department of the United States army required that a prophylactic dose of i,000 units of tetanus antitoxin be given to all wounded, whatever the nature or severity of the wound, as soon as possible after the infliction of the wound. In such cases, at least one subsequent dose of i,000 units was to be given after an interval of seven days. Tetanus antitoxin was also to be administered as a routine measure in the following conditions: (I) Upon the recognition of "trench foot," with or without skin abrasions. (2) In case of frost bite. (3) During operations performed under conditions of unsatisfactory asepsis. (4) During secondary operations necessary in the course of treat ment of wounds received seven or more days previously. (5) Following the manipulations incident to the reduction of com pound fractures or dislocations, after the removal of adherent drains, or any other procedure resulting in the disturbance of the healing process in a wound seven or more days old. As a resultant of these means, the incidence of tetanus in the United States army during the World War was decidedly low; so low, indeed, that only 36 cases were reported as being associated with 176,132 battle injuries. There were but 23 primary admissions to hospital because of tetanus.
The effect is not always to prevent absolutely. But even in those cases in which tetanus does supervene in spite of the inoculations, the incubation period is lengthened and the death rate is lowered; other things being equal, a long incubation period tends to result in a milder attack than a short incubation period, thus any cir cumstance prolonging the incubation period will also tend to lower the death rate. Only 26.9% of the inoculated are attacked
during the first fortnight, whereas 68.9% of the uninoculated are attacked. Among the protected 40.0% have an incubation period of more than 35 days; among the unprotected only 6-5%. The average incubation among inoculated is 45.5 days, among uninocu lated 10-9 days. Indeed, in each year of the war the incubation period tended to rise. Further, the inoculations tended to limit the degree of tetanus, converting what would be generalized cases into local or one-limb cases. The following table illustrates this: Local tetanus tends to occur in the wounded or injured limb and to be confined to that limb. It is much less severe and far less fatal than the generalized type. Naturally the death rate re flected these successes. Among the unprotected and unrecorded the death rate was s3.5%. Among the protected it was 23.0%. The "unrecorded" here undoubtedly include cases which had re ceived a dose. The method employed during the war fully justi fied the hopes which were entertained concerning it.