UNITED STATES PUBLIC HEALTH SERVICE 365 



means of checking this yellow scourge and above all to Drs. Walter Reed 

 and Lazear, whose lives helped to pay the price for the knowledge which 

 finally vanquished yellow fever. Their associates on the board, Drs. 

 Carroll and Agramonte, as well as Dr. Finlay, of Havana, are no less 

 deserving of praise. The work of the Army board completed the excel- 

 lent pioneer work of Surgeon Henry E. Carter on the incubative period 

 of yellow fever. It follows that yellow fever can only be successfully 

 combated by destruction of the mosquitoes by means of which it spreads. 

 Quarantine measures against the disease are therefore concerned with 

 isolation of all cases and very careful exclusion of every possible contact 

 with mosquitoes by screening and elimination of all breeding places. 



Cholera presents an entirely different picture from the standpoint 

 of quarantine. Here we have a disease proved to be caused by an 

 intestinal infection with a definite and characteristic microbe, the so- 

 called "comma" vibrio of Koch. The infection is limited absolutely 

 to the intestinal tract, consequently the entire danger of spread of the 

 disease is limited to the alvine discharges. The bacteria are taken into 

 the system chiefly through the ingestion of infected drinking water, the 

 contamination having arisen from sewage infection or other polluting 

 contact with infected intestinal discharges. Uncooked vegetables and 

 fruits are a secondary source of danger for like reasons. Preventive 

 measures must also be extended to exclude articles of diet such as fresh 

 fruits, for instance, which may tend to excite a tropical diarrhea and so 

 produce a point of lowered resistance where the cholera germs can take 

 effect. Quarantine measures, therefore, aim to isolate all frank cases 

 and suspects, and to detain all who have been exposed, in small groups 

 under close observation for at least five days,' covering the incubation 

 period of cholera. Water and food supply must be above suspicion of 

 carrying the germs, and strict cleanliness of person and quarters must 

 be strictly enforced. It is absolutely essential that intestinal discharges 

 from frank cases and suspects alike be thoroughly disinfected. Before 

 convalescent cases are released from detention the intestinal discharges 

 must be proved free from cholera germs by microscopical examination 

 and bacteriological culture. 



Smallpox is more familiar than the diseases just described, as are 

 also the circumstances embodied in its quarantine control. Vaccination 

 or proof of immunity by having had the disease are required of all per- 

 sons exposed, which, of course, means all on board an infected vessel. 



Typhus fever, the old time " ship " or " famine " fever, is very rare 

 now in the United States, probably because of improved ship hygiene 

 and sanitation, conditions always inimical to the disease. The last 

 epidemics in this country were in Philadelphia in 1883 and in New 

 York in 1891-92. Very rarely is a case seen at quarantine, but it is 

 controlled by isolation, and disinfection of articles and quarters exposed 

 to infection. Drs. Anderson and Goldberger, of the Hygienic Labora- 



