PROPHYLACTIC MEASURES INDICATED IN INFEOTIBLE TERRITORY. 



We will now consider more in detail the prophylactic measures that 

 should be observed in infectible territory. These may be divided 

 into two classes, to wit : (a) Measures directed against the introduc- 

 tion of yellow fever from abroad; (6) those looking to the prevention 

 of its spread when it has been introduced. 



Maritime quarantine. — Measures employed to prevent the entrance 

 of infection from abroad are usually included under the term " mari- 

 time quarantine " and are at present well provided for in the United 

 States by an efficient national quarantine establishment, which is an 

 integral part of the United States Public Health and Marine-Hos- 

 pital Service. 



The measures ordained against the introduction of yellow fever by 

 the quarantine regulations of this service are based on its well-known 

 period of incubation and the processes of disinfection on the mos- 

 quito transmission of the disease, and are directed to the destruction 

 of this insect both in its larval and adult stage. These measures may 

 be stated briefly as follows: 



Vessels which may possibly be infected are detained at the port of 

 arrival five days after disinfection ; vessels known to be infected, six 

 days. The service has medical officers stationed at all the important 

 ports within the yellow- fever zone, and if the vessel is disinfected at 

 the port of departure under the supervision of this officer, the vessel 

 on arrival at a port of the United States within the infectible area 

 is subject to the following modified treatment: If arriving in five 

 days or less, she may be admitted to pratique without disinfection or 

 further detention than is necessary to complete the five days. If ar- 

 riving after five days and within ten days, she may be immediately 

 fumigated and admitted without detention. If arriving after a 

 longer voyage than ten days, she will be considered as not having 

 been subjected to any previous treatment. This last disposition is 

 based on the possibility that a case of yellow fever may have occurred 

 aboard and recovered within the time mentioned. 



Passenger traffic from infected ports, without detention, is also 

 permitted by these regulations under the following conditions: 



Vessels carrying such passengers must be in the best sanitary con- 

 dition and must lie at approved moorings in the open harbor. The 

 crew must not be allowed ashore at the port of departure. The 

 entrance of mosquitoes into the vessel must be prevented, and if they 

 do find ingress must be destroyed. Passengers and crew must be 

 certified as immune by the medical officer issuing the bill of health. 

 The evidences of immunity which may be accepted are proof of a 

 previous attack or ten years' residence in an endemic focus of yellow 

 fever. These regulations apply, of course, only during the close quar- 

 antine season— that is, from the 1st of May to the 1st of November. 



