598 TROPICAL HYGIENE, SANITATION, ETC. 



In tropical countries it is more difficult and costly to carrv out 

 these measures althoug'h the dangers are greater. 



At ports where large numbers of coolies or immigrants are arriving, 

 there is usually a strict quarantine for fourteen days at a quarantine 

 station. 



This is followed by the disinfection of the clothes and the bathing 

 of the bodies of natives. 



For English Regulations in detail see the Local Government Board 

 Order of September 9th, 1907. 



IMMUNITY, VACCINES AND SERA. 



SOME PROPHYLACTIC MEASURES FOR COMMON INFECTIVE 



DISEASES. 



. Vaccines and sera are administered in order to produce partial or 

 complete immunity against given diseases. 



The fundamental principle of vaccine therapy is "to exploit in the 

 interest of the infected tissues the unexercised immunizing capacities 

 of the uninfected tissues " (Wright). 



Immunity depends upon some property in the living blood serum 

 which opposes or annuls, in part or wholly, the products and action of 

 the infecting organisms (Whitelegge and Newman). 



Natural Immunity denotes natural resistance to some given disease, 

 e.g., white rats are immune to anthrax; the lower animals are immune 

 to cholera and typhus fever; man is immune to swine fever. 



Acquired Immunity may be acquired as the result of a natural attack 

 of a disease, e.g., smallpox, or it may be after an artificial attack of 

 the disease, e.g., inoculation. 



Active Acquired Immunity is produced as the result of inoculating 

 attenuated bacteria into the tissues, e.g., as for rabies. 



Passive Acquired Immunity is produced by inoculation of anti- 

 toxins into the tissues, e.g., diphtheria. 



Vaccination is an inoculation by an attenuated virus. 



Vaccines are prepared from laboratorv bacteria or bacteria from the 

 patients about to be treated. These latter are known as autogenous 

 vaccines. The bacteria are isolated, cultivated, killed by heat or anti- 

 septics, tested for sterility, counted and preserved in antiseptics. 



Imported vaccines do not keep at all well in the tropics. To pre- 

 serve them for the longest time possible cut a portion of banana stem, 

 clear out the central core, insert the vaccines, plug up the ends of the 

 banana stem with a piece of the same material and keep in a cool 

 place. The internal temperature of a banana stem is 23° to 25° C, 

 and is fairlv constant for some davs. When becominsf drv make 

 another. The interior can be cooled dailv by sprinkling it and its 

 contents with ethvl chloride. 



