CAUSE OF THE KEAPPEAEANCE OP CHOLERA. 



97 



around, but the failure to find the organism is due to the change in its 

 morphology. It also appears probable that at such times as the organism 

 can not be recognized as the cholera vibrio, there is a stage during which it 

 is capable of producing cases resembling cholera, such as have been noted 

 in each instance before an actual outbreak. 



CONCLUSION". 



In conclusion, then, it may be justifiable to state that, it appears highly 

 probable, cholera is endemic in the city of Manila ; that the habitat of the 

 organism is in the sewers of the city; that outbreaks in the Philippines 

 outside of Manila are probably due to direct infection from the city of 

 Manila by the food products which are sent out from here, or by direct in- 

 fection by the means of persons carrying the disease. The cases which 

 occurred in the provinces which can be reached by land outside of Manila 

 are in nearly every instance caused by direct infection by means of human 

 beings, and not from food products. This peculiarity is probably due to 

 the fact that very little food is sent from Manila to near-by towns, because 

 they have similar supplies within their own borders. 



Briefly, then, it is believed that if the sewer system of Manila could 

 be throughly disinfected and rendered free of the cholera organism in 

 any of its forms, and the egress of vermin could be stopped, one of the 

 principal sources of the disease would be removed and the early dis- 

 appearance of the infection from the Islands could be hoped for. 



The following tables demonstrate that the average duration of cholera 

 in a town is about two months. 



Table IV. — Cholera statistics arranged in the order in which the towns 

 became infected. 



JANUARY TO JULY, 1906. 



Date of 



first case. 



Town. 



Province. 



Highest 

 number 

 of cases. 



Date of 

 last case. 



Total 

 number 

 of cases. 



Jan. 3 

 Jan. 3 

 Jan. 4 

 Jan. 4 

 Jan. 4 

 Jan. 4 

 Jan. 4 

 Jan. 4 

 Jan. 4 

 Jan. 5 

 Jan. 5 

 Jan. 5 

 Jan. 5 

 Jan. 5 

 Jan. 5 

 Jan. 5 







Jan. 24 

 May 21 

 Jan. 16 

 Feb. 15 

 Jan. 31 

 Jan. 15 

 . Jan. 4 

 Jan. 11 

 Mar. 24 

 Jan. 5 

 Jan. 5 

 Jan. 5 

 Jan. 5 

 Jan. 12 

 Jan. 17 

 June 16 



Feb. 26 

 June 28 

 Mar. 8 

 Mar. 2 

 Feb. 3 

 June 29 

 June 30 

 June 30 

 Apr. 5 

 Mar. 8 

 Jan. 5 

 Jan. 15 

 Jan. 15 

 Mar. 7 

 Feb. 5 

 June 30 



195 

 97 

 66 

 19 

 58 

 65 

 41 

 88 

 36 

 33 

 2 

 3 

 2 

 30 

 50 

 120 

























do 





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