92 



CHOLERA-LIKE OASES PRECEDING TRUE OUTBREAKS. 



It is noteworthy that between March, 190-1, and August, 1905, cases 

 resembling cholera were encountered ever)' few weeks in and about Ma- 

 nila. These died with practically all the clinical symptoms of cholera, 

 but upon bacteriological examination, cholera vibrios could not be demon- 

 strated in the stools or at autopsy. This fact has received considerable 

 attention and since 1905 it can definitely be stated that the last three 

 outbreaks in Manila, namely that of August, 1905; of June, 190.6, and of 

 August, 1907, were invariably preceded by suspicious deaths of the kind 

 mentioned above. Cases suspicious of cholera occurred at intervals of 

 one to four weeks in various sections of the city of Manila as early as 

 April, 1905. 4 Possibly, in all, from 10 to 15 deaths of this kind in 

 which a positive microscopical diagnosis could not be made came under 

 observation before each outbreak. In view of the fact that all deaths 

 in the city of Manila are investigated before a burial permit is issued. 

 it is not likely that many of these cases escaped observation. 



Even after the disease establishes itself it rarely happens that two infec- 

 tions occur in any one house or in a group of houses, or even in the same 

 block. The isolation of the case and the prompt disinfection which is 

 made of the premises in each case may account for this -fact in part. 



OTHER OBSERVATIONS IN REGARD TO THE EPIDEMIOLOGY. 



Many isolated observations, which seemed in some way to be intimately 

 connected with the spread of the disease were made since 1903. It has 

 been noted that when flies are particularly active and persistent and refuse 

 to be driven away, as, for instance, is the case in the United States before 

 a thunderstorm, or when large numbers of roaches, water bugs, and other 

 vermin were seen to be moving about actively in the streets, or when the 

 humidity is relatively high, or bright sunshine is absent with only a 

 small amount of rain, immediately a considerable increase in the nmn- 

 ber of cholera cases almost invariably follows. In 1903 it was observed 

 that the still water in the bends of the Pasig Eiver was infected with 

 cholera organisms, while the main current of the river remained un- 

 contaminated. 



The outbreak of the disease, for instance in Manila, practically always 

 commences among the lowest members of society and frequently beggars 

 or other persons who eke out a precarious existence are the first to be 

 attacked. An examination of the order in which cases appeared in the 

 city of Manila during 1905 and a comparison with the subsecjuent out- 

 breaks shows that the same condition of affairs which existed then has 

 been present ever since, namely, one case will occur in Tondo district, 

 the next possibly in Malate, the next perhaps in Sampaloc, all generally 



