The Philippines insurrection and the 1902–4 cholera epidemic: Part I—Epidemiological diffusion processes in war

Abstract

This, the first of a two-part paper, presents an historical case study of the impact of war and its aftermath upon the spread of an infectious disease, cholera. The choice of area (Philippine Islands), the time (a year-long period in the immediate aftermath of the Insurrection against US annexation, March 1902–February 1903) and the epidemic (cholera) are conditioned by the detailed reports prepared by the Chief Quarantine Officer for the Philippine Islands, and published weekly in the contemporary USPublic Health Reports. The reports include textual accounts of the progress of the epidemic, and numerical evidence regarding the weekly incidence of cholera in over 440 settlements. This information is used to reconstruct the routes by which cholera diffused through the archipelago and to model the diffusion process on the geographical levels of province, island and nation. It is shown that a spatially contagious component dominated the spread of cholera in many geographical areas and at all spatial levels. In contrast, hierarchical diffusion was generally found to be of only limited significance in the transmission process. These results correlate with the lack of a well-developed urban hierarchy in many parts of the Philippines. Part II of the paper, to be published in Vol. 24, Number 2 (April 1998) of theJournal, goes on to compare the spatial diffusion patterns described here with those found in a subsequent peacetime cholera wave in the Philippines (May 1903–February 1904). Results from both parts of the paper are used to assess the manner in which war can affect diffusion processes and the circumstances under which spread is likely to be dominated by contagious, hierarchical or mixed diffusion processes.