THE GREAT PLAGUE OF HONG KONG
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disease to man remained a mystery and the two Japanese researchers could only conclude that the bacillus was drawn from the air by breathing.
Further investigations soon established a positive relationship between the incidence of plague first among rats and subsequently among man. On this account, Simpson reported in 1902 that “no success is likely to accrue from the adoption of any measure limited to dealing with plague in human beings and which does not take cognizance of the fact that plague in rats and mice also disseminates the infection. It does not serve any very useful purpose to remove the sick and cleanse everything in the infected houses and above the ground if the infection is being carried by plague-stricken rats from house to house or district to district by the subterranean movements of rats, whether this be effected by rat burrows or by sewers and drains. Both rat and human plague possess infective powers and each can spread the disease not only to its own species but also to the other”.*
Simpson could offer no explanation as to the medium of infection although he did make a number of observations as to the conditions which appeared to favour the spread of the disease. In particular, he drew attention to the extremely crowded and insanitary conditions under which the majority of the Chinese population lived, the virtually unrestricted migration of thousands of people from infected areas in China to Hong Kong, and the fact that the colony served as a great emporium with hongs and godowns filled with stores and infested with rats.
Simpson saw the solution to the problem by way of the strict enforcement of various preventive measures. Besides the already well-established procedures for the disinfection of houses, public latrines, and the like, he recommended in 1902 the appointment of medical men in every health district to register cases and find out causes of the disease. He also urged the strict control over the disposal of dead bodies in the street and harbour, and, to this end, suggested the enforcement of collective fines on all households in any street where a dead body was discovered. He further saw the necessity for the bacteriological examination of rats as part of an
* First Memorandum from W. J. Simpson, M.D., to James Stewart Lockhart, Sanitary Board Office, 20th January 1902, p. 1 in Blue Book Reports on Bubonic Plague 1894-1907.
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