September 15, 1892] 



NATURE 



467 



kovi. We know, too, that in man cholera is produced 

 by what is drunk, and yet animals fed with 

 the vibrio do not get any of the symptoms 

 which have been mentioned, unless they are 

 " prepared " by a course of treatment, either by neutral- 

 izing the acidity of the contents of the stomach, and 

 subsequently giving a dose of opium to quiet the intestines, 

 or by giving a dose of alcohol with the vibrio. This vibrio 

 cannot get through the acid stomach alive. The answer 

 to the question as to how it gets through the human 

 stomach rests partly in the fact that in the early part of 

 digestion, or in between meals, the stomach is not very 

 acid, and so there may not be a sufficient degree of acidity 

 to kill the vibrio. Such remarks would, however, equally 

 apply to the guinea-pig stomach ; and the question as to 

 why in animals the swallowed vibrio does not produce 

 choleraic symptoms unless the animal is " prepared " is 

 still unanswered ; although such animal may be killed 

 by an injection of the virulent preparation of the vibrio 

 into its veins. This difficult point can only be settled by 

 investigations along new lines, probably chiefly chemical. 

 One point suggested by the investigations of the cholera 

 vibrio which we surmised previously to 1884, is that the 

 infective agent in the disease not only primarily attacks 

 the intestines, but grows there, producing the symptoms 

 of the disease by its chemical products, without itself 

 entering the blood stream This has an important bear- 

 ing on the question of vaccination for cholera. The 

 e.xperimental investigation of vaccination against infective 

 disorders is a product of modern bacteriological research. 

 It is too long a question to deal with in a short article ; 

 it is sufficient to say that it is based on the fact that a 

 mild form of the disease may be produced in an animal, 

 which will then be protected from the virulent disease. 

 As in Pasteur's historical experiments, the attenuated or 

 weakened anthrax bacilli were found, when injected into a 

 sheep, to prevent theanimal dying when it received a dose of 

 virulentbacilli, which would undoubtedly kill it in ordinary 

 circumstances. This vaccination, when put into practice, 

 was found to diminish the amount of natural anthrax in 

 sheep in France. Similar results have been obtained 

 with the vibrio of Asiatic cholera by some of Koch's 

 assistants, and latterly by M. Haffkine, in the Institut 

 Pasteur in Paris. Haffkine attenuated the virulent vibrio 

 by means of a current of air and other means, and 

 obtained a culture which did not kill animals, but pro- 

 tected them against a subsequent injection of the virulent 

 vibrio itself. The vaccine was also injected into human 

 beings (who lent themselves for experiment), and was 

 found to produce a local inflammation associated with 

 some degree of fever, all the symptoms passing away in 

 a short period. It is probable that the majority of 

 " vaccines" would produce these symptoms. It is, how- 

 ever, a great step to apply vaccination experiments in 

 animals to human beings when the etiology of the par- 

 ticular disease is not completely worked out, and there is, 

 perhaps, too great a tendency in modern research to ex- 

 tend " vaccination " experiments in infective diseases 

 before a correct knowledge of the mode of action of 

 the infective agent has been obtained. It has been 

 pointed out that doubt rests on the vibrio cholerae 

 Asiaticaj as the true cause of Asiatic cholera. It may 

 be ; but to impartial observers it has not been proved to 

 be. Vaccination for cholera on a large scale would there- 

 fore at present be a mistake, as it might possibly lead to 

 carelessness in the carrying out of better tried preventive 

 measures, which depend not only upon the State but also 

 on the private individual. As a promising field of research, 

 it might be applied to man, since the vaccination itself 

 appears to do no harm. But it requires a long time to 

 decide so difficult a question, and in the meantime the 

 community is face to face with cholera. It is therefore 

 more practical to consider preventive measures than 

 vaccination. 



NO. I 194. VOL. 46] 



Preventive measures against cholera are of two kinds, 

 those taken by the State to prevent the importation of 

 the disease from cholera-stricken districts, and those 

 which ought to be practised by individuals when cholera 

 is prevalent in the community. Both sets of measures 

 depend upon two well-ascertained facts, viz. that each 

 cholera patient acts as a focus of the disease, and that 

 the disease is spread by the evacuations contaminating 

 the water supply. The State can prevent the importation 

 of cholera by quarantine, but this method has been aban- 

 doned in England for many good and obvious reasons, 

 and another substituted for it which is considered as 

 Ukely to be more effectual, but which can only be applied 

 with an efficiently working sanitary organization. In this 

 country we get cholera by ships bringing cholera-stricken 

 people, who are landed. At all the ports, in times of 

 cholera, the ships are boarded by the medical officer, and 

 if any cases of the disease are present they are taken to 

 isolation hospitals, whilst those who are well are allowed 

 to land after leaving their names and destinations. The 

 medical officer of their district is communicated with, and 

 keeps them under surveillance for some days. The 

 cholera ship is moored to a special buoy and disinfected. 

 If no cases of cholera are present on the ship, the pas- 

 sengers and crew are allowed to land, the taking of the 

 names and addresses being left to the discretion of the 

 medical officer who inspects them. It is possible that no 

 better method than this could have been devised, which, 

 with the least inconvenience to the individual, would at 

 the same time keep under surveillance all the imported 

 cases of cholera, and thus check the spread of the disease. 

 It is evident that such a method is quite impracticable 

 without efficient sanitary officers ; it would, for example, 

 be useless in a country like Turkey, where the system 

 of quarantine and sanitary cordons exists as in most 

 other European countries. And in our country the applica- 

 tion of this method of isolation and surveillance is sur- 

 rounded by practical difficulties and dangers which may 

 become serious, and which are in any case worthy of dis- 

 cussion. It is quite possible that the medical officer of 

 the port will have too much to do. At present the 

 cholera epidemic at the Continental ports, even in Ham- 

 burg, appears to be diminishing, and it may disappear 

 when the cold weather comes, to reappear with unabated 

 virulence next spring. As this is probable, no decrease 

 of vigilance of medical inspection is permissible during 

 the winter months ; and it is to be hoped that the sense 

 of security felt by the community at the diminution of 

 cholera on the appearance of cold weather will not extend 

 to the medical officers in whose keeping the general health 

 of the nation lies. \^, next spring, cholera becomes dis- 

 seminated along the Channel on our opposite shore, the 

 medical officers of our ports may be exercised to their 

 utmost in providing accommodation for patients on 

 cholera-stricken ships, and some, apparently well, may 

 proceed to their homes and develop the disease before 

 the medical officer of their district has been advised of 

 their advent. This is, no doubt, a danger which might 

 come even from a ship which has been passed by the 

 port medical officer with a clean bill of health. 



The personal measures to be taken when cholera is in 

 our midst are important, but need only be mentioned. 

 vSince cholera spreads by the evacuations, these must be 

 disinfected with hydrochloric acid, carbolic acid, or 

 corrosive sublimate as soon as they are passed ; and all 

 linen soiled by a cholera patient must be rigidly disin- 

 fected. Since the water supply may become con- 

 taminated, all water used for drinking, washing utensils, 

 &c., must be boiled, and all articles of food, such as milk, 

 likely to be contaminated with unboiled water, should 

 also be subjected to the heat of boiling water. When 

 these and similar measures for personal protection are 

 rigidly observed, it is not too much to say that cholera 

 will not spread. 



