It is especially prevalent after hot, dry seasons and less so when the summer has been wet and cold. Recent experiments by Robertson demonstrate the fact the typhoid-fever germs grow luxuriantly in the soil during the summer and remain dormant in the winter.
Locality seems to make little differ ence. It occurs with equal prevalence in cities, towns, villages, and country houses. Soldiers in camps seem especially liable to the disease, on account of the ease whereby the virus may be conveyed from one to another.
Antityphoid inoculations used in India on British troops, using lysolized, four weeks'-old cultures of a virulent typhoid bacillus, prepared twelve months pre viously. The quantity employed for each inoculation varied between 0.5 and 0.7 cubic centimetre. Some vaceine-material was also prepared in Calcutta and Agra with virulent typhoid cultures grown for twenty-four hours in nutrient agar at a temperature of 37° C., and sterilized at GO° C. The quantity of this employed at each inoculation varied be tween 0.3 and 0.5 cubic centimetre. Both varieties gave fairly severe reactions in man, and showed a distinct degree of protection when the case-mortality of the inoculated was compared with that of the uninoculated. A. E. Wright (Lancet, Jan. 20, 1900).
Results of the use of vaccine in four teen nurses. These were inoculated in the evening and allowed to rest the next day. Since 1S95 the nurses on the staff have shown from 3 to S cases of typhoid fever yearly, while from September, 1S99, to March, 1000, the time during which the inoculations have been carried out, not one case had been seen, unless one doubtful case was typhoid. Marsden (Brit. Med. Jour.. Apr. 2S, 1900).
Question recently asked in the British Parliament as to the measure of protec tion conferred upon soldiers by the inocu lations introduced by Professor Wright. Out of 11,000 men, 2S35 were treated, and most of these were young and unsea soned. Of these only 27, or 0.95 per cent., contracted enteric fever, and 5 died there from. Of the uninoculated, 213, or 2.5 per cent., contracted it and 23 died. These statistics were called for from every station at home and abroad.
(Treatment, June, 1900.) Typhoid among the American soldiers in 1898; more than 90 per cent. of the volunteer regiments developed typhoid fever within eight weeks after assembling in encampments, and all of the regular regiments in less than eight weeks. It became epidemic both in the small en campments of one regiment camp, and in the larger ones, containing one army corps, in the North as well as in the South.
The investigations confirm the doctrine of the specific origin of typhoid fever. Infection was due to the great difficulty of disposing of the excretions in camps. Pollution of the latter was the main source, though some camps were un wisely located. The space allotted to some regiments was also inadequate, and many commands were allowed to remain on one site too long. Requests for change, made by medical men, were not always granted. Greater authority should be given medical officers in such matters.
The tub system, as well as that of the regulation pits. is condemned. In perma nent camps where water carriage cannot be secured, all faecal matter should be disinfected and then carried away from the camp. Flies serve as carriers of in fection. but infected water was not an important factor in the spread of the dis ease. Personal contact was a probable means of infection; dust-laden air may have contributed somewhat to its spread. An infected command does not lose the infection by change of location. Besides this change of camping-ground. there must be a thorough disinfection of all equipment. The percentage of deaths among the cases of typhoid fever was about 7.5. V. C. Vaughan (.Jour. Amer. Med. Assoc., June 9, 1900).
At Ladysmith the proportion of at tacks and deaths from typhoid fever was seven times smaller in the inoculated than in the uninoculated. if the num ber of men who had previously an ffered from typhoid fever had been subtracted from the number of the uninoculated, the statistics would have shown even better results. As it is, the proportion attacked by typhoid fever was but one•seventh as great in the inoculated as in the uninocu lated. A. E. Wright (Lancet, July 14, 1900).