Study on the Epidemiology of Typhoid Fever

Abstract

A study was made of the available statistical data bearing on the epidemiology of typhoid in Palestine. It apears from this analysis that:1. The typhiod epidemicity is not due to a single source such as contaminated water or food. The seasonal prevalence of the disease corresponds with the normal seasonal incidence of typhiod, and is, therefore, in the nature of a contact infection.2. There is no striking difference in age, sex or race susceptibility. In Tel Aviv the age group 5–14 shows a lower incidence than the corresponding age group in Jerusalem or the higher age group 15–29 in Jerusalem and Tel Aviv. There is, however, no difference in susceptibility between the age group 15–29 in Jerusalem and that in Tel Aviv.3. From a graphic comparisos, the calculation of the coefficient of correlation of the limited experience (six years), and a comparison of the prevalence of the disease in the immigrant and indigenous population, there appears to be a significant correlation between the net population increment and epidemicity. These results, if confirmed by a longer experience, are in accord with those obtained in the remarkable mice experiments conducted by the English and American investigators.4. Although, at the beginning, the morbidity and mortality is higher in the immigrant group, there is an evident tendency at equalisation, and in the second year the incidence in the indigenous population is the same as that among the immigrants.5. The above results indicate the path of control: (a) every immigrant, particularly those between the ages 5–29, should be properly vaccinated against typhoid. By raising the resistance of the new population, the possibility of epidemics among them, and consequently later among the resident population, will be averted; (b) the reduction of endemic typhoid can be brought about by reducing the dosage of the infectious microbes. This can only be brought about by concentration of effort on the early detection and isolation of cases and the vaccination of all contacts. These two measures would seem to offer a prompt and relatively simple solution to the typhoid problem in Palestine.