a1 Gade's Institute, Department of Bacteriology, Bergen, Norway
a2 Bergen City Hospital, Department of Infectious Diseases, Bergen, Norway
1. In a material consisting of 417 cases of typhoid fever and 1055 cases of paratyphoid B investigated over a period of 28 years, infection with S. typhi was found to be considerably more serious than infection with S. paratyphi B. In childhood and among young folk the S. paratyphi B mortality was low, but in the age group over 30 it reached 5%. But even in childhood infection with S. typhi gave a mortality of 8·5%, rising at a higher age to 16%.
2. Of the 1387 patients surviving the infections 13·3% were found to be excreters during convalescence, 11% being temporary and 2·3 % being chronic carriers.
3. Of the temporary carriers, 7·9% were faecal and 3·7 % were urinary carriers. The percentage of temporary excreters was approximately the same for the typhoid and paratyphoid B patients—40% were men and 60% were women. The number of temporary carriers rose with the patients' age, and in the age group over 30 years, about 15% were temporary carriers in the case of both infections.
4. Of the temporary carriers, only one-tenth discharged the specific germ for more than 4 weeks after the cessation of the illness. After an interval of 3 months, it is most exceptional for the carrier state to cease spontaneously. We may, therefore, feel justified in fixing this interval as the dividing line between the temporary and the chronic carrier state.
5. Of the typhoid patients 3·3%, and of the paratyphoid B patients 1·9%, became chronic carriers. Thirty-one of them were faecal and only one was a urinary excreter. There was only one child found to be a chronic typhoid carrier. Chronic carriers were also rare among young folk, and the incidence of this state rose much with age, as many as twelve of the total of thirty-two chronic carriers being over the age of 50. Eleven of these twelve were women, five being typhoid and six being paratyphoid B carriers.
6. Most of the chronic carriers have been kept under control for a long time. The only chronic typhoid carrier to recover spontaneously was a woman, aged 52. Cholecystectomy was performed on fourteen chronic carriers. In all the cases in which the carrier state had lasted for at least a year, gall-stones and chronic cholecystitis were found, and the specific germ was obtained in pure culture from the gall-bladder. A woman who had continued to discharge S. typhi for more than 1½ years after the operation, ceased to do so after this interval. The object of the operation was not achieved in one case.
(Received July 30 1948)