Th. M. Vogelsang

Temporary and chronic carriers of Salmonella typhi and Salmonella paratyphi B

In both typhoid fever and paratyphoid B, man is the original source of infection in the overwhelming majority of cases. Salmonella typhi has been found in the faeces of Greenland sleigh dogs which feed on human faeces (Krogh-Lund, 1940), and S. paratyphi B has been found in the faeces of cows (Kauffmann, 1941), but such modes of infection play a quite subordinate part. In the few cases which have come to light, the hosts should be regarded rather as vehicles of infection than as sources of it. It is only in the human body that both S. typhi and S. paratyphi B persist and reproduce themselves. In tracking down sources of infection we therefore ultimately come back to the living human being. Both /S. typhi and S. paratyphi B are in the main discharged from the human body with the faeces and urine. This process takes place, npt only in the course of the disease, but may also continue during convalescence (temporary carriers) and may, under special conditions, persist for the rest of life (chronic or permanent carriers). To prevent further spread of the infection it is, therefore, essential to examine faeces and urine for the specific germ before the patient is declared free from infection. To throw more light on the frequency with which a delayed or persistent discharge of »S. typhi and S. paratyphi B in the faeces and urine takes place in a large number of cases, an examination was undertaken of the typhoid and paratyphoid B patients treated in the Bergen City Hospital in the period 1920-47. The patients who had discharged other Salmonella types than S. typhi and S. paratyphi B were not included in this investigation. The diagnosis depended partly on serological tests, partly on positive blood culture or the demonstration of the D u r a t i o n o f t h e c h r o n i c c a r r i e r s t a t e

THE CAMPAIGN AGAINST TYPHOID AND PARATYPHOID B IN WESTERN NORWAY. RESULTS OF CHOLECYSTECTOMY.

INTRODUCTION At the beginning of this century a considerable number of typhoid and paratyphoid B cases were notified every year in western Norway. The figures also remained high during the First World War and the following years. However, since 1922 there has been a uniform decline, and in recent years only a few cases have been notified. The distribution of the two diseases has been exceedingly uneven in the various districts in western Norway. Such distribution is a cogent argument for the opinion that the infection is conveyed by chronic carriers. The first chronic carrier in western Norway was detected in 1918 (Madsen, 1918). In 1920 the guiding principles were formulated for the institution of a systematic campaign against enteric diseases in western Norway. In particular, great pains have been taken to discover the original sources of infection in the form of chronic carriers. Since 1918, 147 individuals have been found to be chronic carriers, 84 being carriers of Salmonella typhi, and 63 of Salmonella paratyphi B. The chronic carriers of older date discovered by systematic searching for the source of infection among the contacts of new cases of typhoid, numbered 91. Among these chronic carriers were 37 who had previously suffered from enteric fever. Twelve of these were first found to be carriers more than 20 years after infection, and several of them were not found to be carriers till after the age of 70. Cases kept under constant control from the time of their illness and found to discharge the specific organisms after recovery from it, numbered 39. Three were found to be carriers following bacteriological examination of gall-bladders after their removal on account of attacks of biliary colic. On systematic bacteriological examination of the gall-bladder carried out at all the post-mortem examinations conducted at The Gade Institute, 14 individuals were found to have been carriers. In only 2 of these cases had there been a history of enteric fever. Of the 147 chronic carriers, 23 were males and 124 females. Thus, in this material women were much in the majority, accounting for 84 % of the chronic carriers. Most of the carriers were elderly folk, 96 (65 %) being over the age of 50 when their carrier state was discovered. There were 37 carriers over the age of 70 at this stage. Prigge (1912) associated the high chronic carrier rate in elderly persons with the incidence of gall-stones, which also rises with age. The post-mortem material from the Bergen City Hospital for the period 1912-28 (Vogelsang, 1929), consisting of