CANCER MORTALITY IN CHRONIC TYPHOID AND PARATYPHOID CARRIERS

It has been shown in vitro that bacteria are able to form or release c arcinogens, mutagens, or promoters from intestinal secretions such as bile, or from excretions such as urine. It is, therefore, of interest to find out whether chronic infection of the gallbladder is associated with carcinogens, as in chronic infection of the urinary bladder. A s tudy of cancer risk in chronic typhoid and paratyphoid carriers showed a large excess (observed/expected cases) for cancer of the gallbladde r (167.0; 95% confidence interval 54.1-389) and also excess risks of c ancer of the pancreas (8.1), colorectum (3.0), lung (2.5), and all neo plasms (2.6). There was no similar excess risk in a group of 386 peopl e with typhoid from the 1964 Aberdeen outbreak. This indicates that it is long-term typhoid carriage, not acute infection, which is the risk factor. This has important implications for cancer prevention. Eradic ation of chronic carriage, by use of antibiotics or elective cholecyst ectomy, should be re-emphasised, and the need for good documentation o f carriers is, therefore, of great importance.