| Popis: |
Summary The importance of the tuberculous infectivity of progressive massive fibrosis, the more serious form of coalworkers' pneumoconiosis, has been investigated by further analysis of data from the two Rhondda Fach surveys in 1950–51 and 1953. During this period the number of cases of infectious tuberculosis amongst females fell satisfactorily, but the same was not true of males. The prevalence of positive sputum amongst men with massive fibrosis (17 per 1,000), the attack rate of positive sputum in such cases (4 per 1,000 per annum) and the fatality of cases with overt tuberculosis (4 per cent per annum) suggest that they form the most important source of tuberculous infection in mining areas in South Wales. An investigation into the results of Mantoux tests on the children of men with progressive massive fibrosis did not suggest that many infectious cases were being missed. It is suggested that when massive fibrosis has been diagnosed radiologically routine sputum tests are likely to contribute more than routine chest x-rays to the control of tuberculous infection in mining communities. |
