| Abstract: | Pulmonary tuberculosis is not uncommon in the elderly, particularlythose in institutions, and is notoriously difficult to diagnose.Few bacilli are excreted by individuals with non-cavitatingdisease and positive cultures are usually required to confirmthe diagnosis. Radiography is a poor screening method, and therole of the Mantoux test in this population controversial. Thevalue of sputum culture as a screening procedure in elderlypeople with a productive cough was therefore investigated. Ina prospective surveillance study over 26 months, all permanentresidents in homes for the elderly were entered on the basisof a productive cough for 3 weeks or more irrespective of anyknown or presumed cause. Both smears and cultures were performedon sputum specimens, and Mantoux tests and chest radiographswere performed on those who were sputum positive. The 205 subjects investigated yielded 446 smears, seven of whichwere positive for acid-fast bacilli, and 433 cultures, 32 ofwhich were positive for M. tuberculosis. From this 19 patientswith pulmonary tuberculosis were identified, 18 of whom hadnon-cavitating disease on chest radiography. The numbers ofbacilli in these patients were shown to be low and the excretionpattern haphazard. Smears were not sufficiently sensitive todiagnose non-cavitating tuberculosis in this population, andthe sputum must be cultured in order to exclude the diagnosis.Four negative cultures are required in order to exclude thepresence of pulmonary tuberculosis. |
