Transmission of tuberculosis in Barbados

ABSTRACT

Tuberculosis morbidity in Barbados has fallen rapidly in recent years. This study was undertaken to discover whether the epidemiological situation has altered sufficiently to require a change in our policies on BCG-vaccination and case-finding. Tuberculin tests were carried out and read on 500 children aged about 5 years at 12 schools in three of the island's eleven parishes, using PPD 10 TU in 0.1 mil given intradermally. Only one natural reactor was found among the 500 children, though 15 others who had previously had BCG vaccination gave a positive response. 478 children showed no induration at all, and only 6 reactions fell in the range 1-8 mm, indicating that there is very little infection with atypical mycobacteria among the tested children. The results indicate that the transmission of tuberculosis in Barbados is at a very low level, comparable with that of the countries of Europe and North America. In the United States the low prevalence of tuberculin reactors among children has given rise to the concept of localised tuberculosis epidemics occurring round a single infectious case, and the object of control measures is to identify and stamp out these outbreaks. This is done by finding cases, especially among high risk groups, treating them promptly, and protecting tuberculin-positive and tuberculin-negative contacts with chemoprophy. The importance of the survey in planning immunization and control programmes will be considered for Barbados (AU)