The use of BCG vaccine in mantoux-positive and Mantoux-negative persons in East Africa

Abstract

A group of 1,750 African children in Northern Tanganyika were tuberculin tested (Mantoux test with 10 TU of Old Tuberculin). Four days later all were vaccinated intradermally with 0·1 ml. freeze-dried BCG vaccine (Pasteur). The children were examined after seventy-two hours and again after seven weeks. One thousand, six hundred and ten had pre-vaccination tuberculin reactions of less than 5 mm. diameter. In 223 (14 per cent) of these there was a local reaction seventy-two hours after vaccination (‘Koch reaction’), 35 of the reactions being 15 or more mm. diameter. One hundred and forty had pre-vaccination reactions of 5 or more mm. diameter. No early local reaction to vaccination occurred in 11: in the remaining 129 (92 per cent) there was a reaction, 113 having reactions of 15 mm. or more diameter. Of the whole group of 1,750, 53 per cent had no visible reaction to vaccination when examined after seven weeks. There were ulcers in 10 per cent, local abscesses in 3 per cent, enlarged nodes in 5 per cent and either scars or cutaneous nodules at the vaccination site in 30 per cent. Three hundred and fifty-two had ‘Koch reactions’. When examined after seven weeks there was no visible reaction in 20 per cent, ulcers in 20 per cent, local abscesses in 6 per cent, enlarged nodes in 10 per cent and scars or cutaneous nodules in 49 per cent. All the ulcers and abscesses healed and enlarged nodes subsided without causing further trouble. Two cases of progressing tuberculosis are known to have occurred. One child developed cervical adenitis seven months after vaccination and another had enlarged hilar nodes four months after vaccination. Both had been negative to 10 TU before vaccination. No case of progressing tuberculosis is known in the group positive to 10 TU before vaccination. The dangers of vaccinating individuals with tuberculin sensitivity demonstrated by the 10 TU Mantoux test seem to have been exaggerated; but if vaccination is done without preliminary tuberculin testing there will be an increased number of early reactions and persisting skin lesions. These are more irritating than dangerous. The conversion rate at seven weeks among the whole group was only 80 per cent, although in those over 10 years old it was 92 per cent. It is possible that the freezedried vaccine (Pasteur) was not of high potency. If a more potent vaccine is used the proportion of troublesome local reactions with unselective vaccination might be higher than that found in this series.