BCG vaccination of children against leprosy: fourteen-year findings of the trial in Burma.

The value of BCG vaccination in preventing leprosy among children was studied in an area of high leprosy endemicity in Burma through a controlled trial; one group of 13 066 children received BCG and another group of 13 176 served as controls. The overall protective effect of BCG, which was only about 20% over the 14-year period, was found to vary with the batch of vaccine, as well as age, sex, and contact status of the children. BCG protection was found to be independent of the initial tuberculin status of the children. The protective effect of BCG against the lepromatous type of leprosy could not be measured because of the low incidence. Protection was observed throughout the fourteen years of the study except for the first year. The results are compared with those of three other major BCG trials in leprosy. The trial has shown that BCG provides only a very modest level of protection and that BCG vaccination is not likely to be an important solution for leprosy control.

Epidemiological information on leprosy in the Singu area of Upper Burma.

In the course of a WHO trial designed to evaluate the possible protective action of BCG vaccine against leprosy, a longitudinal epidemiological study of the whole population was carried out in an area of very high endemicity in Burma from 1964 to 1976. Two mass surveys of the whole population with an interval of 4 years and annual re-examination of the 28 000 children (0-14 years) in the BCG trial were carried out. The data collected yielded important information about general prevalence and yearly incidence of the disease as well as on sex, age, and classification of cases. The general prevalence rate declined from 32.6 per 1000 in the first survey to 25.2 per 1000 in the second. The number of cases among males was significantly higher than among females. Incidence rate among contacts of already known cases was 9.8 per 1000 person-years. The estimated yearly incidence among non-contacts was 5.9 per 1000. Prevalence rates reached a peak in the 20-39-year age group. The prevalence rate of multibacillary patients also reached a peak in the same age bracket. It is stressed that a further period of epidemiological surveillance will be essential in order to have a correct estimate of the expected number of new infections, especially multibacillary cases, in the 20-39-year group. The value of this information is considered unique for planning and programming of future control activities.

Case detection rates for Central Burma (1962-1972).

A short description of the leprosy control program in Burmpa is given and the decrease of the case detection rates during thhe period 1962-1972 are presented to show the effects of control measures in the program emphasizing the importance of early case detection through annual examination of household contacts and school children, regular treatment and health education.

BCG vaccination of children against leprosy: nine-year findings of the controlled WHO trial in Burma.

The leprosy incidence rates so far in the vaccinated and unvaccinated children aged 5-9 and 10-14 years are similar. The BCG-vaccinated children aged 0-4 years at intake had an incidence rate lower than that of children in the control group. BCG vaccination did not protect household contacts or children aged 5-14 years not exposed in the household, and did not influence the distribution of the forms of leprosy in the cases detected. The lepromin reaction in relation to the age at intake was consistently stronger in the vaccinated children than in those of the control group; the younger the age group the more pronounced was the difference, which was only slight in the age group 10-14 years at intake. If the results of the late lepromin reaction are related to the age at onset (when the children are older than at intake), the differences between the BCG and the control groups tend to decrease. It does not seem that the BCG-vaccinated children suffer from a less serious form of leprosy than the nonvaccinated children (most of them nonreactors to tuberculin).