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.

Proposed method for estimating leprosy prevalence based on rates in children.

The authors suggest that, where leprosy prevalence data for the entire population are lacking, the prevalence in schoolchildren may be a valuable index for estimating the magnitude of the problem in areas where leprosy is endemic.

Correlation between leprosy rates in villages different distances apart.

In order to study the role of genetic factors in susceptibility to leprosy infection, the prevalence of leprosy in 118 pairs of Burmese villages different distances apart was investigated. The distribution pattern of the correlation coefficients for leprosy rates was compared with that known to occur for genetic markers under similar conditions. The correlation coefficients decreased rapidly as the distance between the pairs of villages increased and then showed periodicity with distance, becoming negative at almost regular intervals of 4 km: negative values were preponderant for villages more than 25 km apart.