Serological survey. I. Immunity status of some Burmese nationals to diphtheria

The sera of 1,068 healthy Burmese adults of both sexes, having no history of active immunization against diphtheria or of classical clinical diphtheria, were titrated for antitoxin levels in order to determine their immunity status towards diphtheria. The rabbit intradermal test (Jensen, 1933) at the Lr/1000 level was used. Only 25 (2.3%) had antitoxin titres of less than 0.01 mu/ml and were classified as non-immune while the remaining 1043 (97.7%) possessed titres of 0.01 mu/ml or more and were therefore immune. The percentage of non-immune females, 6.9% (13 out of 188) was significantly different (p > 0.01) from non-immune males, being 1.4% (12 out of 880). No significant differences were found between the age groups regarding immunity status either in males or in females.