The role of sex in the transmission of measles in a Gambian village.

Data from the 1984-1985 epidemic of measles in Keneba, a Gambian village, have been reanalysed in order to test the effect of same sex vs. opposite sex transmission of measles on the severity of infection. A person infected by someone of the opposite sex was more likely to have severe infection with pulmonary complications than a person infected by someone of the same sex [RR (relative risk) = 2.8, 95% confidence interval (CI): 0.9-9.7]. A secondary case infected by someone of the opposite sex was significantly more likely to have a more severe illness relative to the primary case than a patient infected by someone of the same sex (P = 0.026, Fisher's exact test). There were slightly more female than male primary cases while male secondary cases had a higher risk than female cases of being infected by someone of the opposite sex (RR = 2.6, 95% CI: 0.9-6.9).