[Higher mortality due to measles in Senegal for children with siblings of the opposite sex].

The impact on case fatality of contracting measles infection from a sibling of the opposite sex was examined using data collected over a 20 year period in 31 isolated villages in Eastern Senegal. The interval between outbreaks of measles in a village was usually greater than ten years. During outbreaks, 766 children lived in families with two maternal siblings under ten years of age; 107 (14.0%) died of measles. The risk of dying of measles decreased with age, increased with the age difference between siblings and decreased with the size of the village. Adjusting for these factors, children in families with a boy and girl were found to have higher mortality than children in families with two boys or two girls (odds ratio (OR) = 1.81 (1.17-2.82)). The increase in risk was the same for boys and girls in male-female families. Cross-sex transmission of measles may be an important determinant of severity of infection.