Abstract
A 29-year-old woman with an upper respiratory tract infection due to Haemophilus influenzae, gave birth to a premature infant who died after 3 h. The mother's strain was non-capsulated, as were the strains cultured from the infant's blood, lungs, nose, and throat. Antigen analyses revealed, however, that the strains were not identical. The infant probably acquired the infection via the transplacental route. The uncommon infection was in this case attributed to a transient dysgammaglobulinemia in the mother.