Horace M. Gezon

Proteus mirabilis infections in a hospital nursery traced to a human carrier.

Abstract Serious infections due to Proteus mirabilis occurred in 11 full-term newborn infants in a hospital nursery over a four-year period. Bacteremia was demonstrated in 10, meningitis in six, and osteomyelitis in two. Four of the babies died of the infection. The usual factors predisposing to neonatal infection were absent. Epidemiologic investigations pointed to one nurse as the source. The organisms were most probably transmitted to the infants by manipulation of the umbilical cord during the admitting procedures. P. mirabilis was cultured from the hands, vagina and rectum of the nurse and from the umbilicus of seven of 12 consecutive newborn infants whom she admitted, including one who became ill with bacteremia. Among the several markers of P. mirabilis studied, susceptibility to tetracycline best delineated the epidemic strains from others cultured during a study of colonization among patients in the nursery affected, and in another where there had been no infections.