Transmission of herpes-simplex virus type 1 in a nursery for the newborn. Identification of viral isolates by D.N.A. "fingerprinting".

The occurrence of herpes-simplex-virus type-1 infections in two newborn infants in a nursery within a one-month period suggested the possibility of transmission in the nursery. One infant may have been infected by his father, who had active herpes labialis at the time of the child's birth. The source of the second infant's infection was not apparent. Viruses isolated from the two infants were "fingerprinted" by cleaving the virus-specific D.N.A. with several restriction endonucleases and comparing the electrophoretic patterns. Isolates from the two infants were identical and differed from other isolates from epidemiologically unrelated cases. This observation confirmed the possibility of transmission of herpes-simplex virus type 1 in the nursery, but did not define the mode of transmission. Type-1 infections are serious in neonates: one of the infants died and an oesophageal stricture developed in the other. The "fingerprinting" technique provides a useful epidemiological technique for tracing the transmission of herpes virus infections.