Nosocomial influenza A (H1N1) infection

In late February 1979, 21 days after admission to the hospital for a diagnostic evaluation of weight loss and abdominal pain, a 25-year-old female developed nosocomial influenza. The case was presumed to be associated with an outbreak of influenza involving nursing students at the same hospital. Viral cultures obtained from the patient and two of the nursing students yielded influenza A/Brazil/11/78 (H1N)-likelike viruses. A retrospective study of the 136 nursing students indicated that 58 (43 percent) had experienced an influenza-like illness during the period mid-December 1978 to mid-March 1979 with a peak of 50 (37 percent) illnesses occurring the month of February. To the authors' knowledge, the illness involving this patient represents the first reported nosocomial case of influenza A/Brazil/78 in literature.