DUAL RESPIRATORY VIRUS-INFECTIONS

We retrospectively reviewed eight prospective epidemiological studies conducted between 1991 and 1995 for dual respiratory virus infection ( DRVI) to determine the frequency, associated comorbid conditions, clin ical presentations, and morbidity related to DRVI among immunocompeten t persons. Two viruses were identified as the cause of 67 (5.0%) of 1, 341 acute respiratory virus infections. DRVI was detected in patients from <1 year to 79 years of age, in both sexes, and in many races. For ty-two percent of patients with DRVI were less than or equal to 4 year s old. Fifty-eight percent of patients with DRVI had underlying chroni c lung disease, DRVI was associated with upper respiratory tract illne ss; lower respiratory tract illness, including pneumonia; systemic inf luenza-like illnesses; and exacerbations of asthma or chronic obstruct ive pulmonary disease. All of the common acute respiratory viruses wer e identified; picornaviruses and influenzavirus A were the most common . The rate of DRVI (11.6%) was highest in the epidemiological studies in which cell culture, serology, and polymerase chain reaction were us ed together. Patients with DRVI were hospitalized significantly more o ften than those with respiratory infection due to a single virus (46.3 % vs. 21.7%; P < .01), The percentage of DRVIs increased proportionall y with the number of diagnostic methods used.