title: Mixed respiratory viral infections in Estonia: a long-term laboratory study.
abstract: During the period of 1981-1997, a total of 13,110 patients with acute respiratory viral infections were tested simultaneously for influenza virus A and B, parainfluenza, adenovirus and respiratory syncytial virus (RSV) infections. Of 3,800 laboratory-confirmed cases mixed infections were established in average in 27%. The incidence varied in dependence on the season between 12% and 36%. All infections were involved in mixed infections, yet their participation greatly varied in different seasons. During a season when the incidence of two respiratory viral infections increased, the case number of their mixed infections also increased. We assume that respiratory viruses widely co-circulating among human population also simultaneously infected the same persons. Therefore a proportion of respiratory viral diseases may represent in fact mixed infections which, in turn, may lead to the emergence of mixtures of different viruses and their spread in humans.
authors.affiliation: Department of Virology, Institute of Experimental and Clinical Medicine, Tallinn, Estonia.
authors.forename: K
authors.initials: K
authors.lastname: Subi
mesh_terms: D004957:Estonia / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D012141:Respiratory Tract Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D012621:Seasons