Molecular epidemiology of adenovirus type 21 in the Netherlands and the Federal Republic of Germany from 1960 to 1985.

After a period of high prevalence in the early 1960s, adenovirus serotype 21 (Ad21) was identified in The Netherlands only very sporadically for more than 20 years. From December 1984 to July 1985, Ad21 was isolated relatively often from hospitalized children living in different parts of The Netherlands. The patients in question suffered from respiratory, gastrointestinal, meningeal, or ocular disorders. An increase in the incidence of Ad21 infections was also observed in the Federal Republic of Germany during this period. The DNAs of 93 isolates of Ad21 were subjected to restriction enzyme analysis with eight endonucleases. All 50 strains isolated in The Netherlands between 1960 and 1963 proved to be DNA variant Ad21/D2/20655/Netherlands/60. This variant has already been described (T. Adrian, R. Wigand, and J. C. Hierholzer, Arch. Virol. 84:79-89, 1985) as typical for the Ad21 strains circulating since 1960. Analysis of the DNAs of the 28 Ad21 strains isolated in The Netherlands or in the Federal Republic of Germany in 1984 and 1985 showed them to belong to two new, closely related DNA variants designated Ad21/D7/1857/Netherlands/84 and Ad21/D8/5398/Netherlands/85. The BglI and KpnI restriction profiles were characteristic for these recent DNA variants.