Genome analysis of adenovirus type 31 strains from immunocompromised and immunocompetent patients.

Adenovirus type 31 (Ad31) was isolated from 15 immunocompromised patients in 12 of whom seroconversion was also recorded. Ad31 infection has a substantial clinical relevance since 8 of 10 with lower respiratory tract infection and 4 of 4 with hepatitis died. Therefore, Ad31 isolates from immunocompetent and immunodeficient hosts were compared by restriction endonuclease analysis. Nine genome types were identified among the 79 Ad31 isolates. Pairwise comparison of comigrating restriction fragments indicated that the genome types could be divided into three genomic clusters. Several Ad31 genome types were isolated from immunocompromised patients, but no highly virulent genome type could be found. A genome type was identified in a child with severe combined immunodeficiency who originally was infected with another genome type. This observation is suggested to have evolutionary implications.