Genotyping of adenoviruses isolated in an outbreak in a bone marrow transplant unit shows that diverse strains are involved

In the Bone Marrow Transplant Unit of the "Centre Hospitalier Universitaire " in Nancy, from October 1995 to May 1996, 13 patients of 65 (20%) had a po sitive adenovirus (Ad) culture after bone marrow transplant. This unusually high rate raised fears of nosocomial spread and so isolates were serotyped . Fourteen Ad strains were isolated from the 13 patients, nine were of sero type 1, 2 or 3, and 5 were non-typable. These five latter strains were resp onsible for four cases of severe infection with fatal outcome within a two- month period. They were further submitted to restriction fragment length po lymorphism analysis of their DNA which showed the isolates differed by a pe rcentage similarity of 8-79%. In this outbreak, different strains were invo lved, and there was no evidence of a nosocomial origin of Ad infection. (C) 2000 The Hospital Infection Society.