Abstract
Six children presented during one year with clinical features of infectious mononucleosis, but with laboratory findings of leucocytosis with neutrophilia, increased erythrocyte sedimentation rate, and hypergammaglobulinaemia. Serology for Epstein-Barr virus, cytomegalovirus, adenovirus, and Toxoplasma gondii was negative, while anti-Bartonella henselae IgM with high IgG titre (>/=1/1024) was present in all. All children had contact with kittens. No specific treatment was administered and all recovered.