The present invention relates to methods of detecting an increased likelihood of virus infection in a subject. In particular, the present invention relates to methods of detecting an increased likelihood of virus infection in a subject by detecting an altered level of at least one microRNA (miRNA), as well as methods of treating or preventing virus infection. The present invention also relates to nucleotide arrays, oligonucleotides and kits useful for the detection of miRNAs associated with an increased likelihood of virus infection in a subject.