ABSTRACT
Human metapneumovirus (HMPV, MPV) is a member of the Paramyxoviridae family that causes upper and lower respiratory tract disease in humans. The MPV genome is a single-stranded, negative-sense ribonucleic acid. Analysis of sequences and gene identification placed the novel virus in the genus Metapneumovirus with sequence homology most similar to APV-type C (APV-C). Thus, the virus was named human metapneumovirus, and it is the only identified human pathogen in this genus. Sequence data for MPV revealed eight genes, which code for nine proteins. MPV genes have high sequence identity with APV-C and some similarities to other Pneumoviruses in the open reading frame regions. The MPV F protein, a type I glycoprotein, also contains two regions of glycine-poor heptad repeats. The fact that MPV was identified only recently can be partially attributed to poor virus growth in common continuous cell lines, including tertiary monkey kidney and Vero cells.
