Use of the P gene to genotype human metapneumovirus identifies 4 viral subtypes.

This study, conducted during 2001-2003, undertook the screening of patients with acute infectious respiratory-tract disease. A random selection of positive specimens was used for sequencing studies of the human metapneumovirus (hMPV) nucleoprotein gene and the phosphoprotein (P) gene. Australian and international sequences were compared, and a global classification scheme was developed. The hMPV P gene was an ideal molecular target for the detection and genotyping of hMPV. The region contained conserved sequences for reverse-transcriptase-polymerase chain-reaction primers and adequate variability to permit the accurate genotyping of the virus into 2 main lineages and 4 sublineages. Establishing viral identity is essential for the linking of genotype and disease severity.