| genetic variability of human metapneumovirus infection: evidence of a shift in viral genotype without a change in illness. | human metapneumovirus (hmpv) was identified in 2001 as a cause of acute respiratory illness, but its characteristics are still being defined. we analyzed 3740 nasopharyngeal-wash specimens obtained during 2002-2004, using assays for common respiratory viruses and real-time polymerase chain reaction for hmpv. we detected hmpv in 5% of all specimens, compared with 28% for other respiratory viruses. nucleotide sequence analysis of hmpv isolates revealed the predominant circulation of hmpv genotype ... | 2006 | 16388487 |