Métapneumovirus humain

Abstract

The human metapneumovirus (hMPV) is a new Pneumovirinae related to the avian metapneumovirus type C. hMPV genome differs from human respiratory syncytial virus (RSV) genome by the gene order and the lack of nonstructural genes. Two genetic sub-groups and four sub-types of hMPV are identified. hMPV infections evolve as regular winter outbreaks which have roughly the same size and overlaping RSV epidemics. Among hospitalized children in Caen, hMPV is detected in 9.7% of the cases after RSV (37%), rhinovirus (18%), influenza virus (14.5%), adenovirus (9%), and parainfluenza virus (5%). Most of hMPV infections are observed in children suffering from bronchiolitis, but the localization to lower respiratory tract and the severity of the disease are less frequent in comparison with RSV infections. hMPV is very difficult to isolate using cell culture. Up to now, the only way for hMPV diagnosis was the TS-CRP assays. But the recent apparition of direct antigenic tests allows us to get a fair, rapid, and economic diagnostic tool.

Ten years of human metapneumovirus research

“…6 Of all respiratory viral infections requiring hospitalization, 10% will be due to hMPV, 40% to hRSV and 5% to adenoviruses. 6 In adults, hMPV is the cause of between 4% and 5% of severe acute respiratory diseases.…”

“…6 Of all respiratory viral infections requiring hospitalization, 10% will be due to hMPV, 40% to hRSV and 5% to adenoviruses. 6 In adults, hMPV is the cause of between 4% and 5% of severe acute respiratory diseases. 6 hMPV shares epidemiologic features with hRSV in that it: (i) is present in all continents; (ii) has a seasonal distribution with main occurrence in winter and spring; (iii) is also likely transmitted via airborne respiratory droplets.…”

“…6 In adults, hMPV is the cause of between 4% and 5% of severe acute respiratory diseases. 6 hMPV shares epidemiologic features with hRSV in that it: (i) is present in all continents; (ii) has a seasonal distribution with main occurrence in winter and spring; (iii) is also likely transmitted via airborne respiratory droplets. 7 hMPV has also been found to infect chimpanzees (61% seroprevalence in captive animals in one study) with potential human-to-gorilla transmission cases.…”

“…6,14 Other cells (Hep2 and HepG2) can support the replication of some hMPV strains. 15,16 Its growth in cell culture is difficult and long and cytopathic effects (CPEs) are variable.…”

“…The hMPV-induced CPE is characterized by a rounding of infected cells, subsequent detachment from cell culture matrix and occasionally the presence of small syncytia which do not usually appear before the second week of culture in LLC-MK2 cells. 1,17 The frequent need for initial blind passages before such virological features can be observed, 6 partly explains the relatively late discovery of hMPV. More rapid diagnostic techniques, such as direct immunofluorescence (DFA) or ELISA-based antigen detection can also be used.…”