Sixteen years of evolution of human respiratory syncytial virus subgroup A in Buenos Aires, Argentina: GA2 the prevalent genotype through the years

Abstract

Human respiratory syncytial virus (HRSV) is the main viral cause of acute lower respiratory tract infections (LRTI) in children worldwide. In recent years, several preclinical trials with vaccine candidates have been reported. It is in this sense that molecular epidemiological studies become important. Understanding viral dispersion patterns before and after the implementation of a vaccine can provide insight into the effectiveness of the control strategies. In this work we analyzed the molecular epidemiology of HRSV-A over a period of sixteen years (1999-2014) in Buenos Aires. By bioinformatic tools we analyzed 169 sequences of the G glycoprotein gene from hospitalized pediatric patients with LRTI. We found that GA2 was the most prevalent genotype (73.35%). GA5 genotype co-circulated in our region until 2009 when it was no longer detected, except in 2011. The recently globally emerging ON1 lineage with a 72-nt duplication increased its frequency to become the only lineage detected in Buenos Aires in 2014. By discrete phylogeographic analysis of global ON1 strains we could determine that Panama could be the location of the MRCA dated June 20, 2010; and this lineage could be introduced in Argentina from Spain in April 2011. This analysis also showed temporary and geographical clustering of ON1 strains observed as phylogenetic clades with strains exclusively associated from a single country, nevertheless among our 44 ON1 strains from three outbreaks (2012-2014) we could also detect posterior reintroductions and circulation from United States, Cuba, South Korea, and Spain. The continuous phylogeographic analysis of one sublineage of Argentine ON1 strains allowed us to establish that there could be a local clustering of some strains even in neighborhoods. This work shows the potential of this type of bioinformatic tools in the context of a future vaccine surveillance network to trace the spread of new genetic lineages in human populations.

Molecular epidemiology of human respiratory syncytial virus among children in Japan during three seasons and hospitalization risk of genotype ON1

“…We have previously observed a similar pattern in one prefecture in Japan over a period of 9 seasons, between 2001 through 2010 [ 16 ]. This alternate pattern of HRSV-A and -B seasons has been also observed in other countries including Finland[ 39 ], China [ 40 – 42 ], the Philippines [ 43 , 44 ], Argentina [ 45 ], Malaysia [ 46 ], and Senegal [ 47 ]. The alternation between the HRSV subgroups in subsequent seasons can be attributed to the variation in the immunity of the host population.…”

“…Other countries, such as Vietnam, the Philippines, Italy and Kenya, reported that the shift from NA1 to ON1 predominance occurred during the 2012–2013 season, almost one to two years earlier than in Japan and mainland China[ 22 , 44 , 56 , 67 ]. Evolutionary analysis of the ON1 strain suggests that this genotype might have emerged from the Americas, specifically in Panama around 2010 [ 45 ]. Our data and those from previous studies suggest that the ON1 rapidly spread worldwide after its emergence [ 25 ] and the time needed to replace the previous RSV-A genotype NA1 was 2 to 4 years [ 22 , 42 , 44 ].…”

Spread and Evolution of Respiratory Syncytial Virus A Genotype ON1, Coastal Kenya, 2010–2015

“…Reports from Italy ( 14 ), South Korea ( 36 ), United States ( 17 ), Malaysia ( 37 ), Japan ( 19 ), Thailand ( 16 ), Latvia ( 38 ), and Cyprus ( 33 ) indicate varied RSV ON1 prevalence of 20%–70%. A recent article reported that ON1 was the sole (100%) RSV-A genotype in Buenos Aires, Argentina, in 2014 ( 39 ). The varying prevalence suggests that even though ON1 is rapidly spreading globally, host or ecologic differences may determine RSV spread.…”

Respiratory syncytial virus genotypes NA1, ON1, and BA9 are prevalent in Thailand, 2012–2015

“…For RSV-A, NA1 was the major genotype found in our previous study conducted between 2010 and 2011 ( Auksornkitti et al, 2014 ) and was also seen here in 2012. More recently, ON1 has displaced NA1 to become the predominantly circulating RSV-A strain ( Eshaghi et al, 2012 ; Valley-Omar et al, 2013 ; Pierangeli et al, 2014 ; Kim et al, 2014 ), although it does not appear to cause more severe disease than other genotypes ( Panayiotou et al, 2014 ; Viegas, Goya & Mistchenko, 2016 ). Our study confirms findings of previous studies in that NA1 and ON1, but not NA3, are frequently identified in Southeast Asia ( Arnott et al, 2011 ; Yoshihara et al, 2016 ).…”

“…It is noteworthy that the BA genotypes, like the ON1, only recently emerged to replace all other RSV-B strains ( Trento et al, 2010 ). Furthermore, the BA genotypes also possessed duplication in the HVR2, which is hypothesized to enhance RSV transmissibility by changing the antigenic epitope and facilitate immune evasion ( Viegas, Goya & Mistchenko, 2016 ).…”