Molecular epidemiology of respiratory syncytial virus between 2010–2015, in Portugal

Abstract

ResultsOver the study period were detected 114 (5.2%) RSV in 2187 tested NPS. Of these 67 (59%) were from subtype A and 47 (41%) from subtype B. ConclusionsOur study highlights the importance of RSV in ILI cases, showing a seasonal circulation each winter season during influenza epidemic. RSV accounted for 5.2% of the cases reported in the scope of influenza surveillance, assuming a huge importance in young children and elderly. Molecular data for RSV A revealed co circulation of NA1 and ON1 between 2010-2012. After this period, ON1 was exclusively detected suggesting a strain replacement by this antigenically advantageous genotype. Globally ON1 is also predominantly detected. For RSVB subtype was observed the circulation of only BA genotypes (BA9 and BA10), which were first identified in 1999 in Buenos Aires and since then are predominant in many countries. AcknowledgmentsThe authors would like to thank to the GP Sentinel network, Non-sentinel Influenza Network (Emergency and Obstetric Units) that contributed to the clinical and virological components of the National Influenza Surveillance Programme during 2010-2015 seasons.

Epidemiology and genetic variability of respiratory syncytial virus in Portugal, 2014–2018

“…However, the fact that this genotype was not found between these two periods might be due to the sequencing bias. In Portugal, ON1 genotype was detected during the 2011/12 season for the first time [27], and since then, it has predominated in the country as reported worldwide [48,49]. Regarding RSV-B genetic diversity, all belonged to BA genotype, which has already been detected in at least 23 countries [50].…”

“…Regarding RSV-B genetic diversity, all belonged to BA genotype, which has already been detected in at least 23 countries [50]. BA9 genotype has predominated in Portugal since 2010 [27,42] as in other countries [10,45,49,51], being detected alongside with BA10 genotype until 2015/16, when BA9 remained the only genotype detected onwards. Since 2001, new genotypes have been added over time by different authors following the proposed criteria by Venter et al [5].…”

“…RSV-A and RSV-B subtypes co-circulated between 2010 and 2018 in Portugal [27,42]. RSV-A subtype was the most prevalent in the 2015/ 16 season, whereas RSV-B subtype dominated in the next two consecutive seasons (2016/17 and 2017/2018).…”

“…Alignments were performed with the MUSCLE method and phylogenetic trees were generated using the Neighbor-Joining method and pdistance model (bootstrap re-sampling of 1000 replicates) on MEGA 7.0. In addition to worldwide reference strains (RSV-A and RSV-B) that were retrieved from GenBank (https://www.ncbi.nlm.nih.gov/ genbank/), 20 RSV-A strains from a previous study in Portugal (2010/11-2013/14) [27] were used for the tree construction together with the sequences generated in this study. Sequences with 100% homology in the nucleotide sequence were represented by one strain and submitted to GenBank database with accession numbers MN122441-MN122562 (RSV-A) and MN122563-MN122694 (RSV-B).…”