RESUMEN
BACKGROUND: Influenza A virus infections occur in different species, causing mild-to-severe symptoms that lead to a heavy disease burden. H1N1, H1N2 and H3N2 are major subtypes of swine influenza A viruses in pigs and occasionally infect humans. METHODS: A case infected by novel influenza virus was found through laboratory surveillance system for influenza viruses. Clinical specimens were tested by virus culture and/or real-time RT-PCR. The virus was identified and characterized by gene sequencing and phylogenetic analysis. RESULTS: In 2021, for the first time in Taiwan, an influenza A(H1N2)v virus was isolated from a 5-year old girl who was suffering from fever, runny nose and cough. The isolated virus was designated A/Taiwan/1/2021(H1N2)v. Full-genome sequencing and phylogenetic analyses revealed that A/Taiwan/1/2021(H1N2)v is a novel reassortant virus containing hemagglutinin (HA) and neuraminidase (NA) gene segments derived from swine influenza A(H1N2) viruses that may have been circulating in Taiwan for decades, and the other 6 internal genes (PB2, PB2, PA, NP, M and NS) are from human A(H1N1)pdm09 viruses. CONCLUSION: Notably, the HA and NA genes of A/Taiwan/1/2021(H1N2)v separately belong to specific clades that are unique for Taiwanese swine and were proposed to be introduced from humans in different time periods. Bidirectional transmission between humans and swine contributes to influenza virus diversity and poses the next pandemic threat.
Asunto(s)
Subtipo H1N1 del Virus de la Influenza A , Gripe Humana , Infecciones por Orthomyxoviridae , Enfermedades de los Porcinos , Animales , Virus ADN , Humanos , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N2 del Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/genética , Gripe Humana/epidemiología , Neuraminidasa/genética , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , Filogenia , Virus Reordenados , PorcinosRESUMEN
BACKGROUND: The rapid identification and isolation of individuals infected with SARS-CoV-2 are fundamental countermeasures for the efficient control of the COVID-19 pandemic, which has affected millions of people around the world. Real-time RT-PCR is one of the most commonly applied reference methods for virus detection, and the use of pooled testing has been proposed as an effective way to increase the throughput of routine diagnostic tests. However, the clinical applicability of different types of real-time RT-PCR tests in a given group size remains inconclusive due to inconsistent regional disease prevalence and test demands. METHODS: In this study, the performance of one dual-target conventional and two point-of-care real-time RT-PCR tests in a 5-specimen pooled testing strategy for the detection of SARS-COV-2 was evaluated. RESULTS: We demonstrated the proof of concept that all of these real-time RT-PCR tests could feasibly detect SARS-CoV-2 from nasopharyngeal and oropharyngeal specimens that contain viral RNA loads in the range of 3.48 × 105 to 3.42 × 102 copies/ml through pooled testing in a group size of 5 with overall positive percent agreement (pooling vs. individual testing) ranging from 100% to 93.75%. Furthermore, the two POC real-time RT-PCR tests exhibited comparable sensitivity to that of the dual-target conventional one when clinical specimens were tested individually. CONCLUSION: Our findings support the feasibility of using real-time RT-PCR tests developed as a variety of platforms in routine laboratory detection of suspected COVID-19 cases through a pooled testing strategy that is beneficial to increasing the daily diagnostic capacity.