biostudies-literatureZarate SSecretaria de Educación, Ciencia, Tecnología e Innovación de la Ciudad de MéxicoSecretaría de Ciencia, Humanidades, Tecnología e Innovación996https://www.ebi.ac.uk/biostudies/studies/S-EPMC12567045biostudies-literatureUnknown14(10)Respiratory syncytial virus (RSV) remains a leading cause of pneumonia in young children in Mexico and worldwide. To investigate RSV dynamics in Mexico, we conducted a multicenter study from August 2021 to July 2023 in six hospitals across five States, analyzing respiratory samples from children under five years with pneumonia. Multiplex RT-PCR identified 203 RSV-positive cases, of which 123 were RSV-B and 80 RSV-A. Interestingly, 77% of the collected samples showed evidence of coinfection with other respiratory pathogens, with rhinovirus, <i>Haemophilus influenzae</i>, and <i>Streptococcus pneumoniae</i> being the most common. Also, RSV-B dominated in 2021-2022, whereas RSV-A prevailed in 2022-2023, mirroring trends observed in the United States. Sequences of the genes encoding G and F prPathogens (Basel, Switzerland)Circulation of RSV Subtypes A and B Among Mexican Children During the 2021-2022 and 2022-2023 Seasons.PMC12567045303081SECTEI/138/2024Zarate SBautista-Carbajal PNoyola DEGarcia-Leon MLTabla-Orozco VTorres-Rivera KRojas-Larios FSanchez-Flores AMartinez-Arce PAArias CFMartinez-Aguilar GJuarez-Tobias MSEspinosa-Sotero MDCWong-Chew RMTaboada BfalseCirculation of RSV Subtypes A and B Among Mexican Children During the 2021-2022 and 2022-2023 Seasons.Respiratory syncytial virus (RSV) remains a leading cause of pneumonia in young children in Mexico and worldwide. To investigate RSV dynamics in Mexico, we conducted a multicenter study from August 2021 to July 2023 in six hospitals across five States, analyzing respiratory samples from children under five years with pneumonia. Multiplex RT-PCR identified 203 RSV-positive cases, of which 123 were RSV-B and 80 RSV-A. Interestingly, 77% of the collected samples showed evidence of coinfection with other respiratory pathogens, with rhinovirus, <i>Haemophilus influenzae</i>, and <i>Streptococcus pneumoniae</i> being the most common. Also, RSV-B dominated in 2021-2022, whereas RSV-A prevailed in 2022-2023, mirroring trends observed in the United States. Sequences of the genes encoding G and F pr2025-01-01T00:00:00Z2025 Oct2026-05-14T03:21:51.878Z2026-05-14T03:12:51.902ZS-EPMC125670454115660710.3390/pathogens14100996