CLINICAL BURDEN, SEASONALITY AND MOLECULAR EPIDEMIOLOGY OF RSV IN CHILDREN =5 YEARS IN MEXICO: A SYSTEMATIC REVIEW ACROSS PRE-PANDEMIC, PANDEMIC, AND POST-PANDEMIC PERIODS
Author(s)
Cassia Veiga, PhD1, Felype Castelhano, BSc1, Mariana Rosim, PhD1, Dara Ferreira, BSc1, Emilia Prieto, PhD2, Karen Bobadilla, PhD3, Cintia Parellada, PhD1.
1MSD Brazil, São Paulo, Brazil, 2MSD Colombia, Bogotá, Colombia, 3MSD Mexico, Mexico City, Mexico.
1MSD Brazil, São Paulo, Brazil, 2MSD Colombia, Bogotá, Colombia, 3MSD Mexico, Mexico City, Mexico.
OBJECTIVES: To synthesize Mexico-specific evidence on RSV clinical burden, healthcare resource utilization, molecular patterns and seasonality across pre-pandemic, pandemic, and post-pandemic periods.
METHODS: Six databases (PubMed, Embase, Cochrane Library, Scopus, SciELO, LILACS) and grey literature sources were searched (January 2015-May 2026). Eligible studies included observational studies reporting laboratory-confirmed RSV in children ≤5 years in Mexico (clinical burden) or population-based RSV seasonality patterns and genomic data (all ages). Two reviewers independently screened, extracted data, and assessed risk of bias using design-appropriate tools.
RESULTS: A total of 640 records were screened, and 20 studies were included; most were published from 2023 onward. Pre-pandemic, RSV was a major cause of pediatric LRTI hospitalization, concentrated in infants <12 months, with predictable autumn-winter seasonality and RSV-A dominance. During the pandemic, RSV activity was markedly suppressed, with reduced genomic diversity and RSV-B dominance. Post-pandemic, RSV positivity ranged from 41% to 44% among RSV hospitalized children ≤5 years tested using RT-PCR-based methods. Severity remained comparable to the pre-pandemic period among children ≤5 years (case-fatality rate 1.1-1.9%; ICU admission 3.6-3.9%), but shifted toward older children, with the mean age at RSV hospitalization increasing from ~10 to 15-18 months. Seasonality pattern re-emerged with altered timing and reduced predictability, including off-season peaks in 2024. Molecular characterization revealed RSV-A re-dominance (63-68%) across multiple A.D lineages, while RSV-B circulation remained limited.
CONCLUSIONS: RSV remains a major contributor to pediatric hospital burden in Mexico, with less predictable post-pandemic circulation and shifts in age distribution. These findings inform the timing and targeting of RSV prevention strategies under evolving epidemiological conditions. Registration: PROSPERO CRD420251019476
METHODS: Six databases (PubMed, Embase, Cochrane Library, Scopus, SciELO, LILACS) and grey literature sources were searched (January 2015-May 2026). Eligible studies included observational studies reporting laboratory-confirmed RSV in children ≤5 years in Mexico (clinical burden) or population-based RSV seasonality patterns and genomic data (all ages). Two reviewers independently screened, extracted data, and assessed risk of bias using design-appropriate tools.
RESULTS: A total of 640 records were screened, and 20 studies were included; most were published from 2023 onward. Pre-pandemic, RSV was a major cause of pediatric LRTI hospitalization, concentrated in infants <12 months, with predictable autumn-winter seasonality and RSV-A dominance. During the pandemic, RSV activity was markedly suppressed, with reduced genomic diversity and RSV-B dominance. Post-pandemic, RSV positivity ranged from 41% to 44% among RSV hospitalized children ≤5 years tested using RT-PCR-based methods. Severity remained comparable to the pre-pandemic period among children ≤5 years (case-fatality rate 1.1-1.9%; ICU admission 3.6-3.9%), but shifted toward older children, with the mean age at RSV hospitalization increasing from ~10 to 15-18 months. Seasonality pattern re-emerged with altered timing and reduced predictability, including off-season peaks in 2024. Molecular characterization revealed RSV-A re-dominance (63-68%) across multiple A.D lineages, while RSV-B circulation remained limited.
CONCLUSIONS: RSV remains a major contributor to pediatric hospital burden in Mexico, with less predictable post-pandemic circulation and shifts in age distribution. These findings inform the timing and targeting of RSV prevention strategies under evolving epidemiological conditions. Registration: PROSPERO CRD420251019476
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
EPH196
Topic
Epidemiology & Public Health
Topic Subcategory
Public Health
Disease
Respiratory-Related Disorders (Allergy, Asthma, Smoking, Other Respiratory)