Seasonal trends, clinical outcomes, and viral coinfections of human metapneumovirus infections in Mexican children from 2021 to 2024.

PURPOSE: Human Metapneumovirus (hMPV) is a respiratory pathogen of global concern, particularly in paediatric populations. To gain a better understanding of hMPV infection in children, this study analysed the seasonal distribution, clinical characteristics, and epidemiological relevance of hMPV among Mexican children from 2021 to 2024.

METHODS

A retrospective analysis was performed on 10,513 nasopharyngeal swabs collected from symptomatic paediatric patients. hMPV was detected using a multiplex PCR-based assay. Positive cases were stratified by age, disease severity, comorbidities, and viral coinfections. Descriptive and inferential statistical analyses were conducted to evaluate the demographic, clinical, and microbiological characteristics of paediatric patients infected with hMPV, stratified by disease severity and comorbidity profiles.

RESULTS

A total of 753 samples (7.2%) were positive for hMPV. Peaks occurred in autumn 2023 and spring 2023-2024. Among 639 cases with clinical data, children under two years old were more likely to either present moderate to severe illness (69.0%) and be hospitalised compared to older children (OR = 2.91, 95% CI: 1.18-6.85, p = 0.016). While common comorbidities were unrelated to severity, certain chronic conditions showed significant associations (OR = 3.98, 95% CI: 2.19-7.85, p < 0.001). Coinfections, particularly with Rhinovirus/Enterovirus, were prevalent in moderate cases (20.0%; p = 0.011) and showed a borderline association with increased risk of hospitalisation (OR = 1.53, 95% CI: 1.00-2.40, p = 0.057).

CONCLUSIONS

hMPV can cause significant disease in young or medically complex children, underscoring the need for ongoing surveillance and clinical vigilance in Mexican paediatric health systems and other countries with a high number of respiratory diseases.