Title: Respiratory virus detections among children hospitalized with pneumonia, Ulaanbaatar, Mongolia
Abstract:
Surveillance for novel respiratory viruses is critical for pandemic preparedness. Children are particularly susceptible to respiratory viral infections. We conducted a cross-sectional study among children (≤18 years) hospitalized with pneumonia at the national centre for maternal and child health in Ulaanbaatar, Mongolia. Participants (n=200) were enrolled from February to April 2025 via informed consent. Nasopharyngeal swabs were studied with molecular assays for specific viruses (alphaviruses, enteroviruses and influenza A, B, and D viruses), and multiple pan-species molecular assays for viruses in the Adenoviridae, Coronaviridae, Flaviridae, Pneumoviridae, Paramyxoviridae viral families. Pneumoviruses were the most prevalent virus (26.5%) virus detected. These included Human Meta Pneumo Virus (HMPV, n=38) and Respiratory Syncytial Virus (RSV, n=15). Genotype analysis revealed that HMPV subtype B2 and RSVB clade B.D.4.1.1 were the most prevalent. Adenoviruses (6%), paramyxoviruses (4%) including one case of measles virus genotype B3, coronaviruses (2.5%), and a single enterovirus were also identified. No alphaviruses, influenza A, B, or D viruses, or flaviviruses were detected. These findings suggest a localized HMPV epidemic may have occurred during the study period. The diversity of viral etiologies highlights the value of employing multiple viral diagnostic techniques to guide clinical care and to strengthen respiratory virus surveillance in Mongolia.
