WU polyomavirus detected in respiratory tract specimens from young children in Japan

Area of Science:

• Virology
• Pediatrics
• Infectious Diseases

Background:

• Polyomaviruses WU (WUPyV) and KI (KIPyV) are recognized globally as potential causes of respiratory tract disease (RTD).
• The prevalence and clinical significance of WUPyV and KIPyV in Japan, particularly among children with lower RTD, remain largely uncharacterized.

Purpose of the Study:

• To investigate the incidence and seasonal distribution of WUPyV and KIPyV in children hospitalized with lower respiratory tract disease in Japan.
• To assess the co-detection rate of other respiratory viruses in WUPyV/KIPyV-positive patients and identify potential WUPyV/KIPyV-associated cases without other known pathogens.

Main Methods:

• A 2-year prospective study was conducted involving 345 children hospitalized with lower RTD.
• Polyomavirus WUPyV and KIPyV detection was performed using molecular methods.
• Co-detection of other common respiratory viruses was assessed.

Main Results:

• WUPyV was detected in 48 (13.9%) children, while KIPyV was detected in five (1.4%) children.
• The incidence of WUPyV and KIPyV detection showed a seasonal pattern, primarily in spring and early summer.
• Other respiratory viruses were co-detected in 51% of WUPyV/KIPyV-positive patients.
• Eight WUPyV-positive patients (2.3% of total WUPyV cases) tested negative for other known respiratory pathogens, suggesting a potential primary role for WUPyV.

Conclusions:

• WUPyV is detected with notable frequency in Japanese children hospitalized with lower respiratory tract disease, indicating its potential etiological role.
• KIPyV appears less common in this pediatric population in Japan.
• The findings highlight the importance of considering WUPyV in the differential diagnosis of pediatric respiratory infections, especially when other pathogens are absent.