Norovirus-associated diarrhea and asymptomatic infection in children aged under 4 years: a community-cohort study in the Philippines.

Objectives: This study aimed to estimate the incidence of norovirus (NoV)-associated diarrhea and asymptomatic infections in children under 4 years of age and identify the genotypes of multiple NoV infections.

Methods: A community-based cohort study was conducted in Tarlac, Philippines. Children aged 0-2 years were followed up for 2 years.

Serological analyses against endemic human coronaviruses and SARS-CoV-2 in children and adults using samples collected before the COVID-19 pandemic.

Objectives: Four endemic human coronaviruses (HCoVs), HCoV-229E, HCoV-NL63, HCoV-HKU1, and HCoV-OC43, infect humans during childhood and cause the common cold. COVID-19 caused by SARS-CoV-2 leads to mild symptoms in children, possibly owing to the protection conferred by immunity developed during a previous HCoV infection. This study analyzed the seroreactivity of four endemic HCoVs and SARS-CoV-2 in children and adults.

Identification of Various Recombinants in a Patient Coinfected With the Different SARS-CoV-2 Variants.

Background: Viral recombination that occurs by exchanging genetic materials between two viral genomes coinfecting the same host cells is associated with the emergence of new viruses with different virulence. Herein, we detected a patient coinfected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta and Omicron variants and identified various recombinants in the SARS-CoV-2 full-length spike gene using long-read and Sanger sequencing.

Methods: Samples from five patients in Japan with household transmission of coronavirus disease 2019 (COVID-19) were analyzed using molecular assays for detection and identification of SARS-CoV-2.

Characterization of human respiratory syncytial virus in children with severe acute respiratory infection before and during the COVID-19 pandemic.

Objectives: Annual outbreaks of human respiratory syncytial virus (HRSV) are caused by newly introduced and locally persistent strains. During the COVID-19 pandemic, global and local circulation of HRSV significantly decreased. This study was conducted to characterize HRSV in 2018-2022 and to analyze the impact of COVID-19 on the evolution of HRSV.