Abstract Title
Molecular Epidemiology of Norovirus among Children less than 5 years of age in the Philippines, 2016-2023
Presenter
(not set)
Co-Author(s)
Joseph M. Bonifacio1, Mary Ann U. Igoy1, Jan Vinjé, PhD2, Johanna Beulah T. Sornillo1, C. Eures Iyar G. Lazaro1, Mayan U. Lumandas1, Carren Anne B. Bocaling1
1Research Institute for Tropical Medicine, Muntinlupa City, Philippines
2Division of Viral Diseases, Centers for Disease Control and Prevention
Abstract Category
Molecular Epidemiology & Evolution
Abstract
Diarrheal disease remains to be a significant health concern in the Philippines, leading to hospitalization among young children. Findings from previous studies in the Philippines indicated that enteric viruses remained the leading etiology of acute watery diarrhea in children under 5; however, limited data are available on the prevalence and genotype of norovirus in children under 5.
Patients admitted from 2016-2023 following the case definition for the rotavirus surveillance were included in the study. A systematic random was done to identify which samples will be tested for norovirus real-time PCR and norovirus genotyping.
A total of 4,465 cases were selected from the surveillance samples. Results showed the average norovirus positivity at 21.4% which 2018 was the highest at 30.4%. During 2016-2023, our study documented 32 norovirus genotypes causing illness in young children. GII.4 Sydney[P16] was the most common strain every year except in 2016 where GII.4 Sydney[P16] was the highest at 35.5%, and in 2022 where GII.3[P12] was highest at 35.1%. The presence of unusual, rare and animal genotypes were also noted in low percentages: GI.4[P4], GI.5[P12], GI.5[P4], GI.6[P11], GI.6[P6], GI.8[P8], GI.9[P9], GII.7[P7], GII.10[P16], GII.13[P16] and GIX.1[P15]
The data gathered from the study showed norovirus positivity remained significant over the years. While the GII.4 Sydney[P16] is the most common genotype observed thus far, the emergence of rare norovirus strains during the study period shows a growing diversity in norovirus genotypes in the Philippines. This suggests the need for continued monitoring and highlights the importance of norovirus vaccination in the country.
Patients admitted from 2016-2023 following the case definition for the rotavirus surveillance were included in the study. A systematic random was done to identify which samples will be tested for norovirus real-time PCR and norovirus genotyping.
A total of 4,465 cases were selected from the surveillance samples. Results showed the average norovirus positivity at 21.4% which 2018 was the highest at 30.4%. During 2016-2023, our study documented 32 norovirus genotypes causing illness in young children. GII.4 Sydney[P16] was the most common strain every year except in 2016 where GII.4 Sydney[P16] was the highest at 35.5%, and in 2022 where GII.3[P12] was highest at 35.1%. The presence of unusual, rare and animal genotypes were also noted in low percentages: GI.4[P4], GI.5[P12], GI.5[P4], GI.6[P11], GI.6[P6], GI.8[P8], GI.9[P9], GII.7[P7], GII.10[P16], GII.13[P16] and GIX.1[P15]
The data gathered from the study showed norovirus positivity remained significant over the years. While the GII.4 Sydney[P16] is the most common genotype observed thus far, the emergence of rare norovirus strains during the study period shows a growing diversity in norovirus genotypes in the Philippines. This suggests the need for continued monitoring and highlights the importance of norovirus vaccination in the country.