Abstract Title
Characterization of human norovirus and host genetic susceptibility profiling in South African children with gastroenteritis
Presenter
Ronewa Khumela, University of Pretoria
Co-Author(s)
Authors: 1Ronewa Khumela, 2Jean-Pierre Kabue, 3Marcia Terezinha Baroni de Moraes, 4Johan Nordgren, 2Afsatou Ndama Traore and 2Natasha Potgieter
Affiliations
1Department of Medical Virology, Faculty of Health Sciences, University of Pretoria; Pretoria 0001, South Africa
2Department of Biochemistry and Microbiology, Faculty of Science, Engineering and Agriculture, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa
3Laboratory of Comparative and Environmental Virology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation (FIOCRUZ), Avenida Brasil, 4365-Manguinhos, Rio de Janeiro, RJ, Brazil
4Division of Molecular Virology, Department of Clinical and Experimental Medicine, Linköping University, 581 85 Linköping, Sweden
Abstract Category
Molecular Epidemiology & Evolution
Abstract
Human norovirus are the leading cause of acute gastroenteritis (AGE) worldwide, with histo-blood group antigens (HBGAs) playing a crucial role in viral attachment to host cells. However, there is still limited data on their molecular epidemiology and host susceptibility factors in African settings. This study aimed to characterize circulating norovirus strains and assess host genetic susceptibility through HBGA profiling in South African children from rural communities with AGE.
A total of 300 stool samples were collected between 2019 and 2022 from both symptomatic and healthy children under five years in Vhembe District, SA. Norovirus detection and genotyping were performed on stool samples using RT-PCR and Sanger sequencing. Saliva samples were used for HBGAs phenotypes and FUT2/FUT3 genotypes via ELISA, touchdown PCR and sequencing.
Norovirus was significantly more prevalent in symptomatic (37%) than asymptomatic (14%) children (p < 0.0001). Genogroup II predominated in AGE cases (80%) with GII.4[P31] (59%) as the most common genotype, while GI were more frequent (12%) in asymptomatic children. Majority of children were secretor positive (84%) and norovirus infection (93%) was associated with host secretor profiles. FUT2/FUT3 genotyping confirmed phenotypic findings.
The findings highlight the predominance of GII.4 norovirus strains and the strong association between secretor status and norovirus infection. These results emphasize need for continuous surveillance and integration of HBGA variability in vaccine and therapeutic designs, such as drugs that may inhibit norovirus and HBGAs interaction.
Keywords: Norovirus, gastroenteritis, histo-blood group antigens
A total of 300 stool samples were collected between 2019 and 2022 from both symptomatic and healthy children under five years in Vhembe District, SA. Norovirus detection and genotyping were performed on stool samples using RT-PCR and Sanger sequencing. Saliva samples were used for HBGAs phenotypes and FUT2/FUT3 genotypes via ELISA, touchdown PCR and sequencing.
Norovirus was significantly more prevalent in symptomatic (37%) than asymptomatic (14%) children (p < 0.0001). Genogroup II predominated in AGE cases (80%) with GII.4[P31] (59%) as the most common genotype, while GI were more frequent (12%) in asymptomatic children. Majority of children were secretor positive (84%) and norovirus infection (93%) was associated with host secretor profiles. FUT2/FUT3 genotyping confirmed phenotypic findings.
The findings highlight the predominance of GII.4 norovirus strains and the strong association between secretor status and norovirus infection. These results emphasize need for continuous surveillance and integration of HBGA variability in vaccine and therapeutic designs, such as drugs that may inhibit norovirus and HBGAs interaction.
Keywords: Norovirus, gastroenteritis, histo-blood group antigens