# Genetic detection and analysis of porcine norovirus in pigs farmed in north Vietnam

## TL;DR

This study identifies and genetically characterizes porcine norovirus in pigs from northern Vietnam, finding it closely related to Chinese strains.

## Contribution

The study reports the detection and genetic characterization of porcine norovirus Genotype II.19 in Vietnam.

## Key findings

- Five (4.9%) of 102 fecal samples tested positive for porcine norovirus.
- The detected viruses were Genotype II.19 with high nucleotide identity (97.77–99.62%).
- The Vietnamese strains were closely related to Chinese porcine norovirus strains from 2009.

## Abstract

Norovirus (NoV) causing gastroenteritis symptoms, which has been reported in several hosts, including humans, pigs, and rats. This study was conducted to identify porcine viral infection and to characterize NoV strains from pigs in some provinces in north Vietnam. Totally, 102 fecal samples from diarrheal pigs on farms in six cities and provinces in northern Vietnam during July 2022 to March 2023 were collected. Polymerase chain reaction was used to identify the viral genome. Positive samples were used for nucleotide sequencing of the partial RNA-dependent RNA polymerase gene sequence. Five (4.9 %) positive stool samples were detected from animals farmed in five different farms, with one positive animal identified in each farm. Genetic analysis indicated that nucleotide identity was in the range 97.77–99.62 % among the 5 NoVs in this study. Phylogenetic analysis pointed out that the five NoVs were Genotype II.19 viruses. Genetically, these strains were closely related to porcine NoV strains that were reported in China in 2009.