Livestock pigs and porcine norovirus could be candidate tools
for future studies on the geographic isolation of norovirus.
In this study, we provide the first evidence for geographic
isolation of the host as a determinant of the distribution of
subgenotypes of the porcine norovirus genogroup II (GII)
genotype 11. Environmental water samples were collected
from peri-urban streams and estuaries in South Korea between
2014 and 2020. In total, 488 GII region C sequences of
norovirus open reading frame 2 were isolated. A total of 14
genotypes were detected, two of which (GII.11 and GII.18)
corresponded to porcine norovirus. Five human norovirus
genotypes (GII.2, GII.3, GII.4, GII.6, and GII.17) and one
porcine norovirus genotype (GII.11) comprised the subgenotypes.
Integrated analysis of seasonal and geographical factors
revealed that the possibility of the co-emergence of different
GII.11 subgenotypes in the same province was lower
than that of human norovirus subgenotypes in the same province.
Additional algorithms designed to eliminate potential
biases further supported the estimated restricted geographical
spread of the GII.11 subgenotypes. Fecal contamination
source tracking revealed low detection rates of porcine norovirus
in the absence of upstream pig farms. These results suggest
that a one-sided viral transmission route, mainly dependent
on indirect contact owing to the limited chance of direct
contact between geographically separated livestock pig populations,
may be responsible for the restricted geographical
spread of the GII.11 subgenotypes.
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Swine Norovirus: Past, Present, and Future Lara Cavicchio, Andrea Laconi, Alessandra Piccirillo, Maria Serena Beato Viruses.2022; 14(3): 537. CrossRef