The epidemiology of norovirus gastroenteritis in China: disease burden and distribution of genotypes

Honglu Zhou,Lorenz Von Seidlein,Songmei Wang,Xuanyi Wang

doi:10.1007/s11684-019-0733-5

Abstract

With the improvements of sanitation and nationwide safe water supply the occurrence of bacterial diarrhea declined remarkably, while viruses became the leading causes of acute gastroenteritis (AGE). Of these viruses, noroviruses (NoVs) are responsible for a considerable burden of gastroenteritis, especially in children < 2 years and elderly ⩾ 65 years. NoVs circulating in the Chinese population are antigenically highly diverse with the genotype GII.4 being the dominant strain followed by GII.3. Given the widespread contamination in environmental sources, and highly infectious nature of NoVs, vaccination would be the desirable strategy for the control of NoV infections. However, a better understanding of acquired immunity after infection, and a reliable immunological surrogate marker are urgently needed, since two vaccine candidates based on virus-like particles (VLPs) are currently moving into clinical evaluations in China.

Highlights

Despite significant advances in sanitation improvement, safe water supplies, and vaccination, diarrheal disease remained worldwide the fourth most frequent cause of death for children < 5 years of age in 2016 [1]
Province and Sanjiang County, Guangxi Zhuang Autonomous Region between 2011 and 2013 [18]. These findings suggest that considerable disease burden is caused by NoV in China
Of 6 shellfish groups, oysters had the highest detection rate (35%) of NoVs, followed by blood clams (22%) [43]. These results suggest that uncooked seafood is a potential public health hazard in China

Summary

Introduction

Despite significant advances in sanitation improvement, safe water supplies, and vaccination, diarrheal disease remained worldwide the fourth most frequent cause of death for children < 5 years of age in 2016 [1]. The current understanding, that NoVs infections confers immunity for 6 months and 2 years comes from human challenge studies, which fails to explain the low incidence of NoV related disease in this population. GII. had been an emergent strain causing a number of outbreaks in China in 2014 and 2015 It spread rapidly since 2013, from an initial 4.0% to 79.6% in 2015, and eventually accounted for 10.9% of GenBank sequences. Of 6 shellfish groups (clams, oysters, mussels, razor clams, blood clams, and scallops), oysters had the highest detection rate (35%) of NoVs, followed by blood clams (22%) [43] These results suggest that uncooked seafood is a potential public health hazard in China. Phylogenetic analyses suggests that homologous NoV genotypes circulate between human populations, seafood and aquaculture water [48] This suggestion is supported by studies conducted in Guangdong Province. NoVs genomes were detected in air samples taken in 3 distinct locations on patient wards: (1) inside the room of patients with AGE symptoms ( < 24 h), (2) in the hallways or the common room outside of the rooms of patients with symptoms, and (3) at the nurses’ station, where concentrations ranged from 1.35 Â 101 to 2.35 Â 103 genomes/m3 in 47% of air samples [49]

Summary

Findings

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