Epidemiological and etiological analysis of a case cluster caused by norovirus in a nursing home in Lanzhou
Zhongguo Bingdubing Zazhi = Chinese Journal of Viral Diseases
; - (5):353, 2022.
Article
in English
| ProQuest Central | ID: covidwho-2119063
ABSTRACT
Objective To understand the epidemiology and etiology of a cluster of cases with gastroenteritis in a nursing home in Anning district of Lanzhou, and to provide a scientific evidence for the prevention and control of norovirus diarrhea in community nursing centers. Methods From January 28 to February 4 2021, an epidemiological investigation was conducted on all diarrhea cases, nursing staff and chefs in a nursing home in Anning district, Lanzhou city.Samples of patients′ anal swabs, feces, vomitus were collected for norovirus detection by real-time fluorescent PCR.ORF1/ORF2 junction region of norovirus in some selected positive samples(Ct value ≤ 25) was sequenced.MEGA-X software was used to construct a phylogenetic tree for genetic evolution analysis using the neighboring method. Results The first case was confirmed on January20,2021,and the number of cases peaked during January 25and 29.A total of 58clinically diagnosed cases were reported,57were older people,with an incidence of(57/360,15.83%).Diarrhea(50/58,86.21%),vomiting(35/58,60.34%),nausea(13/58,22.41%)and abdominal pain(6/58,10.34%)were common symptoms,all cases were mild.Fifty-three asymptomatic cases were detected among chefs,housekeepers and nurses.A total of 163specimens were tested,the positive rate of norovirus GⅡwas 49.08%(80/163).The positive rate of fecal samples collected from nurses,chefs and housekeepers was 48.62%(53/109),and was11.11%(2/18)in environmental surface swabs.The possibility of other pathogenic infections such as SARS-CoV-2was ruled out by further tests.Thirteen positive samples were selected for sequencing,and 9were successfully sequenced,they were all recombinant GⅡ.4Sydney_2012 [P16]genotypes,forming an independent cluster,while in a large evolutionary branch with the 2020GⅡ.10 [P16]and 2019GⅡ.2 [P16]virus strains in Lanzhou city,showing a relative close genetic connection. Conclusions GⅡ.4Sydney_2012[P16]genotype of norovirus is found to be causative pathogen of this outbreak,and close contact is the main reason of the outbreak and persistence of the infection,so asymptomatic infections of norovirus play an important role in the disease spreading.Therefore,public health management in nursing homes and other centralized nursing facilities should be strengthened especially for asymptomatic workers in order to prevent virus transmission.
Full text:
Available
Collection:
Databases of international organizations
Database:
ProQuest Central
Type of study:
Etiology study
/
Observational study
Language:
English
Journal:
Zhongguo Bingdubing Zazhi = Chinese Journal of Viral Diseases
Year:
2022
Document Type:
Article
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