Epidemiological and etiological analysis of a case cluster caused by norovirus in a nursing home in Lanzhou

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.

Feasibility analysis and mechanism exploration of Rhei Radix et Rhizome-Schisandrae Sphenantherae Fructus (RS) against COVID-19.

Introduction. As a novel global epidemic, corona virus disease 2019 (COVID-19) caused by SARS-CoV-2 brought great suffering and disaster to mankind. Recently, although significant progress has been made in vaccines against SARS-CoV-2, there are still no drugs for treating COVID-19. It is well known that traditional Chinese medicine (TCM) has achieved excellent efficacy in the treatment of COVID-19 in China. As a treasure-house of natural drugs, Chinese herbs offer a promising prospect for discovering anti-COVID-19 drugs.Hypothesis/Gap Statement. We proposed that Rhei Radix et Rhizome-Schisandrae Sphenantherae Fructus (RS) may have potential value in the treatment of COVID-19 patients by regulating immune response, protecting the cardiovascular system, inhibiting the production of inflammatory factors, and blocking virus invasion and replication processes.Aim. We aimed to explore the feasibility and molecular mechanisms of RS against COVID-19, to provide a reference for basic research and clinical applications.Methodology. Through literature mining, it is found that a Chinese herbal pair, RS, has potential anti-COVID-19 activity. In this study, we analysed the feasibility of RS against COVID-19 by high-throughput molecular docking and molecular dynamics simulations. Furthermore, we predicted the molecular mechanisms of RS against COVID-19 based on network pharmacology.Results. We proved the feasibility of RS anti-COVID-19 by literature mining, virtual docking and molecular dynamics simulations, and found that angiotensin converting enzyme 2 (ACE2) and 3C-like protease (3 CL pro) were also two critical targets for RS against COVID-19. In addition, we predicted the molecular mechanisms of RS in the treatment of COVID-19, and identified 29 main ingredients, 21 potential targets and 16 signalling pathways. Rhein, eupatin, (-)-catechin, aloe-emodin may be important active ingredients in RS. ALB, ESR1, EGFR, HMOX1, CTSL, and RHOA may be important targets against COVID-19. Platelet activation, renin secretion, ras signalling pathway, chemokine signalling pathway, and human cytomegalovirus infection may be important signalling pathways against COVID-19.Conclusion. RS plays a key role in the treatment of COVID-19, which may be closely related to immune regulation, cardiovascular protection, anti-inflammation, virus invasion and replication processes.

Progressive liver injury and increased mortality risk in COVID-19 patients: A retrospective cohort study in China.

BACKGROUND: Liver injury is common and also can be fatal, particularly in severe or critical patients with coronavirus disease 2019 (COVID-19). AIM: To conduct an in-depth investigation into the risk factors for liver injury and into the effective measures to prevent subsequent mortality risk. METHODS: A retrospective cohort study was performed on 440 consecutive patients with relatively severe COVID-19 between January 28 and March 9, 2020 at Tongji Hospital, Wuhan, China. Data on clinical features, laboratory parameters, medications, and prognosis were collected. RESULTS: COVID-19-associated liver injury more frequently occurred in patients aged ≥ 65 years, female patients, or those with other comorbidities, decreased lymphocyte count, or elevated D-dimer or serum ferritin (P < 0.05). The disease severity of COVID-19 was an independent risk factor for liver injury (severe patients: Odds ratio [OR] = 2.86, 95% confidence interval [CI]: 1.78-4.59; critical patients: OR = 13.44, 95%CI: 7.21-25.97). The elevated levels of on-admission aspartate aminotransferase and total bilirubin indicated an increased mortality risk (P < 0.001). Using intravenous nutrition or antibiotics increased the risk of COVID-19-associated liver injury. Hepatoprotective drugs tended to be of assistance to treat the liver injury and improve the prognosis of patients with COVID-19-associated liver injury. CONCLUSION: More intensive monitoring of aspartate aminotransferase or total bilirubin is recommended for COVID-19 patients, especially patients aged ≥ 65 years, female patients, or those with other comorbidities. Drug hepatotoxicity of antibiotics and intravenous nutrition should be alert for COVID-19 patients.