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1.
Infect Dis Poverty ; 11(1): 74, 2022 Jun 29.
Article in English | MEDLINE | ID: covidwho-1910355

ABSTRACT

BACKGROUND: During the coronavirus disease 2019 (COVID-19) pandemic, seasonal influenza activity declined globally and remained below previous seasonal levels, but intensified in China since 2021. Preventive measures to COVID-19 accompanied by different epidemic characteristics of influenza in different regions of the world. To better respond to influenza outbreaks under the COVID-19 pandemic, we analyzed the epidemiology, antigenic and genetic characteristics, and antiviral susceptibility of influenza viruses in the mainland of China during 2020-2021. METHODS: Respiratory specimens from influenza like illness cases were collected by sentinel hospitals and sent to network laboratories in Chinese National Influenza Surveillance Network. Antigenic mutation analysis of influenza virus isolates was performed by hemagglutination inhibition assay. Next-generation sequencing was used for genetic analyses. We also conducted molecular characterization and phylogenetic analysis of circulating influenza viruses. Viruses were tested for resistance to antiviral medications using phenotypic and/or sequence-based methods. RESULTS: In the mainland of China, influenza activity recovered in 2021 compared with that in 2020 and intensified during the traditional influenza winter season, but it did not exceed the peak in previous years. Almost all viruses isolated during the study period were of the B/Victoria lineage and were characterized by genetic diversity, with the subgroup 1A.3a.2 viruses currently predominated. 37.8% viruses tested were antigenically similar to reference viruses representing the components of the vaccine for the 2020-2021 and 2021-2022 Northern Hemisphere influenza seasons. In addition, China has a unique subgroup of 1A.3a.1 viruses. All viruses tested were sensitive to neuraminidase inhibitors and endonuclease inhibitors, except two B/Victoria lineage viruses identified to have reduced sensitivity to neuraminidase inhibitors. CONCLUSIONS: Influenza activity increased in the mainland of China in 2021, and caused flu season in the winter of 2021-2022. Although the diversity of influenza (sub)type decreases, B/Victoria lineage viruses show increased genetic and antigenic diversity. The world needs to be fully prepared for the co-epidemic of influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus globally.


Subject(s)
COVID-19 , Influenza, Human , Orthomyxoviridae , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , COVID-19/epidemiology , China/epidemiology , Humans , Influenza, Human/epidemiology , Neuraminidase/genetics , Orthomyxoviridae/genetics , Pandemics , Phylogeny , SARS-CoV-2 , Seasons
2.
Disease Surveillance ; 36(12):1231-1234, 2021.
Article in Chinese | GIM | ID: covidwho-1771272

ABSTRACT

Objective: To assess the risk of public health emergencies, both the indigenous ones and the imported ones, which might occur in the mainland of China in December 2021.

3.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-329581

ABSTRACT

Emerging in December 2019, coronavirus disease 2019 (COVID-19) eventually became a pandemic and has posed a tremendous threat to global public health. However, the origins of SARS-CoV-2, the causative agent of COVID-19, remain to be determined. It has reported that a certain number of the early case clusters had a contact history with Huanan Seafood Market. Therefore, surveillance of SARS-CoV-2 within the market is of vital importance. Herein, we presented the SARS-CoV-2 detection results of 1380 samples collected from the environment and the animals within the market in early 2020. By SARS-CoV-2-specific RT-qPCR, 73 environmental samples tested positive for SARS-CoV-2 and three live viruses were successfully isolated. The viruses from the market shared nucleotide identity of 99.980% to 99.993% with the human isolate HCoV/Wuhan/IVDC-HB-01. In contrast, no virus was detected in the animal swabs covering 18 species of animals in the market. The SARS-COV-2 nucleic acids in the positive environmental samples showed significant correlation of abundance of Homo sapiens with SARS-CoV-2. In summary, this study provided convincing evidence of the prevalence of SARS-CoV-2 in the Huanan Seafood Market during the early stage of COVID-19 outbreak.

4.
Disease Surveillance ; 36(8):745-750, 2021.
Article in Chinese | CAB Abstracts | ID: covidwho-1524241

ABSTRACT

Objective: To assess the risk of public health emergencies, both the indigenous ones and the imported ones, which might occur in the mainland of China in August 2021.

5.
China CDC Wkly ; 3(44): 918-922, 2021 Oct 29.
Article in English | MEDLINE | ID: covidwho-1506116

ABSTRACT

INTRODUCTION: During the coronavirus disease 2019 (COVID-19) pandemic, the circulation of seasonal influenza virus declined globally and remained below previous seasonal levels. We analyzed the results of the epidemiology, antigenic, and genetic characteristics, and antiviral susceptibilities of seasonal influenza viruses isolated from the mainland of China during October 5, 2020 through September 5, 2021, to better assess the risk of influenza during subsequent influenza season in 2021-2022. METHODS: Positive rates of influenza virus detection during this period were based on real-time polymerase chain reaction (PCR) detection by the Chinese National Influenza Surveillance Network laboratories, and isolated viruses from influenza positive samples were submitted to the Chinese National Influenza Center. Antigenic analyses for influenza viruses were conducted using the hemagglutination inhibition assay. Next-generation sequencing was used for genetic analyses. Viruses were tested for resistance to antiviral medications using a phenotypic assay and next-generation sequencing. RESULTS: In southern China, the influenza positivity rate was elevated especially after March 2021 and was higher than the same period the previous year with the COVID-19 pandemic. In northern China, influenza positive rate peaked at Week 18 in 2021 and has declined since then. Nearly all isolated viruses were B/Victoria lineage viruses during the study period, and 37.3% of these viruses are antigenically similar to the reference viruses representing the vaccine components for the 2020-2021 and 2021-2022 Northern Hemisphere influenza season. All seasonal influenza viruses were susceptible to neuraminidase inhibitors and endonuclease inhibitors. CONCLUSIONS: Influenza activity has gradually increased in the mainland of China in 2021, although the intensity of activity is still lower than before the COVID-19 pandemic. The diversity of circulating influenza types/subtypes decreased, with the vast majority being B/Victoria lineage viruses. The surveillance data from this study suggest that we should strengthen influenza surveillance during the upcoming traditional influenza season. It also provided evidence for vaccine recommendations and prevention and control of influenza and clinical use of antiviral drugs.

8.
Science ; 373(6557): 918-922, 2021 08 20.
Article in English | MEDLINE | ID: covidwho-1367378

ABSTRACT

Zoonotic avian influenza A virus (IAV) infections are rare. Sustained transmission of these IAVs between humans has not been observed, suggesting a role for host genes. We used whole-genome sequencing to compare avian IAV H7N9 patients with healthy controls and observed a strong association between H7N9 infection and rare, heterozygous single-nucleotide variants in the MX1 gene. MX1 codes for myxovirus resistance protein A (MxA), an interferon-induced antiviral guanosine triphosphatase known to control IAV infections in transgenic mice. Most of the MxA variants identified lost the ability to inhibit avian IAVs, including H7N9, in transfected human cell lines. Nearly all of the inactive MxA variants exerted a dominant-negative effect on the antiviral function of wild-type MxA, suggesting an MxA null phenotype in heterozygous carriers. Our study provides genetic evidence for a crucial role of the MX1-based antiviral defense in controlling zoonotic IAV infections in humans.


Subject(s)
Influenza A Virus, H7N9 Subtype , Influenza, Human/genetics , Influenza, Human/virology , Myxovirus Resistance Proteins/genetics , Agricultural Workers' Diseases/genetics , Agricultural Workers' Diseases/virology , Animals , Cell Line , Genetic Predisposition to Disease , Genetic Variation , Heterozygote , Humans , Influenza A Virus, H7N9 Subtype/physiology , Influenza A virus/physiology , Mutation, Missense , Myxovirus Resistance Proteins/chemistry , Myxovirus Resistance Proteins/metabolism , Poultry , Viral Zoonoses , Whole Genome Sequencing
11.
12.
Nat Commun ; 12(1): 3249, 2021 05 31.
Article in English | MEDLINE | ID: covidwho-1249208

ABSTRACT

Coronavirus disease 2019 (COVID-19) was detected in China during the 2019-2020 seasonal influenza epidemic. Non-pharmaceutical interventions (NPIs) and behavioral changes to mitigate COVID-19 could have affected transmission dynamics of influenza and other respiratory diseases. By comparing 2019-2020 seasonal influenza activity through March 29, 2020 with the 2011-2019 seasons, we found that COVID-19 outbreaks and related NPIs may have reduced influenza in Southern and Northern China and the United States by 79.2% (lower and upper bounds: 48.8%-87.2%), 79.4% (44.9%-87.4%) and 67.2% (11.5%-80.5%). Decreases in influenza virus infection were also associated with the timing of NPIs. Without COVID-19 NPIs, influenza activity in China and the United States would likely have remained high during the 2019-2020 season. Our findings provide evidence that NPIs can partially mitigate seasonal and, potentially, pandemic influenza.


Subject(s)
COVID-19/epidemiology , Influenza, Human/epidemiology , Models, Statistical , Pandemics , Respiratory Tract Infections/epidemiology , COVID-19/transmission , COVID-19/virology , China/epidemiology , Humans , Influenza, Human/transmission , Influenza, Human/virology , Orthomyxoviridae/pathogenicity , Orthomyxoviridae/physiology , Personal Protective Equipment , Physical Distancing , Quarantine/organization & administration , Respiratory Tract Infections/transmission , Respiratory Tract Infections/virology , SARS-CoV-2/pathogenicity , SARS-CoV-2/physiology , Seasons , United States/epidemiology
13.
China CDC Wkly ; 3(21): 441-447, 2021 May 21.
Article in English | MEDLINE | ID: covidwho-1237076

ABSTRACT

What is known about this topic? Few major outbreaks of coronavirus disease 2019 (COVID-19) have occurred in China after major non-pharmaceutical interventions and vaccines have been deployed and implemented. However, sporadic outbreaks that had high possibility to be linked to cold chain products were reported in several cities of China.. What is added by this report? In July 2020, a COVID-19 outbreak occurred in Dalian, China. The investigations of this outbreak strongly suggested that the infection source was from COVID-19 virus-contaminated packaging of frozen seafood during inbound unloading personnel contact. What are the implications for public health practice? Virus contaminated paper surfaces could maintain infectivity for at least 17-24 days at -25 ℃. Exposure to COVID-19 virus-contaminated surfaces is a potential route for introducing the virus to a susceptible population. Countries with no domestic transmission of COVID-19 should consider introducing prevention strategies for both inbound travellers and imported goods. Several measures to prevent the introduction of the virus via cold-chain goods can be implemented.

14.
Biosaf Health ; 2(4): 206-209, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-996700

ABSTRACT

Since coronavirus disease 2019 (COVID-19) might circulate in the following seasons, it is essential to understand how COVID-19 influences other respiratory diseases, especially influenza. In this study, we analyzed the influenza activity from mid-November 2019 to March 2020 in Chinese mainland and found that the influenza season ended much earlier than previous seasons for all subtypes and lineages, which may have resulted from the circulation of COVID-19 and measures such as travel control and personal protection. These findings provide rudimentary knowledge of the co-circulation patterns of the two types of viruses.

15.
J Infect Dis ; 222(11): 1780-1783, 2020 11 09.
Article in English | MEDLINE | ID: covidwho-967699

ABSTRACT

To suppress the ongoing COVID-19 pandemic, the Chinese government has implemented nonpharmaceutical interventions (NPIs). Because COVID-19 and influenza have similar means of transmission, NPIs targeting COVID-19 may also affect influenza transmission. In this study, the extent to which NPIs targeting COVID-19 have affected seasonal influenza transmission was explored. Indicators of seasonal influenza activity in the epidemiological year 2019-2020 were compared with those in 2017-2018 and 2018-2019. The incidence rate of seasonal influenza reduced by 64% in 2019-2020 (P < .001). These findings suggest that NPIs aimed at controlling COVID-19 significantly reduced seasonal influenza transmission in China.


Subject(s)
COVID-19/epidemiology , COVID-19/prevention & control , Influenza, Human/epidemiology , Influenza, Human/prevention & control , COVID-19/transmission , COVID-19/virology , China/epidemiology , Communicable Disease Control , Humans , Incidence , Influenza, Human/transmission , Pandemics , Public Health , SARS-CoV-2/isolation & purification , Seasons
16.
EBioMedicine ; 62: 103125, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-938894

ABSTRACT

BACKGROUND: The pharmacokinetics and appropriate dose regimens of favipiravir are unknown in hospitalized influenza patients; such data are also needed to determine dosage selection for favipiravir trials in COVID-19. METHODS: In this dose-escalating study, favipiravir pharmacokinetics and tolerability were assessed in critically ill influenza patients. Participants received one of two dosing regimens; Japan licensed dose (1600 mg BID on day 1 and 600 mg BID on the following days) and the higher dose (1800 mg/800 mg BID) trialed in uncomplicated influenza. The primary pharmacokinetic endpoint was the proportion of patients with a minimum observed plasma trough concentration (Ctrough) ≥20 mg/L at all measured time points after the second dose. RESULTS: Sixteen patients were enrolled into the low dose group and 19 patients into the high dose group of the study. Favipiravir Ctrough decreased significantly over time in both groups (p <0.01). Relative to day 2 (48 hrs), concentrations were 91.7% and 90.3% lower in the 1600/600 mg group and 79.3% and 89.5% lower in the 1800/800 mg group at day 7 and 10, respectively. In contrast, oseltamivir concentrations did not change significantly over time. A 2-compartment disposition model with first-order absorption and elimination described the observed favipiravir concentration-time data well. Modeling demonstrated that less than 50% of patients achieved Ctrough ≥20 mg/L for >80% of the duration of treatment of the two dose regimens evaluated (18.8% and 42.1% of patients for low and high dose regimen, respectively). Increasing the favipravir dosage predicted a higher proportion of patients reaching this threshold of 20 mg/L, suggesting that dosing regimens of ≥3600/2600 mg might be required for adequate concentrations. The two dosing regimens were well-tolerated in critical ill patients with influenza. CONCLUSION: The two dosing regimens proposed for uncomplicated influenza did not achieve our pre-defined treatment threshold.


Subject(s)
Amides , Influenza, Human/drug therapy , Oseltamivir , Pyrazines , Aged , Amides/administration & dosage , Amides/pharmacokinetics , Drug Therapy, Combination , Female , Humans , Influenza, Human/blood , Male , Middle Aged , Oseltamivir/administration & dosage , Oseltamivir/pharmacokinetics , Pyrazines/administration & dosage , Pyrazines/pharmacokinetics , Severity of Illness Index
17.
Disease Surveillance ; 35(1):6-9, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-833504

ABSTRACT

Objective: To assess the risks of public health emergencies, both the indigenous ones and the imported ones, which might occur in the mainland of China in January 2020.

18.
Biosaf Health ; 2(4): 202-205, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-739785

ABSTRACT

After 56 days without coronavirus disease 2019 (COVID-19) cases, reemergent cases were reported in Beijing, China on June 11, 2020. Here, we report the genetic characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequenced from the clinical specimens of 4 human cases and 2 environmental samples. The nucleotide similarity among six SARS-CoV-2 genomes ranged from 99.98% to 99.99%. Compared with the reference strain of SARS-CoV-2 (GenBank No. NC_045512), all six genome sequences shared the same substitutions at nt241 (C â†’ T), nt3037 (C â†’ T), nt14408 (C â†’ T), nt23403 (A â†’ G), nt28881 (G â†’ A), nt28882 (G â†’ A), and nt28883 (G â†’ C), which are the characteristic nucleotide substitutions of L-lineage European branch I. This was also proved by the maximum likelihood phylogenetic tree based on the full-length genome of SARS-CoV-2. They also have a unique shared nucleotide substitution, nt6026 (C â†’ T), which is the characteristic nucleotide substitution of SARS-CoV-2 in Beijing's Xinfadi outbreak. It is noteworthy that there is an amino acid D614G mutation caused by nt23403 substitution in all six genomes, which may enhance the virus's infectivity in humans and help it become the leading strain of the virus to spread around the world today. It is necessary to continuously monitor the genetic variation of SARS-CoV-2, focusing on the influence of key mutation sites of SARS-CoV-2 on viral transmission, clinical manifestations, severity, and course of disease.

20.
Lancet ; 395(10224): 565-574, 2020 02 22.
Article in English | MEDLINE | ID: covidwho-80

ABSTRACT

BACKGROUND: In late December, 2019, patients presenting with viral pneumonia due to an unidentified microbial agent were reported in Wuhan, China. A novel coronavirus was subsequently identified as the causative pathogen, provisionally named 2019 novel coronavirus (2019-nCoV). As of Jan 26, 2020, more than 2000 cases of 2019-nCoV infection have been confirmed, most of which involved people living in or visiting Wuhan, and human-to-human transmission has been confirmed. METHODS: We did next-generation sequencing of samples from bronchoalveolar lavage fluid and cultured isolates from nine inpatients, eight of whom had visited the Huanan seafood market in Wuhan. Complete and partial 2019-nCoV genome sequences were obtained from these individuals. Viral contigs were connected using Sanger sequencing to obtain the full-length genomes, with the terminal regions determined by rapid amplification of cDNA ends. Phylogenetic analysis of these 2019-nCoV genomes and those of other coronaviruses was used to determine the evolutionary history of the virus and help infer its likely origin. Homology modelling was done to explore the likely receptor-binding properties of the virus. FINDINGS: The ten genome sequences of 2019-nCoV obtained from the nine patients were extremely similar, exhibiting more than 99·98% sequence identity. Notably, 2019-nCoV was closely related (with 88% identity) to two bat-derived severe acute respiratory syndrome (SARS)-like coronaviruses, bat-SL-CoVZC45 and bat-SL-CoVZXC21, collected in 2018 in Zhoushan, eastern China, but were more distant from SARS-CoV (about 79%) and MERS-CoV (about 50%). Phylogenetic analysis revealed that 2019-nCoV fell within the subgenus Sarbecovirus of the genus Betacoronavirus, with a relatively long branch length to its closest relatives bat-SL-CoVZC45 and bat-SL-CoVZXC21, and was genetically distinct from SARS-CoV. Notably, homology modelling revealed that 2019-nCoV had a similar receptor-binding domain structure to that of SARS-CoV, despite amino acid variation at some key residues. INTERPRETATION: 2019-nCoV is sufficiently divergent from SARS-CoV to be considered a new human-infecting betacoronavirus. Although our phylogenetic analysis suggests that bats might be the original host of this virus, an animal sold at the seafood market in Wuhan might represent an intermediate host facilitating the emergence of the virus in humans. Importantly, structural analysis suggests that 2019-nCoV might be able to bind to the angiotensin-converting enzyme 2 receptor in humans. The future evolution, adaptation, and spread of this virus warrant urgent investigation. FUNDING: National Key Research and Development Program of China, National Major Project for Control and Prevention of Infectious Disease in China, Chinese Academy of Sciences, Shandong First Medical University.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , Genome, Viral , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , Receptors, Virus/metabolism , Betacoronavirus/metabolism , Bronchoalveolar Lavage Fluid/virology , COVID-19 , China/epidemiology , Coronavirus Infections/diagnosis , Coronavirus Infections/transmission , DNA, Viral/genetics , Disease Reservoirs/virology , Genomics/methods , High-Throughput Nucleotide Sequencing/methods , Humans , Phylogeny , Pneumonia, Viral/diagnosis , Pneumonia, Viral/transmission , SARS-CoV-2 , Sequence Alignment
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