Background. Understanding the epidemiological dynamics of influenza virus is central to surveillance and vaccine strain selection. It has been suggested that tropical and subtropical regions represent the global source of influenza epidemics. However, our understanding of the epidemiological dynamics of influenza virus in these regions is limited by a relative lack of long-term data. Methods. We analyzed epidemiological and virological data on influenza recorded over a period of 15 years from the metropolitan city of Shenzhen in subtropical southern China. We used wavelet analysis to determine the periodicity of influenza epidemics and molecular phylogeographic analysis to investigate the role of Shenzhen and southern China in the global evolution of influenza virus. Results. We show that southern China is unlikely to represent an epicenter of global influenza activity, because activity in Shenzhen is characterized by significant annual cycles, multiple viral introductions every year, limited persistence across epidemic seasons, and viruses that generally are not positioned on the trunk of the global influenza virus phylogeny. Conclusions. We propose that novel influenza viruses emerge and evolve in multiple geographic localities and that the global evolution of influenza virus is complex and does not simply originate from a southern Chinese epicenter.
Human enteroviruses contain over 100 serotypes. We have routinely conducted enterovirus surveillance in northern Taiwan; but about 10% of isolates could not be serotyped using traditional assays. Next-generation sequencing (NGS) is a powerful tool for genome sequencing.
A 47-year-old male (Patient A) passenger from Vietnam whose nucleic acid results for coronavirus disease 2019 , also known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), were positive at Pingxiang Customs on April 29, 2021, and subsequently confirmed by Guangxi CDC laboratories on April 30.On April 30, four accompanying persons (Patient B-E) of Patient A returned from Vietnam.After being tested by the laboratory of Pingxiang Customs using nasopharyngeal swab tests for COVID-19, the results for patients showed COVID-19 positive.All five patients were transported to the Pingxiang Emergency Medical Center for isolated treatment by ambulance.Clinical conditions of the five patients included normal body temperature, blood tests, and liver-kidney functions.Abnormalities in chest computed tomography (CT) suggested infectious lesions, four patients (A/B/D/E) classified as mild type of COVID-19, and one (patient C) was classified as severe type.Preliminary epidemiological investigation revealed those patients were on a business trip from April 9, when they came to Yen Bai Province, Vietnam, and were isolated in a designated isolation hotel until April 22.From April 23 to 28, all five patients performed their business and travel in Vietnam.The latest negative results for Patients A, B, and C were on April 22 and were on April 27 for Patients D and E, respectively.Further investigations demonstrated a group of Indian nationals who were isolated in the hotel on April 18, and four of these individuals eventually tested positive for COVID-19 on April 19.In addition, guests of the hotel had activity unrestricted in the hotel during the quarantine, and there was only one attendant who took no relevant precautionary measures against COVID-19 when on duty.The attendant was later confirmed positive for COVID-19
Acute respiratory infection (ARI) with respiratory syncytial virus (RSV) is the most common cause of both hospitalizations and mortality in young infants worldwide. Repeat infections with RSV are common throughout life in both pediatric and elderly populations. Thus far, cotton rats (Sigmodon hispidus) are found to be the best animal model to study RSV infection. However, the lack of a cotton rat reference genome limits genome-wide host gene expression studies. We constructed the first lung tissue de novo transcriptome for the cotton rat. Cotton rat lung tissue transcripts were assigned to 12,211 unique UniProt genes, which were then utilized to profile the host immune response after RSV infection. Differential expression analysis showed up-regulation of host genes involved in cellular functions including defense responses to viral infection and immune system processes. A number of transcripts were downregulated during the later stage of infection. A set of transcripts unique to RSV-infected cotton rats was identified. To validate RNA-Seq data of three such transcripts (TR453762, TR529629, and TR5333), their expression was confirmed by quantitative real-time polymerase chain reaction.
On March 1, 1919, in Seoul of Korea the independence movement broke out, which is of great significance in Korean modern history. Two months later, in Beijing China, the May 4 Movement broke out, which is of great sense of enlightenment in Chinese modern history. These two great movements had produced profound influences on Fengtian, even on the whole Northeast China. However, if explored in some specific aspects, the former seems have more direct and durable effects.
The emergence and rapid global spread of the swine-origin H1N1/09 pandemic influenza A virus in humans underscores the importance of swine populations as reservoirs for genetically diverse influenza viruses with the potential to infect humans. However, despite their significance for animal and human health, relatively little is known about the phylogeography of swine influenza viruses in the United States. This study utilizes an expansive data set of hemagglutinin (HA1) sequences (n = 1516) from swine influenza viruses collected in North America during the period 2003–2010. With these data we investigate the spatial dissemination of a novel influenza virus of the H1 subtype that was introduced into the North American swine population via two separate human-to-swine transmission events around 2003. Bayesian phylogeographic analysis reveals that the spatial dissemination of this influenza virus in the US swine population follows long-distance swine movements from the Southern US to the Midwest, a corn-rich commercial center that imports millions of swine annually. Hence, multiple genetically diverse influenza viruses are introduced and co-circulate in the Midwest, providing the opportunity for genomic reassortment. Overall, the Midwest serves primarily as an ecological sink for swine influenza in the US, with sources of virus genetic diversity instead located in the Southeast (mainly North Carolina) and South-central (mainly Oklahoma) regions. Understanding the importance of long-distance pig transportation in the evolution and spatial dissemination of the influenza virus in swine may inform future strategies for the surveillance and control of influenza, and perhaps other swine pathogens.
We compared the characteristics of cases of highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI) A(H7N9) virus infections in China. HPAI A(H7N9) case-patients were more likely to have had exposure to sick and dead poultry in rural areas and were hospitalized earlier than were LPAI A(H7N9) case-patients.
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