So, President Trump is right… how about media being real journalists for a change? Tell Hillary, CNN and the rest that Trump is hardly “racist” and “xenophobic.”
Let’s travel over to Basel, Switzerland shall we?
Primer: MDPI is the Molecular Diversity Preservation International/Multidisciplinary Digital Publishing Institute founded in 1996 located in Basel. The organization is an open access repository of medical journals where each paper has citations from medical academics and experts. Health issues include various human health conditions such as obesity, autism, Alzheimer’s disease, cancer, and many, many others.
So, media, when it comes to China and SAR-CoV, review their summary. (BTW, it is full of citations)
Fifteen years after the first highly pathogenic human coronavirus caused the severe acute respiratory syndrome coronavirus (SARS-CoV) outbreak, another severe acute diarrhea syndrome coronavirus (SADS-CoV) devastated livestock production by causing fatal diseases in pigs. Both outbreaks began in China and were caused by coronaviruses of bat origin [1,2]. This increased the urgency to study bat coronaviruses in China to understand their potential of causing another virus outbreak.
In this review, we collected information from past epidemiology studies on bat coronaviruses in China, including the virus species identified, their host species, and their geographical distributions. We also discuss the future prospects of bat coronaviruses cross-species transmission and spread in China.
2. Why Study Bat Coronaviruses in China?
2.1. Coronavirus Taxonomy
Coronaviruses (CoVs) belong to the subfamily Orthocoronavirinae in the family Coronaviridae and the order Nidovirales. CoVs have an enveloped, crown-like viral particle from which they were named after. The CoV genome is a positive-sense, single-strand RNA (+ssRNA), 27–32 kb in size, which is the second largest of all RNA virus genomes. Typically, two thirds of the genomic RNA encodes for two large overlapping polyproteins, ORF1a and ORF1b, that are processed into the viral polymerase (RdRp) and other nonstructural proteins involved in RNA synthesis or host response modulation. The other third of the genome encodes for four structural proteins (spike (S), envelope (E), membrane (M), and nucleocapsid (N)) and other accessory proteins. While the ORF1a/ORF1b and the four structural proteins are relatively consistent, the length of the CoV genome is largely dependent on the number and size of accessory proteins .
Compared with other RNA viruses, the expanded genome size of CoVs is believed to be associated with increased replication fidelity, after acquiring genes encoding RNA-processing enzymes . Genome expansion further facilitates the acquisition of genes encoding accessory proteins that are beneficial for CoVs to adapt to a specific host . As a result, genome changes caused by recombination, gene interchange, and gene insertion or deletion are common among CoVs. The CoV subfamily is expanding rapidly, due to the application of next generation sequencing which has increased the detection and identification of new CoV species. As a result, CoV taxonomy is constantly changing. According to the latest International Committee of Taxonomy of Viruses (ICTV) classification, there are four genera (α-, β-, δ-, and γ-) consisting of thirty-eight unique species in the subfamily . The number of species will continue to increase, as there are still many unclassified CoVs [7,8].
CoVs cause disease in a variety of domestic and wild animals as well as in humans, where α- and β-CoVs mainly infect mammals and γ- and δ-CoVs mainly infect birds (Table 1). Two highly pathogenic β-CoVs, SARS-CoV, and MERS-CoV have caused pandemics in humans since 2002 [1,9]. Originating in China and then spreading to other parts of the world, SARS-CoV infected around 8000 individuals with an overall mortality of 10% during the 2002–2003 pandemic . Since its emergence in 2012 in the Middle East, MERS-CoV spread to 27 countries, resulting in 2249 laboratory-confirmed cases of infection with an average mortality of 35.5% (until September 2018) . Besides these two viruses, α-CoVs 229E and NL63 and β-CoVs OC43 and HKU1 can also cause respiratory diseases in humans . Moreover, CoVs cause pandemic disease in domestic and wild animals (Table 1). SADS-CoV was recently identified as the etiological agent responsible for a large-scale outbreak of fatal disease in pigs in China that caused the death of more than 20,000 piglets . Porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV) that belong to α-CoV and porcine δ-CoV (PDCoV) are also important emerging and re-emerging viruses in pigs that pose significant economic threat to the swine industry . In addition, avian infectious bronchitis virus (IBV, γ-CoV) causes a highly contagious disease that affects poultry production worldwide . Coronaviruses have also been associated with catarrhal gastroenteritis in mink (MCoV) and whale deaths (BWCoV-SW1) [13,14].
This content was originally published here.