U.S. Study Shows That SARS-CoV-2 Has Already Spread Extensively In The Wildlife. Expect Debut Of SARS-CoV-3 Sometime In 2023!
Source: Medical News - SARS-CoV-2 Wildlife Nov 13, 2022 2 years, 1 week, 2 days, 15 hours, 45 minutes ago
A new study by researchers from Virginia Tech, Blacksburg, Virginia - USA has shown that the SARS-CoV-2 coronavirus has already spread extensively among various wildlife including racoons, squirrels, possums, deer, foxes, skunks etc.
Image Credit: Encyclopedia Britannica
Thailand
Medical News would like to add that with the human populations around the world currently under attack by a variety of more than 300 plus different SARS-CoV-2 Omicron variants and sub-variants and also new recombinant variants, the fact that many wildlife now also carrying the novel coronavirus while some are also themselves reservoirs for other viruses including different types of coronaviruses, and taking into consideration the nature of the SARS-CoV-2 Omicron variants that seem to possess a greater potential for evolving and also for recombinant events, it is very likely that sometime in 2023, due to the current kinetics of the whole SARS-CoV-2 pandemic, we would see a new SARS-CoV-3 coronavirus emerge alongside the various emerging SARS-CoV-2 variants and sub-lineages and hopefully, it would be more pathogenic, virulent and lethal.
The spillover of SARS-CoV-2 into humans has caused one of the most devastating pandemics in recorded history. Human-animal interactions have led to transmission events of SARS-CoV-2 from humans to wild and captive animals and in some cases back.
Many questions however remain about how extensive SARS-CoV-2 exposure is in wildlife, the factors that influence wildlife transmission risk, and whether sylvatic cycles can generate novel variants with increased infectivity and virulence.
The study team sampled 18 different wildlife species in the Eastern U.S. and detected widespread exposure to SARS-CoV-2 across wildlife species.
Utilizing quantitative reverse transcription polymerase chain reaction and whole genome sequencing, the study team conclusively detected SARS-CoV-2 in the Virginia opossum and had equivocal detections in six additional species. Species considered human commensals like squirrels, and raccoons had high seroprevalence, ranging between 62%-71%, and sites with high human use had three times higher seroprevalence than low human-use areas.
Worryingly, SARS-CoV-2 genomic data from an infected opossum and molecular modeling exposed previously uncharacterized changes to amino acid residues observed in the receptor binding domain (RBD), which predicts improved binding between the spike protein and human angiotensin-converting enzyme (ACE2) compared to the dominant variant circulating at the time of isolation.
However, these mutations were not identified in human samples at the time of collection.
The study findings highlight widespread exposure to SARS-CoV-2 in wildlife and suggest that areas with high human activity may serve as important points of contact for cross-species transmission.
More worryingly, Furthermore, the study findings highlight the potential role of wildlife in fueling de novo mutations that may eventually appear in humans.
The study findings were published on a preprint server and are currently being peer reviewed.
/>
https://www.biorxiv.org/content/10.1101/2022.11.04.515237v1
The SARS-CoV-2 spillover onto humans has led to the devastating COVID-19 (coronavirus disease 2019) pandemic that has caused significant morbidity and mortality across the globe. To date, official figures show that more than 640 million people have been exposed to the SARS-CoV-2 virus and more than 6.6 million people have died. (In reality the actual figures are about 5 to 6- fold!). Excess deaths as a result of exposure to the virus are also increasing with time globally and reinfections are also contributing to these excess deaths though the newer variants and sub-lineages appear mild in the majority except those in the vulnerable groups. ( ie. The aged, the young, the obese, the immunocompromised, those with existing comorbidities including high blood pressure, diabetes and heart issues, etc and those with a certain genetic makeup.)
The interactions of humans with animals have caused the reverse transmission of SARS-CoV-2 from humans to captive and wild animal species. However, data on the extent of SARS-CoV-2 exposure among wildlife, factors influencing SARS-CoV-2 transmission risks among wildlife, and the potential generation of novel, more virulent, and immune-evasive SARS-CoV-2 variants by sylvatic cycles are lacking.
The study team are among the first to evaluate the SARS-CoV-2 exposure of wild animals.
A total of eighteen wild animal species and 333 individuals from 32 counties of Virginia were sampled in the Eastern regions of the United States (US) and subjected to RT-qPCR (quantitative reverse transcription polymerase chain reaction) and WGS (whole genome sequencing) analyses.
Nasopharyngeal (NP) swabs were obtained for detecting the SARS-CoV-2 spike (S), nucleocapsid (N), and envelope (E) genes and for amplifying a housekeeping-type gene to assess the prevalence of active COVID-19 cases.
The detailed impact of urbanization and human activity on SARS-CoV-2-neutralizing antibody titers was evaluated in six areas of the southwestern region of Virginia to investigate previous SARS-CoV-2 exposure among wild animals from human interactions. NP swabs and sera samples were obtained from eleven species for detailed analysis. In addition, unique SARS-CoV-2 mutations identified in wildlife were examined.
Precise molecular modeling was performed to estimate structural alterations that enhanced the receptor binding of the S protein-hACE2 (human angiotensin-converting enzyme).
Lastly, the study team performed an in-depth investigation to evaluate the impact of the E471V and G798D mutations on the SARS-CoV-2 S structure using MM/GBSA (molecular mechanics/generalized borne surface area) free energy calculations for which the SARS-CoV-2 Omicron BA.2 S was utilized in the open conformation.
The study findings showed widespread SARS-CoV-2 exposure among wildlife. SARS-CoV-2 was identified in Virginia’s opossum (Didelphis virginiana) and equivocally among six other species. Raccoons and squirrels showed high SARS-CoV-2 seroprevalence ranging between 62% and 71%, and the seroprevalence was three times higher among high human-activity areas than low human-activity areas.
Worryingly, molecular modeling findings and data of the SARS-CoV-2 genome obtained from a SARS-CoV-2-infected opossum revealed RBD (receptor binding domain) mutations previously uncharacterized that enhanced the RBD-hACE2 binding.
Also, amplifying ≥2 genes of SARS-CoV-2 yielded conclusive SARS-CoV-2 detection in a D. virginiana sample (63 individuals, two percent). Based on one SARS-CoV-2 gene amplification, the prevalence of active SARS-CoV-2 infections infection was four percent, with equivocal viral detections in five other species.
Interestingly, the highest seroprevalence was observed among Vulpes vulpes (red foxes, 20%), Odocoileus virginianus (white-tailed deer, 10%), and Virginia’s opossum (eight percent). Neutralizing antibodies indicating previous SARS-CoV-2 exposure were detectable among several wild animals (49% seroprevalence). Detectable antibody titers were observed in sera of Virginia opossum (63%), Mephitis mephitis (striped skunk, 66%), Procyon lotor (raccoon,64%), Eastern grey squirrel (71.0%), Peromyscus leucopus (white-footed mice, 17%) and Peromyscus maniculatus (deer mouse,29%).
The study team found a positive association between urbanization and seroprevalence among wildlife.
Importantly, the most significant (80%) antibody titers were observed at a minimally urbanized site (mean imperviousness of two percent), closely matching the seroprevalence observed among two other urbanized areas.
However, human visits to the urbanized areas were greater than 70-times higher than at other sites. High human activity was associated with 3.0-fold greater seroprevalence compared to low-human activity sites.
Alarmingly, the sequence of SARS-CoV-2 obtained from the infected Virginia opossum shared mutations in the Omicron BA.2 open reading frame 1a/b (ORF1a/b), membrane (M), E, and S genes. The detected isolate was found to cluster in the Omicron clade and was assigned the Omicron sub-variant BJ.1 or BA.2.10.1. The BA.2.10.1 subvariant comprised the G798D amino acid substitution in the S protein. The most proximal neighbor (EPI_ISL_14334179) comprised all mutations as the Virginia opossum sequence, except for the A22974T (E471V) mutation, found uniquely in the Virginia opossum.
Also, the mutation E471V was detected in the receptor-binding motif (RBM) of SARS-CoV-2 S RBD (receptor-binding domain) and enhanced the estimated free energy of hACE2 binding.
The study findings showed hydrophobic interactions at residues 469 to 474, especially 471.
Importantly, the G798D missense mutation was identified in the S protein subunit 2 (S2) at residues 686 to 1273 and within the fusion peptide domain (residue 788 to residue 806) proximal to the N801 site of glycosylation. Of interest, D798 altered the probability of N801 glycosylation and could affect S membrane interactions and structural stability.
The study findings highlighted the widespread SARS-CoV-2 exposure among wildlife and showed that high human-use areas could be critical contact points for cross-species SARS-CoV-2 transmission.
The study findings suggest that wildlife can contribute unique mutations that are more likely to be transmitted to humans.
For the latest SARS-CoV-2 Research, keep on logging to Thailand Medical News.
Share
Tweet
Share
