Study reveals mouth as primary source of COVID-19 infection

While most COVID-19 research has focused on the nose and lungs, this is the first study to identify the mouth as a primary site for coronavirus infection and underscores the importance of wearing a face covering and physical distancing.

By University Communications, Thursday, October 29th, 2020

A team of researchers led by the University of North Carolina at Chapel Hill and the National Institute of Dental and Craniofacial Research reveals coronavirus can take hold in the salivary glands where it replicates, and in some cases, leads to prolonged disease when infected saliva is swallowed into the gastrointestinal tract or aspirated to the lungs where it can lead to pneumonia.

While most COVID-19 research has focused on the nose and lungs, this is the first study to identify the mouth as a primary site for coronavirus infection and underscores the importance of wearing a face covering and physical distancing. The results have not been peer-reviewed.

“Our results show oral infection of COVID-19 may be underappreciated,” said senior study author Kevin M. Byrd, research instructor at the UNC Adams School of Dentistry and the Anthony R. Volpe Research Scholar at the American Dental Association Science and Research Institute. “Like nasal infection, oral infection could underlie the asymptomatic spread that makes this disease so hard to contain.”

Byrd along with Blake Warner, chief of the Salivary Disorders Unit at the National Institute of Dental and Craniofacial Research, coordinated the research conducted at the National Institutes of Health, Wellcome Sanger Institute, UNC Marsico Lung Institute and the J. Craig Venter Institute.

Researchers are just beginning to explore the oral symptoms patients experience during COVID-19, such as loss of taste or smell and persistent dry mouth.

In the study, researchers report preliminary results from a clinical trial of 40 subjects with COVID-19 which showed sloughed epithelial cells lining the mouth can be infected with SARS-CoV-2, the coronavirus that causes COVID-19. The amount of virus in patient saliva was positively correlated with taste and smell changes, according to the study.

Relying on oral cell identity maps, researchers also looked at where in the mouth the virus infects. They surveyed oral tissues with the highest levels of ACE2, the receptor that helps coronavirus grab and invade human cells.

Based on ACE2 expression and analysis of cadaver tissue, the most likely sites of infection in the mouth are the salivary glands, tongue and tonsil, the study showed.

The findings provide more evidence of the role of saliva in COVID-19. COVID-19 infection, specifically in the mouth, can allow the virus to spread internally and to others as the infected person breathes, speaks and coughs.

For More Information: https://www.unc.edu/posts/2020/10/29/study-reveals-mouth-as-primary-source-of-covid-19-infection/

Pathological findings in organs and tissues of patients with COVID-19: A systematic review

Authors: Sasha Peiris 1 2Hector Mesa 3Agnes Aysola 4Juan Manivel 5Joao Toledo 1 2Marcio Borges-Sa 6Sylvain Aldighieri 1 2Ludovic Reveiz 2 7

Abstract

Background: Coronavirus disease (COVID-19) is the pandemic caused by SARS-CoV-2 that has caused more than 2.2 million deaths worldwide. We summarize the reported pathologic findings on biopsy and autopsy in patients with severe/fatal COVID-19 and documented the presence and/or effect of SARS-CoV-2 in all organs.

Methods and findings: A systematic search of the PubMed, Embase, MedRxiv, Lilacs and Epistemonikos databases from January to August 2020 for all case reports and case series that reported histopathologic findings of COVID-19 infection at autopsy or tissue biopsy was performed. 603 COVID-19 cases from 75 of 451 screened studies met inclusion criteria. The most common pathologic findings were lungs: diffuse alveolar damage (DAD) (92%) and superimposed acute bronchopneumonia (27%); liver: hepatitis (21%), heart: myocarditis (11.4%). Vasculitis was common only in skin biopsies (25%). Microthrombi were described in the placenta (57.9%), lung (38%), kidney (20%), Central Nervous System (CNS) (18%), and gastrointestinal (GI) tract (2%). Injury of endothelial cells was common in the lung (18%) and heart (4%). Hemodynamic changes such as necrosis due to hypoxia/hypoperfusion, edema and congestion were common in kidney (53%), liver (48%), CNS (31%) and GI tract (18%). SARS-CoV-2 viral particles were demonstrated within organ-specific cells in the trachea, lung, liver, large intestine, kidney, CNS either by electron microscopy, immunofluorescence, or immunohistochemistry. Additional tissues were positive by Polymerase Chain Reaction (PCR) tests only. The included studies were from numerous countries, some were not peer reviewed, and some studies were performed by subspecialists, resulting in variable and inconsistent reporting or over statement of the reported findings.

Conclusions: The main pathologic findings of severe/fatal COVID-19 infection are DAD, changes related to coagulopathy and/or hemodynamic compromise. In addition, according to the observed organ damage myocarditis may be associated with sequelae.

For More Information: https://pubmed.ncbi.nlm.nih.gov/33909679/

Long covid: Damage to multiple organs presents in young, low risk patients

Authors: Gareth Iacobucci BMJ 2020; 371 doi: https://doi.org/10.1136/bmj.m4470 (Published 17 November 2020)Cite this as: BMJ 2020;371:m4470

Young, low risk patients with ongoing symptoms of covid-19 had signs of damage to multiple organs four months after initially being infected, a preprint study has suggested.1

Initial data from 201 patients suggest that almost 70% had impairments in one or more organs four months after their initial symptoms of SARS-CoV-2 infection.

The results emerged as the NHS announced plans to establish a network of more than 40 long covid specialist clinics across England this month to help patients with long term symptoms of infection.

The prospective Coverscan study examined the impact of long covid (persistent symptoms three months post infection) across multiple organs in low risk people who are relatively young and had no major underlying health problems. Assessment was done using results from magnetic resonance image scans, blood tests, and online questionnaires.

The research has not yet been peer reviewed and could not establish a causal link between organ impairment and infection. But the authors said the results had “implications not only for [the] burden of long covid but also public health approaches which have assumed low risk in young people with no comorbidities.”

The study enrolled participants at two UK sites in Oxford and London between April and August 2020. Two hundred and one individuals (mean age 44 (standard deviation 11.0) years) completed assessments after SARS-CoV-2 infection a median of 140 days after initial symptoms.

Participants were eligible if they tested positive for SARS-CoV-2 by random polymerase chain reaction swab (n=62), a positive antibody test (n=63), or had typical symptoms and were determined to have covid-19 by two independent clinicians (n=73).

The prevalence of pre-existing conditions was low (obesity: 20%, hypertension: 6%, diabetes: 2%, heart disease: 4%), and less than a fifth (18%) of individuals had been hospitalised with covid-19.

The most commonly reported ongoing symptoms—regardless of hospitalization status—were fatigue (98%), muscle ache (88%), shortness of breath (87%), and headache (83%). There was evidence of mild organ impairment in the heart (32% of patients), lungs (33%), kidneys (12%), liver (10%), pancreas (17%), and spleen (6%).

For More Information: https://www.bmj.com/content/371/bmj.m4470

Pathological findings in organs and tissues of patients with COVID-19: A systematic review

  1. Authors: Sasha Peiris, Hector Mesa, Agnes Aysola, Juan Manivel, Joao Toledo, Marcio Borges-Sa, Sylvain Aldighieri, Ludovic Reveiz

Abstract

Background

Coronavirus disease (COVID-19) is the pandemic caused by SARS-CoV-2 that has caused more than 2.2 million deaths worldwide. We summarize the reported pathologic findings on biopsy and autopsy in patients with severe/fatal COVID-19 and documented the presence and/or effect of SARS-CoV-2 in all organs.

Methods and findings

A systematic search of the PubMed, Embase, MedRxiv, Lilacs and Epistemonikos databases from January to August 2020 for all case reports and case series that reported histopathologic findings of COVID-19 infection at autopsy or tissue biopsy was performed. 603 COVID-19 cases from 75 of 451 screened studies met inclusion criteria. The most common pathologic findings were lungs: diffuse alveolar damage (DAD) (92%) and superimposed acute bronchopneumonia (27%); liver: hepatitis (21%), heart: myocarditis (11.4%). Vasculitis was common only in skin biopsies (25%). Microthrombi were described in the placenta (57.9%), lung (38%), kidney (20%), Central Nervous System (CNS) (18%), and gastrointestinal (GI) tract (2%). Injury of endothelial cells was common in the lung (18%) and heart (4%). Hemodynamic changes such as necrosis due to hypoxia/hypoperfusion, edema and congestion were common in kidney (53%), liver (48%), CNS (31%) and GI tract (18%). SARS-CoV-2 viral particles were demonstrated within organ-specific cells in the trachea, lung, liver, large intestine, kidney, CNS either by electron microscopy, immunofluorescence, or immunohistochemistry. Additional tissues were positive by Polymerase Chain Reaction (PCR) tests only. The included studies were from numerous countries, some were not peer reviewed, and some studies were performed by subspecialists, resulting in variable and inconsistent reporting or over statement of the reported findings.

Conclusions

The main pathologic findings of severe/fatal COVID-19 infection are DAD, changes related to coagulopathy and/or hemodynamic compromise. In addition, according to the observed organ damage myocarditis may be associated with sequelae.

For More Information: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0250708

Late Complications of COVID-19; a Systematic Review of Current Evidence

Authors: SeyedAhmad SeyedAlinaghi,1Amir Masoud Afsahi,2Mehrzad MohsseniPour,1Farzane Behnezhad,3Mohammad Amin Salehi,1Alireza Barzegary,4Pegah Mirzapour,1Esmaeil Mehraeen,5,* and Omid Dadras6

Introduction

Introduction:

COVID-19 is a new rapidly spreading epidemic. The symptoms of this disease could be diverse as the virus can affect any organ in the body of an infected person. This study aimed to investigate the available evidence for long-term complications of COVID-19.

Methods:

This study was a systematic review of current evidence conducted in November 2020 to investigate probable late and long-term complications of COVID-19. We performed a systematic search, using the keywords, in online databases including PubMed, Scopus, Science Direct, Up to Date, and Web of Science, to find papers published from December 2019 to October 2020. Peer-reviewed original papers published in English, which met the eligibility criteria were included in the final report. Addressing non-human studies, unavailability of the full-text document, and duplicated results in databases, were characteristics that led to exclusion of the papers from review.

Results:

The full-texts of 65 articles have been reviewed. We identified 10 potential late complications of COVID-19. A review of studies showed that lung injuries (n=31), venous/arterial thrombosis (n=28), heart injuries (n=26), cardiac/brain stroke (n=23), and neurological injuries (n=20) are the most frequent late complications of COVID-19.

For More Information: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7927752/

The pathophysiology of bronchiectasis

Authors : King P

Abstract: 

Bronchiectasis is defined by permanent and abnormal widening of the bronchi. This process occurs in the context of chronic airway infection and inflammation. It is usually diagnosed using computed tomography scanning to visualize the larger bronchi. Bronchiectasis is also characterized by mild to moderate airflow obstruction. This review will describe the pathophysiology of noncystic fibrosis bronchiectasis. Studies have demonstrated that the small airways in bronchiectasis are obstructed from an inflammatory infiltrate in the wall. As most of the bronchial tree is composed of small airways, the net effect is obstruction. The bronchial wall is typically thickened by an inflammatory infiltrate of lymphocytes and macrophages which may form lymphoid follicles. It has recently been demonstrated that patients with bronchiectasis have a progressive decline in lung function. There are a large number of etiologic risk factors associated with bronchiectasis. As there is generally a long-term retrospective history, it may be difficult to determine the exact role of such factors in the pathogenesis. Extremes of age and smoking/chronic obstructive pulmonary disease may be important considerations. There are a variety of different pathogens involved in bronchiectasis, but a common finding despite the presence of purulent sputum is failure to identify any pathogenic microorganisms. The bacterial flora appears to change with progression of disease.

For More Information: https://www.dovepress.com/the-pathophysiology-of-bronchiectasis-peer-reviewed-fulltext-article-COPD

The Severe Acute Respiratory Syndrome

Authors: Joseph S.M. Peiris, M.D., D.Phil., Kwok Y. Yuen, M.D., Albert D.M.E. Osterhaus, Ph.D., and Klaus Stöhr, Ph.D.

The severe acute respiratory syndrome (SARS) is responsible for the first pandemic of the 21st century. Within months after its emergence in Guangdong Province in mainland China, it had affected more than 8000 patients and caused 774 deaths in 26 countries on five continents. It illustrated dramatically the potential of air travel and globalization for the dissemination of an emerging infectious disease and highlighted the need for a coordinated global response to contain such disease threats. We review the cause, epidemiology, and clinical features of the disease.

Cause

An unusual atypical pneumonia emerged in Foshan, Guangdong Province, mainland China, in November 2002.1,2 In February and March 2003, the disease spread to Hong Kong and then to Vietnam, Singapore, Canada, and elsewhere (Table 1).3,4 The new disease was named the severe acute respiratory syndrome (SARS), and a preliminary case definition was established.4 A novel coronavirus (SARS-CoV) was identified as the causative agent.5-10 Coronaviruses are a family of enveloped, single-stranded–RNA viruses causing disease in humans and animals, but the other known coronaviruses that affect humans cause only the common cold.

The presence of SARS-CoV has been demonstrated by reverse-trancriptase polymerase chain reaction (RT-PCR) and the isolation of the virus from respiratory secretions, feces, urine, and tissue specimens from lung biopsy,11,12 indicating that the infection is not confined to the respiratory tract. The experimental infection of cynomolgus macaques with SARS-CoV produced a pneumonia that was pathologically similar to SARS in humans.8,9 Other pathogens, including human metapneumovirus13,14 and chlamydia,7,15 have been detected together with SARS-CoV in some patients with SARS, but they have not been found consistently.5,9 The experimental infection of macaques with human metapneumovirus did not lead to a SARS-like disease, and coinfection of macaques with human metapneumovirus and SARS-CoV did not enhance the pathogenicity of the SARS-CoV in this animal model.8 Thus, all the information that is available to date suggests that SARS-CoV is necessary and sufficient for the causation of SARS in humans, but it remains to be determined whether microbial or other cofactors enhance the severity or transmissibility of the disease. The complete genetic sequence of the SARS-CoV genome was determined, and it provided confirmation that SARS-CoV belongs to a new group within the coronavirus family.

For More Information: https://www.nejm.org/doi/10.1056/NEJMra032498

What Does COVID Do to Your Blood?

Authors: Panagis Galiatsatos, M.D., M.H.S., Robert Brodsky, M.D.

COVID-19 is a very complex illness. The coronavirus that causes COVID-19 attacks the body in many different ways, ranging from mild to life threatening. Different organs and tissues of the body can be affected, including the blood.

Robert Brodsky, a blood specialist who directs the Division of Hematology, and Panagis Galiatsatos, a specialist in lung diseases and critical care medicine, talk about blood problems linked to SARS-CoV-2 — the coronavirus that causes COVID-19 — and what you should know.

Coronavirus Blood Clots

Blood clots can cause problems ranging from mild to life threatening. If a clot blocks blood flow in a vein or artery, the tissue normally nourished by that blood vessel can be deprived of oxygen, and cells in that area can die.

Some people infected with SARS-CoV-2 develop abnormal blood clotting. “In some people with COVID-19, we’re seeing a massive inflammatory response, the cytokine storm that raises clotting factors in the blood,” says Galiatsatos, who treats patients with COVID-19.

“We are seeing more blood clots in the lungs (pulmonary embolism), legs (deep vein thrombosis) and elsewhere,” he says.

Brodsky notes that other serious illnesses, especially ones that cause inflammation, are associated with blood clots. Research is still exploring if the blood clots seen in severe cases of COVID-19 are unique in some way. 

The Impact of Coronavirus Blood Clots Throughout the Body

In addition to the lungs, blood clots, including those associated with COVID-19, can also harm:

The nervous system. Blood clots in the arteries leading to the brain can cause a stroke. Some previously young, healthy people who have developed COVID-19 have suffered strokes, possibly due to abnormal blood clotting.

The kidneys. Clogging of blood vessels in the kidney with blood clots can lead to kidney failure. It can also complicate dialysis if the clots clog the filter of the machine designed to remove impurities in the blood.

Peripheral blood vessels and “COVID toe.” Small blood clots can become lodged in tiny blood vessels. When this happens close to the skin, it can result in a rash. Some people who test positive for COVID-19 develop tiny blood clots that cause reddish or purple areas on the toes, which can itch or be painful. Sometimes called COVID toe, the rash resembles frostbite.

For More Information: https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/what-does-covid-do-to-your-blood

SARS-CoV-2 Spike Protein Impairs Endothelial Function via Downregulation of ACE 2

Authors: Yuyang LeiJiao ZhangCara R. SchiavonMing HeLili ChenHui ShenYichi ZhangQian YinYoshitake ChoLeonardo AndradeGerald S. ShadelMark HepokoskiTing LeiHongliang WangJin ZhangJason X., et. al.

SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection relies on the binding of S protein (Sprotein (Spike glycoprotein) to ACE (angiotensin-converting enzyme) 2 in the host cells. Vascular endothelium can be infected by SARS-CoV-2,1 which triggers mitochondrial reactive oxygen species production and glycolytic shift.2 Paradoxically, ACE2 is protective in the cardiovascular system, and SARS-CoV-1 S protein promotes lung injury by decreasing the level of ACE2 in the infected lungs.3 In the current study, we show that S protein alone can damage vascular endothelial cells (ECs) by downregulating ACE2 and consequently inhibiting mitochondrial function.

For More Information: https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.121.318902

COVID-19 is, in the end, an endothelial disease

Authors: Peter LibbyThomas Lüscher

The vascular endothelium provides the crucial interface between the blood compartment and tissues, and displays a series of remarkable properties that normally maintain homeostasis. This tightly regulated palette of functions includes control of haemostasis, fibrinolysis, vasomotion, inflammation, oxidative stress, vascular permeability, and structure. While these functions participate in the moment-to-moment regulation of the circulation and coordinate many host defence mechanisms, they can also contribute to disease when their usually homeostatic and defensive functions over-reach and turn against the host. SARS-CoV-2, the aetiological agent of COVID-19, causes the current pandemic. It produces protean manifestations ranging from head to toe, wreaking seemingly indiscriminate havoc on multiple organ systems including the lungs, heart, brain, kidney, and vasculature. This essay explores the hypothesis that COVID-19, particularly in the later complicated stages, represents an endothelial disease. Cytokines, protein pro-inflammatory mediators, serve as key danger signals that shift endothelial functions from the homeostatic into the defensive mode. The endgame of COVID-19 usually involves a cytokine storm, a phlogistic phenomenon fed by well-understood positive feedback loops that govern cytokine production and overwhelm counter-regulatory mechanisms. The concept of COVID-19 as an endothelial disease provides a unifying pathophysiological picture of this raging infection, and also provides a framework for a rational treatment strategy at a time when we possess an indeed modest evidence base to guide our therapeutic attempts to confront this novel pandemic.

For More Information: https://academic.oup.com/eurheartj/article/41/32/3038/5901158