How does coronavirus kill? Clinicians trace a ferocious rampage through the body, from brain to toes

Authors: By Meredith WadmanJennifer Couzin-FrankelJocelyn KaiserCatherine MatacicApr. 17, 2020 , 6:45 PM

On rounds in a 20-bed intensive care unit one recent day, physician Joshua Denson assessed two patients with seizures, many with respiratory failure and others whose kidneys were on a dangerous downhill slide. Days earlier, his rounds had been interrupted as his team tried, and failed, to resuscitate a young woman whose heart had stopped. All shared one thing, says Denson, a pulmonary and critical care physician at the Tulane University School of Medicine. “They are all COVID positive.”

As the number of confirmed cases of COVID-19 surges past 2.2 million globally and deaths surpass 150,000, clinicians and pathologists are struggling to understand the damage wrought by the coronavirus as it tears through the body. They are realizing that although the lungs are ground zero, its reach can extend to many organs including the heart and blood vessels, kidneys, gut, and brain.

“[The disease] can attack almost anything in the body with devastating consequences,” says cardiologist Harlan Krumholz of Yale University and Yale-New Haven Hospital, who is leading multiple efforts to gather clinical data on COVID-19. “Its ferocity is breathtaking and humbling.”

Understanding the rampage could help the doctors on the front lines treat the fraction of infected people who become desperately and sometimes mysteriously ill. Does a dangerous, newly observed tendency to blood clotting transform some mild cases into life-threatening emergencies? Is an overzealous immune response behind the worst cases, suggesting treatment with immune-suppressing drugs could help? What explains the startlingly low blood oxygen that some physicians are reporting in patients who nonetheless are not gasping for breath? “Taking a systems approach may be beneficial as we start thinking about therapies,” says Nilam Mangalmurti, a pulmonary intensivist at the Hospital of the University of Pennsylvania (HUP).

What follows is a snapshot of the fast-evolving understanding of how the virus attacks cells around the body, especially in the roughly 5% of patients who become critically ill. Despite the more than 1000 papers now spilling into journals and onto preprint servers every week, a clear picture is elusive, as the virus acts like no pathogen humanity has ever seen. Without larger, prospective controlled studies that are only now being launched, scientists must pull information from small studies and case reports, often published at warp speed and not yet peer reviewed. “We need to keep a very open mind as this phenomenon goes forward,” says Nancy Reau, a liver transplant physician who has been treating COVID-19 patients at Rush University Medical Center. “We are still learning.”

The infection begins

When an infected person expels virus-laden droplets and someone else inhales them, the novel coronavirus, called SARS-CoV-2, enters the nose and throat. It finds a welcome home in the lining of the nose, according to a preprint from scientists at the Wellcome Sanger Institute and elsewhere. They found that cells there are rich in a cell-surface receptor called angiotensin-converting enzyme 2 (ACE2). Throughout the body, the presence of ACE2, which normally helps regulate blood pressure, marks tissues vulnerable to infection, because the virus requires that receptor to enter a cell. Once inside, the virus hijacks the cell’s machinery, making myriad copies of itself and invading new cells.

As the virus multiplies, an infected person may shed copious amounts of it, especially during the first week or so. Symptoms may be absent at this point. Or the virus’ new victim may develop a fever, dry cough, sore throat, loss of smell and taste, or head and body aches.

If the immune system doesn’t beat back SARS-CoV-2 during this initial phase, the virus then marches down the windpipe to attack the lungs, where it can turn deadly. The thinner, distant branches of the lung’s respiratory tree end in tiny air sacs called alveoli, each lined by a single layer of cells that are also rich in ACE2 receptors.

Normally, oxygen crosses the alveoli into the capillaries, tiny blood vessels that lie beside the air sacs; the oxygen is then carried to the rest of the body. But as the immune system wars with the invader, the battle itself disrupts this healthy oxygen transfer. Front-line white blood cells release inflammatory molecules called chemokines, which in turn summon more immune cells that target and kill virus-infected cells, leaving a stew of fluid and dead cells—pus—behind. This is the underlying pathology of pneumonia, with its corresponding symptoms: coughing; fever; and rapid, shallow respiration (see graphic). Some COVID-19 patients recover, sometimes with no more support than oxygen breathed in through nasal prongs.

But others deteriorate, often quite suddenly, developing a condition called acute respiratory distress syndrome (ARDS). Oxygen levels in their blood plummet and they struggle ever harder to breathe. On x-rays and computed tomography scans, their lungs are riddled with white opacities where black space—air—should be. Commonly, these patients end up on ventilators. Many die. Autopsies show their alveoli became stuffed with fluid, white blood cells, mucus, and the detritus of destroyed lung cells.

For More Information: https://www.sciencemag.org/news/2020/04/how-does-coronavirus-kill-clinicians-trace-ferocious-rampage-through-body-brain-toes

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/

Covid-19 Vaccine Analysis: The most common adverse events reported so far

Authors: DATED: AUGUST 6, 2021 BY SHARYL ATTKISSON 

As of July 19, 2021 there were 419,513 adverse event reports associated with Covid-19 vaccination in the U.S., with a total of 1,814,326 symptoms reported. That’s according to the federal Vaccine Adverse Event Reporting System (VAERS) database.

Report an adverse event after vaccination online here.

Each symptom reported does not necessarily equal one patient. Adverse event reports often include multiple symptoms for a single patient.

Reporting of illnesses and symptoms that occur after Covid-19 vaccination does not necessarily mean they were caused by the vaccine. The system is designed to collect adverse events that occur after vaccination to uncover any patterns of illnesses that were not captured during vaccine studies.

Read CDC info on Covid-19 vaccine here.

Scientists have estimated that adverse events occur at a rate many fold higher than what is reported in VAERS, since it is assumed that most adverse events are not reported through the tracking system. Reports can be made by doctors, patients or family members and/or acquaintances, or vaccine industry representatives. 

Read: Exclusive summary: Covid-19 vaccine concerns.

Some observers claim Covid-19 vaccine adverse events are not as likely to be underreported as those associated with other medicine, due to close monitoring and widespread publicity surrounding Covid-19 vaccination.

Approximately 340 million doses of Covid-19 vaccine have been given in the U.S. Slightly less than half of the U.S. population is fully vaccinated.

According to the Centers for Disease Control (CDC) and Food and Drug Administration (FDA), the benefits of Covid-19 vaccine outweigh the risks for all groups and age categories authorized to receive it.

Watch: CDC disinformation re: studies on Covid-19 vaccine effectiveness in people who have had Covid-19.

The following is a summary of some of the most frequent adverse events reported to VAERS after Covid-19 vaccination. (It is not the entire list.)

Most common Covid-19 vaccine adverse events reported as of July 19, 2021

Yellow highlighted adverse events are subjects of investigations, warnings or stated concerns by public health officials. For details, click here.

128,370 Muscle, bone, joint pain and swelling including:

  • 39,902 Pain in extremity
  • 37,819 Myalgia, muscle pain, weakness, fatigue, spasms, disorders, related
  • 30,138 Arthralgia, joint pain or arthritis, swelling, joint disease, bone pain, spinal osteoarthritis
  • 14,682 Back pain, neck pain
  • 5,829 Muscle and skeletal pain, stiffness, weakness

119,866 Injection site pain, bleeding, hardening, bruising, etc.

105,332 Skin reddening, at injection site or elsewhere, rash, hives

100,564 Fatigue, lethargy, malaise, asthenia, abnormal weakness, loss of energy

89,302 Headache, incl. migraine, sinus

68,252 Vomiting, nausea

68,064 Fever

63,133 Chills

60,913 Pain

49,574 Dizziness

34,076 Flushing, hot flush, feeling hot, abnormally warm skin

31,785 Lung pain or abnormalities, fluid in lung, respiratory tract or lung congestion or infection, wheezing, acute respiratory failure including:

  • 23,005 Dyspnoea, difficulty breathing
  • 1,398 Pneumonia
  • 1,128 Respiratory arrest, failure, stopped or inefficient breathing, abnormal breathing
  • 563 Covid-19 pneumonia
  • 265 Mechanical ventilation
  • 217 Bronchitis

30,909 Skin swelling, pain, tightness, face swelling, swelling under skin, hives, angioedema including:

  • 7,579 Skin pain, sensitivity, burning, discoloration, tenderness

25,319 Heart failure, heart rhythm and rate abnormalities, atrial fibrillation, palpitations, flutter, murmur, pacemaker added, fluid in heart, abnormal echocardiogram including:

  • 3,105 Heart attack or cardiac arrest, sudden loss of blood flow from failure to pump to heart effectively, cardiac failure, disorder

22,085 Itchiness

29,861 Sensory disturbance including:

  • 8,236 Tinnitus, hearing noise
  • 7,951 Abnormal vision, blindness
  • 6,349 Ageusia, loss of taste, altered taste, disorders
  • 2,249 Anosmia, loss of smell, parosmia (rotten smell)
  • 2,075 Hypersensitivity
  • 1,560 Sensitivity or reaction to light 
  • 890 Hearing loss, deafness

Characteristics of SARS-CoV-2 and COVID-19

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and pathogenic coronavirus that emerged in late 2019 and has caused a pandemic of acute respiratory disease, named ‘coronavirus disease 2019’ (COVID-19), which threatens human health and public safety. In this Review, we describe the basic virology of SARS-CoV-2, including genomic characteristics and receptor use, highlighting its key difference from previously known coronaviruses. We summarize current knowledge of clinical, epidemiological and pathological features of COVID-19, as well as recent progress in animal models and antiviral treatment approaches for SARS-CoV-2 infection. We also discuss the potential wildlife hosts and zoonotic origin of this emerging virus in detail.

Introduction

Coronaviruses are a diverse group of viruses infecting many different animals, and they can cause mild to severe respiratory infections in humans. In 2002 and 2012, respectively, two highly pathogenic coronaviruses with zoonotic origin, severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), emerged in humans and caused fatal respiratory illness, making emerging coronaviruses a new public health concern in the twenty-first century1. At the end of 2019, a novel coronavirus designated as SARS-CoV-2 emerged in the city of Wuhan, China, and caused an outbreak of unusual viral pneumonia. Being highly transmissible, this novel coronavirus disease, also known as coronavirus disease 2019 (COVID-19), has spread fast all over the world2,3. It has overwhelmingly surpassed SARS and MERS in terms of both the number of infected people and the spatial range of epidemic areas. The ongoing outbreak of COVID-19 has posed an extraordinary threat to global public health4,5. In this Review, we summarize the current understanding of the nature of SARS-CoV-2 and COVID-19. On the basis of recently published findings, this comprehensive Review covers the basic biology of SARS-CoV-2, including the genetic characteristics, the potential zoonotic origin and its receptor binding. Furthermore, we will discuss the clinical and epidemiological features, diagnosis of and countermeasures against COVID-19.

Emergence and spread

In late December 2019, several health facilities in Wuhan, in Hubei province in China, reported clusters of patients with pneumonia of unknown cause6. Similarly to patients with SARS and MERS, these patients showed symptoms of viral pneumonia, including fever, cough and chest discomfort, and in severe cases dyspnea and bilateral lung infiltration6,7. Among the first 27 documented hospitalized patients, most cases were epidemiologically linked to Huanan Seafood Wholesale Market, a wet market located in downtown Wuhan, which sells not only seafood but also live animals, including poultry and wildlife4,8. According to a retrospective study, the onset of the first known case dates back to 8 December 2019 (ref.9). On 31 December, Wuhan Municipal Health Commission notified the public of a pneumonia outbreak of unidentified cause and informed the World Health Organization (WHO)9 (Fig. 1).

figure1
Fig. 1: Timeline of the key events of the COVID-19 outbreak.

By metagenomic RNA sequencing and virus isolation from bronchoalveolar lavage fluid samples from patients with severe pneumonia, independent teams of Chinese scientists identified that the causative agent of this emerging disease is a betacoronavirus that had never been seen before6,10,11. On 9 January 2020, the result of this etiological identification was publicly announced (Fig. 1). The first genome sequence of the novel coronavirus was published on the Virological website on 10 January, and more nearly complete genome sequences determined by different research institutes were then released via the GISAID database on 12 January7. Later, more patients with no history of exposure to Huanan Seafood Wholesale Market were identified. Several familial clusters of infection were reported, and nosocomial infection also occurred in health-care facilities. All these cases provided clear evidence for human-to-human transmission of the new virus4,12,13,14. As the outbreak coincided with the approach of the lunar New Year, travel between cities before the festival facilitated virus transmission in China. This novel coronavirus pneumonia soon spread to other cities in Hubei province and to other parts of China. Within 1 month, it had spread massively to all 34 provinces of China. The number of confirmed cases suddenly increased, with thousands of new cases diagnosed daily during late January15. On 30 January, the WHO declared the novel coronavirus outbreak a public health emergency of international concern16. On 11 February, the International Committee on Taxonomy of Viruses named the novel coronavirus ‘SARS-CoV-2’, and the WHO named the disease ‘COVID-19’ (ref.17).

The outbreak of COVID-19 in China reached an epidemic peak in February. According to the National Health Commission of China, the total number of cases continued to rise sharply in early February at an average rate of more than 3,000 newly confirmed cases per day. To control COVID-19, China implemented unprecedentedly strict public health measures. The city of Wuhan was shut down on 23 January, and all travel and transportation connecting the city was blocked. In the following couple of weeks, all outdoor activities and gatherings were restricted, and public facilities were closed in most cities as well as in countryside18. Owing to these measures, the daily number of new cases in China started to decrease steadily19.

However, despite the declining trend in China, the international spread of COVID-19 accelerated from late February. Large clusters of infection have been reported from an increasing number of countries18. The high transmission efficiency of SARS-CoV-2 and the abundance of international travel enabled rapid worldwide spread of COVID-19. On 11 March 2020, the WHO officially characterized the global COVID-19 outbreak as a pandemic20. Since March, while COVID-19 in China has become effectively controlled, the case numbers in Europe, the USA and other regions have jumped sharply. According to the COVID-19 dashboard of the Center for System Science and Engineering at Johns Hopkins University, as of 11 August 2020, 216 countries and regions from all six continents had reported more than 20 million cases of COVID-19, and more than 733,000 patients had died21. High mortality occurred especially when health-care resources were overwhelmed. The USA is the country with the largest number of cases so far.

Although genetic evidence suggests that SARS-CoV-2 is a natural virus that likely originated in animals, there is no conclusion yet about when and where the virus first entered humans. As some of the first reported cases in Wuhan had no epidemiological link to the seafood market22, it has been suggested that the market may not be the initial source of human infection with SARS-CoV-2. One study from France detected SARS-CoV-2 by PCR in a stored sample from a patient who had pneumonia at the end of 2019, suggesting SARS-CoV-2 might have spread there much earlier than the generally known starting time of the outbreak in France23. However, this individual early report cannot give a solid answer to the origin of SARS-CoV-2 and contamination, and thus a false positive result cannot be excluded. To address this highly controversial issue, further retrospective investigations involving a larger number of banked samples from patients, animals and environments need to be conducted worldwide with well-validated assays.

For More Information: https://www.nature.com/articles/s41579-020-00459-7

Overweight/obesity as the potentially most important lifestyle factor associated with signs of pneumonia in COVID-19

PLOS
  • Published: November 18, 2020

Abstract

Objective

The occurrence of pneumonia separates severe cases of COVID-19 from the majority of cases with mild disease. However, the factors determining whether or not pneumonia develops remain to be fully uncovered. We therefore explored the associations of several lifestyle factors with signs of pneumonia in COVID-19.

Methods

Between May and July 2020, we conducted an online survey of 201 adults in Germany who had recently gone through COVID-19, predominantly as outpatients. Of these, 165 had a PCR-based diagnosis and 36 had a retrospective diagnosis by antibody testing. The survey covered demographic information, eight lifestyle factors, comorbidities and medication use. We defined the main outcome as the presence vs. the absence of signs of pneumonia, represented by dyspnea, the requirement for oxygen therapy or intubation.

Results

Signs of pneumonia occurred in 39 of the 165 individuals with a PCR-based diagnosis of COVID-19 (23.6%). Among the lifestyle factors examined, only overweight/obesity was associated with signs of pneumonia (odds ratio 2.68 (1.29–5.59) p = 0.008). The observed association remained significant after multivariate adjustment, with BMI as a metric variable, and also after including the antibody-positive individuals into the analysis.

Conclusions

This exploratory study finds an association of overweight/obesity with signs of pneumonia in COVID-19. This finding suggests that a signal proportional to body fat mass, such as the hormone leptin, impairs the body’s ability to clear SARS-CoV-2 before pneumonia develops. This hypothesis concurs with previous work and should be investigated further to possibly reduce the proportion of severe cases of COVID-19.

For More Information: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237799

COVID-19-Associated Bronchiectasis and Its Impact on Prognosis

Authors: Aasir M. SulimanBassel W. BitarAmer A. FarooqiAnam M. ElarabiMohamed R. AboukamarAhmed S. Abdulhadi

Abstract

Coronavirus disease 2019 (COVID-19), which initially emerged in Wuhan, China, has rapidly swept around the world, causing grave morbidity and mortality. It manifests with several symptoms, on a spectrum from asymptomatic to severe illness and death. Many typical imaging features of this disease are described, such as bilateral multi-lobar ground-glass opacities (GGO) or consolidations with a predominantly peripheral distribution. COVID-19-associated bronchiectasis is an atypical finding, and it is not a commonly described sequel of the disease. Here, we present a previously healthy middle-aged man who developed progressive bronchiectasis evident on serial chest CT scans with superimposed bacterial infection following COVID-19 pneumonia. The patient’s complicated hospital course of superimposed bacterial infection in the setting of presumed bronchiectasis secondary to COVID-19 is alleged to have contributed to his prolonged hospital stay, with difficulty in weaning off mechanical ventilation. Clinicians should have high suspicion and awareness of such a debilitating complication, as further follow-up and management might be warranted.

Introduction

Beginning in December 2019, a series of pneumonia cases were reported in Wuhan City, Hubei Province, China. Further investigations revealed that it was a new type of viral pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), which was termed coronavirus disease 2019 (COVID-19). Symptoms are variable, nonspecific, and include dry cough, fever, fatigue, myalgia, dyspnea, anosmia, and ageusia [1]. The real-time reverse transcription-polymerase chain reaction (rRT-PCR) test is the current gold standard for confirming infection and is performed using nasal or pharyngeal swab specimens.

Computerized tomography of the thorax (CT thorax), as a routine imaging tool for pneumonia diagnosis, is of great importance in the early detection and treatment of patients affected by COVID-19. Chest CT may detect the early parenchymal abnormalities in the absence of positive rRT-PCR at initial presentation [2]. Since chest CT was introduced as a diagnostic tool for COVID-19 pneumonia, many typical features of this disease were described such as bilateral multi-lobar ground-glass opacification (GGO) with a prevalent peripheral or posterior distribution, mainly in the lower lobes; sometimes, consolidative opacities superimposed on GGOs could be found [3]. To our knowledge, bronchiectasis is not a classical finding in COVID-19 pneumonia, with a paucity of reporting on its development and progression during the disease course.

For More Information: https://www.cureus.com/articles/59350-covid-19-associated-bronchiectasis-and-its-impact-on-prognosis

Comorbidity and its Impact on Patients with COVID-19

Authors: Adekunle Sanyaolu 1Chuku Okorie 2Aleksandra Marinkovic 3Risha Patidar 3Kokab Younis 4Priyank Desai 5Zaheeda Hosein 6Inderbir Padda 7Jasmine Mangat 6Mohsin Altaf 8

Abstract

A novel human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified in Wuhan, China, in December 2019. Since then, the virus has made its way across the globe to affect over 180 countries. SARS-CoV-2 has infected humans in all age groups, of all ethnicities, both males and females while spreading through communities at an alarming rate. Given the nature of this virus, there is much still to be learned; however, we know that the clinical manifestations range from a common cold to more severe diseases such as bronchitis, pneumonia, severe acute respiratory distress syndrome (ARDS), multi-organ failure, and even death. It is believed that COVID-19, in those with underlying health conditions or comorbidities, has an increasingly rapid and severe progression, often leading to death. This paper examined the comorbid conditions, the progression of the disease, and mortality rates in patients of all ages, infected with the ongoing COVID-19 disease. An electronic literature review search was performed, and applicable data was then collected from peer-reviewed articles published from January to April 20, 2020. From what is known at the moment, patients with COVID-19 disease who have comorbidities, such as hypertension or diabetes mellitus, are more likely to develop a more severe course and progression of the disease. Furthermore, older patients, especially those 65 years old and above who have comorbidities and are infected, have an increased admission rate into the intensive care unit (ICU) and mortality from the COVID-19 disease. Patients with comorbidities should take all necessary precautions to avoid getting infected with SARS CoV-2, as they usually have the worst prognosis.

For More Information: https://pubmed.ncbi.nlm.nih.gov/32838147/

Virology, transmission, and pathogenesis of SARS-CoV-2

Authors: Muge Cevik, clinical lecturer2,  Krutika Kuppalli, assistant professor3,  Jason Kindrachuk, assistant professor of virology4,  Malik Peiris, professor of virology5

What you need to know

  • SARS-CoV-2 is genetically similar to SARS-CoV-1, but characteristics of SARS-CoV-2—eg, structural differences in its surface proteins and viral load kinetics—may help explain its enhanced rate of transmission
  • In the respiratory tract, peak SARS-CoV-2 load is observed at the time of symptom onset or in the first week of illness, with subsequent decline thereafter, indicating the highest infectiousness potential just before or within the first five days of symptom onset
  • Reverse transcription polymerase chain reaction (RT-PCR) tests can detect viral SARS-CoV-2 RNA in the upper respiratory tract for a mean of 17 days; however, detection of viral RNA does not necessarily equate to infectiousness, and viral culture from PCR positive upper respiratory tract samples has been rarely positive beyond nine days of illness
  • Symptomatic and pre-symptomatic transmission (1-2 days before symptom onset), is likely to play a greater role in the spread of SARS-CoV-2 than asymptomatic transmission
  • A wide range of virus-neutralizing antibodies have been reported, and emerging evidence suggests that these may correlate with severity of illness but wane over time.

Since the emergence of SARS-CoV-2 in December 2019, there has been an unparalleled global effort to characterize the virus and the clinical course of disease. Coronavirus disease 2019 (covid-19), caused by SARS-CoV-2, follows a biphasic pattern of illness that likely results from the combination of an early viral response phase and an inflammatory second phase. Most clinical presentations are mild, and the typical pattern of covid-19 more resembles an influenza-like illness—which includes fever, cough, malaise, myalgia, headache, and taste and smell disturbance—rather than severe pneumonia (although emerging evidence about long term consequences is yet to be understood in detail).1 In this review, we provide a broad update on the emerging understanding of SARS-CoV-2 pathophysiology, including virology, transmission dynamics, and the immune response to the virus. Any of the mechanisms and assumptions discussed in the article and in our understanding of covid-19 may be revised as further evidence emerges.

For More Information: https://www.bmj.com/content/371/bmj.m3862

Severe covid-19 pneumonia: pathogenesis and clinical management

Authors: Amy H Attaway, assistant professor of medicine, associate director, COPD center1,  Rachel G Scheraga, assistant professor of medicine2,  Adarsh Bhimraj, head, section of neurological infections; staff, infectious diseases1,  Michelle Biehl, associate staff, pulmonary and critical care medicine; director, post ICU recovery clinic1,  Umur Hatipoğlu, associate professor of medicine; director, respiratory therapy; director, COPD center1

Abstract

Severe covid-19 pneumonia has posed critical challenges for the research and medical communities. Older age, male sex, and comorbidities increase the risk for severe disease. For people hospitalized with covid-19, 15-30% will go on to develop covid-19 associated acute respiratory distress syndrome (CARDS). Autopsy studies of patients who died of severe SARS CoV-2 infection reveal presence of diffuse alveolar damage consistent with ARDS but with a higher thrombus burden in pulmonary capillaries. When used appropriately, high flow nasal cannula (HFNC) may allow CARDS patients to avoid intubation, and does not increase risk for disease transmission. During invasive mechanical ventilation, low tidal volume ventilation and positive end expiratory pressure (PEEP) titration to optimize oxygenation are recommended. Dexamethasone treatment improves mortality for the treatment of severe and critical covid-19, while remdesivir may have modest benefit in time to recovery in patients with severe disease but shows no statistically significant benefit in mortality or other clinical outcomes. Covid-19 survivors, especially patients with ARDS, are at high risk for long term physical and mental impairments, and an interdisciplinary approach is essential for critical illness recovery.

Introduction

The ongoing outbreak of the coronavirus disease 2019 (covid-19) has posed immense challenges for the research and medical communities. This review focuses on the epidemiologic and clinical features of covid-19, the pathophysiologic mechanisms, inpatient respiratory support, and the evidence to date on drug treatments. It also covers the recovery and long term management of patients with covid-19 pneumonia. The review is aimed at clinicians and intensivists caring for patients with severe covid-19 pneumonia as defined by the National Institutes of Health,1 referring to individuals with SARS-CoV-2 infection confirmed by polymerase chain reaction (PCR) testing who have SpO2 <94% on room air at sea level, a ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO2/FiO2) <300 mm Hg, respiratory frequency >30 breaths/min, or lung infiltrates >50%.

For More Information: https://www.bmj.com/content/372/bmj.n436

Platelets Promote Thromboinflammation in SARS-CoV-2 Pneumonia

Authors: Francesco TausGianluca SalvagnoStefania CanèCristiano FavaFulvia MazzaferriElena CarraraVarvara PetrovaRoza Maria BarouniFrancesco DimaAndrea DalbeniSimone Romano,

Abstract

Objective:

Pulmonary thrombosis is observed in severe acute respiratory syndrome coronavirus 2 pneumonia. Aim was to investigate whether subpopulations of platelets were programmed to procoagulant and inflammatory activities in coronavirus disease 2019 (COVID-19) patients with pneumonia, without comorbidities predisposing to thromboembolism.

For More Information: https://www.ahajournals.org/doi/10.1161/ATVBAHA.120.315175