Tag: covid

Categories : COVID Immune SystemTags :

Almost ‘Superhuman’ Immune Response Found in Certain People

On By ModernMedia
Photo by Klaus Nielsen from Pexels

A series of studies in recent months has found that, thanks to the mRNA vaccine and previous infection, some people mount an extraordinarily powerful immune response against SARS-CoV-2 which some scientists have referred to as ‘superhuman’.

Called ‘hybrid immunity’, their bodies produce very high levels of antibodies, with great flexibility: likely capable of fighting off the SARS-CoV-2 variants currently circulating but also likely effective against future variants.

“Overall, hybrid immunity to SARS-CoV-2 appears to be impressively potent,” Crotty wrote in commentary in Science published in June.

“One could reasonably predict that these people will be quite well protected against most  and perhaps all of — the SARS-CoV-2 variants that we are likely to see in the foreseeable future,” says Paul Bieniasz, a virologist at Rockefeller University who helped lead several of the studies.

Bieniasz and his colleagues found antibodies in these individuals capable of strongly neutralising the six variants of concern tested, including Delta and Beta, as well as several other viruses related to SARS-CoV-2, including SARS-CoV-1.

“This is being a bit more speculative, but I would also suspect that they would have some degree of protection against the SARS-like viruses that have yet to infect humans,” Bieniasz said.

People who have had a ‘hybrid’ exposure to the virus, were infected with it in 2020 and then immunised with mRNA vaccines this year. “Those people have amazing responses to the vaccine,” said virologist Theodora Hatziioannou at Rockefeller University, who also helped lead several of the studies. “I think they are in the best position to fight the virus. The antibodies in these people’s blood can even neutralize SARS-CoV-1, the first coronavirus, which emerged 20 years ago. That virus is very, very different from SARS-CoV-2.”

These antibodies were so effective they were even able to deactivate a virus purposefully engineered to be highly resistant to neutralisation, containing 20 mutations that are known to prevent SARS-CoV-2 antibodies from binding to it. Antibodies from those who were only vaccinated or who only had prior coronavirus infections were ineffecgtive against this engineered virus..

This shows how powerful the mRNA vaccine can be in those infected with SARS-CoV-2, she said. “There’s a lot of research now focused on finding a pan-coronavirus vaccine that would protect against all future variants. Our findings tell you that we already have it.

The catch is getting COVID. “After natural infections, the antibodies seem to evolve and become not only more potent but also broader. They become more resistant to mutations within the [virus].”

Hatziioannou and colleagues don’t know if this applies to all those mRNA-vaccinated and previously COVID-infected. “We’ve only studied the phenomena with a few patients because it’s extremely laborious and difficult research to do,” she said.
“With every single one of the patients we studied, we saw the same thing.” The study reports data on 14 patients.

Several other studies lend credence to her hypothesis and reinforce the idea that exposure to both a coronavirus and an mRNA vaccine triggers an exceptionally powerful immune response. In one study in NEJM, scientists analysed antibodies generated by people who had been infected with SARS-CoV-1 back in 2002 or 2003 and who then received an mRNA vaccine this year.

Remarkably, these people also produced high levels of antibodies that could neutralise a whole range of variants and SARS-like viruses. Many questions remain, such as the effect of a third booster shot, or being infected again.

“I’m pretty certain that a third shot will help a person’s antibodies evolve even further, and perhaps they will acquire some breadth [or flexibility], but whether they will ever manage to get the breadth that you see following natural infection, that’s unclear.”

Immunologist John Wherry, at the University of Pennsylvania, is a bit more hopeful. “In our research, we already see some of this antibody evolution happening in people who are just vaccinated,” he said, “although it probably happens faster in people who have been infected.”

In a recent study, Wherry and colleagues showed that, over time, uninfected people with only two doses of the vaccine begin to produce more flexible antibodies, so a third dose would give even more of an evolutionary boost to the antibodies, Wherry said. So a person will be better equipped to fight off whatever variant the virus puts out there next.

“Based on all these findings, it looks like the immune system is eventually going to have the edge over this virus,” said Bieniasz, of Rockefeller University. “And if we’re lucky, SARS-CoV-2 will eventually fall into that category of viruses that gives us only a mild cold.”

Source: NPR

Categories : COVIDTags :

C.1.2 Variant Slows in SA; Colombian Variant Named Mu

On By ModernMedia
Computer image of SARS-CoV-2. From CDC at Pexels
Source: CDC on Pexels

The Network for Genomic Surveillance in South Africa (NGS-SA) has reported that the C.1.2 variant is spreading less slowly than in July, from 2.2% of all sequenced COVID cases to 1.5% in August, and is therefore unlikely to become a dominant variant.

Meanwhile, B.1.621,  another variant that first emerged in Colombia in January has been recently classified by the World Health Organization (WHO) as a variant of interest (VOI), receiving the Greek letter “Mu”. Since its first detection, it has spread across North America, South America and Europe, and has also been detected in Asia. The majority of the Mu sequences (5123) have been detected in North America (55%, n=2841) followed by South America (23%, n=1328), Europe (18%, n=948) and Asia (0.1%, n=6). As of 3 September 2021, Mu has not been detected in Africa. Thus far, it makes up less than 1% of the globally circulating viruses with Delta accounting for 88%.

NGS-SA, which includes the National Institute for Communicable Diseases (NICD), continuously and rigorously monitors SARS-CoV-2 sequences circulating in South Africa. This work is crucial in the early detection of SARS-CoV-2 variants, including Mu.

Many of the mutations within the spike protein which define the Mu variant (T95I, E484K, N501Y, D614G, P681H and D950) have been seen before in other VOIs or variants of concern (VOCs) including Beta and Delta. Some of these mutations have previously been associated with decreased antibody responses and increased transmissibility. Therefore it is likely that Mu will have similar properties to other variants with increased transmissibility and reduced sensitivity to antibodies in vaccines and those who have recovered from COVID.

The NICD advises that both COVID vaccines being used in South Africa have high levels of protection against severe disease requiring hospitalisation and death even against VOI/VOCs such as Beta and Delta and therefore will likely also protect against Mu. 

Source: NICD

Categories : COVID Immune SystemTags :

Metabolic Changes in Plasma, Immune Cells Linked to COVID Severity

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Analysing plasma from patients infected with SARS-CoV-2, researchers have uncovered underlying metabolic changes that regulate how immune cells react to COVID, these are associated with disease severity and could be used to predict patient survival. The findings were published in the journal Nature Biotechnology.

“We know that there are a range of immune responses to COVID, and the biological processes underlying those responses are not well understood,” said co-first author Jihoon Lee, a graduate student at Fred Hutchinson Cancer Research Center. “We analyzed thousands of biological markers linked to metabolic pathways that underlie the immune system and found some clues as to what immune-metabolic changes may be pivotal in severe disease. Our hope is that these observations of immune function will help others piece together the body’s response to COVID. The deeper understanding gained here may eventually lead to better therapies that can more precisely target the most problematic immune or metabolic changes.”

The researchers performed two draws on each of nearly 200 patients during the first week after being diagnosed with SARS-CoV-2 infection, and analysed their plasma and single immune cells. The analysis included 1387 genes involved in metabolic pathways and 1050 plasma metabolites.

Increased COVID severity was found to be associated with metabolite alterations, which suggests increased immune-related activity. In addition, each major immune cell type was found to have a distinct metabolic signature.

“We have found metabolic reprogramming that is highly specific to individual immune cell classes (eg “killer” CD8+ T cells, “helper” CD4+ T cells, antibody-secreting B cells, etc.) and even cell subtypes, and the complex metabolic reprogramming of the immune system is associated with the plasma global metabolome and are predictive of disease severity and even patient death,” said co-first and co-corresponding author Dr. Yapeng Su, a research scientist at Institute for Systems Biology. “Such deep and clinically relevant insights on sophisticated metabolic reprogramming within our heterogeneous immune systems are otherwise impossible to gain without advanced single-cell multi-omic analysis.”

“This work provides significant insights for developing more effective treatments against COVID. It also represents a major technological hurdle,” said Dr. Jim Heath, president and professor of ISB and co-corresponding author on the paper. “Many of the data sets that are collected from these patients tend to measure very different aspects of the disease, and are analysed in isolation. Of course, one would like these different views to contribute to an overall picture of the patient. The approach described here allows for the sum of the different data sets to be much greater than the parts, and provides for a much richer interpretation of the disease.”

Source: Max Planck Institute

Categories : COVID VaccinesTags :

MMR and Tdap Vaccines May Confer Some COVID Protection

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Source: Pixabay CC0

Mounting evidence shows that the Measles-Mumps-Rubella (MMR) and Tetanus-Diphtheria-Pertussis (Tdap) vaccines confer limited protection against COVID.

The MMR vaccine, given during early childhood, and Tdap vaccine, given every 10 years, elicit protective responses against the diseases they are designed for. It’s possible that they also elicit cross-reactive memory T cells that can respond to antigens that are present in other pathogens — including the viral antigens in SARS-CoV-2. The idea is that pre-existing memory T cells generated by prior MMR or Tdap vaccination and activated by SARS-CoV-2 infection give the immune system a head start in responding to SARS-CoV-2, lowering the risk of severe COVID.

To find out if the MMR and Tdap vaccines provide additional protection against COVID, researchers at Brigham and Women’s Hospital performed laboratory-based analyses with new techniques to detect and characterise T cell responses to antigens. They applied these techniques to measure T cell responses isolated from the blood of COVID convalescent patients and patients vaccinated against COVID to antigens from SARS-CoV-2 and the MMR and Tdap vaccines. They also leveraged a large, well-annotated cohort of COVID patients and found that prior MMR or Tdap vaccination was associated with decreased disease severity. Their results are published in Med.

“Our Cleveland Clinic colleagues observed an association where individuals with COVID who had either MMR or Tdap vaccines had a much lower frequency of going to the intensive care unit or dying,” said co-author Andrew Lichtman, MD, PhD, an immunologist and senior investigator in the Brigham’s Department of Pathology and professor of Pathology at Harvard Medical School. “Although previous smaller studies suggested a similar link, our in-depth epidemiological analyses, together with our basic research results, suggest that these commonly given vaccines may protect against severe disease.”

“During the COVID pandemic, we know that there was a marked decline in routine vaccinations for children and adolescents,” said corresponding author Tanya Mayadas, PhD, a senior scientist in the Brigham’s Department of Pathology and professor of Pathology at Harvard Medical School. “Our findings emphasise the importance of routine vaccination for children and adults. We know vaccines protect against devastating diseases, and we’re now seeing growing evidence that some of them provide a degree of protection against severe COVID disease.”

An unexpected observation jumpstarted the investigation. Prof Mayadas, her postdoctoral fellow Vijaya Mysore, PhD, and colleagues noted in lab experiments with COVID convalescent blood that whenever they observed a heightened T cell response to SARS-CoV-2 proteins, they also saw a heightened response to proteins from MMR and Tdap, which were controls. This was seen in both COVID convalescent and uninfected individuals vaccinated against SARS-CoV-2.

In a subsequent analysis, Prof Mayadas and colleagues teamed up with researchers at Cleveland Clinic to examine the epidemiological evidence. The Cleveland Clinic team performed a retrospective cohort study using data from more than 75 000 patients seen at the Cleveland Clinic Health System in Ohio or Florida who had tested positive for COVID between March 8, 2020, and March 31, 2021. A statistical analysis found that patients who had previously been vaccinated for MMR had a 38 percent decrease in hospitalisation and a 32 percent decrease in ICU admission/death. Patients previously vaccinated for Tdap had 23 percent and 20 percent decreased rates, for these outcomes, respectively.

“Beyond learning about the potential benefits of the MMR and Tdap vaccines in the context of COVID, this study provides a blueprint for accelerating research,” said co-author Lara Jehi, MD, MHCDS, Chief Research Information Officer of the Cleveland Clinic Health System. “Biomedical hypotheses generated in the laboratory can be explored through robust clinical and epidemiological research in well-curated, real-world data such as the Cleveland Clinic COVID Registry. Knowledge learned through this collaboration is much more than the sum of our individual parts.”

The authors note that epidemiological observations strengthen their lab findings, more work is needed to find a causal association between the MMR and Tdap vaccinations and severity of COVID disease.

“With regards to COVID vaccines, our findings predict that although MMR and Tdap are not a substitute for COVID vaccines they may afford greater and more durable protection, possibly against emerging spike variants than the COVID vaccine alone,” said Prof Mayadas. “And in areas where the COVID vaccines are not available, they could protect infected individuals from developing severe disease.”

Source: Brigham and Women’s Hospital

Categories : COVIDTags :

Small Trial Sees ‘Astounding’ Effect of Fenofibrate in Severe COVID

On By ModernMedia
Source: Fusion Medical Animation on Unsplash

A small interventional trial with 15 severely ill COVID patients showed an ‘astounding’ effect of fenofibrate as a treatment.

Recently, Professor Yaakov Nahmias’ team at the Hebrew University of Jerusalem (HU) reported that COVID causes abnormal accumulation of lipids, known to initiate severe inflammation through a process called lipotoxicity. In 2020, the researchers conducted lab testing of fenofibrate, a lipid-lowering drug, showing it both reduced lung cell damage while blocked virus replication. These results have since been confirmed by other studies, and in October 2020 an observational study was reported to support the original findings. This led to an interventional, single-arm open-label study to validate the findings.

The study recruited 15 severe-hospitalised COVID patients with pneumonia requiring oxygen support, who were given 145 mg/day of fenofibrate for 10 days in addition to standard care and continuously monitored for disease progression and outcomes. 

‘Astounding’ results
“The results were astounding,” Prof Nahmias declared. “Progressive inflammation markers, that are the hallmark of deteriorative COVID, dropped within 48 hours of treatment. Moreover, 14 of the 15 severe patients didn’t require oxygen support within a week of treatment, while historical records show that the vast majority severe patients treated with the standard of care require lengthy respiratory support,” he added. 

No ‘silver bullet’
Fenofibrate is a well-known, FDA-approved drug for the treatment of hypertriglyceridemia, primary hypercholesterolemia, or mixed dyslipidemia and has a good safety profile. “There are no silver bullets,” cautioned Nahmias, “but fenofibrate is far safer than other drugs proposed to date, and its mechanism of action makes is less likely to be variant-specific.”

“All patients were discharged within less than a week after the treatment began and were discharged to complete the 10-day treatment at home, with no drug-related adverse events reported,” noted Professor Shlomo Maayan, head of Infectious Disease Unit at Barzilai, where the study was conducted. “Further, fewer patients reported COVID side effects during their 4-week follow-up appointment,” he added. These preliminary findings are promising for patients who severe the acute phase of severe COVID.

However, the researchers stressed that while the results were extremely promising, only randomised placebo-controlled studies can serve as basis for clinical decisions. “We entered the second phase of the study and are actively recruiting patients,” explained Prof Nahmias, noting that two Phase 3 studies are already being conducted.

The findings, which are currently under peer review, were released on Research Square.

Source: Medical Xpress

Categories : COVID HospitalsTags :

Prone Positioning Reduces Need for Mechanical Ventilation

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Source: Martha Dominguez de Gouveia on Unsplash

A ‘meta-trial’ of 1100 hospitalised COVID patients requiring high-flow nasal cannula oxygen therapy suggests that prone positioning soon after admission can significantly reduce the need for mechanical ventilation.

While acute respiratory distress syndrome patients have been placed prone for years by critical care specialists, this study provides clinical evidence needed to support the use of prone positioning for patients with COVID requiring high-flow nasal cannula oxygen therapy.

The findings, published today in the Lancet Respiratory Medicine, were conducted on severely ill COVID patients between April 2020 and January 2021.

“Breathing in the prone position helps the lungs work more efficiently,” explained the study’s lead author Dr. Jie Li, associate professor and respiratory therapist at Rush University Medical Center. “When people with severe oxygenation issues are laying on their stomachs, it results in better matching of the blood flow and ventilation in the lungs which improves blood oxygen levels.”

Prof Li noted that several interventions are available to improve oxygenation in critically ill patients, but that there was little outcomes-focused clinical evidence to show that prone positioning prior to mechanical ventilation is beneficial.

Adult patients with COVID needing respiratory support from a high-flow nasal cannula agreed to participate in this clinical trial, and were randomly assigned to the supine or prone positioning groups. They were asked to stay in that position for as long as they could tolerate. Both positioning groups received high-flow oxygen therapy and standard medical management.

Patients were continually monitored to determine if mechanical ventilation was needed. This study’s data showed that patients in the prone positioning group were significantly less likely to require mechanical ventilation (33% in the awake prone positioning group vs 40% in the supine group).

Another study lead author, Stephan Ehrmann, MD, PhD, said that “for the clinical implications of our study, awake prone positioning is a safe intervention that reduces the risk of treatment failure in acute severe hypoxemic respiratory failure due to COVID-19. Our findings support the routine implementation of awake prone positioning in critically ill patients with COVID19 requiring high flow nasal cannula oxygen therapy. It appears important that clinicians improve patient comfort during prone positioning, so the patient can stay in the position for at least 8 hours a day.”

Reducing the need for mechanical ventilation cuts down on resources needed. “Ventilators can indeed save the lives of people who are no longer able to breathe on their own. That said, we now have strategies to keep patients off the ventilator, saving those devices for the sickest patients who truly need them.” Prof Li added.

Source: Medical Xpress

Categories : Diseases, Syndromes and ConditionsTags :

Another COVID-scale Pandemic in 59 Years ‘Statistically Likely’

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A new study based on 400 years of historical records asserts that extreme pandemic events such as COVID are more common than believed.

The Duke University study, published in Proceedings of the National Academy of Sciences, used records of past outbreaks to estimate the intensity of those events and the yearly probability of them recurring.

It found the probability of a pandemic with similar impact to COVID is about 2% in any year, meaning that someone born in the year 2000 by now would have about a 38% chance of experiencing one. That probability is only increasing, highlighting the need to adjust perceptions of pandemic risks and expectations for preparedness, the researchers said.

“The most important takeaway is that large pandemics like COVID and the Spanish flu are relatively likely,” said study co-author William Pan, PhD, associate professor of global environmental health at Duke. The understanding that pandemics are not so rare should raise the priority of future prevention and control efforts, he said.

The study employed new statistical methods to measure the scale and frequency of disease outbreaks for which there was no immediate medical intervention over the past four centuries. Their analysis, including deadly pathogens including plague, smallpox, cholera, typhus and novel influenza viruses, found pandemics occurred with great variability in the past. But they also identified patterns that allowed them to describe the probabilities of similar-scale events happening again.

In the case of a pandemic like the Spanish flu, which killed more than 30 million people between 1918 and 1920, the probability of a pandemic of similar magnitude occurring ranged from 0.3% to 1.9% per year over the time period studied. Taken together, it is statistically likely that such a massive pandemic would occur within the next 400 years.

However, the data also show that the risk of intense outbreaks is increasing rapidly. Based on the increasing rate at which novel pathogens such as SARS-CoV-2 have broken loose in human populations in the past 50 years, the study estimates that the probability of novel disease outbreaks will likely triple in the next few decades.

With this increased risk factor, the researchers estimate that a COVID-scale pandemic is likely within a span of 59 years (by the year 2090), a result they write is “much lower than intuitively expected.” Although not included in the paper, they also calculated the probability of a pandemic capable of eliminating all human life, finding it statistically likely within the next 12 000 years. 

That does not mean it will be 59 years before the next COVID-like pandemic, nor that the Spanish flu for another 300 years. Such events are equally probable in any year during the span, said Duke University Professor Gabriel Katul, another of the paper’s authors.

“When a 100-year flood occurs today, one may erroneously presume that one can afford to wait another 100 years before experiencing another such event. This impression is false. One can get another 100-year flood the next year,” explained Prof Katul.

Dr Pan noted that population growth, changes in food systems, environmental degradation and more frequent contact between humans and disease-harboring animals all may be significant factors for increasing frequency of pandemics. However, he stresses that the statistical techniques are not to explain the pandemics.

However, he hopes the study will spark deeper exploration of the factors that may be making devastating pandemics more likely – and how to counteract them.

“This points to the importance of early response to disease outbreaks and building capacity for pandemic surveillance at the local and global scales, as well as for setting a research agenda for understanding why large outbreaks are becoming more common,” Dr Pan said.

Source: Duke University

Categories : COVIDTags :

Anticoagulation Improves Survival Odds of Moderately Ill COVID Patients

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If treated with therapeutic-dose anticoagulation, moderately ill patients hospitalised with COVID have better odds of survival, according to an international study published in The New England Journal of Medicine.

COVID patients frequently develop a pro-coagulative state caused by virus-induced endothelial dysfunction, cytokine storm and complement cascade hyperactivation. Thrombotic risk appears directly related to disease severity and worsens patients’ prognosis.

Moderately ill COVID patients treated with therapeutic-dose anticoagulation with unfractionated or low molecular-weight heparin were 27% less likely to need cardiovascular respiratory organ support such as intubation, said Ambarish Pandey, MD, Assistant Professor of Internal Medicine at UT Southwestern, who served as site investigator and . Moderately ill patients had a 4% increased chance of survival until discharge without requiring organ support with anticoagulants, according to the study involving 2200 patients.

“The 4% increase in survival to discharge without needing organ support represents a very meaningful clinical improvement in these patients,” said Dr Pandey, a Texas Health Resources Clinical Scholar specialising in preventive cardiology and heart failure with preserved ejection fraction. “If we treat 1,000 patients who are hospitalized with COVID with moderate illness, an additional 40 patients would have meaningful improvement in clinical status.”

Moderately ill patients were defined as those who did not need intensive care unit-level support. The participating platforms for the study, included Antithrombotic Therapy to Ameliorate Complications of COVID-19 (ATTACC); A Multicenter, Adaptive, Randomized Controlled Platform Trial of the Safety and Efficacy of Antithrombotic Strategies in Hospitalized Adults with COVID-19 (ACTIV-4a); and Randomized, Embedded, Multifactorial Adaptive Platform Trial for Community-Acquired Pneumonia (REMAP-CAP). 

A parallel study reported in The New England Journal of Medicine found however that therapeutic-dose anticoagulation did not help severely ill patients.

Source: UT Southwestern Medical Center

Categories : COVID General InterestTags :

After Anti-vaxx Protest, Western Cape Government Speaks Out

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After a group of anti-vaxxer demonstrators gathered outside Groote Schuur Hospital (GSH), Western Cape Health authorities have slammed anti-vaxxers for inflaming vaccine hesitancy. Even so, there was a record vaccination turnout on Friday when inoculations were offered to over 18s.

“I just don’t understand why people don’t believe us when we say that the vaccines are safe,” Western Cape Health Department’s Dr Saadiq Kariem said, warning of the damage that misinformation can do.

“There’s no 3G in the vaccine. There’s certainly no conspiracy theory. All we’re trying to do is help by making sure that the population is as protected as possible against coronavirus,” Dr Kariem said, adding that it was even more dangerous when medical professionals were against the shots.

“It just baffles my mind how other medical professionals can, in fact, be anti-vaccination because people will believe professionals, you know, and take their word as they’ve studied this field,” he added. Some of the protesters were carrying signs in support of controversial anti-vaxxer doctors.

IOL reports that one man who was employed by the hospital and chose not to be named, stood alone in the street and faced down the protesters with a sign saying “Covidiots”. He said the pandemic had been happening for 18 months, and that the ignorance of the crowd was disgraceful.

Just before the protests got underway, the University of Cape Town had released a statement in support of GSH. “The Faculty stands in solidarity with the staff (including cleaners, security, admin staff, drivers etc) of GSH. We stand in support of their work and the herculean efforts they have taken across the era of this pandemic under extremely challenging circumstances and often at personal risk. We salute the work of our partners in delivering the best possible care in responding to the world’s greatest human tragedy.”

Source: Eyewitness News

Categories : Antibiotics COVIDTags :

Bacterial Superinfections in COVID Rarer Than Expected

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Only 21 percent of patients with severe pneumonia caused by SARS-CoV-2 have a documented bacterial superinfection at the time of intubation, resulting in potential overuse of antibiotics, according to new research.

Superinfection occurs when another, usually different, infection is superimposed on the initial infection. In this case, it is bacterial pneumonia during severe viral pneumonia.

Dr Wunderink and co-authors reported their findings in a study published online in the Journal of Respiratory and Critical Care Medicine, which shows that the usual clinical criteria used to diagnose bacterial pneumonia could not distinguish between those with bacterial superinfection and those with severe SARS-CoV-2 infection only.

According to the authors, there is weak evidence behind current guidelines recommending that patients with SARS-CoV-2 pneumonia receive empirical antibiotics on hospital admission for suspected bacterial superinfection. In other published clinical trials of patients with SARS-CoV-2 pneumonia, rates of superinfection pneumonia are unexpectedly low.
“More accurate assessment other than just reviewing clinical parameters is needed to enable clinicians to avoid using antibiotics in the majority of these patients, but appropriately use antibiotics in the 20-25 percent who have a bacterial infection as well,” said Dr Wunderink.

The team conducted an observational study to determine the prevalence and cause of bacterial superinfection at the time of initial intubation and the incidence and cause of subsequent bacterial ventilator-associated pneumonia (VAP) in 179 patients with severe SARS-CoV-2 pneumonia which required mechanical ventilation.

The researchers analysed 386 bronchoscopic bronchoalveolar lavage fluid samples from patients, and actual antibiotic use was compared with guideline-recommended therapy. Bacterial superinfection within 48 hours of intubation was detected in 21 percent of patients; 72 patients (44.4 percent) developed at least one VAP episode; and 15 (20.8 percent) of initial VAPs were caused by difficult-to-treat bacteria.

The authors found that in patients with severe SARS-CoV-2 pneumonia, bacterial superinfection at the time of intubation occurred in less than 25 percent of patients. Guideline-based empirical antibiotic management at the time of intubation would have resulted in antibiotic overuse.

The researchers believe that their findings have multiple implications for antibiotic guidelines: “Rapid diagnostic tests are important for helping identify suspected pneumonia in intubated patients. This can have major clinical implications because the current approach of using clinically defined risk factors for suspected methicillin-resistant staphylococcus aureus (MRSA) or pseudomonas bacteria as the cause of pneumonia still grossly overestimate the true incidence of these pathogens. In addition, the recommendation for empirical antibiotic treatment of worsening viral community-acquired pneumonia (now requiring intubation) may need to be revisited. This is not only true for SARS-CoV-2 but potentially for severe influenza as well.”

“An accurate diagnosis of suspected pneumonia allows clinicians to safely avoid or use narrow spectrum antibiotics for many patients,” Dr Wunderink added.  “While multiple interventions impact mortality in these critically ill patients, the low mortality in our study with more limited antibiotic treatment suggests that our approach was safe.”

Source: American Thoracic Society