Month: July 2021

Categories : COVIDTags :

Asymptomatic and Presymptomatic COVID Transmission is Significant

On By ModernMedia

A study of COVID transmission in a US university indicates that at least a fifth of asymptomatic COVID cases passed the infection on, suggesting that containing the SARS-CoV-2 virus is more difficult than previously thought. 

Even as multiple resurgences of the COVID pandemic occur in many countries, the risk posed by various degrees of infection, from asymptomatic through presymptomatic to symptomatic SARS-CoV-2 infection is still undefined.

Researchers in a new study found that at least a third of infected individuals were asymptomatic, and a fifth of them successfully passed on the virus to others. In comparison, about a quarter of symptomatic cases did so, especially when the symptoms included fever, cough and shortness of breath. In these instances, up to 30% of them transmitted the virus. The findings of the study are available on the medRxiv preprint server, and are not yet peer reviewed.

Asymptomatic carriage has been suspected and reported since the pandemic’s outset, though the exact proportion has been described to be anywhere between 40% and 77%. Such differences in ascertainment could be from varying demographic, testing, and interaction patterns.

Most systematic reviews have quoted figures of 30-45% as asymptomatic, which are considered to be much less transmissible. Secondary attack rates (SAR) of as low as 0.7% are reported in these cases, compared to 21% for symptomatic cases. Most of these studies had a lack of follow-up, meaningthat asymptomatic and presymptomatic cases could have been combined or misclassified.

The study was based on a campus population at a Midwestern university in the USA, during the northern hemisphere autumn of 2020. The study included about 13 000 students and 1600 confirmed cases.

The researchers found not only that SAR differed when patients were classified by symptom presence or absence, but the nature of the symptoms also determined the SAR. This could hamper containment efforts, especially as economic activity is burgeoning after a long hiatus.

Moreover, daily checks on individuals such as employees and students which are meant to help define transmission risk, may not yield the desired results when the wide difference in symptom types and timing in relation to infection, as well as the SAR, are taken into account.

The college campus in this study had a set of measures in place to reduce the risk of viral spread. In particular, this included a daily requirement to assess one’s own health and report on any issues; testing for the virus; contact tracing; case isolation and contact quarantine; and surveillance testing to monitor the spread of the virus.

In August, students began to come back to campus, and this was associated with 151 positive tests for the virus by reverse transcriptase polymerase chain reaction (RT PCR). This led to the suspension of in-person classes, with all teaching being online until August 24.

At this point, graduate and professional students again had in-person classes, while the others continued with online classes until September 2. The number of cases detected by a positive PCR test went down, from just over 600 in August to approximately 150 by September.

A second rise was seen in the middle of October, and by the end of the semester, on November 20, over 1500 students were positive. Of these, daily health data was present for at least half the days for about 1200 students.

Testing was administered by a rapid antigen test if a student had symptoms suggestive of SARS-CoV-2 infection or had a history of exposure to someone with COVID. Negative results were validated by a PCR, with the result coming within 1-2 days during which time they were quarantined.

Positive rapid antigen tests led to 14 days isolation, along with contact tracing and quarantine. The quarantined students were also advised to do an antigen test, which, if positive, necessitated a PCR test. They were also expected to quarantine until tests on days four and seven were also negative, at which point they were released. The university also conducted surveillance monitoring to hopefully catch asymptomatic or presymptomatic cases.

The scientists found that nasal congestion, headache and dry cough was higher among those who tested positive within five days, with fever and sensory disturbances (anosmia/dysgeusia/ageusia) were higher among positives only three and two days previous to testing positive. Loss of taste and smell occurred in the greatest proportion of cases by day four after testing positive.

The SAR was 19% vs 25% for asymptomatic vs symptomatic index cases on day 14 after virus exposure. In the four days immediately following exposure, symptomatic cases showed a higher SAR, with presymptomatic cases showing lower SAR and asymptomatic cases the lowest.

Perhaps this was because symptomatic cases have delayed testing, indicating that they had more time to transmit the virus before testing positive.

After this period, presymptomatic COVID had the highest SAR, but symptomatic case SAR began to rise, becoming almost identical thereafter. At seven days post-exposure, the SAR in all categories flattened, therefore making it the quarantine limit for contacts.

Symptoms varied in their predictive capacity, but fever, shortness of breath and a dry cough at the onset of infection were found to be associated with an SAR of 30%, provided body aches and/or chills were also reported. The investigators suggest this could be owing to higher viral loads, and therefore greater ability to shed and spread the virus.  

The authors concluded that daily virus surveillance does not by itself help in containing transmission. The only way out may be rigorous face mask use until sufficient vaccine coverage is reached, along with social distancing, testing and quarantine. Both asymptomatic and presymptomatic viral transmission are significant contributors to viral spread, impeding efforts to stop the virus, especially with novel emerging SARS-CoV-2 strains.

Source: News-Medical.Net

Journal information: Krieg, S. J. et al. (2021). Symptomatic, Presymptomatic, and Asymptomatic Transmission of SARS-CoV-2. medRxiv preprint. doi: https://doi.org/10.1101/2021.07.08.21259871. https://www.medrxiv.org/content/10.1101/2021.07.08.21259871v1.

Categories : Gender Obstetrics & GynaecologyTags :

A New Antibody-based Contraceptive for Women

On By ModernMedia
Photo by nine koepfer on Unsplash
Photo by nine koepfer on Unsplash

Researchers have developed a topical antibody-based contraceptive for use by women, which works like a glue, clumping and trapping sperm. 

Over 40 percent of pregnancies worldwide are unintended, even though multiple forms of contraception are available. As well as fuelling population growth, unintended pregnancies can negatively impact the physical, mental and economic wellbeing of mothers.

To address these problems, researchers from Boston University School of Medicine and ZabBio have developed an anti-sperm monoclonal antibody, the Human Contraception Antibody (HCA), which laboratory tests showed was safe and had potent sperm agglutination (clumping) and immobilisation activity.

“HCA appears to be suitable for contraceptive use and could be administered vaginally in a dissolvable film for a woman-controlled, on-demand birth control method,” explained senior author Deborah Anderson, PhD, professor of Medicine.

In order to assess its applicability as a topical contraceptive, the team tested HCA over a wide range of concentrations and under different physiologically relevant conditions in vitro. HCA was mixed with sperm from normal, healthy volunteers and then tested. Sperm became immobilised within 15 seconds, becoming stuck together. The researchers also found that HCA did not seem to cause vaginal inflammation in lab tissue culture tests.

Thanks to its safety and efficacy, HCA could fill current gaps in the contraception field. “HCA could be used by women who do not use currently available contraception methods and may have a significant impact on global health,” said Prof Anderson.  HCA is currently being tested in a Phase I Clinical Trial.

The researchers also believe that a combination of HCA with other antibodies such as anti-HIV and anti-HSV antibodies could make a multipurpose prevention technology, a product that would both serve as a contraceptive and prevent sexually transmitted infections.

These findings appear online in the journal EBioMedicine.

Source: Boston University School of Medicine

Journal information: Gabriela Baldeon-Vaca et al, Production and characterization of a human antisperm monoclonal antibody against CD52g for topical contraception in women, EBioMedicine (2021). DOI: 10.1016/j.ebiom.2021.103478

Categories : COVID VaccinesTags :

Flu Shots May Offer Some COVID Protection

On By ModernMedia
Photo by Raghavendra V. Konkathi on Unsplash
Photo by Raghavendra V. Konkathi on Unsplash

The flu vaccine may provide a level of protection against COVID, a new study concludes.

An analysis of patient data from around the world strongly suggests that the annual flu shot reduces the risk of stroke, sepsis and DVT in patients with COVID. Flu-vaccinated COVID patients were also less likely to visit the emergency department and be admitted to the intensive care unit (ICU). The research was presented online at research being presented at the European Congress of Clinical Microbiology & Infectious Diseases (ECCMID).

Global COVID vaccination is a daunting challenge and, although production and distribution of vaccines increases daily, some countries are not expected to vaccinate large numbers of their population until the start of 2023.

Recently, several modestly-sized studies suggested that the flu vaccine may provide some measure of protection against COVID.

Ms Susan Taghioff, of the University of Miami Miller School of Medicine, and colleagues carried out a retrospective analysis of data on tens of thousands of patients from around the world to find out more.

In the largest study of its kind, the team screened de-identified electronic health records held on the TriNetX research database of more than 70 million patients to identify two groups of 37 377 patients, from countries including the US, UK, Germany, Italy, Israel and Singapore.

The two groups were matched for factors that could affect their risk of severe COVID-19, including age, gender, ethnicity, smoking and health problems such as diabetes, obesity and chronic obstructive pulmonary disease.

The first group had received the flu vaccine between two weeks and six months before COVID diagnoses. The second group also had COVID but were not vaccinated against flu. 

The incidence of 15 adverse outcomes, including sepsis and death, within 120 days of testing positive for COVID was then compared between the two groups. Analysis showed that those not vaccinated for flu were significantly more likely (up to 20%) to have been admitted to ICU.

They were also significantly more likely to visit the Emergency Department (up to 58%), to develop sepsis (up to 45%), to have a stroke (up to 58%) and a deep vein thrombosis (up to 40%). However, the risk of death was not reduced.

It isn’t known exactly how the flu jab provides protection against COVID but most theories centre around it boosting the innate immune system.

The results strongly suggest that the flu vaccine protects against several severe effects of COVID, according to the study authors. Further research is needed to prove this possible link but, in the future, the flu shot could be used to help bolster protection in countries short of COVID vaccine doses.

Senior author Dr Devinder Singh, professor of plastic surgery at the University of Miami Miller School of Medicine, said: “Only a small fraction of the world has been fully vaccinated against COVID to date and, with all the devastation that has occurred due to the pandemic, the global community still needs to find solutions to reduce morbidity and mortality.

“Having access to real-time data of millions of patients is a powerful research tool. Together with asking important questions it has allowed my team to observe an association between the flu vaccine and lower morbidity in COVID patients.

“This finding is particularly significant because the pandemic is straining resources in many parts of the world. Therefore, our research – if validated by prospective randomised clinical trials – has the potential to reduce the worldwide burden of disease.”

Ms Taghioff added: “Influenza vaccination may even benefit individuals hesitant to receive a COVID vaccine due to the newness of the technology.

“Despite this, the influenza vaccine is by no means a replacement for the COVID vaccine and we advocate for everyone to receive their COVID vaccine if able to.

“Continued promotion of the influenza vaccine also has the potential to help the global population avoid a possible ‘twindemic’ – a simultaneous outbreak of both influenza and coronavirus.

“Regardless of the degree of protection afforded by the influenza vaccine against adverse outcomes associated with COVID, simply being able to conserve global healthcare resources by keeping the number of influenza cases under control is reason enough to champion continued efforts to promote influenza vaccination.”

Source: EurekAlert!

Categories : HospitalsTags :

Gauteng’s Ambulance Fleet: Coping with COVID, Riots and Furniture

On By ModernMedia
Photo by camilo jimenez on Unsplash

Gauteng Health MEC Nomathemba Mokgethi acknowledged that many ambulance pickups were being delayed in the province, but placed the blame for this on the referral system.

Starting in 2019, the Gauteng government has taken over most municipal emergency services. However, due to the pressure placed by COVID, City of Tshwane and City of Ekurhuleni municipalities will receive temporary licences to continue operating ambulance services. “So, combined they will be able to respond to our communities on time,” said MEC Nomathemba Mokgethi.

The province’s ambulances and crews are under severe strain as they cope with a lack of resources, the COVID pandemic, and most recently, violent protests.

The Gauteng Emergency Services has been augmenting its fleet with new vehicles, including a pair of Mfezi armoured ambulances for use in dangerous situations, such as riots, where normal soft-skinned ambulances cannot venture.

For example, these armoured vehicles were deployed during New Year’s Eve at Hillbrow, during which time old furniture is often thrown onto the street as a way to ‘start afresh’ for the New Year. This tradition started in the 1990s. Though there may not be as many defenestrated refrigerators in recent years, numerous injuries from the tradition have required the police to clamp down.

The City of Tshwane, which continues to operate under its own ambulance licence, also acquired an armoured ambulance in 2019.

Jack Bloom of the DA said that the Gauteng Health Department has botched its takeover of all ambulance services in the province. Of the original 90 ambulances in Johannesburg before the transition were available, only 40 were now available, according to Bloom. 

Meanwhile, in KwaZulu-Natal, more than 30 private ambulance operators have taken their vehicles off the roads to protect them from the ongoing violence.

Categories : COVIDTags :

Woman, 90, Succumbs to Double COVID Variant Infection

On By ModernMedia
Double COVID Variant Infection

Researchers in Belgium report on the case of a 90-year-old woman who was simultaneously infected with two different COVID variants.

On March 3 2021, the woman, with an unremarkable medical history, was admitted to a Belgian hospital after a spate of falls. She tested positive for COVID on the same day. She received nursing care at home, where she lived alone, and had not received a COVID vaccination.

At first, no signs of respiratory distress were seen, and oxygen saturation was good. However, she went on to develop rapidly worsening respiratory symptoms, and died five days later.

PCR testing revealed that she had been infected by two different strains of the virus — one which originated in the UK, known as B.1.1.7 (Alpha), and another that was first detected in South Africa (B.1.351; Beta).

“This is one of the first documented cases of co-infection with two SARS-CoV-2 variants of concern”, says lead author and molecular biologist Dr. Anne Vankeerberghen from the OLV Hospital in Aalst, Belgium. “Both these variants were circulating in Belgium at the time, so it is likely that the lady was co-infected with different viruses from two different people. Unfortunately, we don’t know how she became infected.”

The Alpha variant had been detected in the south east of England in December and within weeks, this variant displaced the viral strains circulating there. Since then, it has spread to more than 50 countries, including Belgium. The Beta variant was reported on December 18, 2020, and has since spread to 40 countries, which also includes Belgium.
Scientists in Brazil reported in January 2021 that two people had been simultaneously infected with two different strains of the coronavirus—the Brazilian variant known as B.1.1.28 (E484K) and a novel variant VUI-NP13L, which had previously been discovered in Rio Grande do Sul. However, this study has yet to be published in a scientific journal.

“Whether the co-infection of the two variants of concern played a role in the fast deterioration of the patient is difficult to say”, said Vankeerberghen. “Up to now, there have been no other published cases. However, the global occurrence of this phenomenon is probably underestimated due to limited testing for variants of concern and the lack of a simple way to identify co-infections with whole genome sequencing.”

She continued, “Since co-infections with variants of concern can only be detected by VOC-analysis of positive samples, we would encourage scientists to perform fast, easy and cheap VOC-analysis by PCR on a large proportion of their positive samples, rather than just whole genome sequencing on a small proportion. Independent of the technique used, being alert to co-infections remains crucial.”

Source: EurekAlert!

Categories : COVIDTags :

Emerging Variants Threaten a Worsening of the Pandemic

On By ModernMedia
Photo by Viktor Forgacs on Unsplash

Progress against the COVID pandemic has been impeded by the emergence of new variants of concern (VOC), and new ones may further worsen and prolong it.

VOCs increase the transmissibility of the SARS-CoV-2 virus and hence raise the reproduction number. Furthermore, they enhance the immune escape capabilities of the virus and blunt the effectiveness of available vaccines. Finally, they increase the pathogenicity of the infection.

Alpha, Beta, and Gamma VOCs with the N501Y mutation replaced the initial wild-type SARS-CoV-2 strains in Ontario, Canada, and then the Delta variant dominated during the period between February to June 2021. While enhanced virulence of VOCs having the N501Y mutation has been reported, there is a lack of comprehensive analyses that demonstrate increased virulence of the Delta variant.

Researchers from Toronto University, Canada, recently showed that these emerging VOCs were linked to increased virulence, as determined by hospitalisation risk, ICU admission, and mortality. This study is currently available on the medRxiv preprint server.

The researchers created a retrospective cohort of patients testing positive for SARS-CoV-2 in Ontario and screening for VOCs between February 3 and July 1, 2021. Case data was gathered from the Ontario provincial Case and Contact Management (CCM) database. All PCR positive COVID-19 specimens with a cycle threshold (Ct) ≤ 35 were screened for the N501Y mutation using the real-time PCR assay from the Public Health Ontario Laboratory. Whole genome sequencing (WGS) was performed on 5% of specimens regardless of the presence of mutations.

Results show that infection by VOCs with the N501Y mutation significantly elevated risk of hospitalization, ICU admission, and death in patients in Ontario.

Compared to non-VOC strains of SARS-CoV-2, the increase in risk associated with N501Y-positive variants was 138% (105-176%) for ICU admission; 74% (62-86%) for hospitalisation; and 83% (57-114%) for death, after adjusting for age, sex, and comorbidity. Increase in risks associated with the delta variant was even higher- 241% (163-344%) for ICU admission; 105% (80-133%) for hospitalisation; and 121% (57-211%) for death.

VOCs with the N501Y mutation were found to be associated with a significantly higher risk of hospitalisation, ICU admission, and death in infected individuals in Ontario, Canada. They also reveal that the Delta variant, becoming dominant in Ontario, has increased these risks even further.

“Individuals infected with VOCs were, on average, younger and less likely to have comorbid conditions than those infected with non-VOC, but nonetheless had higher crude risks of hospitalisation and ICU admission,” the authors found.

According to the authors, the clear and significant elevation of risks of even delayed outcomes such as death visible in their analysis is remarkable given the relatively small number of delta variant infections in the time period of this study. The fact that Canada is one of the leading countries in the world in terms of COVID vaccination rates has certainly mitigated the impact of these VOCs.

In summary, the researchers showed that despite excellent vaccination rates in Ontario, Canada, and VOCs infecting predominantly younger and healthier individuals, these VOCs are associated with an increase in virulence and risk of death. In particular, the Delta variant is more virulent compared to previously dominant VOCs possessing the N501Y mutation. It is the authors’ view that the progressive increase in transmissibility, immune escape and virulence of emerging VOCs could result in the pandemic being more drawn out and deadly.

Source: News-Medical.Net

Categories : Cardiovascular Disease General Interest PaediatricsTags :

Young Boy’s Triumph Over Rare Heart Condition

On By ModernMedia
Photo by Danijel Durkovic on Unsplash
Photo by Danijel Durkovic on Unsplash

Hannah Lewis was expecting to learn the sex of her first child at 20 weeks of her pregnancy. Anxious about becoming a mother at just 19, Lewis was thrilled when she learned she was having a boy.

However, with a worried look on her face, her doctor told her that the baby’s organs looked healthy – except for his heart.

The baby was diagnosed with hypoplastic left heart syndrome, or HLHS, a rare condition where the heart’s left side is underdeveloped, doubling the workload for the right side. Days later, doctors at a children’s hospital in Nashville, Tennessee, confirmed the diagnosis.

But Lewis said her faith gave her the strength to believe she was meant to raise this child as a single mother, as well as her own experiences being raised by a single mother herself.

The rest of the pregnancy was filled with checkups and tests but remained uneventful. Then, at 37 weeks, doctors realised he was developing foetal hydrops, a life-threatening condition in which an abnormal amount of fluid accumulates in the tissue around the lungs, heart or abdomen, or under the skin.

Even in shock from induced labour followed by a caesarean, she remembers hearing her son’s first cries:

“They let me see him for just a second,” she said. “I loved him at first sight obviously, but I was super scared because they took him directly to the heart cath lab and for like 12 hours, we didn’t know what was going on. I was very sick so they wouldn’t let me go see him.”

She named him Bennett after learning the moniker means “God’s gift of hope” or “little blessed one”.

“It was so fitting for what he was about to face,” Lewis said.

HLHS is usually treated with either three different surgeries at certain stages of development or a heart transplant.

Because of the complications introduced by foetal hydrops, Bennett Sayles was 6 days old when he underwent his first open-heart surgery. Although the procedure went well, Bennett remained in critical condition on a ventilator. Then, when he was 2 months old, he had a stroke.

After three open-heart surgeries, 9 month old Bennett had stabilised enough to go home. But shortly before he was discharged, he went into cardiac arrest, and was without a heartbeat for six minutes.

“Then, out of nowhere, his heartbeat came back and it was strong,” Lewis said.

Two weeks later, days before his first Christmas, Bennett went home for the first time. After he turned 2, Bennett underwent the second HLHS surgery, which didn’t work and days later, he needed a fifth open-heart surgery.

Some weeks later he went home, but in hours, Bennett was back in the emergency room with staph infection in his chest. However, Bennett made it home again in time for Christmas. And ever since that series of setbacks, things have improved for him.

“His mental capacity is anywhere from 3 to 5 years old, but he’s got this amazing personality,” Lewis said. “He’s just got such a caring heart. When he’s in the room, he really does light it up and he changes the way you see things. I’m inspired every day because of how amazing he is and he doesn’t let anything hold him back or stop him.”

Two years ago, Bennett’s doctors determined that he would never be a candidate for the other surgeries needed to treat HLHS. He could, however, become eligible for a heart transplant.

“It’s debatable whether he’ll get there, but having known Bennett for the last nine years is not surprising at all that he has progressed to this point,” said Dr. Gerald Johnson, the boy’s paediatric cardiologist. “One of the beauties of working with kids is that they fight and they work to get better, and they work through things in ways that we as adults don’t necessarily do. Bennett’s been a particular fighter on that score and his mother is very proactive and in tune with his needs.”

Raising Bennett has taught Lewis and her family to focus on the present. “We don’t know what’s in store for Bennett,” Lewis said. “He could live his whole life like this or we can have him just a few more years. We love every minute we get to have with him.”

Source: American Heart Association

Categories : Neurodegenerative Diseases New Compounds and TreatmentsTags :

Probe over Controversial Alzheimer’s Drug’s Approval

On By ModernMedia
Amyloid plaques and neurons. Source: NIAH

The interim commissioner of the US Food and Drug Administration, Janet Woodcock, MD, last week requested the country’s Office of Inspector General to perform an independent investigation into the regulator’s decision to approve Biogen’s controversial Alzheimer’s drug Aduhelm.

Dr Woodcock noted in her letter that there “continues to be concerns raised” regarding the contact between FDA officials and Biogen ahead of the agency’s decision, “including some that may have occurred outside of the formal correspondence process.”

Dr Woodcock’s request comes after a bombshell report from Stat, which found that Biogen executives met with FDA officials, specifically Billy Dunn, MD, director of the FDA’s neuroscience unit, as early as 2019 to discuss a regulatory pathway for Aduhelm. The meetings took place even when it seemed there was no progress for the drug.

Earlier this week, a US House Representative, charged Biogen with “undue influence” over the FDA’s review process. Less than two weeks earlier, the House Committee on Oversight and Reform said it would conduct its own probe into the approval along with Biogen’s pricing strategies.

In the letter from Friday, Dr Woodcock said the agency would fully cooperate with the potential investigation to determine whether any of its interactions with Biogen were inconsistent with FDA policies and procedures.

“Given the ongoing interest and questions, today I requested that @OIGatHHS conduct an independent review and assessment of interactions between representatives of Biogen and FDA during the process that led to the approval of Aduhelm,” tweeted Dr Woodcock.

However, she maintained that she has “tremendous confidence” in the leadership at the FDA’s Center for Drug Evaluation and Research, which was involved in the review of Aduhelm.

“We believe this review and assessment will help ensure continued confidence in the integrity of FDA’s regulatory processes and decision-making,” Woodcock said in a tweet.

A spokesperson from Biogen told Fierce Pharma that the company would “of course” cooperate with “any inquiry in connection with a possible review of the regulatory process.”

The commissioner’s request is only the latest event in a bizarre and twisted story since the FDA’s Aduhelm approval just one month prior.

Facing fierce criticism of its wide-labelled approval, the FDA made the surprising move to narrow Aduhelm’s label last week Thursday, restricting the recommendation to just those with milder Alzheimer’s.

This comes after Biogen’s drug was essentially allowed access to the nation’s some 6 million Alzheimer’s patients. That decision was met with almost immediate pushback, as it was pointed out that the drug could overwhelm the payer budgets of most Alzheimer’s patients.

Source: Fierce Pharma

Categories : COVIDTags :

Positives as Well as Criticism for Ivermectin Review

On By ModernMedia
Source: Pixabay CC0


An eagerly awaited review and meta-analysis on ivermectin for COVID has arrived, however while it seems positive there are many shortcomings and unanswered questions. 

The findings of the study, led by Andrew Hill, PhD, of the University of Liverpool, were published in Open Forum Infectious Diseases. The review and meta-analysis was conducted as part of the International Ivermectin Project Team from December 2020 to May 2021. Ivermectin proponents alleged that Dr Hill was conducting the analysis for the WHO, but MedPage Today was not able to make a confirmation of this. A separate review published on June 28 in the journal Clinical Infectious Diseases found no benefits for ivermectin use in COVID.

Dr Hill and colleagues assessed 24 randomised trials enrolling a total of 3328 patients that involved some type of control, whether it was standard of care or some other therapy. Sample sizes ranged from 24 to 400 participants. Of these, eight were published studies.

In the 11 trials with 2127 patients that focused on moderate or severe infection, a 56% reduction in mortality was seen (P=0.004), with 3% of patients on ivermectin dying compared with 9% of controls.

However, the researchers noted that the total number of deaths was small (128) and in the subgroup with severe disease, there was no difference between ivermectin and controls. As for moderate disease, they reported a 70% improvement in survival with ivermectin (P=0.0004).
Compared with controls, ivermectin use was also associated with a reduction in time to recovery of 1.58 days (P=0.01) and with a shorter duration of hospitalisation of 4.27 days (P=0.05).

However, the drug was not associated with a lower risk of hospitalisation, though a sensitivity analysis that included any hospitalizations within 12 hours of taking the drug did show a reduction with ivermectin (RR 0.32, 95% CI 0.13-0.80, P=0.01).

A key limitation was the lack of peer review for many studies included in the analysis; there was also wide variation in terms of dosage, treatment duration, and inclusion criteria. There were also many different comparators, including hydroxychloroquine, lopinavir/ritonavir, standard of care, and placebo.

The authors concluded that their results “need to be validated in larger confirmatory trials”. David Boulware, MD, MPH, of the University of Minnesota, agreed with this. Dr Boulware has been interested in evaluating ivermectin for COVID outpatients, agreed with. On Twitter, he noted that no mention was made of whether patients used steroids, which could seriously confound results.

Only two of seven trials showed a reduction in symptom duration in outpatient trials. No analysis was done to see if early treatment cut hospitalisation risk.

He tweeted that there was a need for phase III randomised clinical trials “in order to delineate what is the clinical benefit of early treatment”, such as quicker resolution and fewer symptoms. He would have also liked to see more distinction between outpatient and in-hospital therapy.

“Of course, rolling out vaccination as quickly and widespread as possible would negate the need to use ivermectin as a treatment,” he added. “So big picture, vaccines are the better solution.”

There are multiple ongoing phase III randomised controlled trials “which will provide definitive results,” Boulware noted. These include the UK-based PRINCIPLE outpatient trial which has a target of 1500 patients for its ivermectin arm.

Source: MedPage Today

Categories : Implants and Prostheses Medical Research & TechnologyTags :

Carbon Fibre Electrodes Allow Unprecedented Neural Recording

On By ModernMedia
Image by Robina Weemeijer on Unsplash

A tiny, implantable carbon fibre electrode has the potential to provide a long-term brain-computer interface which can record electrical signals over lengthy periods of time.

The carbon fibre electrodes were developed at the University of Michigan and demonstrated in rats. The new research shows the promise of carbon fibre electrodes in recording electrical signals from the brain without damaging brain tissue. Directly implanting carbon fiber electrodes into the brain allows the capturing of bigger and more specific signals than current technologies.

This technology could lead to advances that could give amputees and those with spinal injuries control of advanced prosthetics, stimulate the sacral nerve to restore bladder control, stimulate the cervical vagus nerve to treat epilepsy and provide deep brain stimulation as a possible treatment for Parkinson’s.  

“There are interfaces out there that can be implanted directly into the brain but, for a variety of reasons, they only last from months to a few years,” said Elissa Welle, a recent PhD graduate from the U-M Department of Biomedical Engineering. “Any time you’re opening up the skull for a procedure involving the brain, it’s a big deal.”

Brain implants are typically made from silicon due to its ability to conduct electricity and its historic use in cleanroom technology. But silicon is not very biocompatible and leads to the formulation of scar tissue over long periods. Such electodes will eventually degrade and no longer capture brain signals, requiring removal.

Carbon fibres may be the answer to getting high-quality signals with an interface that lasts years, not months. And by laser cutting and sharpening carbon fibers into tiny, subcellular electrodes in the lab with the help of a small blowtorch, U-M engineers have harnessed the potential for excellent signal capture in a form the body is more likely to accept.

“After implantation, it sits inside the brain in a way that does not interfere with the surrounding blood vessels, because it’s smaller than those blood vessels,” Welle said. “They’ll move around and adjust to an object that small, rather than get torn as they would when encountering larger implants.”

Part of the electrode’s compatibility in brain tissue is down to smaller size, but its needle-like shape may also minimise compacting of any surrounding tissue. Larger carbon-based electrodes have been shown to actually encourage neural tissue to grow instead of degrading. The team is hopeful that similar potential for their carbon fibre electrodes will be revealed by further testing.

Carbon fibre electrodes in a previous study dramatically outperformed conventional silicon electrodes with 34% of electrodes recording a neuron signal compared to 3%. Laser cutting then improved this number to 71% at 9 weeks after implantation. Flame sharpening has now enabled these high performance probes to be implanted directly into the cerebral cortex, negating the need for a temporary insertion aid, or shuttle, as well as into the rat’s cervical vagus nerve.

It is relatively easy to insert electrodes into the brain. But the researchers have also taken on the more difficult task of inserting the sharpened carbon fibre electrodes into nerves, with micrometre diameters.

Those findings show that potential for these electrodes goes beyond prosthetic manipulation, according to Cindy Chestek, a U-M associate professor of biomedical engineering, and principal investigator of the The Cortical Neural Prosthetics Lab.

“Someone who is paralysed may have no control over things like their bladder, for example,” Prof Chestek said. “We may be able to utilise these smaller electrodes to stimulate and record signals from areas that can’t be reached by larger ones, maybe the neck or spinal cord, to help give patients some level of control.”

Source: University of Michigan