Day: May 11, 2023

Categories : Antibiotics Surgeries & ProceduresTags : Leave a comment

New Guidance Advises Stopping Antibiotics after Incision Closure

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Antibiotics administered before and during surgery should be discontinued immediately after a patient’s incision is closed, according to updated recommendations for preventing surgical site infections.

Experts found no evidence that continuing antibiotics after a patient’s incision has been closed, even if it has drains, prevents surgical site infections. Continuing antibiotics does increase the patient’s risk of C. difficile infection, which causes severe diarrhoea, and antimicrobial resistance.

Strategies to Prevent Surgical Site Infections in Acute Care Hospitals: 2022 Update, published in the journal Infection Control and Healthcare Epidemiology, provides evidence-based strategies for preventing infections for all types of surgeries from top experts from five medical organisations led by the Society for Healthcare Epidemiology of America.

“Many surgical site infections are preventable,” said Michael S. Calderwood, MD, MPH, lead author on the updated guidelines. “Ensuring that healthcare personnel know, utilise, and educate others on evidence-based prevention practices is essential to keeping patients safe during and after their surgeries.”

Surgical site infections are among the most common and costly healthcare-associated infections, occurring in approximately 1% to 3% of patients undergoing inpatient surgery. Patients with surgical site infections are up to 11 times more likely to die compared to patients without such infections.

Other recommendations:

  • Obtain a full allergy history from patients who self-report penicillin allergy. Many patients with a self-reported penicillin allergy can safely receive cefazolin, a cousin to penicillin, rather than alternate antibiotics that are less effective against surgical infections.
  • For high-risk procedures, especially orthopaedic and cardiothoracic surgeries, decolonise patients with an anti-staphylococcal agent in the pre-operative setting. Decolonization, which was elevated to an essential practice in this guidance, can reduce post-operative S. aureus infections.
  • For patients with an elevated blood glucose level, monitor and maintain post-operative blood glucose levels between 110 and 150mg/dL regardless of diabetes status. Higher glucose levels in the post-operative setting are associated with higher infection rates. However, more intensive post-operative blood glucose control targeting levels below 110mg/dL has been associated with a risk of significantly lowering the blood glucose level and increasing the risk of stroke or death.
  • Use antimicrobial prophylaxis before elective colorectal surgery. Mechanical bowel preparation without use of oral antimicrobial agents has been associated with significantly higher rates of surgical site infection and anastomotic leakage. The use of parenteral and oral antibiotics prior to elective colorectal surgery is now considered an essential practice.
  • Consider negative-pressure dressings, especially for abdominal surgery or joint arthroplasty patients. Placing negative-pressure dressings over closed incisions was identified as a new option because evidence has shown these dressings reduce surgical site infections in certain patients. Negative pressure dressings are thought to work by reducing fluid accumulation around the wound.

Additional topics covered in the update include specific risk factors for surgical site infections, surveillance methods, infrastructure requirements, use of antiseptic wound lavage, and sterile reprocessing in the operating room, among other guidance.    

Hospitals may consider these additional approaches when seeking to further improve outcomes after they have fully implemented the list of essential practices. The document classifies tissue oxygenation, antimicrobial powder, and gentamicin-collagen sponges as unresolved issues according to current evidence.  

Source: Society for Healthcare Epidemiology of America

Categories : NeurologyTags : Leave a comment

Functional MRI is Now Able to Read People’s Minds

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Photo by Mart Production on Pexels

In a study in Nature, researchers reported being able to identify words and phrases in volunteers undergoing fMRI imaging reasonable accuracy. The process is non-invasive, unlike implanted electrodes, but requires hours of preparation and scanning.

This technology would be a significant breakthrough for people suffering debilitating conditions that prevent them from speaking or otherwise communicating. Previously, decoding language required the use of extensive electrode implants.

The participants, two male and one female, listened to recordings of radio shows. This was used to train a language model which was based on an early version of ChatGPT. By looking at the brain’s responses, the language model was able to capture the gist of what the participants were thinking, sometimes replicating exact words or entire phrases.

Marked safe from ‘Big Brother’… for now

At this stage, the technology used requires the subject to cooperate, the researchers wrote, allaying concerns over any malicious use of this technology to tap into people’s private thoughts. Testing the decoding model on people who it hadn’t been trained on produced unintelligible results, as was the case when the trained participants put up resistance.

While the technology cannot be used for nefarious mind-reading, the march of progress means that one day such concerns will become real.

Nita Farahany, JD, PhD, of Duke University in Durham, North Carolina, told MedPage Today that the technology could one day be used against people. “This research illustrates the rapid advances being made toward an age of much greater brain transparency, where even continuous language and semantic meaning can be decoded from the brain.

“While people can employ effective countermeasures to prevent decoding their brains using fMRI, as brain wearables become widespread that may not be an effective way to protect us from interception, manipulation, or even punishment for our thoughts.”

While lugging around a massive MRI machine would be a challenge for future thought police, smaller, more portable means of measuring brain activity remotely. Senior author Alexander Huth, PhD, of the University of Texas at Austin, says that one such technology could be functional near-infrared spectroscopy (fNIRS).

“fNIRS measures where there’s more or less blood flow in the brain at different points in time, which, it turns out, is exactly the same kind of signal that fMRI is measuring,” Huth said. “So, our exact kind of approach should translate to fNIRS,” but the resolution with fNIRS would be lower.

Categories : COVID Obstetrics & GynaecologyTags : Leave a comment

Limited Evidence for Menstrual Changes After COVID Vaccination

On By ModernMedia
Photo by Gustavo Fring on Pexels

Results from a Swedish study of nearly three million women and girls published by The BMJ found that there was no evidence of an increased risk of post-COVID vaccination menstrual changes that were significant enough for healthcare interaction.

The researchers found only weak and inconsistent associations were found between COVID vaccination and contact with healthcare for postmenopausal bleeding. These were even less consistent for menstrual disturbance and premenstrual bleeding.

These findings do not provide any substantial support for a causal association between COVID vaccination and diagnoses related to menstrual or bleeding disorders, say the researchers.

Many women have reported changes to their periods after a COVID vaccination, such as the number of days they bleed and the heaviness of the flow. Self-reporting may capture events that normally would not result in a healthcare contact but may still be sufficiently disturbing to be relevant for the affected women. But calculating the strength of a potential association based on self reports can be unreliable.

To address this, researchers in Sweden drew on high quality health registry data to evaluate the risks of menstrual disturbance and bleeding after COVID vaccination in 2 946 448 women and girls aged 12-74 years from December 2020 to February 2022.

Contact with healthcare included primary care visits, specialist outpatient visits, and days of hospital stay related to menstrual disturbance or bleeding before or after menopause.

Risks were assessed by vaccine (Pfizer-BioNTech, Moderna, or Oxford-AstraZeneca) and dose (unvaccinated and first, second, and third dose) over two time windows (1-7 days, considered the control period, and 8-90 days).

In the main analysis, more than 2.5 million (88%) of women received at least one covid-19 vaccination and over 1.6 million (64%) of vaccinated women received three doses during the study period.

The highest risks for bleeding in postmenopausal women were seen after the third dose in the 1-7 days risk window (28%) and in the 8-90 days risk window (25%).

Adjusting for socioeconomic factors, previous healthcare use, and for several specific medical conditions had only a modest effect on these results.

Analyses of individual vaccines and risk of postmenopausal bleeding suggested a 23-33% increased risk after 8-90 days with Pfizer-BioNTech, and Moderna after the third dose, but a less clear association with Oxford-AstraZeneca.

In premenopausal women, weak associations were found for menstrual disturbance or bleeding after vaccination with any dose (13% or 8% after 1-7 days and 6% or 1% after 8-90 days, respectively). However, adjusting for other factors almost completely removed these weak associations, suggesting that a causal effect is unlikely.

These are observational findings and the authors point to several limitations, including the fact that the time between onset, start of symptoms, and date of healthcare contact might be considerable, making the interpretation of effect of different risk windows challenging. 

But this was a large study with near complete follow-up, using mandatory data from nationwide registers.

As such, they say: “We observed weak and inconsistent associations between SARS-CoV-2 vaccination and healthcare contacts for postmenopausal bleeding, and even less consistent for menstrual disturbance, and premenstrual bleeding.”

They add: “These findings do not provide any substantial support for a causal association between SARS-CoV-2 vaccination and healthcare contacts related to menstrual or bleeding disorders.”

Source: The BMJ

Categories : Obstetrics & Gynaecology VaccinesTags : Leave a comment

Preterm Births Concern Raised Over New Maternal RSV Vaccine

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Experts have called for further scrutiny of a new Pfizer vaccine given during pregnancy to prevent respiratory infection in infants, after trials of a similar GSK vaccine were stopped after increased preterm birth and infant deaths. Pfizer says its vaccine is safe and effective, but experts contacted as part of an investigation published by The BMJ say that Pfizer’s trial data should be reviewed in light of the trend for preterm births seen in GSK’s trial.

Pfizer’s maternal RSV vaccine aims to protect infants from severe illness caused by the respiratory syncytial virus (RSV). RSV is very common but can be fatal, especially in young children. In 2019, an estimated 3.6% of all deaths worldwide in children aged 1-6 months were due to RSV, with 97% of these deaths occurring in low and middle income countries.

The vaccine has not yet been approved for use, but a decision by the US Food and Drug Administration is expected by August. The European Medicines Agency is also set to make a decision about the vaccine later this year.

In February 2022, GSK halted vaccination in its phase 3 trials of its maternal RSV vaccine after finding an increased risk of preterm birth in vaccinated mothers, mainly in low and middle income countries.

Pfizer published the results of an interim analysis of its phase 3 trial last month, saying that the vaccine was effective against medically attended severe RSV in children and that no safety concerns were identified.

And while the difference in preterm births in the Pfizer trials was not statistically significant, the results have raised concerns about a possible increase in preterm births, and now experts are calling for further analyses of the data and post-approval monitoring of the vaccine should the FDA approve it.

“My interpretation of all these data is that there may be a safety signal for preterm births that should be followed up on,” said Klaus Überla, director of the Virological Institute of the University Hospital Erlangen and member of the RSV working group of the Standing Committee on Vaccination (STIKO), which develops national recommendations for the use of licensed vaccines in Germany. 

And a scientist at the National Institutes of Health (NIH) said the Pfizer data should be analysed using more sensitive measures such as average birth weight and subgroup analyses to detect possible signals.

Meanwhile, Cody Meissner, professor of paediatrics and medicine at the Dartmouth Geisel School of Medicine and consultant in the US Centers for Disease Control and Prevention (CDC)’s maternal RSV working group, predicts that possible adverse effects such as premature births will be “closely monitored” in assessment programs by FDA and CDC.  “We need a safe vaccine,” he added.

Pfizer did not respond when asked about a possible increase in preterm births associated with its vaccine, but told The BMJ that “no imbalance of neonatal deaths was observed” in its phase 3 trial. 

In a linked editorial, researchers point to challenges for RSV vaccine development and the main approaches to protection currently being pursued. 

They argue that, while the burden of illness caused by RSV is substantial worldwide, it is particularly important that new vaccines and other prevention strategies are available to infants in low and middle income countries, where the greatest illness and deaths occur.

And they say further research is urgently needed “to identify the best prevention strategies for low and middle income countries, where affordability is paramount and timing of administration is complicated by the lack of predictable seasonal RSV epidemics.”

Source: EurekAlert!

Categories : HIVTags : Leave a comment

Tuberculosis Weakens HIV Antibody Response in Those with HIV

On By ModernMedia
Tuberculosis bacteria. Credit: CDC

According to new research findings published in iScience, people living with HIV with a history of pulmonary tuberculosis had broader and more potent HIV antibody responses and differences in HIV sequences predicted to be antibody-resistant as compared to those without tuberculosis. The study suggests that concomitant tuberculosis disease has a significant impact on HIV immune responses and the viruses circulating in people living with HIV.

Tuberculosis infects more than 2 billion people in the world, and although tuberculosis is the most common co-infection in people living with HIV, previous studies have not examined how tuberculosis impacts HIV immune responses and virus characteristics.

This study suggest that tuberculosis may impact the efficacy of antibody based prevention and therapeutic strategies. Vaccines to elicit antibodies and antibodies are also being investigated as a means to treat and cure HIV. Higher prevalence of antibody resistant strains along with tuberculosis disease implies that these antibody-based interventions are more likely to in fail in these individuals.

“Tuberculosis is extremely common, especially in regions of the world with high levels of ongoing HIV transmission, and impacts both the immune responses and the characteristics of the circulating virus in people living with HIV so it is imperative we understand the relationship between the two,” said Manish Sagar, MD, an internist at Boston Medical Center and Professor of Medicine at Boston University Chobanian & Avedisian School of Medicine. “These studies have implications for HIV vaccines and antibody based HIV therapeutics.”

Researchers worked closely with investigators in Uganda and at the AIDS Clinical Trial Group (ACTG) to collect samples from people newly diagnosed with HIV that either did or did not have tuberculosis. From these individuals, they examined samples collected prior to and about 6 months after the start of HIV medications. Researchers compared antibodies, plasma inflammatory markers, and HIV sequences in the baseline and in treatment samples.

Tuberculosis disease is associated with higher prevalence of the some antibody-resistant HIV. High ongoing HIV transmission in areas of the world with frequent tuberculosis disease suggest that a potential vaccine that elicits broad and potent antibodies may not work because these geographic regions are more likely to have antibody resistant strains.

This has implications for HIV vaccine strategies as they aim to generate antibodies that can block the virus after exposure. Generating broad and potent HIV antibodies remains a monumentally difficult goal. Understanding the biological pathways behind the broadly potent antibody responses generated by tuberculosis could provide insight into how tuberculosis enhances HIV antibody responses. This in turn could be leveraged to develop novel strategies for eliciting broad and potent HIV antibodies.

Source: Boston Medical Center

Categories : GeneticsTags : Leave a comment

Neanderthal DNA Shaped Noses in Some Human Populations

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Diagram comparing the nose shape of a Neanderthal with that of a modern human by Dr Macarena Fuentes-Guajardo.

Humans inherited genetic material from Neanderthals that affects the shape of noses of many populations, finds a new study published in Communications Biology. The new study finds that a particular gene, which leads to a taller nose (from top to bottom), may have been the product of natural selection as ancient humans adapted to colder climates after leaving Africa, and is even found in native populations of the Americas.

Co-corresponding author Dr Kaustubh Adhikari (UCL Genetics, Evolution & Environment and The Open University) said: “In the last 15 years, since the Neanderthal genome has been sequenced, we have been able to learn that our own ancestors apparently interbred with Neanderthals, leaving us with little bits of their DNA.

“Here, we find that some DNA inherited from Neanderthals influences the shape of our faces. This could have been helpful to our ancestors, as it has been passed down for thousands of generations.”

The study used data from more than 6000 volunteers across Latin America, of mixed European, Native American and African ancestry, who are part of the UCL-led CANDELA study, which recruited from Brazil, Colombia, Chile, Mexico and Peru. The researchers compared genetic information from the participants to photographs of their faces, specifically looking at distances between points on their faces, such as the tip of the nose or the edge of the lips, to link different facial traits to different genetic markers.

The researchers newly identified 33 genome regions associated with face shape, 26 of which they were able to replicate in comparisons with data from other ethnicities using participants in east Asia, Europe, or Africa.

In one genome region in particular, called ATF3, the researchers found that many people in their study with Native American ancestry (as well as others with east Asian ancestry from another cohort) had genetic material in this gene that was inherited from the Neanderthals, contributing to increased nasal height. They also found that this gene region has signs of natural selection, suggesting that it conferred an advantage for those carrying the genetic material.

First author Dr Qing Li (Fudan University) said: “It has long been speculated that the shape of our noses is determined by natural selection; as our noses can help us to regulate the temperature and humidity of the air we breathe in, different shaped noses may be better suited to different climates that our ancestors lived in. The gene we have identified here may have been inherited from Neanderthals to help humans adapt to colder climates as our ancestors moved out of Africa.”

Co-corresponding author Professor Andres Ruiz-Linares (Fudan University, UCL Genetics, Evolution & Environment, and Aix-Marseille University) added: “Most genetic studies of human diversity have investigated the genes of Europeans; our study’s diverse sample of Latin American participants broadens the reach of genetic study findings, helping us to better understand the genetics of all humans.”

The finding is the second discovery of DNA from archaic humans, distinct from Homo sapiens, affecting our face shape. The same team discovered in a 2021 paper that a gene influencing lip shape was inherited from the ancient Denisovans.*

The study involved researchers based in the UK, China, France, Argentina, Chile, Peru, Colombia, Mexico, Germany, and Brazil.

Source: University College London