Sunnybrook

Mpox DNA can persist in the body for up to four weeks: Study

rahul.kalvapalle — Tue, 12 Mar 2024 20:04:03 +0000

Mpox DNA can persist in the body for up to four weeks: Study

rahul.kalvapalle Tue, 03/12/2024 - 16:04

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A sign containing information about monkeypox is seen in International Airport Treviso A. Canova, in Treviso, Italy, on Nov. 30, 2022 (photo by Manuel Romano/NurPhoto via Getty Images)

Betty Zou

Topic

Breaking Research

EPIC

Institutional Strategic Initiatives

Temerty Faculty of Medicine

Unity Health

Dalla Lana School of Public Health

ihpme

St. Michael's Hospital

Sunnybrook

Subheadline

The study is one of several projects supported by the mpox rapid research response launched by U of T's Emerging and Pandemic Infections Consortium (EPIC) and its hospital partners

DNA from the mpox virus can be found in different parts of the body for up to four weeks after symptom onset, according to a study led by researchers at Unity Health Toronto, the Sunnybrook Research Institute and the University of Toronto.

The researchers analyzed samples from 64 men who contracted mpox, including participants from the Mpox Prospective Observational Cohort Study led by Darrell Tan, an infectious disease physician at St. Michael’s Hospital, part of Unity Health Toronto – where some of Toronto’s first patients with mpox were identified and cared for – and associate professor in the department of medicine and the Institute of Medical Science at U of T's Temerty Faculty of Medicine and in the Institute of Health Policy, Management and Evaluation (IHPME) at the Dalla Lana School of Public Health.

They found that persistence of mpox virus DNA varied depending on where the samples were taken from. Among the key findings was that the DNA was detectable in nearly half of genital skin swabs and one in five skin swabs from other sites a week after symptoms had resolved.

The study, which was published in Open Forum Infectious Diseases, is one of several projects supported by the mpox rapid research response launched by the Emerging and Pandemic Infections Consortium (EPIC), an institutional strategic initiative, and its hospital partners during the global outbreak of mpox – previously known as monkeypox – in 2022.

According to the World Health Organization, nearly 94,000 confirmed cases of mpox, including 179 deaths, have been reported from 117 countries since January 2022. As of September 2023, 1,515 cases have been confirmed in Canada, mostly in Ontario and Quebec.

“Even though we’ve known about mpox for over 70 years, it was new to us because we hadn’t seen it outside the endemic regions,” said Robert Kozak, one of the study’s authors and a clinical microbiologist at Sunnybrook Research Institute and assistant professor in the department of laboratory medicine and pathobiology at Temerty Medicine. “There was still a lot about the virus and disease that we didn’t know,”

To answer key questions about viral shedding, Kozak teamed up with Tan and Sharmistha Mishra, an infectious disease physician at St. Michael’s Hospital and associate professor in the Temerty Faculty of Medicine’s department of medicine and Institute of Medical Science and IHPME.

(L-R) Robert Kozak, Sharmistha Mishra and Darrell Tan (supplied images)

The researchers used a technique called quantitative polymerase chain reaction (qPCR) to determine the persistence of mpox virus DNA. Samples were taken from six different sites on the body — genital region, nasal cavity, semen, skin, throat and urine — and over an extended period of time.

On average, mpox DNA was detected in skin swabs from the genital and perianal region and from other skin sites at 30 and 22 days after symptom onset, respectively. These findings are consistent with the sexually transmitted nature of mpox during the recent global epidemic, which primarily affected gay, bisexual and men who have sex with men.

The researchers were unable to detect viral DNA in a large proportion of semen samples and nasal cavity swabs taken when individuals first presented with symptoms, whereas in urine and throat swab samples, mpox DNA persisted for roughly two weeks after symptom onset.

Interestingly, the researchers did not observe a difference in the length of viral DNA persistence between people who received the antiviral drug tecovirimat and those who did not. Tan noted that while study participants were not randomly assigned to receive the drug, these results underscore the uncertainty around tecovirimat’s effectiveness in treating mpox infections.

He added the study provides several key learnings for his clinical colleagues. “First, we’ve documented the breadth of clinical samples in which mpox DNA can be identified and therefore can be used to confirm a diagnosis. Our findings also reinforce that it’s worthwhile for clinicians to collect such samples in individuals where an mpox diagnosis is being considered, even after symptoms of feeling unwell are gone," Tan said.

The researchers caution that just because mpox DNA can be detected up to four weeks after symptom onset, it doesn’t mean that individuals are infectious for that long.

“We don’t know for sure whether the presence of detectable viral DNA necessarily means that the virus is transmissible to other people, so more research definitely needs to be done to determine definitively the period of infectiousness,” Tan said.

To that end, Jacklyn Hurst, a postdoctoral fellow in Kozak’s lab, recently started work in the Toronto High Containment Facility to look for live virus in the same samples from which mpox DNA was detected. The researchers are also using the facility’s biobank of mpox patient samples to identify biomarkers that could predict whether a person will have a mild or severe infection.

“Without the Toronto High Containment Facility, we wouldn’t be able to do any of this. Having that facility will help us answer a lot of questions about this virus and how to stop it,” said Kozak.

He acknowledged the immense contributions of the patient community to this work. “A huge thank you to all the study participants. We wouldn’t be able to do this work without their sacrifice and commitment.”

Alzheimer's, mood disorders: U of T partners with industry for open source collaboration

sgupta — Wed, 12 Nov 2014 08:13:16 +0000

Alzheimer's, mood disorders: U of T partners with industry for open source collaboration sgupta Wed, 11/12/2014 - 03:13

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Professor Ruth Ross, director of the Centre for Collaborative Drug Research (photo by Rick Chard/CAMH)

Liam Mitchell

Author legacy

Liam Mitchell

Health

Sunnybrook

St. Michael's Hospital

Subheadline

Working with Johnson and Johnson Innovation and Janssen to find neuroscience therapies

A new collaboration aimed at developing therapies for mood disorders and Alzheimer’s disease – known as the Neuroscience Catalyst – launched on November 6.

The new public-private partnership brings together the University of Toronto with Janssen Inc. and the Johnson & Johnson Innovation Center in California to support collaborative, open-source research.

“Mood disorders and Alzheimer’s disease are chronic illnesses that affect millions of people worldwide,” said Catharine Whiteside, U of T’s dean of medicine and vice-provost, relations with health care institutions. “By 2040, these debilitating brain diseases could surpass cancer as the second-leading cause of death.

“Finding solutions that bring relief to those who face these aliments, and the family and friends who care for them, are what makes this partnership so important.”

Researchers at U of T and its affiliated hospitals through the Toronto Academic Health Science Network (TASHN) are welcome to submit collaborative proposals. Scientists from Janssen will work with U of T researchers to provide the drug-discovery expertise required to rapidly develop new medicines from basic science innovations. The open nature of the research means the findings can be published and researchers are free to commercialize their work with any company they wish.

The Neuroscience Catalyst is based at the Centre for Collaborative Drug Discovery (CCDR), which is a multidisciplinary initiative bringing together researchers from U of T’s Faculty of Medicine, the Leslie Dan Faculty of Pharmacy and the Centre for Addiction and Mental Health (CAMH).

“There is a tremendous amount of incredible blue sky, curiosity-driven research being conducted at U of T,” said Ruth Ross. The Centre’s inaugural director, Ross is a professor and chair of toxicology and pharmacology in the Faculty of Medicine and senior scientist with the Campbell Family Mental Health Research Institute at the Centre for Addiction and Mental Health (CAMH).

"When we launched the CCDR, we began by looking across the fields of research in Toronto and asked ‘Where is there an opportunity and a need for us to add real impact in drug discovery?’”

Neuroscience is one area where Ross and partners saw CCDR could help to create a collaborative network to accelerate the translation of bench research into new treatments. In addition to the Neuroscience Catalyst, there will be other venues for researchers to share information and meet as a community.The first meeting will be held on November 27 when the Centre hosts Neuroscience Research Day on New Targets in Neurodegeneration and Neuropsychiatry.

Ross said the focus in neuropsychiatry and neurodegeneration highlights the “…urgent and compelling need for scientists, government and industry to work together in partnership, using their collective expertise to seek safe effective new interventions for debilitating conditions such as depression and Alzheimer’s disease.”

The Neuroscience Catalyst is overseen by a joint steering committee with representatives from U of T, CAMH, St. Michael's Hospital, Sunnybrook Hospital, University Health Network and Janssen Inc. Ross believes the partnership is an example for future open innovation consortia with additional industry partners.

Liam Mitchell is a writer with the Faculty of Medicine at the University of Toronto.

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Worse than toilets: hospital elevator buttons a hidden source of bacteria

sgupta — Tue, 08 Jul 2014 14:19:17 +0000

Worse than toilets: hospital elevator buttons a hidden source of bacteria sgupta Tue, 07/08/2014 - 10:19

Cutline

“Use alcohol-based hand sanitizer before and after touching the buttons, or avoid touching them altogether by using the tip of a pen or your elbow,” suggests Dr. Christopher Kandel (photo by Allan Foster via Flickr)

Sybil Edmonds

Author legacy

Sybil Edmonds

Topic

The benefit of prolonged heart monitoring after unexplained strokes: New England Journal of Medicine

sgupta — Thu, 26 Jun 2014 12:45:00 +0000

The benefit of prolonged heart monitoring after unexplained strokes: New England Journal of Medicine sgupta Thu, 06/26/2014 - 08:45

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Dr. David Gladstone led the EMBRACE trial (photo by Doug Nicholson/Media Source)

Topic

St. Michael's Hospital

Subheadline

Prevention of stroke due to atrial fibrillation “global health issue”

A major 16-centre Canadian study, published June 26 in the prestigious New England Journal of Medicine, shows the benefit of prolonged heart monitoring to diagnose silent, but dangerous, irregular heart rhythms in people who have unexplained strokes.

Findings of the three-year EMBRACE trial represent “an important advance” in determining the cause of up to a third of ischemic strokes, which result from blood clots to the brain, writes Cornell University neurologist Dr. Hooman Kamel in an editorial accompanying the study.

“The results . . . indicate that prolonged monitoring of heart rhythm should now become part of the standard care of patients with cryptogenic (unexplained) stroke,” Dr. Kamel writes.

Led by Dr. David Gladstone, an associate professor in the Department of Medicine at the University of Toronto and clinician-scientist at Sunnybrook Research Institute, the EMBRACE trial followed 572 patients ages 55 and older with a recent stroke or TIA (transient ischemic attack) and in whom standard diagnostic tests (including conventional heart monitoring for at least 24 hours) failed to detect the cause.

The study found that, by monitoring patients at home with a new chest electrode belt for 30 consecutive days, atrial fibrillation (irregular heart rhythm) was detected in 16 per cent of patients, as compared with the standard 24-hour monitoring which found the arrhythmia in only three per cent of patients.

Prevention of stroke due to atrial fibrillation is “a global public health issue,” according to the Canadian Stroke Network-funded study, the largest clinical trial of heart monitoring in stroke patients. Atrial fibrillation is known to cause some of the most disabling, deadliest, and most costly types of strokes.

However, the challenge has been that atrial fibrillation is often hard to diagnose because the irregular heartbeat may last for just a few minutes at a time, after which the heart reverts back to its normal rhythm. Unless an individual is wearing a heart monitor at the time it occurs, the diagnosis is usually missed. In practice, stroke patients have traditionally received only short-duration heart monitoring (e.g. for 24 hours) to screen for atrial fibrillation – a strategy that now appears inadequate according to the study’s findings.

“The harder we look with more intensive heart monitoring, the greater the chance of finding this hidden risk factor – it’s like medical detective work,” said Gladstone, whose research was supported by the Heart and Stroke Foundation (HSF) and the HSF Canadian Partnership for Stroke Recovery.

In the study, enhanced detection of atrial fibrillation led to significantly more patients being prescribed stronger anti-clotting medications to prevent recurrent strokes. Atrial fibrillation is a risk factor for stroke because it can promote the formation of blood clots in the heart that can travel to the brain. It is important to detect because it can be effectively treated with certain anti-clotting medications, which cut the risk of clots and strokes by two-thirds or more.

Gladstone has already begun implementing the study’s findings in practice by offering prolonged heart monitoring to patients at Sunnybrook Health Sciences Centre, where he directs the Regional Stroke Prevention Clinic.

“With improved detection and treatment of atrial fibrillation, the hope is that many more strokes and deaths will be prevented,” Gladstone said. The New England Journal of Medicine published a second U.S-based study on prolonged monitoring this month, called CRYSTAL AF, which further supported the practice change.

The EMBRACE trial was conducted by investigators of the Canadian Stroke Consortium and coordinated at the Li Ka Shing Knowledge Institute of St. Michael’s Hospital in Toronto.

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