Category: Diseases, Syndromes and Conditions

Environmental Monitoring Offers Low-cost Tool for Typhoid Fever Surveillance

Detection of the viruses that infect the typhoid fever bacterium in sewage indicates disease burden

Researchers can accurately track where typhoid fever cases are highest by monitoring environmental samples for viruses called bacteriophages that specifically infect the bacterium that causes typhoid fever. Senjuti Saha of the Child Health Research Foundation in Bangladesh and colleagues report these findings in a new study published February 15 in the open access journal PLOS Neglected Tropical Diseases.

Typhoid fever is a common infection in many low- and middle-income countries and causes an estimated 135 000 deaths and 14 million infections globally each year. The World Health Organization has prequalified two typhoid vaccines, but for policymakers to plan effective vaccination strategies, they need accurate, high-resolution estimates of where the burden is highest.

Traditionally, people have cultured the bacterium that causes typhoid fever from blood samples to determine where the infection is most common, but in the new paper, researchers tried a more cost-effective surveillance approach. They tested environmental water samples from sewage and other locations to detect bacteriophages specific to the water-borne pathogen that causes typhoid fever, Salmonella Typhi.

The team tested 303 water samples from two locations in Bangladesh: the urban capital city, Dhaka, and a rural district, Mirzapur. They found that bacteriophages specific for Salmonella Typhi were present in 31% of environmental samples in Dhaka, compared to just 3% of samples from Mirzapur. This corresponds to results from more than 8,400 blood cultures, in which 5% of cultures from Dhaka and 0.05% from Mirzapur tested positive.

The new results suggest that detecting bacteriophages specific for Salmonella Typhi may be a rapid environmental surveillance method that could help decision makers understand the presence of typhoid fever in the community. The researchers propose that environment monitoring of bacteriophage could be a simple, cost-effective and scalable tool to assist policy decisions on typhoid control.

The authors add: “Looking for bacteriophages in wastewater is a low-cost method for identifying typhoid hotspots without doing expensive blood cultures on thousands of people.”

Rare-X 2024 a Beacon of Hope for Those Living with Rare Diseases

Source: Unsplash CC0

Amongst the intricacies of South Africa’s healthcare landscape, a silent but significant challenge lurks – the prevalence of rare diseases. Behind the curtain of mainstream medical discourse, millions grapple with the complexities of these often overlooked conditions, a stark reality often overshadowed by the glare of more prevalent health concerns. 

With more than 7000 identified rare diseases to date, they affect as many as 4.2 million South Africans, of which 50 – 70% are children1. These conditions are more prevalent than predicted, each posing unique and often debilitating challenges for patients and families alike. 

With 29 February commemorated as Rare Diseases Day, Rare Diseases South Africa (RDSA), is hosting its third biennial rare diseases conference, Rare-X 2024, at the Indaba Hotel in Fourways, from 14 to 17 February. 

More than just a conference, Rare-X 2024 will focus on patient advocacy, education, policy reform, and improving equitable access to ensure better outcomes and support for individuals living with rare diseases.

As the first in-person conference since the COVID-19 pandemic, the event brings together patients, policymakers, academics, government and pharmaceutical companies to discuss the plight of rare diseases and find collaborative ways to improve patients’ lives and treatment efforts. 

The conference will comprise several activities, including keynote speeches by renowned experts in rare diseases; interactive panel discussions; workshops and training sessions; scientific presentations; networking opportunities and policy roundtables. 

Some of the renowned speakers to share their insights and global developments on rare diseases include Prof Alex van den Heever, Chair of Social Security Systems Administration and Management Studies at the Wits School of Governance; Professor Fatima Suleman, Professor in the School of Health Sciences at the University of KwaZulu-Natal; and Professor Chris Hendriksz, Global Clinical Development Lead for Rare Diseases at Nestle Health Science, amongst others. Bringing a wealth of practical experience following his work with health professionals, will be traditional health practitioners (THPs), Mr Elliot Makhathini and Dr Conradie from North-West University’s Centre for Human Metabolomics, to name a few.

A rare disease relates to a condition that is considered rare when it affects one person in 20002. Currently, South Africa does not have its own definition of a rare disease, which is one of the major issues that need to be addressed by the government3.

As a patient-focused non-profit organisation, RDSA was launched in 2013 by CEO and Rare-X Director, Kelly du Plessis. The mother of a child with a rare condition, du Plessis realised the dire need for support for a highly under-acknowledged community, with the organisation advocating that people living with rare diseases and congenital disorders experience greater recognition, support, improved health services, and overall, a better quality of life. 

“Despite the need for increased representation, the rare diseases community remains vulnerable from a medical and policy perspective,” says du Plessis. “As part of our mandate, RDSA brings together international best practice and local medical innovation, driving a collective voice and playing a fundamental role in bridging the gap between vulnerable communities and medical advancement.”

To date, RDSA has successfully launched initiatives that have positively impacted the lives of over 6500 patients including engaging with various governmental departments, organs of state, industry players and strategic stakeholders to raise awareness and move rare disease policy forward.

For more information on the Rare-X conference, kindly visit www.rare-x.co.za 

References:

1. Marhebe, HL. Introducing the South African Rare Diseases Access Initiative. SAMJ. 2023;113(8).

2. Reserved IUA. Orphanet: About rare diseases [Internet]. [cited 2024 Feb 2]. Available from: https://www.orpha.net/consor/cgi-bin/Education_AboutRareDiseases.php?lng=EN

3. FAQs [Internet]. Rare Diseases SA. [cited 2024 Feb 2]. Available from: https://www.rarediseases.co.za/faqs

Rickets in the Industrial Revolution Driven by Low Vitamin D

Photo by Mayur Gala on Unsplash

Rickets ran rife in children following the Industrial Revolution, but University of Otago-led research has found factory work and polluted cities aren’t entirely to blame for the period’s vitamin D deficiencies.

In a study published in PLOS One, researchers sampled teeth from a cemetery site in industrial era England, looking for microscopic markers of nutritional disease.

Lead author Dr Annie Sohler-Snoddy, Research Fellow in Otago’s Department of Anatomy, says they uncovered some of the first clear evidence of seasonal vitamin D deficiency in an archaeological sample.

She says it has been known for many years that there was an increase in rickets, a childhood bone disease caused by vitamin D deficiency, in 18th and 19th Century Europe.

“It has been assumed that this was due to more people, including children, working long hours indoors, living in crowded housing and in smog-filled environments, all of which reduce the amount of sunlight that reaches a person’s skin, which is the main way humans make vitamin D.”

However, new bioarchaeological methods enabled the researchers to get a much clearer picture of how vitamin D deficiency affected the people living in industrial England, rather than looking at bone deformities alone.

The study, from Otago, Durham University, University of Edinburgh, University of Brighton, and University of Queensland, found markers associated with vitamin D deficiency in the interior part of 76% of the teeth analysed.

In many samples, these occurred regularly, in annual increments.

“This shows clear evidence of seasonal vitamin D deficiency in the teeth of people living in the north of England.

“This is exciting because it highlights that latitude and seasonal lack of sunlight was a major factor in the amount of vitamin D these people could make in their skin – it’s more complicated than the factors associated with the industrial revolution like working indoors more,” Dr Sohler-Snoddy explains.

Poor vitamin D status is associated with several negative health outcomes including increased risk for infectious diseases, cardiovascular disease, and cancers.

Vitamin D deficiency has been an ongoing problem in society and Dr Sohler-Snoddy believes it is important to study what happened in the past in order to inform modern approaches to the ailment.

“We tend to think of archaeological human remains as belonging to a different world, but our biology hasn’t changed in the last 200 years.

“Teeth provide a really important source of information for archaeologists as they form in a very precise chronology and, importantly, their tissues do not change over the lifespan. This means that they lock in a record of a person’s development and this stays with them until they die, or the tooth is lost.

“Understanding how vitamin D deficiency impacted past populations and why gives us an important deep-time perspective on the disease,” she says.

Source: University of Otago

Antibiotic-resistant Bacteria can Persist in the Body for Years

Photo by CDC on Unsplash

People with pre-existing conditions in particular can carry resistant germs and suffer from repeated infections for years, according to a study in the scientific journal Nature Communications.

Some bacteria have developed the ability to break down beta-lactam antibiotics like penicillins and cephalosporins, making them ineffective.

Once a patient’s body has been colonised by these resistant bacteria, they can persist for a long time, reports Professor Sarah Tschudin Sutter’s research group at the Department of Clinical Research of the University of Basel and University Hospital Basel.

The researchers looked at a much longer period of time than previous studies and focused on older people with pre-existing conditions, analysing multiple samples taken from over 70 individuals over a period of ten years.

Their key question: whether and how resistant Klebsiella pneumoniae and Escherichia coli bacteria in the body change over this long period and how they differ in various parts of the body.

Recurring illness

DNA analysis indicates that the bacteria initially adapt quite quickly to the conditions in the colonized parts of the body, but undergo few genetic changes thereafter.

The resistant bacteria could still be detected in the patients up to nine years later.

“These patients not only repeatedly become ill themselves, they also act as a source of infection for other people — a reservoir for these pathogens,” says Dr Lisandra Aguilar Bultet, the study’s lead author.

“This is crucial information for choosing a treatment,” explains Professor Tschudin Sutter.

If someone has previously been infected with resistant bacteria and later requires another course of treatment because of a new infection, there is a risk that standard antibiotics will again fail to work.

Transmission of resistance

In addition, the researchers found that in some patients, bacterial strains of the same species, as well as of different species (specifically, Klebsiella pneumoniae and Escherichia coli), share identical genetic mechanisms of resistance through what are known as mobile genetic elements (such as plasmids). The most likely explanation is that they have transmitted these elements to each other.

Hospitals use special protective measures if a patient has been infected with resistant bacteria in the past.

In everyday life, however, it is difficult to reduce the risk of pathogen transmission.

These findings about the bacterial genetic diversity expected to develop in individual patients over time are a valuable basis for future studies to analyse factors found in both bacteria and patients that correlate with duration of colonisation and progression from colonisation to infection.

Source: University of Basel

SGLT-2 Inhibitor Use Associated with Decreased Risk of Kidney Stones

Photo by Robina Weermeijer on Unsplash

Type 2 diabetes is associated with increased risk of kidney stones, but some forms of treatment for this condition may also have the benefit of lowering risk of kidney stones. In a study led by investigators from Mass General Brigham, researchers found that there was an association between the use of sodium-glucose cotransporter 2 (SGLT2) inhibitors and a lower risk of developing kidney stones. Their findings are reported in JAMA Internal Medicine.

Rates of kidney stones are on the rise in the United States and around the world. Type 2 diabetes is associated with increased risk of kidney stones, but some forms of treatment for this condition may also have the benefit of lowering risk of kidney stones.

The study included data from three nationwide databases of patients with type 2 diabetes who were seen in routine clinical practice.

The team analysed information from 716,406 adults with type 2 diabetes who had started taking an SGLT2 inhibitor or two other classes of diabetes medications known as GLP1 receptor agonists or dipeptidyl peptidase 4 (DPP4) inhibitors.

Patients who began taking SGLT2 inhibitors had a 30% lower risk of developing kidney stones than those taking GLP1 agonists and about a 25% lower risk than those taking DPP4 inhibitors.

The findings were consistent across sex, race/ethnicity, history of chronic kidney disease and obesity.

“Our findings could help inform clinical decision making for patients with diabetes who are at risk for developing kidney stones,” said corresponding author Julie Paik, MD, ScD, MPH, of the Division of Pharmacoepidemiology and Pharmacoeconomics and the Division of Renal (Kidney) Medicine at Brigham and Women’s Hospital.

Source: Mass General Brigham

Materials provided by Mass General BrighamNote: Content may be edited for style and length.


Journal Reference:

  1. Julie M. Paik, Helen Tesfaye, Gary C. Curhan, Heidi Zakoul, Deborah J. Wexler, Elisabetta Patorno. Sodium-Glucose Cotransporter 2 Inhibitors and Nephrolithiasis Risk in Patients With Type 2 DiabetesJAMA Internal Medicine, 2024; DOI: 10.1001/jamainternmed.2023.7660

Healthcare Workers among Those Who Conceal their Infectious Illness

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A startling number of people – including healthcare workers – conceal an infectious illness to avoid missing work, travel, or social events, new research at the University of Michigan suggests. The findings however, reported in Psychological Science, exclude being ill with COVID.

Across a series of studies involving healthy and sick adults, 75% of the 4110 participants said they had either hidden an infectious illness from others at least once or might do so in the future.

Many participants reported boarding planes, going on dates, and engaging in other social interactions while secretly sick.

More than 61% of healthcare workers participating in the study also said they had concealed an infectious illness.

Interestingly, the researchers found a difference between how people believe they would act when ill and how they actually behave, said Wilson N. Merrell, a doctoral candidate and lead author on the study.

More than 61% of healthcare workers participating in the study also said they had concealed an infectious illness.

Interestingly, the researchers found a difference between how people believe they would act when ill and how they actually behave, said Wilson N. Merrell, a doctoral candidate and lead author on the study.

“Healthy people forecasted that they would be unlikely to hide harmful illnesses – those that spread easily and have severe symptoms – but actively sick people reported high levels of concealment regardless of how harmful their illness was to others,” Merrell said.

In the first study, Merrell and his colleagues, psychology professor Joshua M. Ackerman and PhD student Soyeon Choi, recruited 399 university healthcare employees and 505 students.

The participants reported the number of days they felt symptoms of an infectious illness, starting in March 2020, when the COVID pandemic began.

They then rated how often they actively covered up symptoms from others, came to campus or work without telling others they were feeling ill, or falsified mandatory symptom screeners that the university had required for anyone using campus facilities.

More than 70% of the participants reported covering up their symptoms.

Many said they hid their illness because it would conflict with social plans, while a small percentage of participants cited pressure from institutional policies (eg, lack of paid time off). Only five participants reported hiding a COVID infection.

In a second study, the researchers recruited 946 participants online and randomly assigned them to one of nine conditions in which they imagined being either moderately or severely sick while in a social situation.

In each condition, the risk of spreading the illness was designated as low, medium, or high.

(To control for the special stigma associated with COVID at the time, the researchers asked participants not to imagine being sick with that disease.) Participants were most likely to envision themselves hiding their sickness when symptom severity was low, and least likely to conceal when symptoms were severe and highly communicable.

Source: Association for Psychological Science

Hydroxyurea for Children with Sickle Cell Anaemia Significantly Reduces Infections

Sickle cell disease. Credit: National Institutes of Health

A clinical trial in Uganda has revealed that hydroxyurea significantly reduces infections in children with sickle cell anaemia. Their latest findings enhance strong evidence of hydroxyurea’s effectiveness and could ultimately reduce death in children in Africa, the continent most burdened by the disease.

The group’s research, appearing in the journal Blood, revealed that hydroxyurea treatment resulted in a remarkable 60% reduction in severe or invasive infections, including malaria, bacteraemia, respiratory tract infections and gastroenteritis, among Ugandan children with sickle cell anaemia.

“Our investigation provides powerful justifications for hydroxyurea’s use in children with sickle cell anaemia in Africa,” said Dr Chandy John, paediatrics professor at IU School of Medicine and co-lead investigator of the latest study.

“Given the high rates of infection in this region, we hope our evidence will encourage ministries of health to continue supporting and expanding access to hydroxyurea for young patients who can greatly benefit from the treatment.”

Sickle cell anaemia is a genetic blood disorder that alters the structure of red blood cells and affects oxygen distribution throughout the body, increasing susceptibility to serious health complications and life-threatening infections.

According to the World Health Organization, more than 300 000 children worldwide are born with sickle cell disease each year, with a high prevalence found in African countries.

While hydroxyurea has had U.S. Food and Drug Administration approval as a sickle cell disease treatment for children since 2017, its accessibility and acceptance in Africa have been comparatively limited.

As hydroxyurea has become more recognised in African countries for its effectiveness in treating sickle-cell-related complications, John and his colleagues noticed a knowledge gap about the treatment’s effect on infections.

This led the research group to incorporate hydroxyurea treatment and analysis into their established clinical trial, Zinc for Infection Prevention in Sickle Cell Anemia, led by Indiana University School of Medicine and collaborators in Uganda.

During the study, the researchers examined the effects of hydroxyurea on 117 children in Uganda and focused on a range of infections. After hydroxyurea treatment, results showed a substantial decrease in the incidence of these infections.

Additionally, eight of the nine deaths that occurred in the trial were children whose parents declined hydroxyurea treatment. The only death in a child on hydroxyurea treatment occurred four days after starting treatment, providing insufficient time for hydroxyurea to have an effect.

Of the five children for whom a cause of death was known, all five died of infectious causes.

The high death rate in the study, despite expert clinical care by study personnel, provides further evidence of the urgent need for additional interventions to decrease mortality in children with sickle cell disease in Africa.

“Infections commonly precede other complications related to sickle cell anaemia and often result in hospitalizations that can lead to death,” said Dr Ruth Namazzi, site principal investigator, first author and a lecturer in the Department of Pediatrics and Child Health at Makerere University in Uganda.

“We believe incorporating hydroxyurea treatment as the standard of care for sickle cell anaemia across Africa will not only reduce infections but will more importantly save countless lives.”

Source: Indiana University

GLP-1 Agonists Associated with Reduced Risk of Liver Diseases

By HualinXMN – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=133759262

GLP1 agonists such as Ozempic (semaglutide) are associated with a reduced risk of developing cirrhosis and liver cancer in people with type 2 diabetes and chronic liver disease, according to a nationwide study from Karolinska Institutet published in the journal Gut.

GLP1 agonists reduce blood sugar levels and are mainly used to treat type 2 diabetes. Since the drug also reduces appetite, it is now increasingly used to treat obesity and has become a popular weight-loss drug.

Reduced risk of liver damage

Results from early clinical trials also suggest that GLP1 agonists may reduce the risk of liver damage. Therefore, researchers at Karolinska Institutet included all people in Sweden with chronic liver disease and type 2 diabetes in a register-based study. They then compared the risk of severe liver damage in those who were treated with GLP1 agonists and those who were not. The results show that those who took the drug for a long period of time had a lower risk of later developing more severe forms of liver disease such as cirrhosis and liver cancer.

According to the researchers, this suggests that GLP1 agonists could be an effective treatment to avoid severe liver disease in people with concurrent type 2 diabetes.

“Fatty liver disease is estimated to affect up to one in five people in Sweden, many of whom have type 2 diabetes, and about one in twenty develop severe liver disease,” says first author Axel Wester, assistant professor at the Department of Medicine, Huddinge, Karolinska Institutet. “Our findings are interesting because there are currently no approved drugs to reduce this risk.”

Many of the people in the study stopped taking GLP1 agonists, resulting in a lack of protective effect. However, those who continued taking their medication over a ten-year period were half as likely to develop severe liver disease.

Clinical trials needed for confirmation

“The results need to be confirmed in clinical trials, but it will take many years for these studies to be completed,” says Axel Wester. “Therefore, we use existing registry data to try to say something about the effect of the drugs before that.”

A limitation of the method is that it is not possible to control for factors for which there is no data, such as blood tests to describe the severity of liver disease in more detail. However, the researchers have recently built a new database called HERALD where they have access to blood samples from patients in Region Stockholm.

“As a next step, we will investigate the effect of GLP1 agonists in this database,” says the study’s last author Hannes Hagström, consultant in hepatology at the Karolinska University Hospital and adjunct professor at the Department of Medicine, Huddinge, Karolinska Institutet. “If we get similar results, it would further strengthen the hypothesis that GLP1 agonists can be used to reduce the risk of severe liver disease.”

The research was mainly funded by Region Stockholm (CIMED), the Swedish Research Council and the Swedish Cancer Society. Hannes Hagström’s research group has received funding from Astra Zeneca, EchoSens, Gilead, Intercept, MSD, Novo Nordisk and Pfizer, although no industry-supported funding was obtained for this specific study.

Source: Karolinska Institutet

‘Exhalation’ System Improves Symptoms for Chronic Sinusitis

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An exhalation delivery system that uses a patient’s own breath to carry the anti-inflammatory compound fluticasone (EDS-FLU) directly to the sinuses reduced chronic sinusitis symptoms as well as aggravations and infections associated with chronic sinus inflammation by more than 50%, researchers from the Perelman School of Medicine at the University of Pennsylvania reported.

The two randomised, international clinical trials (NCT03781804 and NCT03960580), published in The Journal of Allergy and Clinical Immunology: In Practice, compared EDS-FLU to a placebo in more than 500 adults with chronic rhinosinusitis with or without nasal polyps. Patients used either EDS-FLU or a placebo twice daily for 24 weeks.

EDS-FLU works through a patient exhaling into the device to send the medication deep into the far reaches of their sinus cavities, where the topical medication is most effective. Sinus symptom scores and CT scan results were significantly improved vs placebo.

Symptoms of nasal congestion, nasal discharge, facial pain/pressure, and loss of smell improved dramatically with EDS-FLU compared to placebo, as measured by the sinonasal outcome test-22, a standardized scoring measure for sinonasal symptoms.

“Chronic sinusitis affects as much of 10 percent of the United States population, and can make breathing uncomfortable and negatively impact a person’s daily life,” said lead author James N. Palmer, MD, professor of otorhinolaryngology and director of Rhinology at Penn Medicine.

“These findings provide strong evidence for an effective, non-invasive treatment option for people who continue to experience symptoms after over-the-counter medications have failed.”

Millions of Americans experience the symptoms of chronic sinus infections and inflammation, a largely inflammatory condition that causes nasal congestion, sinus pressure, and pain, when the sinus membranes are inflamed for long periods of time.

Although over-the-counter nasal sprays offer marginal relief, no FDA-approved medication exists for the most common form of the condition, chronic rhinosinusitis without nasal polyps, known as “chronic sinusitis.”

While some nasal sprays may offer some symptom relief, patients who were using a standard-delivery nasal spray before study enrollment still reported similar improvements in symptoms compared to others in the study.

These are the first placebo-controlled clinical trials to show that a medication reduces subjective symptoms and objective measures of sinus disease for patients with chronic sinusitis, both with and without polyps.

Currently, patients whose symptoms are not resolved by over-the-counter nasal sprays or other medications, have limited options for relief, including antibiotics, surgery, or in the case of nasal polyps, lifelong biologic therapies.

EDS-FLU was determined to be as safe as standard over the counter nasal sprays.

Source: University of Pennsylvania School of Medicine

Clear Link between Autoimmune Disease and Perinatal Depression

This is a pseudo-colored image of high-resolution gradient-echo MRI scan of a fixed cerebral hemisphere from a person with multiple sclerosis. Credit: Govind Bhagavatheeshwaran, Daniel Reich, National Institute of Neurological Disorders and Stroke, National Institutes of Health

Women with autoimmune disease are more likely to suffer from depression during pregnancy and after childbirth; conversely, women with a history of perinatal depression are at higher risk of developing autoimmune disease, according to a new study from Karolinska Institutet which is published in the journal Molecular Psychiatry.

Some of the most common autoimmune diseases are gluten intolerance (coeliac disease), autoimmune thyroiditis, rheumatoid arthritis, type 1 diabetes, and multiple sclerosis (MS). 

In the present study, researchers used data from the Swedish Medical Birth Register and identified all women who had given birth in Sweden between 2001 and 2013. Out of the resulting group of approximately 815 000 women and 1.3 million pregnancies, just over 55 000 women had been diagnosed with depression during their pregnancy or within a year after delivery. 

The researchers then compared the incidence of 41 autoimmune diseases in women with and without perinatal depression, controlling for familial factors such as genes and childhood environment by also including the affected women’s sisters.

Strongest association for MS

The results reveal a bidirectional association between perinatal depression and autoimmune thyroiditis, psoriasis, MS, ulcerative colitis, and coeliac disease. Overall, women with autoimmune disease were 30 per cent more likely to suffer perinatal depression. Conversely, women with perinatal depression were 30 per cent more likely to develop a subsequent autoimmune disease.

The association was strongest for the neurological disease MS, for which the risk was double in both directions. It was also strongest in women who had not had a previous psychiatric diagnosis.

“Our study suggests that there’s an immunological mechanism behind perinatal depression and that autoimmune diseases should be seen as a risk factor for this kind of depression,” says the study’s first author Emma Bränn, researcher at the Institute of Environmental Medicine at Karolinska Institutet.

Can have serious consequences

The researchers will now continue to examine the long-term effects of depression during pregnancy and in the first year following childbirth.

“Depression during this sensitive period can have serious consequences for both the mother and the baby,” says Dr Bränn. “We hope that our results will help decision-makers to steer funding towards maternal healthcare so that more women can get help and support in time.”

Since this was an observational study, no conclusions on causality can be drawn.

The study was financed by Karolinska Institutet, Forte (the Swedish Research Council for Health, Working Life and Welfare), the Swedish Research Councill and the Icelandic Research Fund. The researchers report no conflicts of interest.

Source: Karolinska Institutet