A new wearable device developed by engineers in Britain that promises to revolutionise the way dengue fever is treated is being trialled in Vietnam.
The device, called D-Scape (Dengue Shock and Classification Prediction Wearable), consists of a small wrist-mounted band that looks like a high-tech smartwatch, and a second sensor clipped to the little finger.
Together with on-board AI algorithms, they monitor the vital signs of dengue patients non-invasively, providing doctors with a continuous stream of data about their condition to help them spot which ones are progressing to severe disease.
While in Europe and the West we are, so far, largely unaffected by dengue, it has far reaching effects on swathes of the developing world. Nearly half the world’s population lives alongside the Aedes mosquitoes that carry it, leading to between 100 and 400 million infections a year.
While many who catch it will suffer only flu-like symptoms and recover on their own, dengue – also known as break-bone fever – can be an exceptionally nasty disease.
In severe cases it takes on characteristics more akin to a haemorrhagic fever like Ebola or Marburg, causing plasma to leak from your blood vessels, leading to severe organ damage and uncontrollable bleeding. In 2024 some 9,500 people died in this way.
But dengue is also fickle, and spotting the point at which an infection has progressed to a severe state is a challenge – patients will often deteriorate suddenly after the fever subsides – and early identification gives the best chance of a successful outcome.
“The thing with dengue is that we have a lot of patients with infections – but we don’t know who will progress to severe disease,” said Dr Ho Quang Chanh, Head of the Dengue Research Group at the Oxford University Clinical Research Unit (OUCRU) in Ho Chi Minh City, who helped oversee the D-Scape trial.
“So that leads to really major problems with the resources that we need to spend, all of the capacity we need to build for the disease. And it happens every year,” he said.
“We need to check on the patients every three to four hours. In severe cases, every hour. So these nurses and doctors here – during the [dengue] season, during the night shifts – they can’t sleep because we need to be constantly checking on the patients’ vital signs, measuring them manually with blood tests.”
The device could spot early signs of severe dengue to reduce reliance on invasive tests and improve care – OUCRU Vietnam
It is hoped that the new device can change the way dengue is treated, giving doctors a much clearer picture of how their patients are progressing without the need for invasive tests that can be difficult to administer in over-stretched dengue wards.
At the heart of the wrist mounted device is essentially a more advanced version of the flickering green sensor under your smartwatch, which uses light to ‘see’ through the skin and measure minute changes in the blood through a process called photoplethysmography (PPG).
Along with blood pressure and blood oxygen levels, what the device is looking at is the proportion of red blood cells in the blood – also known as haematocrit – which is a key indicator of the plasma leak syndrome that occurs in some dengue infections.
Prof Pantelis Georgiou, who developed the technology with a team at Imperial College London with support from OUCRU and LifeArc, the not-for-profit medical research organisation, said: “We shine light at different wavelengths to what you would expect in a conventional wrist-worn PPG sensor such as a smartwatch. And we get a lot of information from the blood.
“We’re getting continuous data of haemodynamic parameters from the patient, and with that, we can classify if somebody’s progressing to severe dengue.”
The device’s makers say it could also be used to monitor other life-threatening conditions, including other infections and sepsis.
The pilot phase of the trial in Vietnam involved 25 dengue patients using a first-generation device which is performing well, said Prof Georgiou.
“It’s performing very well because it’s giving us rich information in real time, which you wouldn’t have otherwise,” he said.
The researchers plan to expand their trial with a second-generation device and 100 patients, before bringing the final product to market.
“We’re advancing through this project to a version that is completely miniature. So it’ll be a watch and a finger probe that you can wear and be mobile,” said Prof Georgiou.
“Because we’re designing it for low- and middle-income countries, we’re trying to reduce the cost as much as possible so that it’s affordable and widely deployable,” he said, adding that the current target was for the final device to cost less than $500 (£365).
Dr Ho Quang Chanh treats a dengue patient in Vietnam – OUCRU Vietnam
Having a device that is portable and easy enough for patients to use could allow doctors to send them home – something which would ease the pressure dengue can exert on hospital bed space when an outbreak really gets going.
Dr Chanh said: “I think the future of dengue management is if we can find a way to monitor the patient and keep most of the patients safe at home, instead of admitting a bunch of people into the hospital and just waiting for five per cent of them to develop severe disease.”
Despite how widespread dengue is, doctors have relatively few tools in their arsenal to treat it. There is no specific treatment available – pain is usually managed with paracetamol – and while there is a vaccine, it is generally only recommended for people who have already had dengue and are therefore at heightened risk from a second infection.
Dengue is a growing global threat, with the mosquitoes that carry it encroaching on new areas including Italy and France because of a range of factors including climate change and international trade.
Dr Chanh, who has worked on dengue for over a decade, said: “In the last 50 years, there has been a 30-times increase in dengue incidence. And in the last 10 years, I think the incidence has doubled.”
The burden this is having on the globe is significant – dengue is predicted to cost the global economy some $306 bn between 2020 and 2050.
Ghada Zoubiane, Head of Global Health at LifeArc, which is funding the trial, said: “Wearable technology is rapidly becoming part of everyday life, and D-Scape takes this further, offering a non-invasive and more accessible monitoring method to predict severe dengue and ultimately save lives.”
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