The research has created the first detailed and up-to-date map of dengue distribution worldwide, enabling researchers to estimate the total numbers of people affected by the virus globally, regionally and nationally. The findings will help to guide efforts in vaccine, drug and vector control strategies.
The study was led by Professor Simon Hay, a Wellcome Trust Senior Research Fellow at the University of Oxford, as part of the International Research Consortium on Dengue Risk Assessment, Management and Surveillance.
Dengue, also known as 'breakbone fever', is a viral infection that is transmitted between humans by mosquitoes. In some people, it causes life-threatening illness.
There are currently no licensed vaccines or specific treatments for dengue, and substantial efforts to control the mosquitoes that transmit the disease have not stopped its rapid emergence and global spread. Until now, little was known about the current distribution of the risk of dengue virus infection and its public health burden around the world.
Dr Samir Bhatt, who led the modelling for the study, says: "Our aim was to take all of the evidence that is currently available on the distribution of dengue worldwide and combine it with the latest in mapping and mathematical modelling to produce the most refined risk maps and burden estimates. We then hope to use this knowledge to help predict the future burden of the disease."
The findings reveal that dengue is ubiquitous throughout the tropics, with local spatial variations in risk influenced strongly by rainfall, temperature and urbanisation. The team estimate that there are 390 million dengue infections across the globe each year, of which 96 million reach any level of clinical or subclinical severity. This is more than triple the WHO's most recent estimates of 50-100 million infections per year.
Professor Simon Hay explains: "We found that climate and population spread were important factors for predicting the current risk of dengue around the world. With globalisation and the constant march of urbanisation, we anticipate that there could be dramatic shifts in the distribution of the disease in the future: the virus may be introduced to areas that previously were not at risk, and those that are currently affected may experience increases in the number of infections.
"We hope that the research will initiate a wider discussion about the significant global impact of this disease."
Of the 96 million apparent infections, Asia bore 70 per cent of the burden. India alone accounted for around one-third of all infections. The results indicate that with 16 million infections, Africa's burden is almost equivalent to that of the Americas and is significantly larger than previously appreciated. The authors suggest that the hidden African dengue burden could be a result of the disease being masked by symptomatically similar illnesses, under-reporting and highly variable treatment-seeking behaviour.
Professor Jeremy Farrar, Director of the Wellcome Trust Vietnam Research Programme and Oxford University Clinical Research Unit Hospital for Tropical Diseases in Vietnam, explains that the map and estimates produced by Hay's group set the benchmark for the disease: "This is the first systematic robust estimate of the extent of dengue. The evidence that we've gathered here will help to maximise the value and cost-effectiveness of public health and clinical efforts, by indicating where limited resources can be targeted for maximum possible impact
With endemic transmission in Asia and the Americas, recent outbreaks in Portugal, the ever-increasing incidence in Africa, and the challenges of making an effective dengue vaccine or controlling the vector, Professor Farrar stresses: "This really does represent a crucial period in the global spread of dengue."
Jimmy Whitworth, Head of International Activities at the Wellcome Trust, said: "Over time, this comprehensive map of global disease burden will also help to demonstrate which control measures are making the biggest difference in reducing the number of people suffering from dengue infection. Without a vaccine or specific treatment options, it's crucial that we understand where best to direct the limited resources available for preventing this resurgent disease."
The International Research Consortium on Dengue Risk Assessment, Management and Surveillance is a multinational team of researchers funded by the European Commission to develop new and innovative tools to be applied to the control of dengue in a global context. This study also received funding from the Wellcome Trust, the Department of Homeland Security, Li Ka Shing Foundation and the Fogarty International Center, National Institutes of Health.
The publication of the findings coincides with the first regional meeting of the World Health Summit in Singapore, where health care policy makers, experts, and practitioners are coming together to exchange ideas and find solutions for today's health challenges in Asia.
Jen Middleton | EurekAlert!
Investigators may unlock mystery of how staph cells dodge the body's immune system
22.09.2017 | Cedars-Sinai Medical Center
Monitoring the heart's mitochondria to predict cardiac arrest?
21.09.2017 | Boston Children's Hospital
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy