April 8, 2013
Three Times More People Suffering From Dengue Fever Than Previously Believed
redOrbit Staff & Wire Reports - Your Universe Online
Nearly 400 million people are infected with dengue fever each year, meaning that the world´s fastest-spreading tropical illness is affecting three times more people than the World Health Organization (WHO) had previously estimated.Following several years of research, experts from the University of Oxford and the Wellcome Trust revealed those statistics, as well as a detailed map of regions affected by the mosquito-borne virus, in Sunday´s edition of the journal Nature.
The new figures include 96 million severe cases and approximately 300 million mild cases of the disease, compared to the WHO´s most recent estimate of 50 to 100 million episodes each year, reports Ben Hirschler of Reuters.
“Dengue is one of the few infectious diseases increasing its global spread and the number of cases annually,” Jeremy Farrar, a clinician and infectious disease specialist at the University of Oxford Clinical Research Unit in Ho Chi Minh City, Vietnam, told Science Now on Sunday.
He added that it is “crucial” that scientists “understand where the disease is today and have an understanding of where it may be tomorrow,” but said that those efforts have been hampered by incomplete reporting, a lack of data on mild-cases of the disease, and unscientific approximations.
To better understand exactly how large a threat dengue fever is, Farrar and epidemiologist Simon Hay established a team which completed more than 8,000 reports of infections of the viral illness. They also considered new evidence on risk factors, including population growth in urban areas where disease-carrying mosquitoes could bite and infect multiple people in a short period of time.
Using a new set of modeling techniques, the researchers determined that 96 million people were forced to go to medical centers or miss work or school because of the ailment also known as “breakbone fever” due to the severe pain it causes. Another 294 million had low-grade or asymptomatic infections, they added.
Of the 96 million noticeable infections, 70 percent of them were in Asia, and India alone was responsible for roughly one-third of all cases. They also reported that Africa had 16 million infections — far more than previously believed. The authors hope that their more precise statistics and mapping of the disease´s distribution will help public health officials better plan their vaccination and mosquito control efforts in the future.
“We found that climate and population spread were important factors for predicting the current risk of dengue around the world. With globalization and the constant march of urbanization, 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,” Hay said in a statement. “We hope that the research will initiate a wider discussion about the significant global impact of this disease.”
“This is the first systematic robust estimate of the extent of dengue. The evidence that we've gathered here will help to maximize the value and cost-effectiveness of public health and clinical efforts, by indicating where limited resources can be targeted for maximum possible impact,” Farrar added.