# 5264
2010 was the year that Dengue Fever finally began to receive the public attention here in the United States (and in the rest of the developed world) that it truly deserves.
As is too often the case, our newfound concern has been largely spurred – not by concerns over the huge burden the disease has placed in poorer tropical regions for decades – but by the recent influx of cases into more developed countries.
The return of dengue fever to Florida after an absence of 60 years, and the worst epidemic of Dengue fever in Puerto Rico in decades, have both raised awareness.
Similarly, locally acquired dengue has been showing up in Australia and Hong Kong, and in travelers returning from areas where the virus is endemic.
As Maryn McKenna wrote yesterday in her blog (see Spreading cholera, maybe polio: Now will we care about Haiti?) - “infectious diseases do not respect borders”.
Unlike even a few decades ago, we cannot depend upon vast oceans and prolonged travel times to protect us against the encroachment of exotic diseases into previously immunologically naive regions.
Simply put, we neglect them at our own peril.
While our dengue awareness may be relatively new, the explosion in cases has been accelerating for decades. The World Health Organization now estimates there may be as many as 50 million dengue infections each year.
Since the 1950s a rare, but far more serious form of the disease – DHF or (Dengue Hemorrhagic Fever) – has emerged.
PAHO recently released new numbers on dengue in the Americas for 2010, in this pdf file, dated December 10th. So far, more than 1.5 million cases have been reported (many more are likely undiagnosed).
Over the past few months we’ve seen a number of reports on novel attempts to prevent dengue by controlling the mosquito vector, including:
The Cayman Island Mosquito Trials
Malaysia: `Terminator’ Mosquito Field Test On Hold
The introduction of GM (genetically modified) mosquitoes have exciting possibilities, but their effectiveness in the wild remains unproven.
The other big hope is to come up with a safe, effective, and affordable vaccine. And a number of vaccine candidates have been under study for several years.
I’ve written in the past about the race to produce a safe and effective dengue vaccine by number of different companies and entities, including Sanofi, the NIAID vaccine trials, GlaxoSmithKline , Hawaii Biotech Inc (HBI), and an entry created by Inviragen and the CDC.
One of the major obstacles in developing a vaccine is that there are four strains of dengue; DEN1 – DEN4. Single strain live attenuated Dengue vaccines have been developed and tested, and seem effective.
They aren’t considered a good solution, however, because having antibodies to one strain of dengue can make an individual more likely to develop the more dangerous hemorrhagic form of dengue when exposed to a different strain.
Today, a correspondence appears in The Lancet (free registration required for access), outlining progress being made towards a viable dengue vaccine.
The Lancet, Volume 377, Issue 9763, Pages 381 - 382, 29 January 2011
doi:10.1016/S0140-6736(11)60128-
Dengue vaccine prospects: a step forward
Bruno Guy a, Jeffrey Almond a, Jean Lang a
PREVIEW
The worldwide expansion of dengue fever is a growing health problem. Crucial issues surround this global expansion and some of them present some challenges for vaccine development. Nevertheless, several promising approaches are being investigated in both academic and industrial laboratories.1 Vaccine candidates include live, attenuated vaccines obtained via cell passages or by recombinant DNA technology (such as those being developed by the US National Institutes of Allergy and Infectious Diseases, InViragen, Walter Reed Army Institute of Research/GlaxoSmithKline, and Sanofi Pasteur), and subunit vaccines (such as those developed by Merck/Hawaii Biotech).
While the authors state that - `a dengue vaccine is now within reach’ and `we can reasonably expect to address the crucial and urgent medical need for this vaccine in the near future’ - human clinical trials are just starting, and a safe, effective, and available vaccine is still several years away.
But it is progress.
