Antibody Capable Of Neutralizing The Dengue Virus

theyucatantimes.com

Imperial College London

A team of scientists from the Imperial College London have discovered a new class of antibodies capable of neutralizing the four ways in which the dengue virus manifests, published today The British journal “Nature Immunology” .

This new type of antibodies found in humans, which also neutralizes the initial state of this virus in mosquitoes, could lead to the development of effective vaccines and treatments to combat the disease. Dengue fever is a virus transmitted by the bite of mosquitoes “aedes” family and infects about 400 million people each year, especially in tropical and subtropical areas of the world and one of the main problems with the virus, is that there are many types of dengue and the fact of having had one of them, does not immunize the rest.

In the report, the investigators note that the geographical spread of dengue is increasing because there has been an increased number of cases in Latin America and Australia, and could be extended to southern Europe.

 The lead researcher, Professor Gavin Screaton of Imperial College, said in a teleconference with reporters, that has taken more than ten years of study of the virus and said he does not believe that dengue can be controlled until a vaccine is developed. Screaton also noted that the development of a vaccine could take “considerable” time, because first has to be produced and tested it in nonhuman models.

Regarding virus penetration in Latin America, Screaton mentioned that although “there have been countries that have done good practices”, they have not prevented some severe outbreaks.

 Therefore, regarding measures to prevent the spread on a large scale, Screaton highlighted the importance of good practices, such as to fumigation, cleaning of deposits and not to store garbage in cities or in areas conducive to mosquito develops.

For the study, the team of scientists analyzed 145 samples of antibodies from patients who had been infected and developed an immune box. Thus, they found a number of antibodies that are effective neutralizing the virus.

The discovery opens the door to developing a future universal vaccine against dengue, although researchers nuance that still need to understand the human immune response to natural infections and see what their response to the post vaccination. Dengue causes high fever, headache, vomiting and skin rashes, and can be fatal in the hemorrhagic form.

Special rooms set up for dengue patients at Nishtar Hospital
Photo: tribune.com.pk

The World Health Organisation reports that 2.5 billion people, -more than 40 per cent of the world’s population- is at risk from dengue.

JJ Argáez/The Yucatan Times

More info at: http://www.nature.com/

Vaccine for Dengue Fever Possible by Next Year

by Murry Page

4 Nov 14 

mazmessenger.com

 

According to the results of a large clinical trial undertaken by Sanofi Pasteur, the drug’s manufacturer and the trial’s sponsor, the 20,000 people in Latin America, 10,000 of whom lived in México, who received three doses of the vaccine, reduced their overall risk of becoming infected by dengue fever by 60 percent. More significantly, the drug appears to be 95.5 percent protective against the most severe form of the disease, dengue hemorrhagic fever.

“There’s no vaccine for dengue currently, nor is there any specific treatment for managing illness in people who contract symptomatic dengue disease,” says Alain Bernal, a spokesperson for Sanofi Pasteur.

The researchers who conducted the first large clinical trial found that the vaccine was 56.6 percent effective against dengue, whereas results from a second clinical trial found that the vaccine reduced the incidence of dengue by 60.8 percent.

Scott Halstead, scientific adviser to the nonprofit Dengue Vaccine Initiative, told The New York Timesthat the results were “not anywhere close to what we had hoped, something that would reach up into the 90s.” And today, many researchers continue to express a need for a more effective vaccine.

According to Bernal, Sanofi Pasteur plans to file for registration of the vaccine in 2015, in countries where dengue is prevalent. That means that “the world’s first dengue vaccine could be available in the second half of 2015,” he says.

(from Milenio)

Why Mosquitoes Bite Some People More Than Others

Marie Callan - BanderasNews.com
July 24, 2014

Mosquitoes exhibit blood-sucking preferences, say the experts. An estimated 20 percent of people, it turns out, are especially delicious for mosquitoes, and get bit more often on a consistent basis

Puerto Vallarta, Mexico - It's Summer in the tropics, and you know what that means... Mosquitoes! Puerto Vallarta's rainy season means it's mosquito season, too. The little buggers are not just annoying, but also carry diseases like dengue fever. But why do they bite some people more than others?

Mosquitoes exhibit blood-sucking preferences, say the experts. An estimated 20 percent of people, it turns out, are especially delicious for mosquitoes, and get bit more often on a consistent basis. And though researchers have yet to pinpoint what mosquitoes consider an ideal hunk of human flesh, they do know that genetics account for a whopping 85% of our susceptibility to mosquito bites, whether it’s expressed through blood type, metabolism, or other factors.

Here are some of the factors that could play a role:

Blood Type

Not surprisingly — since, after all, the reason mosquitoes seek out human blood is because our blood enables their eggs to become fertile. Most mosquitoes seek out certain blood types and certain characteristics when choosing their prey. If you have Type O Blood, you are twice as likely to be bitten by mosquitoes than those with Type A. People with Type B blood fell somewhere in the middle of this itchy spectrum.

Carbon Dioxide

Mosquitoes can detect carbon dioxide from as far as 75 feet away. We all emit carbon dioxide, but the more carbon dioxide you emit, the more likely a mosquito will bite you. Adults emit more carbon dioxide than children, so in general, adults are more likely to be bit than children. Also people who exhale more of the gas over time — generally, larger people and smokers — have been shown to attract more mosquitoes than others.

Exercise and Metabolism

Scent is the primary indicator for mosquitoes that a human target is within striking distance. In addition to carbon dioxide, mosquitoes find victims at closer range by smelling the lactic acid, uric acid, ammonia and other substances expelled via their sweat, and are also attracted to people with higher body temperatures. Because strenuous exercise increases the buildup of lactic acid and heat in your body, it likely makes you stand out to the insects.

Skin Bacteria

Other research has suggested that the particular types and volume of bacteria that naturally live on human skin affect our attractiveness to mosquitoes. In a 2011 study, scientists found that having large amounts of a few types of bacteria made skin more appealing to mosquitoes. Surprisingly, though, having lots of bacteria but spread among a greater diversity of different species of bacteria seemed to make skin less attractive. This also might be why mosquitoes are especially prone to biting our ankles and feet — they naturally have more robust bacteria colonies.

Secretions

About 80% of us are "secretors," or people who secrete compounds known as saccharides and antigens through their skin and indicate blood type. Mosquitoes are magnets for secretors. Once again, your classification as a secretor or non-secretor is determined by your biology and there isn’t anything you can do to put yourself in the non-secretor category.

Drinking Alcohol and Higher Body Temperature

According to one study, drinking just one can of beer or one mixed drink drastically increases your chances of being bit by a mosquito. This is because drinking alcohol increases your body temperature and increases the amount of ethanol excreted in sweat. Additionally, some people naturally have higher body temperatures than other people. Mosquitoes are drawn to warmer blood.

Pregnancy

In several different studies, pregnant women have been found to attract roughly twice as many mosquito bites as others, likely a result of the fact the unfortunate confluence of two factors: They exhale about 21 percent more carbon dioxide and are on average about 1.26 degrees Fahrenheit warmer than others.

Clothing Color

Mosquitoes use vision (along with scent) to locate humans, so wearing colors that stand out (black, dark blue or red) may make you easier to find. To reduce your risk of getting bit, wear lighter colors.

Natural Repellents

Some researchers have started looking at the reasons why a minority of people seem to rarely attract mosquitoes in the hopes of creating the next generation of insect repellents. Using chromatography to isolate the particular chemicals these people emit, scientists at the UK’s Rothamsted Research lab have found that these natural repellers tend to excrete a handful of substances that mosquitoes don’t seem to find appealing. Eventually, incorporating these molecules into advanced bug spray could make it possible for even a Type O, exercising, pregnant woman in a black shirt to ward off mosquitoes for good.

In the meantime, for those who do not want to bombard their bodies with toxic chemicals that pollute themselves and the environment, HERE is a list of some popular natural repellents. We are not guaranteeing results, but we hope one of these will work for you.

Sources: webmd.com • smithsonianmag.com

Battle Against Dengue Fever Begins in Earnest

by Maureen Dietrich

25 Jun 14 

mazmessenger.com

 

With the goal of eradicating dengue fever in the municipality, the Sinaloa Secretary of Health and Mayor Carlos Felton inaugurated yesterday a “macro operation” involving 300 workers who will go door-to-door in the 20 colonias most vulnerable to the disease. The idea, said the Secretary, is to fumigate Mazatlán little by little.

Under the banner “Que el dengue no te dé depende de ti,” workers will hand out information brochures to citizens at major intersections outlining ways to eliminate mosquito breeding grounds.

The State will spend 40 million pesos on the campaign in Sinaloa which reported 699 confirmed cases of dengue, the highest in the country. (from Noroeste)