 |
|
Malaria -- Effective insecticide-repellent synergy against mosquito vectors
July 18, 2007The mosquitoes responsible for malaria transmission to humans belong to the Anopheles genus. One of the best known and most extensively studied is Anopheles gambiae, Africa's principal malaria vector. The protection recommended by the World Health Organization for people at risk from this devastating disease is the use of mosquito nets impregnated with pyrethroids, of low toxicity for mammals and highly active against mosquitoes. Unfortunately, excessive and inappropriate use of this family of insecticide, particularly by spraying, has induced a disturbing rise in the number of resistant individuals in the Anopheles populations. The mosquito nets treated with pyrethroids can therefore lose their effectiveness. It is therefore essential to devise new control strategies against these malaria vectors that are resistant to these insecticides.
IRD researchers and their partners (1) obtained encouraging results by combining a non-pyrethroid insecticide, propoxur, and a repellent, N,N-diethyl toluamide (DEET). They based their investigations on previous work which had revealed a strong synergy between the two components. A combination of the two had proved to be much more effective than the straightforward addition of their respective properties. Mosquito nets soaked with this mixture had a lethal power and irritant effect that inhibited the mosquitoes from biting. Moreover, the mosquitoes are hit by a powerful paralysing action, known as the "knockdown" effect (3), on contact with the mixture. The mortality rates determined were satisfactory, in that they equalled those obtained by using deltamethrin, a commonly-used synthetic pyrethroid, highly effective against mosquitoes.
The researchers tested two mixtures composed of a non-pyrethroid insecticide of the organophosphate family, combined with either a standard repellent, DEET, or with a new-generation synthetic repellent. Both of these mixtures show a strong synergy in the resulting lethal and paralysing effects on the mosquitoes. However, only the association between the insecticide and the standard repellent produced a synergistic effect that inhibited the mosquito from taking its blood feed. A synergistic effect was also observed with regard to the treatment's residual efficacy which is several months longer than that of either agent applied alone. The advantage of the synergistic property of these combinations is enhanced by the fact that it significantly reduced the necessary effective doses against the mosquitoes (about 6 times that of the insecticide applied alone), to attain an efficacy equivalent to that of deltamethrin.
The nets treated with the two mixtures in the laboratory were subsequently tested in field trials, in the rice-growing area 40 km North of Bobo-Dioulasso, in Burkina Faso. This area has the specificity of harbouring two different forms of Anopheles gambiae. The first appears in May and June in the rice-fields. It shows no resistance to pyrethroids. The second emerges in September and October in puddles left by monsoon rains. These do show resistance to these insecticides. As expected, the usual pyrethroid-treated nets turned out to be effective only against non-resistant mosquitoes of the first population. Conversely, the nets pre-soaked with non-pyrethroid-repellent combinations proved excellent protection for the people of the local villages, whatever the population of mosquitoes present. Nevertheless, their residual efficacy (about 15 days) in real conditions did not match the researchers' expectations. The team consequently envisage working in conjunction with a company able to devise a system for encapsulating the mixture to prolong the residual life of treated mosquito nets.
The efficacy of these mixtures between organophosphates and repellents therefore opens up a new pathway towards controlling pyrethroid-resistant malaria vectors. In the long term, the researchers plan to test their method on mosquitoes resistant to two other types of insecticide utilized against malaria transmission: organophosphates and carbamates.
Institut de Recherche Pour le Développement
The nets treated with the two mixtures in the laboratory were subsequently tested in field trials, in the rice-growing area 40 km North of Bobo-Dioulasso, in Burkina Faso. This area has the specificity of harbouring two different forms of Anopheles gambiae. The first appears in May and June in the rice-fields. It shows no resistance to pyrethroids. The second emerges in September and October in puddles left by monsoon rains. These do show resistance to these insecticides. As expected, the usual pyrethroid-treated nets turned out to be effective only against non-resistant mosquitoes of the first population. Conversely, the nets pre-soaked with non-pyrethroid-repellent combinations proved excellent protection for the people of the local villages, whatever the population of mosquitoes present. Nevertheless, their residual efficacy (about 15 days) in real conditions did not match the researchers' expectations. The team consequently envisage working in conjunction with a company able to devise a system for encapsulating the mixture to prolong the residual life of treated mosquito nets.
The efficacy of these mixtures between organophosphates and repellents therefore opens up a new pathway towards controlling pyrethroid-resistant malaria vectors. In the long term, the researchers plan to test their method on mosquitoes resistant to two other types of insecticide utilized against malaria transmission: organophosphates and carbamates.
Institut de Recherche Pour le Développement
Mosquitoes Current Events and Mosquitoes News RSSActive hearing process in mosquitoes
A mathematical model has explained some of the remarkable features of mosquito hearing. In particular, the male can hear the faintest beats of the female's wings and yet is not deafened by loud noises.
PATH Malaria Vaccine Initiative shares strategy for developing 'next-generation' malaria vaccines
Marking its tenth anniversary year, the PATH Malaria Vaccine Initiative (MVI) today unveiled a new strategy that sets the stage for an aggressive push targeting the long-term goal of eliminating and eradicating malaria. Malaria is one of the world's deadliest infectious diseases, killing nearly 900,000 people a year, most of them children in sub-Saharan Africa.
Media availability: The role of biomedical research in malaria eradication
Although malaria has been controlled in many local and regional populations, the permanent elimination of malaria parasites throughout the world remains an elusive goal, and the disease continues to claim nearly one million lives each year.
UC Davis researchers identify dominant chemical that attracts mosquitoes to humans
Scientists at the University of California, Davis, have identified the dominant odor naturally produced in humans and birds that attracts the blood-feeding Culex mosquitoes, which transmit West Nile virus and other life-threatening diseases.
UM School of Medicine researchers find extreme genetic variability in malaria parasite
Researchers at the University of Maryland School of Medicine Center for Vaccine Development (CVD) have charted the extreme genetic differences that occur over time in the most dangerous malaria parasite in the world.
Research ensures 50 million vaccinated against deadly brain infection
Research at the University of Liverpool has supported the vaccination of more than 50 million people against a zoonotic brain infection that affects thousands of children across Asia every year.
Scientists discover how to send insects off the scent of crops
Biotechnology and Biological Sciences Research Council (BBSRC)-funded research, published this week in Chemical Communication, describes how scientists have discovered molecules that could confuse insects' ability to detect plants by interfering with their sense of smell. This could reduce damage to crops by insect pests and contribute to food security.
UH Manoa researcher examines possible implications of daily commute and mosquito-borne diseases
University of Hawaii at Manoa assistant researcher Durrell Kapan recently published a paper, Man Bites Mosquito: Understanding the Contribution of Human Movement to Vector-Borne Disease Dynamics, in PLoS One. Published August 26, the paper highlights how daily commuting patterns in mega-cities may be a critically overlooked factor in understanding the resurgence of mosquito-borne diseases such as dengue fever, infecting 50-100 million people annually.
Decade-long US project to fight malaria builds thriving African mosquito net industry
In a decade-long initiative to protect millions of families from malaria in sub-Saharan Africa, a U.S. government-funded project helped sell 50 million bed nets in seven countries, crafted a voucher system to allow the poor to receive them for free or partial cost, and created enough incentives for private companies that they invested $88 million to expand their businesses.
New research confirms potential deadly nature of emerging new monkey malaria species in humans
Researchers in Malaysia have identified key laboratory and clinical features of an emerging new form of malaria infection.
More Mosquitoes Current Events and Mosquitoes News Articles
 |
Mosquitoes: A Novel by William Faulkner (Author), Frederick R. Karl (Introduction) A delightful surprise, Faulkner wrote his second novel "for the sake of writing because it was fun." Mosquitoes centers around a colorful assortment of passengers, out on a boating excursion from New Orleans. The rich and the aspiring, social butterflies and dissolute dilettantes are all easy game for Faulkner's barbed wit in this engaging high-spirited novel which offers a fascinating glimpse of Faulkner as a young artist."It approaches in the first half and reaches in the second half a brilliance that you can rightfully expect only in the writings of a few men. It is full of the fine kind of swift and lusty writing that comes from a healthy, fresh pen."--Lillian Hellman, New York Herald Tribune . |
 |
SpringStar - Mosquito Trap by SpringStar This unique mosquito trap catches only the ones that bite. Particularly effective on the Culex mosquito, the one that spreads west nile virus. The trap works by luring female mosquitoes inside using a pheromone- once inside they cannot escape. Two per average yard will reduce the population significantly. Trap can be rinsed out and reused many times during the season, more bait will be required (SpringStar mosquito refill lure, item S1519). Try it, you'll like it. |
 |
Mosquitos III by The Mosquitos On their third album, this Brazilian-flavored, New York City-based trio make it clear that they're wielding a vivid palette, curious minds and active imaginations. The opening "Moonshine" finds a slide guitar being punctuated by exuberant drums, followed by a brief, airy vocal. It ends in less than a minute and a piano enters for the second number, with Chris Root's intimate singing sounding at once but like a sunny bossa nova chanteuse and a late night continental cabaret balladeer. In less than forty minutes Mosquito manage to offer up fifteen finely chiseled slices of refreshing songcraft. Anchored by guitar or keyboards, the melodies are hook-filled without being cloying. And all the while the percussion of JuJu Stulbach dances around and through the proceedings like a giddy bird.... |
 |
Mosquito Squadron Starring: David McCallum, Suzanne Neve, Charles Gray, David Buck, David Dundas Directed By: Boris Sagal David McCallum ("The Man From U.N.C.L.E.") stars in an epic adventure that perfectly captures the explosive action and emotional torment of war. With its astonishing special effects, stark cinematography and brilliantly choreographed aerial combat sequences, Mosquito Squadron catapults the viewer into the searing heat of battle! As Allied forces struggle against the awesome might of the German Luftwaffe, an even greater threat is posed by the destructive V3 rocket nearing completion at a secret testing center. The Royal Air Force's Mosquito Squadron gears up to destroy the site, but its leader, Quint Monroe (McCallum), becomes conflicted when he discovers that the air strikemay kill hundreds of British POWsincluding the squad's former commander! |
|
Duncan: Mosquito Yo-Yo by Duncan Toys Co. High speed ball-bearing axle. Lightweight butterfly body for high speed string tricks. Aerodynamic rim-weighted shape. Uses Duncan Friction Stickers for perfect response. Long spin times. Take-apart design. Colors may vary Ages 8+ years. Size:2.25" Made in China | |
 |
Pramex Long Lasting Insecticidal Net- Ideal for Two People by Valent BioSciences Corporation USE PRAMEX LONG LASTING INSECTICIDAL NETS when you want PROTECTION FROM BITING MOSQUITOES. Whether hiking, camping, hunting, fishing or traveling to destinations where mosquitoes are a problem, Pramex Long Lasting Insecticidal Nets are the answer. Our mosquito nets are THE ONLY NETS IN THE US THAT ARE MADE WITH OLYSET CONTROLLED RELEASE INSECTICIDE TECHNOLOGY. This unique technology automatically recharges the surface of the nets with insecticide as needed. The nets provide a physical barrier to houseflies, mosquitoes and other flying insects and REPEL MOSQUITOES on contact. FOR INTERNATIONAL TRAVELERS - The CDC recommends using treated mosquito nets when traveling to countries where mosquitoes and the serious diseases they carry can be a problem (Malaria, West Nile Virus, Dengue, etc).... |
 |
Mr. Mosquito by Eidos Interactive It's wrong to love Mister Mosquito. Wrong because of the repetitive gameplay, the lackluster graphics, and the awkwardness of the controls. I could also mention the repetitive dialogue, laughable AI, and interminable load times. And did I mention how short it is? But somehow none of this matters if, like I do, you fall for the charm and originality of this game. You play as a nameless mosquito whose job it is to suck the blood of the Yamada family. There are only two modes, battle and suck. To suck blood you have to first hover and wait for a target area to flash red somewhere on your victim's body, then swoop in, pierce the skin, and extract blood by twirling the right analog stick. Suck too fast or too long and you're liable to get swatted, a fate you can avoid if you keep... |
 |
iTouchless 3-Layer Portable Electric Power Bug, Fly, Mosquito, Spider Swatter/Zapper by iTouchless This patented triple layered electric bug swatter kills/electrocutes all flying insects such as mosquitos, flies, nats and spiders on contact, "just by waving at them." It looks like a small tennis racket (4x19 inches). It has safety switch operation and 2 insulation outer layers for your protection. You can take it anywhere you go such as camping, BBQ, beach, and fishing. THIS IS NOT A TOY! The output power is relatively low, constituting no hazard to humans or pets at all. The Touchless Power Bug Swatter emits no smell and uses no poisonous or harmful material. It's safe for indoor or outdoor use and praised the most effective, convenient and hygienic insect terminator. It leaves no smudge, smear or mess to clean up after. No splats or smears on your clean walls, windows, lighting... |
|
Mosquito Bites by Mcaa Inc /Gold Coast Mail Ctr | |
 |
Mosquito & Insect Hat Net by Dorfman Pacific by Dorfman Pacific Mosquito & Insect Hat Net by Dorfman Pacific. Since 1921 Dorfman Pacific had prided itself in being one of the largest full-line, head wear companies in the world. Available in Khaki. For larger view, please click on the picture(s). |
| © 2009 BrightSurf.com |