Navigation Links
New findings by UCR scientists hold big promise for fight against mosquito-borne diseases

RIVERSIDE, Calif. Female mosquitoes are efficient carriers of deadly diseases such as malaria, dengue and yellow fever, resulting each year in several million deaths and hundreds of millions of cases.

To find human hosts to bite and spread disease, these mosquitoes use exhaled carbon dioxide as a vital cue. A disruption of the vital carbon dioxide detection machinery of mosquitoes, which would help control the spread of diseases they transmit, has therefore been a long sought-after goal.

Anandasankar Ray, an assistant professor of entomology at the University of California, Riverside, and colleagues report in the June 2 issue of Nature (cover story) that they have identified in the lab and in semi-field trials in Africa three classes of volatile odor molecules that can severely impair, if not completely disrupt, the mosquitoes' carbon dioxide detection machinery.

The breakthrough research covers three of the deadliest species of mosquitoes: Anopheles gambiae (spreads malaria), Aedes aegypti (spreads dengue and yellow fever), and Culex quinquefasciatus (spreads filariasis and West Nile virus).

The odor molecules that the researchers identified work by affecting the mosquitoes' carbon dioxide receptors, which are located in tiny, antennae-like appendages called maxillary palps close to the mouths of the mosquitoes.

The three classes of the odor molecules are:

  • Inhibitors: Odor molecules, like hexanol and butanal, that inhibit the carbon dioxide receptor in mosquitoes and flies.
  • Imitators: Odor molecules, like 2-butanone, that mimic carbon dioxide and could be used as lures for traps to attract mosquitoes away from humans.
  • Blinders: Odors molecules, like 2,3-butanedione, that cause ultra-prolonged activation of the carbon dioxide sensing neurons, effectively "blinding" the mosquitoes and disabling their carbon dioxide detection machinery for several minutes.

"These chemicals offer powerful advantages as potential tools for reducing mosquito-human contact, and can lead to the development of new generations of insect repellents and lures," said Ray, who led the study. "The identification of such odor molecules which can work even at low concentrations, and are therefore economical could be enormously effective in compromising the ability of mosquitoes to seek humans, thus helping control the spread of mosquito-borne diseases."

Female mosquitoes spread disease by first obtaining a blood meal from an infected person and subsequently finding an uninfected person to bite. Extremely sensitive to minute changes in carbon dioxide concentrations, they can sense carbon dioxide in our breath from long distances. Upon encountering a carbon dioxide plume, the mosquitoes orient and fly upwind, arriving eventually near us.

Most mosquito-trapping devices also use carbon dioxide to attract mosquitoes. But these devices tend to be expensive and bulky, and suffer from the usual difficulties associated with supplying carbon dioxide via gas cylinders, dry ice or propane combustion.

"Odor molecules that mimic carbon dioxide activity, on the other hand, can lead to the development of small and inexpensive lures to trap mosquitoes a great benefit, especially to developing countries," Ray said. "These highly portable, convenient and easily replenishable lures can be used wherever mosquitoes are a menace."

In the case of the "blinder" class of molecules, Ray's group found that even a brief exposure to these odor molecules (presented in a blend of four odors: 2.3-butanedione, 1-hexanol, 1-butanal and 1-pentanal) activated the carbon dioxide-sensitive neurons in mosquitoes for at least five and a half minutes, and evoked such a strong and prolonged response in the neurons that the mosquitoes' responses to subsequent carbon dioxide stimuli were severely reduced for several minutes.

In collaboration with Ring Card, a distinguished professor of entomology at UCR, Ray's lab tested the effectiveness of this blend in wind-tunnels, and found that the flight of the blend-exposed mosquitoes toward sources of carbon dioxide in the wind-tunnels was disrupted.

Subsequently, Ray's lab tested the effectiveness of the blend of odors in a semi-field study performed in Kenya in collaboration with scientists Tom Guda and John Githure at the International Centre of Insect Physiology and Ecology (ICIPE), Kenya.

The research team released Culex quiquefasciatus females in a large enclosed greenhouse that contained two hut-like structures with carbon dioxide-emitting traps placed in each of them. The researchers then included in one of the huts a source of the ultra-prolonged blend in the form of a small fan-driven odor dispenser. They found that only a few mosquitoes entered this hut and made it to the carbon dioxide trap.

"The majority of the mosquitoes were blinded by the blend, and their behavior was disrupted so that they could not detect the carbon dioxide trap," Ray explained. "We observed no such disruption of attractive behavior in mosquitoes in the control hut the one with just the carbon dioxide trap and no blend."


Contact: Iqbal Pittalwala
University of California - Riverside

Related biology technology :

1. Ceregene Reports New Findings Regarding How Parkinsons Brains Respond to Neurotrophic Factors
2. Microplasmin Meets Primary Endpoint in Second Phase III Trial in VMA, Confirms Positive Findings of First Trial
3. New findings promising for transformation optics, cloaking
4. Findings show promise for nuclear fusion test reactors
5. No New Findings in Atrazine Study Promoted by Discredited Researcher, According to the Hudson Institute Center for Global Food Issues
6. Independent Forensics Company DNalysis Implement Amphora's PatentSafe Solution to Preserve and Secure Findings
7. Promega and SwitchGear Publish Findings from Combined Technologies that Correlate Binding Events and Transcriptional Activity
8. New findings could help hybrid, electric cars keep their cool
9. Helix BioPharma to Present L-DOS47 Analytical Method Development Findings at 2009 AAPS National Biotechnology Conference
10. Innocoll Announces Provisional Findings From Its Three Phase 2 Clinical Trials Investigating CollaRx(R) GENTAMICIN TOPICAL for the Treatment and Prevention of Diabetic Foot Infections
11. Gene Therapy Field Advances With Important Clinical Findings Reported in the New England Journal of Medicine
Post Your Comments:
Related Image:
New findings by UCR scientists hold big promise for fight against mosquito-borne diseases
(Date:11/26/2015)... , November 26, 2015 ... device company specializing in imaging technologies, announced today that it ... as part of the Horizon 2020 European Union Framework Programme ... a large-scale clinical trial in breast cancer. , ... , --> --> The ...
(Date:11/25/2015)... 25, 2015 Studies reveal the ... plaque and pave the way for more effective treatment for ...     --> --> ... health problems in cats, yet relatively little was understood about ... studies have been conducted by researchers from the WALTHAM Centre ...
(Date:11/25/2015)... ... November 25, 2015 , ... ... Organization of Black Aerospace Professionals (OPBAP) has been formalized with the signing of ... team leaders met with OPBAP leaders Capt. Karl Minter and Capt. Albert Glenn ...
(Date:11/24/2015)... Nov. 24, 2015  Asia-Pacific (APAC) holds the ... (CRO) market. The trend of outsourcing to low-cost ... but higher volume share for the region in ... however, margins in the CRO industry will improve. ... ( ), finds that the market ...
Breaking Biology Technology:
(Date:11/2/2015)... , Nov. 2, 2015  SRI International has been ... provide preclinical development services to the National Cancer Institute ... will provide scientific expertise, modern testing and support facilities, ... preclinical pharmacology and toxicology studies to evaluate potential cancer ... The PREVENT Cancer Drug Development Program is an ...
(Date:10/29/2015)... health pioneer, Joseph C. Kvedar , MD, describes ... wellness, and the business opportunities that arise from it ... Healthy Things . Long before health and wellness ... vice president, Connected Health, Partners HealthCare, was creating a ... the hospital or doctor,s office into the day-to-day lives ...
(Date:10/27/2015)... Synaptics Inc. (NASDAQ: SYNA ), the leader ... adopted the Synaptics ® ClearPad ® Series ... newest flagship smartphones, the Nexus 5X by LG and ... --> --> Synaptics works closely with ... in the joint development of next generation technologies. Together, ...
Breaking Biology News(10 mins):