Nav: Home

Tracing the genetic origins of insecticide resistance in malaria-transmitting mosquitoes

March 20, 2019

Researchers have identified a single genetic alteration in a malaria-transmitting mosquito species that confers resistance to a widely-used insecticide, according to a new study. The research, which combines genetic sequencing with field studies of mosquito feeding, underscores the need to develop new insecticides for bed nets, a cornerstone of malaria control efforts. Bed nets are devices that prevent mosquitoes from feeding on humans at night, and are often coated with insecticides such as pyrethroids to enhance their effectiveness. They have been credited with more than 70% of the decrease in malaria deaths in the past 15 years, and one study has estimated that they have helped to avoid more than 663 million cases of malaria. However, mosquitoes have become increasingly resistant to several of the most common insecticides, a development that poses a major threat to current malaria control efforts. Furthermore, attempts to assess or track the impact of insecticide resistance have been hindered by a lack of information about the genes that drive resistance mechanisms. Here, Gareth Weedall and colleagues set out to pinpoint the genetic drivers of pyrethroid resistance in Anopheles funestus, one of the major insect vectors of malaria in Africa. Using a combination of sequencing techniques, they identified a single allele in the gene CYP6P9a that heightened its activity and promoted resistance to pyrethroids. The authors then designed and used a DNA-based field test that detects the presence of this allele, and discovered the allele was common among A. funestus from southern Africa, but was absent in mosquitoes collected in Central and West Africa. What's more, a field study in Cameroon revealed that mosquitoes carrying the resistance allele were better able to feed on human volunteers who slept in huts with pyrethroid-coated bed nets. In a related transcript Q&A, Weedall et al. say their findings represent the first molecular diagnostic for metabolic resistance, 20 years after scientists identified a major cause of insecticide resistance (a modified sodium channel in mosquitos). They further note that their discovery may help inform efforts to better understand how metabolic resistance is spreading across the African continent.
-end-


American Association for the Advancement of Science

Related Malaria Articles:

Breakthrough in malaria research
An international scientific consortium led by the cell biologists Volker Heussler from the University of Bern and Oliver Billker from the Umeå University in Sweden has for the first time systematically investigated the genome of the malaria parasite Plasmodium throughout its life cycle in a large-scale experiment.
Scientists close in on malaria vaccine
Scientists have taken another big step forward towards developing a vaccine that's effective against the most severe forms of malaria.
New tool in fight against malaria
Modifying a class of molecules originally developed to treat the skin disease psoriasis could lead to a new malaria drug that is effective against malaria parasites resistant to currently available drugs.
Malaria expert warns of need for malaria drug to treat severe cases in US
The US each year sees more than 1,500 cases of malaria, and currently there is limited access to an intravenously administered (IV) drug needed for the more serious cases.
Monkey malaria breakthrough offers cure for relapsing malaria
A breakthrough in monkey malaria research by two University of Otago scientists could help scientists diagnose and treat a relapsing form of human malaria.
Getting to zero malaria cases in zanzibar
New research led by the Johns Hopkins Center for Communication Programs, Ifakara Health Institute and the Zanzibar Malaria Elimination Program suggests that a better understanding of human behavior at night -- when malaria mosquitoes are biting -- could be key to preventing lingering cases.
Widely used malaria treatment to prevent malaria in pregnant women
A global team of researchers, led by a research team at the Liverpool School of Tropical Medicine (LSTM), are calling for a review of drug-based strategies used to prevent malaria infections in pregnant women, in areas where there is widespread resistance to existing antimalarial medicines.
Protection against Malaria: A matter of balance
A balanced production of pro and anti-inflammatory cytokines at two years of age protects against clinical malaria in early childhood, according to a study led by ISGlobal, an institution supported by ''la Caixa'' Foundation.
The math of malaria
A new mathematical model for malaria shows how competition between parasite strains within a human host reduces the odds of drug resistance developing in a high-transmission setting.
Free malaria tests coupled with diagnosis-dependent vouchers for over-the-counter malaria treatment
Coupling free diagnostic tests for malaria with discounts on artemisinin combination therapy (ACT) when malaria is diagnosed can improve the rational use of ACTs and boost testing rates, according to a cluster-randomized trial published this week in PLOS Medicine by Wendy Prudhomme O'Meara of Duke University, USA, and colleagues.
More Malaria News and Malaria Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Meditations on Loneliness
Original broadcast date: April 24, 2020. We're a social species now living in isolation. But loneliness was a problem well before this era of social distancing. This hour, TED speakers explore how we can live and make peace with loneliness. Guests on the show include author and illustrator Jonny Sun, psychologist Susan Pinker, architect Grace Kim, and writer Suleika Jaouad.
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.