Mosquitoes and Viruses: How Environmental DNA Can Help Monitor the Spread of Invasive Species

Mosquitoes are not only annoying but also dangerous. They can transmit viruses that cause serious diseases such as Zika, West Nile, dengue, and yellow fever.

These diseases were once confined to tropical and subtropical regions, but are now spreading to other parts of the world due to global trade, climate change, and human mobility.

Mosquitoes also pose a threat to biodiversity, as they can introduce invasive pathogens and parasites to native wildlife and ecosystems.

For example, the Asian tiger mosquito (Aedes albopictus), which is now widespread in Europe, can transmit the avian malaria parasite (Plasmodium relictum) to birds, causing high mortality rates.

The control of mosquitoes and their diseases is therefore a major challenge for public health and environmental protection.

However, conventional methods such as pesticides and genetically modified mosquitoes have limitations and drawbacks, such as environmental impacts, resistance development, ethical concerns, and public acceptance.

A new technology based on environmental DNA and RNA interference

(Photo : GUILLAUME SOUVANT/AFP via Getty Images)

A team of scientists from the Hessian LOEWE Centre for Translational Biodiversity Genomics in Germany and partner institutions has developed a new technology that can protect against the spread of tropical diseases transmitted by mosquitoes in a targeted and environmentally friendly way, as per Phys.org.

Their approach consists of two steps: first, they use environmental DNA (eDNA) to monitor the presence and distribution of mosquitoes and their viruses in water samples.

eDNA is the genetic material that organisms leave behind in their environment, such as skin cells, saliva, or feces.

By analyzing eDNA with high-throughput sequencing methods, the researchers can identify which mosquito species and pathogens are present in a given area.

Second, they use RNA interference (RNAi) to reduce the population of mosquitoes and their ability to transmit diseases.

RNAi is a natural process that silences specific genes by using double-stranded RNA molecules that match the target gene sequence.

The researchers feed the mosquito larvae with food that contains double-stranded RNA molecules that target genes essential for their survival or infection. This way, they can kill the larvae or prevent them from becoming infectious adults.

Also Read: Mosquito Swarm Strikes Farmer's Home After Heavy Rainfall Events in Australia [Video]

A fire brigade against tropical diseases

The researchers call their technology a fire brigade against tropical diseases because it can be deployed quickly and locally when an outbreak occurs or is imminent, as per Alpha Galileo.

Unlike pesticides or genetically modified mosquitoes, their technology does not affect non-target organisms or persist in the environment. It also does not require regulatory approval or public consent, as it uses natural molecules that are already present in living cells.

The researchers have already tested their technology on several mosquito species and pathogens in laboratory experiments and field trials.

They have shown that they can detect invasive mosquitoes and viruses with eDNA analysis and that they can reduce mosquito populations and infection rates with RNAi treatment.

They hope that their technology will provide a new tool for combating mosquito-borne diseases and protecting human health and biodiversity.

They also plan to apply their technology to other insect vectors and pests, such as ticks, flies, and locusts.

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