Mosquito-borne diseases could be prevented by skin cream

A skin cream used to treat warts and skin cancer could help protect people against viral diseases such as Zika and dengue, according to new research.

Their findings have identified a new way we might prevent infection from a wide variety of dangerous viruses.

Scientists studied four types of a virus transmitted by mosquitos and found that applying a cream within an hour of a mosquito bite dramatically reduced infection rates in their models.

They used two different models to understand the effect of the skin cream -- human skin samples and mice. In both cases, applying the skin cream acted like a warning signal which caused rapid activation of the skin's immune response that fights any potential viral threats. This prevented the virus from spreading around the body and causing disease.

The cream, called imiquimod or Aldara, is commonly used to treat genital warts and some forms of skin cancer. The researchers caution that further testing is needed before recommendations can be made for people to start using this cream on mosquito bites.

Their research is published today in Science Translational Medicine.

Lead author Dr Clive McKimmie, from the University of Leeds' School of Medicine, said: "This study shows that a clinically approved, widely used skin cream has the potential to be repurposed as a valuable protector against insect-borne diseases.

"What is especially encouraging about our results is that the cream was effective against a number of distinct viruses, without needing to be targeted to one particular virus.

"If this strategy can be developed into a treatment option then we might be able to use it to tackle a wide range of new emerging diseases that we have not yet encountered.

"Mosquitos are expanding their range across the world as the planet gets hotter due to the climate emergency, so the health impact of mosquito-borne diseases is likely to increase in future."

There are hundreds of viruses spread by biting mosquitoes which can infect humans.

These include the dengue virus, West Nile virus, Zika virus and chikungunya virus, which have all had large outbreaks in recent years.

How does it work?

When a mosquito bites the skin, the body reacts in a very specific way to try and mitigate the physical trauma of the skin being punctured.

The bite causes a wound-healing repair mechanism to begin, however, the skin does not prepare itself to respond to viral attack.

This means mosquito-borne viruses that enter the skin through a bite are able to replicate quickly with little anti-viral response in the skin and then spread throughout the body.

By applying skin cream after a bite, researchers found that they could pre-emptively activate the immune system's inflammatory response before the virus becomes a problem. The cream encouraged a type of immune cell in the skin, called a macrophage, to suddenly spring into action to fight off the virus before it could spread around the body.

https://www.sciencedaily.com/,Science Mission