Research published by Cell suggests that Zika and dengue virus viruses alter the smell of humans and mice they infect.
They are more attracted to mosquitoes which bite them, transmitting the virus to their next victim.
Dengue is a tropical disease that can cause severe symptoms such as fever, rashes, and pain. It can even be fatal.
Zika can cause birth defects in pregnant women, but most people are asymptomatic or mildly affected and recover within a few days.
Researchers at several Chinese laboratories, including the Chinese Centre for Disease Control and Prevention and Tsinghua University in Beijing, discovered that mice with dengue were more likely to be bitten by mosquitoes because of the presence of smelly molecules on their skin.
Acetophenone, the molecule that attracts the most people, is then given to human volunteers. It increases in mice with Zika or dengue.
Researchers are currently looking into treatments that target Acetophenone.
The best way to prevent bites is to cover up with clothes and use insect repellents and bed nets.
It is estimated that there are up to 400 million cases of dengue each year.
Zika has been reported in 86 countries across the globe.
Most of the viruses are found in South and Central America and Africa.
Zika virus family members include West Nile, Japanese Encephalitis, Yellow fever and Japanese Encephalitis.
