Zika: Aedes aegypti mosquitoes love biting humans, and that’s why they spread viruses so well

Your microbiota – the bacteria living on your skin – are another factor in this bouquet. Because we are all host to different groups of bacteria, we each have a different “smell” to the female mosquitoes, and that might be why some people smell more attractive than others.

And all of these factors vary with age. Because we get bigger with age, the skin surface area increases, so we can assume larger people (that is, adults) emit more of these attractants than smaller people (that is, children).

A municipal health worker checks a water tank for mosquito larvae inside a home as as part of the city’s efforts to prevent the spread of the Zika virus vector, the Aedes aegypti mosquito, in Tegucigalpa, Honduras, February 6, 2016. (Credit: Jorge Cabrera/Reuters)

Aedes aegypti lay eggs in human-made containers

Besides finding human blood tasty, female Ae. aegypti tend to lay their eggs in human-made containers such as buckets, leftover cups, tires or cemetery vases that fill with water. Rain or daily watering from sprinkler systems makes containers including potted plant bases, birdbaths and fountains nice homes for the developing larvae.

Other mosquito species prefer natural sources of water to lay eggs, such as small ponds or near flooded creek beds. The species that prefer these habitats won’t have the same proximity to humans as the species that likes to lay eggs in our backyards, like Ae. aegypti.

Because the proximity of water sources to humans affects the chances of being bitten by a potentially infected mosquito, several researchers have begun to classify which water containers are more attractive to female Ae. aegypti. In one extensive study in Iquitos, Peru, where dengue is prevalent, researchers found several factors that make a site more attractive to females:

  • If larvae are already present in a container, the female knows that it has all the necessary requirements for her future offspring. It’s sort of like choosing a restaurant in an unknown city: if it’s crowded, then you know it’s good.
  • A neglected container is more attractive than a managed container, because it can accumulate more nutrients from decaying leaves or other organic matter. The more nutrients, the bigger the larvae will grow.
  • A container that receives more sunlight is more attractive because it’s warmer and mosquitoes need warm temperatures to develop.
  • Finally, size matters. Of those human-made containers that are near human activity, larger containers tend to have more developing larvae than smaller containers. However, even though size matters, we can still find larvae in containers as small as coke cans.

Educating the community about emptying unnecessary containers and covering larger water storage containers are an important part of the control effort and knowing what makes a container attractive can help people target specific containers. In areas where diseases transmitted by Ae. aegypti are present, this becomes extremely important.

A woman looks on next to a banner as soldiers and municipal health workers take part in cleaning of the streets, gardens and homes as part of the city’s efforts to prevent the spread of the Zika virus vector, the Aedes aegypti mosquito, in Honduras, February 6, 2016. (Credit:Jorge Cabrera/Reuters)

Arming ourselves with more knowledge

Knowing that Ae. aegypti prefer humans, we can protect ourselves by wearing long-sleeved shirts and long pants, and using mosquito repellents that contain DEET or other CDC-approved repellents.

By clearing the areas around our homes of containers that can hold water or making sure we periodically empty our containers, we can reduce the population and thus reduce how often we are bitten.

Just because you’ve been bitten by a mosquito doesn’t mean you have been bitten by one that is carrying a disease. Even if you are bitten by an Ae. aegypti mosquito, it doesn’t necessarily mean that you have been exposed to Zika, or any other virus. Not all Ae. aegypti are infected and not all mosquitoes are Ae. aegypti.

The ConversationMegan Wise de Valdez, Assistant Professor of Biology, Texas A&M-San Antonio

This article was originally published on The Conversation. Read the original article.

Featured Image Credit: Josue Decavele/Reuters

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