Spit Makes It Worse

The Zika virus isn't only spread by mosquitos, the infection is actually made worse by mosquito spit! The female mosquito needs blood in order to produce her eggs. So when she feeds she's inserting a flexible straw that can seek out a blood vessel. From the moment she probes the skin, the mosquito starts salivating. That's also where pathogens make full use of both hosts. In the mosquito's saliva are molecules that numb the skin and block our normal immune response.

To test whether mosquito saliva makes the Zika infection worse, researchers in a study used a less harmful relative of Zika called Simliki Forest Virus or SFV. When the virus enters the body, it triggers an immune response that includes macrophages which normally help orchestrate the body's defenses against an infection. Instead, researchers saw that the macrophages were infected by the virus and helped spread the virus throughout the body.

However, when they did the study without mosquito spit, the viral infection could not spread as much, produce as much virus in the body, and was not as lethal. The same can be said of Zika where the virus has evolved to take advantage of and control elements in both its mosquito and human hosts.

What exacerbates the problem is humans develop high enough levels of the virus to infect other uninfected mosquitos, spreading the disease faster .This surely will not be the last mosquito-borne virus to arise from nature, so use bug repellant or other strategies to avoid being bitten by a mosquito. If you are considering pregnancy, be sure to follow the CDC guidelines and talk to your physician about the precautions you should take.