Doctors are concerned about the West Nile Virus and the Powassan Virus that are closely related to Zika, which have caused birth defects.

As of now, there is no medicine or vaccine for the Zika virus.

According to the experts, Zika is mostly spread by the Aedes species which is an infectious mosquito.

The symptoms of the Zika virus are birth defects when infected during pregnancy.

Recently, there has been a massive outbreak of the Zika virus, and doctors are concerned about the West Nile Virus and the Powassan Virus, both flaviviruses like Zika, are capable of causing birth defects.

There was a research that showed over 40% of fetuses infected with these viruses have died.

Through the results, people can notice the capabilities of the West Nile Virus and the Powassan Virus.

Moreover, 2017 study showed that most of the West Nile virus infections originated in poorer areas with poor sewage service.

On the other hand, the Powassan Virus, which is a very rare virus, is reported throughout the United States, Canada, and Russia. Infections occur usually in late spring, early summer, and mid-fall. It is transmitted through the bite of an infected tick.

Dr. Jonathan Miner, a senior author of the study and an assistant professor at Washington University School of Medicine in St. Louis, and his colleagues ran a study of the Powassan, the West Nile virus, the Chikungya virus, and the Mayaro virus.

The Chikungya Virus and the Mayaro Virus are found in Brazil and are called alphaviruses.

They infected pregnant mice with these viruses.

The results were that the West Nile virus infections were 23 to 1500 times higher than the other viruses in the test.

Dr. Jonathan Miner said, "We found that West Nile virus caused injury to the fetal brain and intrauterine growth restriction and that both West Nile virus and Powassan virus led to fetal death in mice.

This is similar to what has been observed after congenital Zika virus infection in mice".

Through these experiments, a lot of people are concerned about the infection from those viruses.

Researchers were also curious about fetus infections in human tissues, so Dr. Jonathan Miner and his colleagues ran a study again.

They infected human tissues with the Chikungunya, the Mayaro, the West Nile, the Powassan, and the Zika virus.

It is said the Zika virus, Powassan virus, West Nile Virus replicated and infected the human tissue efficiently.

However, the Chikungya and the Mayaro virus could not replicate as much as the first three viruses.

Through the results, doctors highly suggest that the West Nile Virus and the Powassan Virus could cause birth defects like the Zika virus.

Disease experts say that they now have to be more careful and monitor pregnant women more.

They also state that in order to respond quickly to disease outbreaks, they need test results because they cannot predict which virus is going to cause an outbreak.

It is also not a definite threat to the pregnant woman and their babies, and it is a possibility.