How is the Zika virus spread through sex? Dr. Sanjay Gupta's Facebook chat

A virus can live in the testicles more safely and for longer periods, which makes it more likely to be sexually transmitted. It may be designed this way so the immune system won't affect the chances of being able to reproduce.

While we don't know how Zika can can live in semen, we do know that Ebola can live there for long periods. When you hear about viruses being sexually transmitted, it happens because of the notion of immune privileges.

The World Health Organization looked into this and found that there isn't a relationship between pesticides and microcephaly, the neurological birth defect that seems to be linked to the Zika virus.

It actually hasn't been confirmed for sure that Zika causes microcephaly, but the evidence is mounting because the virus was found in amniotic fluids and brains of those with the defect. If you are pregnant, you should avoid going to places where Zika is circulating.

The first documented case of the Zika virus in a primate was in the late 1940s. It was found in humans in the mid-1950s. Now we live in a globalized world. People can hop in airplanes and fly anywhere.

Most likely this virus made the jump in someone's body. Someone got infected, got on a plane and traveled somewhere where the mosquito that spreads Zika was present. In 2007, 73% of the tiny island of Yap in Micronesia got infected. Talk about viral. That's what it means to go viral. From there, it went zigzagging and hopscotching around the world.

If your body has never seen a virus, you have no immunity to it and you can spread it to someone else. The more naive the population is to a virus, the more likely it is to spread.

Even if you don't get sick from it, you could be considered a carrier. In South America and in other places around the world, there are many carriers because this is the first time so many people have been exposed to this virus.

Once the mosquito bites someone with Zika, that person will digest and process that virus for at least 14 days before they can infect someone else with it.

The average life span is of the mosquito is 30 days, so it really takes half their life to process the virus. This actually leads to whole area of research of trying to shorten the life of a mosquito so it doesn't have time to process the virus.

If you have a compromised immune system, it's prudent to be even more cautious. That's part of the reason why elderly people are more at risk for getting sick; their immune systems don't work as briskly. Same is the case for very young people.

It's worth stressing that four out of five people who get Zika will have mild or no symptoms. So even if you get infected, doesn't necessarily mean you will get very sick. Even for pregnant woman: While you should avoid it, even if you get it, there is no guarantee you will develop problems with microcephaly.

We don't know what the likelihood is, but it's probably much lower than we think. There are likely a lot of pregnant women who had Zika and had perfectly normal deliveries.

Viruses are constantly mutating. That's why we have a flu shot every year, because different strains spread each year and are always changing. We know Ebola changed several times.

The concern is that it will mutate to something more likely to kill or spread, but the mutation overall is just a natural evolutionary process.

The virus appears to leave the body after around seven days. No evidence that if you had Zika, a future pregnancy will have any risk. In fact, you will likely be immunized after you get it. The concern is for women who are currently pregnant, not who get pregnant in the future.

We don't know all the answers, but looking at all the data, it appears there is more a greater risk earlier in the pregnancy. But the guidance is that if you are pregnant, no matter how far along, there is a risk.

If you don't have to be in a place where Zika is spreading, don't go there while you are still pregnant.

For vast majority of people going to the Olympics in Rio de Janeiro, there's minimal risk. In August, the concern of mosquitoes are lower in Brazil than during their summer (August is during their winter).

Standing water is really the enemy. The Olympic committee is taking measures to reduce standing water where mosquitoes can breed. That even means a small bottle cap size of water. They are also using certain insecticides.

One of the questions is whether the insecticides are safe for pregnant women. The head of the CDC tells me there's no cause to worry from these insecticides because you don't absorb enough across the skin for there to be enough of a problem. Basic precautions should be taken such as insecticides, long sleeves and removing standing water where mosquitoes like to breed and live.

This is a virus that primarily spreads from mosquitoes and sex. Quarantine won't make a difference. One who goes to the supermarket with Zika won't be a risk to other shoppers.

If a man with a pregnant wife travels somewhere where Zika is spreading, then the guidance is to be abstinent or practice absolutely safe sex during the rest of the pregnancy.