Mosquito season is here, and with it comes the possibility of the Zika virus, a relatively new health risk in the continental United States, especially for pregnant women.

The virus has been found to cause microcephaly, which attacks the brain of fetuses, and other birth defects. Health-care officials caution Americans to be cognizant of the threat but not to overreact. Four out of five people who get the virus show no signs of having it.

More than 500 cases of the virus have been reported in the continental United States, but none yet from mosquito transmission. If the infection follows previous outbreaks of dengue and chikungunya — two viruses carried by the same mosquito that also transmits Zika — then mosquito-borne outbreaks are likely to be local and primarily in the southern United States, health officials say.

Advertisement

The virus can also be sexually transmitted, so cases involving people who have traveled to areas of the world where Zika is more prevalent, such as Puerto Rico or Brazil, are likely to be in the headlines this summer.

The mosquitoes that can carry the virus are normally found in Missouri and Illinois. Health officials advise protecting yourself with mosquito repellent, including Deet; to avoid travel to areas known to have the virus if you are pregnant; and for men to use condoms if they have traveled to countries where the disease is mosquito borne, since researchers recently discovered it can be transmitted through sexual intercourse.

Dr. Tom Frieden, the director of the United States’ Centers for Disease Control and Prevention, addressed Zika during a speech at the National Press Club, and he met later with reporters from six news organizations, including the Post-Dispatch.

Here is Frieden’s advice on Zika:

Q: What are your expectations on how widespread the infection will be in the United States?

A: We don’t expect large numbers. Travel-associated, could be thousands, or even more, because (there are) millions of travelers, so lots of travel-associated cases. How many of them are pregnant depends on how many women follow our advice and don’t travel (to areas where the virus has already been known to be transmitted by mosquitoes) and how many men who travel follow our advice and use condoms with pregnant partners. But we don’t expect widespread transmission in the U.S. You can see clusters in some communities for which we really do need to be prepared.

Q: Would you advise people considering getting pregnant to wait until winter?

Advertisement*

A: No, I would not in the continental U.S. change your plans for pregnancy because of Zika. If you are in a place where you are at risk where there might be a cluster … then talk to you doctor about it. …Government is not going to tell you whether to get pregnant or not. If you are in the Florida Keys that has had (mosquito-borne) infections before, you may want to think about it. But, you know, every person is different. The situation is quite different in Puerto Rico, where the risk is substantially higher and the access to contraception is a problem.

Q: If you are a pregnant woman and you are bitten by a mosquito sometime this summer, what do you need to know?

A: At this point we have no locally transmitted Zika in the continental U.S. So at this point a mosquito bite is not known to carry the risk of Zika. But at some point this summer we could have local transmission of Zika, and I can’t guarantee that we will know about that the first time that happens because 80 percent of people (show no outward signs of the disease). What I can say is we are most likely to see it where we have seen dengue before, or chikungunya before.

Q: Is it okay for pregnant women to use mosquito repellent, including Deet?

A: Deet, when used as directed, is effective and safe, including in pregnancy.

Q: What is the timeline for a vaccine against Zika?

A: It is going to be at least a year or two before we know it is safe and effective. … But (the National Institutes of Health) is doing terrific work. They have five different potential vaccine candidates. They expect to be in Phase One trials in September.

(c)2016 the St. Louis Post-Dispatch

Visit the St. Louis Post-Dispatch at www.stltoday.com

Distributed by Tribune Content Agency, LLC.