A、Because it has affected only a handful of people. B、Because it is hard to detect it. C、Because its infection does not bring ha

W: Good afternoon, everybody. Just weeks ago, hardly anyone in the U. S. knew what the Zika virus was, much less worried about it. But the World Health Organization’s warning today put the Americas, including the U. S. , on new notice. And, suddenly, a mosquito-borne virus is raising serious fears, especially for pregnant women. Dr. Anthony Fauci is with the National Institutes of Health, and he updated the situation today. He joins us now from the NIH campus. Welcome back to the program, Dr. Fauci. Just how high a level of concern is there?
M: Well, we certainly are taking this very seriously. This is a new virus for the Western Hemisphere and the Americas. And it’s been explosive in its outbreak in South America and in the Caribbean. One of the issues you mentioned that’s important is that it is associated,(6)at least temporally and geographically, with a disturbing increase in the incidence of a very serious complication of pregnancy, and that is fetuses having what’s called microcephaly.
W: And microcephaly is a problem with the brain, isn’t it?
M: Yes. It is where the skull and the head is small, and there’s a developmental problem and a damage problem to the brain, leading to dire consequences, often death.(7)Zika as a virus infection itself is relatively mild, and that’s the reason why it’s been essentially off the radar screen of people until it came in with a vengeance to South America. It causes a mild illness that lasts anywhere from three to five to seven days, and then it goes away, and you’re fine.
W: So why do we call it a serious illness?
M:(8)It’s the potential complication that we’re seeing in South America and in the Caribbean with regard to pregnancy. And it’s interesting, because it’s an association that hasn’t been completely proven to be cause and effect. It certainly is associated, and it’s puzzling, and we’re trying to figure out just what the nature of this association is between infection and pregnant women.
W: Is it understood why this is spreading so fast?
M:(9)Well, one of the reasons that we see spread like this, Judy, is that, up until now, South America and the Caribbean has been what we call immunologically naive to Zika virus. They have never had Zika virus in the Western Hemisphere or in the Americas. And so when a new infection like this comes in, there’s no background immunity in the population that would blunt the outbreak that we’re seeing now, whereas something like dengue infection has been prevalent in South America, particularly in Brazil, for several years now. So there’s that background immunity to it. No such immunity with Zika.
W: That means it’s perfectly new to them, which makes it much, much easier to explode in the population.
M: Definitely.(10)We should also note the fact that they’re loaded with mosquitoes, who are the vectors of this particular virus infection. The mosquitoes are all over South America and Brazil, which is the perfect vector to spread this infection.
W: Well, we have talked about pregnant women. Should everyone be concerned? Just women? I mean, who should be most worried about it?
M: Well, certainly the focus is on women who are pregnant. And that is the reason why the Centers for Disease Control and Prevention, the CDC, has given a guideline travel alert that, if an individual, a woman is pregnant, planning to be pregnant, not sure if they’re pregnant, they should seriously consider postponing any travel to this region.
W: Dr. Tony Fauci at the NTH, we thank you.
M: Good to be with you.
This is the end of the second interview. Questions 6 to 10 are based on what you have just heard.
6. Which of the following group of people can be easily infected by Zika virus?
7. Why hasn’t Zika been listed as a dangerous virus until it came in with a vengeance to South America?
8. What causes people to take Zika virus into serious consideration?
9. Why is Zika spreading so fast in South America?
10. What helps the spread of Zika in South America?