【有文稿】这不是电影-Zika病毒肆虐 20万军队出动防御

Guest: Prof. Dominic Dwyer, Medical Virologist at Westmead Hospital, Australia ZCG: The World Health Organization says the Zika virus is likely to spread across nearly all of the Americas. It has already been found in 21 countries in the Caribbean, North and South America. MB: For the benefit of our listeners, who are maybe not very familiar with the Zika virus, could you first start by giving us just a general overview of it? I mean, how does it spread and who does it affect? DD: The Zika virus, it’s been around for quite a few decades, it was first detected in Africa, in Uganda, and then it spread to a number of countries, particularly in the Pacific, and of course now a very big outbreak in the Americas. It’s spread by mosquitoes, a particular type of mosquitoes – the same ones that spread yellow fever and dengue virus, as well. So it’s another addition to the mosquito-borne viruses that cause concern in the Americas. MB: And so how does it affect people? What sort of symptoms do people have, and how serious is it? DD: It’s not a terribly serious illness. The people who get sick get a fever, a rash, aches and pains, headaches and so on, and usually recover within a week or so. About 80% of the people who become infected don’t actually develop any symptoms at all, in other words they don’t know they’ve got it, and of course that’s one of the things that contributes to the spread of the virus in the community, you have all those people wandering around who have the infection but are unaware of it. TY: You mentioned there that this virus has been existing for decades. Why haven’t we developed any vaccine for it earlier? DD: Well that’s a very good question; I guess the attention has been on what have been the more important viruses to date, things like yellow fever and dengue infections, and there are vaccines certainly for yellow fever now and one that’s being developed for dengue. Zika hasn’t been as big a problem until recently, so I guess the attention of people was not on Zika, and that’s why we don’t have a vaccine. I do think, though, that the activity in Central America and potentially in North America - and South America, of course - will drive people into producing a vaccine. MB: There have been reports of the vaccine causing birth defects, and women have been warned not to travel to affected areas, and in some cases, like in El Salvador, even not to get pregnant. So how necessary are steps like these? DD: Well this is one thing that is different with the Zika virus compared to some of the others – it looks as though, although we’re not sure yet, that pregnant women who become infected with the Zika virus have an increased risk of birth defects in their babies. Now this has not been described with the other viruses, such as yellow fever and dengue, so there’s something different about Zika. One of the difficulties is we don’t yet really know if it’s the Zika virus, or indeed is it some other virus that might be circulating, or another cause of these birth defects. You must remember that a lot of the areas where these effects are being described have not necessarily the best healthcare systems in the world, and the best environmental protection, so there might be other causes. Anyway, people are very interested in this and are actively researching to try and show the link between Zika infection and bad outcomes in pregnant women. That is why a number of countries have developed suggestions about pregnant women traveling to these areas and so on. TY: Then how likely is it to spread to countries like the United States and beyond the western hemisphere, like developing into an epidemic or pandemic? DD: I think it all depends on what mosquitoes are present. So one of the difficulties in the US is that the mosquitoes that are transmitting the virus in Central America and Brazil, and other countries in South America – those same mosquitoes exist in parts of the United States as well. So it would be quite logical that they would expect to see the Zika virus then occurring in the USA. For other countries, for example Australia or New Zealand, it’s not likely to be a problem, because we don’t have that particular species of mosquitoes.