VOA慢速英语2018 科学家对塞卡病毒和婴儿了解有多少（在线收听）

What Scientists Do and Do Not Know About Zika and Babies

Three years ago, Brazil experienced a major sudden spread of the Zika virus. Doctors learned that the sickness can cause severe development problems for unborn babies.

3年前，巴西经历了一场突如其来的塞卡病毒爆发事件。医生发现这种疾病会造成未出生婴儿出现严重的成长问题。

Here is a look at what scientists know today about Zika and its effect on fetuses.

以下是当今科学家对塞卡病毒及其对胎儿影响的了解。 

Zika began spreading in Brazil in April 2015.

2015年4月塞卡病毒开始在巴西传播。 

The country’s Ministry of Health recorded more than 260,000 probable cases in 2016. It also recorded in the first two years more than 2,500 cases of babies born with very small heads, or microcephaly, and other problems linked to Zika.

据巴西国家卫生部记载，2016年出现了26万多例疑似病情。它还记载到，病毒爆发前两年，有2500多名婴儿出生时头非常小，或者说患有小头症，以及出现了其他与塞卡病毒相关的问题。

The numbers dropped sharply in 2017, with fewer than 18,000 Zika cases and 300 cases of microcephaly.

2017年，这一数字急速下降，还剩不到1.8万个塞卡病毒感染病例和300例小头症患者。 

So far this year, Brazil has seen about 2,200 cases of Zika and 20 cases of microcephaly and other developmental abnormalities.

截止到今年，巴西已有约2200例塞卡病毒病例和20例小头症和其他生长异常患者。 

Many viruses, like rubella and HIV, can cause microcephaly. Exposure to poisonous chemicals can also cause it. Sometimes microcephaly is the result of abnormal genetics. Since the 2015 outbreak, a group of experts organized by the World Health Organization found that Zika is also a cause.

风疹和艾滋等许多病毒都会引起小头症。暴露在有害化学物质中也会引起这种疾病。有时小头症是因为基因异常。自2015年该病毒爆发，世界卫生组织就成立了一组专家，他们发现塞卡病毒也是一个起因。

But scientists noted that Zika appeared to lead to microcephaly more often in northeastern Brazil than it did in other places. They are still not sure why, said Ganeshwaran H. Mochida, a pediatric neurologist and researcher at Boston Children’s Hospital.

但科学家发现塞卡病毒在巴西东北部引起小头症的概率比其他地方法大。他们还并不了解为什么，波士顿儿童医院儿科神经学家研究者持田说道。

Scientists also wonder why an increase in microcephaly cases was not reported during past Zika events. It could be that an increase was not noticed, or that the events were not large enough to produce many brain abnormalities. One study has suggested that a recent mutation to the virus may have made it more likely to cause microcephaly.

科学家也想知道为什么以往出现的塞卡病毒事件中没有小头症病例增长的报道。可能是因为没有注意到增长，或者是因为事件不足以产生许多大脑畸形病例。一项研究暗示，病毒最近发生的突变可能更易引发小头症。

Mochida said, "This may not be the whole story...I don’t think that this explains everything."

持田表示：“这可能不是所有原因，我不认为这可以解释所有事情。” 

Children with microcephaly can have substantial nervous system disabilities that affect vision and hearing. Some will never learn to walk or speak. Scientists are still studying the effects of less severe cases. Microcephaly does not necessarily reduce a person’s life expectancy, but it can lead to other problems that do. For example, many children have trouble swallowing, which makes them likely to breathe liquid or food into their lungs. This can lead to the lung disease pneumonia.

患有小头症的儿童会出现严重的神经系统障碍，这会影响视力和听觉。有些还会影响行动或说话。科学家仍在研究较轻病例的影响。小头症并不一定会减短人的寿命，但是会引起其他问题。例如，许多儿童出现吞咽问题，这会让他们将液体或事物吞入肺中，引起肺炎。

Zika has also been linked to other problems in babies, like seizures, restricted ability to move and poor balance. Scientists are still trying to learn if Zika may cause problems that appear later in a child’s life, even for a baby who appeared healthy at birth.

现在已知塞卡病毒还与其他婴儿疾病相关，如癫痫，它会影响移动能力和平衡感。科学家仍在试图了解塞卡病毒是否还会在孩子之后的生命中引发问题，甚至是出生时看起来健康的儿童。

No vaccine is currently on the market, though several are being developed. Scientists at the U.S. National Institute of Allergy and Infectious Diseases have developed the best possible vaccine so far. It is being tested in 16 places in the United States, the Caribbean and Latin America.

现在市场上还没有任何疫苗，虽然已有几种正在研制中。美国国家过敏和感染病研究所的科学家研发出了目前最好的疫苗。已在美国、加勒比海地区和拉丁美洲16个国家进行试验。

Dr. Anthony Fauci is director of the agency. He said approval for the vaccine could come in 18 months if scientists get data from a future outbreak. Barring that, approval could take three or more years.

福西博士是该机构的一名主任。他表示，如果科学家从未来的爆发中得到了数据，那么这种疫苗18个月后就可获得批准。如果没有获得数据，那就需要3年或更多年才能获得批准。

Words in This Story

pediatric - adj. of or relating to the medical care or illnesses of children

neurologist - n. a doctor who studies the nervous system and the diseases that affect it

mutation - n. a change in the genes of a plant or animal that causes physical characteristics that are different from what is normal

seizure - n. an abnormal state in which you become unconscious and your body moves in an uncontrolled and violent way