C.D.C. Investigating 14 New Reports of Zika Transmission Through Sex
Health authorities in the United States said they were investigating 14 new reports of the Zika virus possibly being transmitted by sex, including to pregnant women. If confirmed, the unexpectedly high number would have major implications for controlling the virus, which is usually spread by mosquito bites.
Scientists had believed sexual transmission of Zika to be extremely rare. Only a few cases have ever been documented. But if all the women in the cases the Centers for Disease Control and Prevention is examining test positive for the virus — as two women already have, and four others have done in preliminary lab tests — officials believe there is no way other than sex that they could have contracted it.
科学家们曾经认为通过性传播感染兹卡的情况极其罕见。有记录的这种病例寥寥无几。但是，如果美国疾病控制与预防中心（Centers for Disease Control and Prevention，简称CDC）正在检测的这些女性病例结果全都呈阳性——两名女性已证实呈阳性，完成了初步实验室检测的其他四人亦然——官员们相信，除了性传播之外，她们没有感染这种病毒的其他途径。
The specter of so many cases — all in the continental United States — brings fresh complexity to the medical mystery of Zika. The virus is suspected to cause birth defects and a rare condition of temporary paralysis.
“We were surprised that there was this number,” Dr. Anne Schuchat, the deputy director at the C.D.C., said in an interview. “If a number of them pan out, that’s much more than I was expecting.”
In all the cases the C.D.C. is examining, women in the continental United States had sex with men who had traveled to countries where the virus is circulating, and developed symptoms associated with the virus within about two weeks of their male partners’ symptoms.
Officials at the C.D.C. reported the potential cases in an alert to health care providers on Tuesday.
The agency did not say exactly how many of the women were pregnant, but it reiterated its recommendation that people returning from Zika-infected areas use condoms or abstain from sex for the duration of their partner’s pregnancy. The alert said there was no evidence that women could transmit Zika virus to their sex partners, but added that more research was needed to be sure.
This country has become a laboratory of sorts to test the sexual transmission of Zika, as scientists race to understand the disease. Transmission by mosquitoes is not yet happening in the continental United States because it is still winter, so health officials say they believe that any infection of an American resident who has not traveled to a place where Zika is circulating has probably been contracted through sex.
“In the U.S., where most people aren’t traveling to these areas, we may be able to uncover the potential risk,” Dr. Schuchat said.
In all, the United States has around 90 cases of Zika, according to the most recent count from the C.D.C., most of them contracted by people who had traveled to Latin America, currently the center of the virus. If confirmed, the new reports of sexual transmission would represent about 15 percent of that total.
Questions about how frequently Zika can be transmitted by sex and how long the virus can stay in semen are particularly urgent here, given the large volume of travel between the United States and Central and South America. There were about 5.5 million visitors from South America to the United States in 2014, and nearly a million from Central America, according to figures from the Department of Commerce.
And with the season for mosquitoes — still believed to be the primary mode of infection — nearing in the United States, Tuesday’s report is likely to further complicate preparations in states across the country.
“This suggests that along with virus in the blood, Zika is gaining access to other fluids, including semen,” said Dr. Peter J. Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine. “Anyone who is pregnant and lives in an area where the Zika virus is circulating will need her male partner to use condoms. In the coming weeks, that may include the U.S. Gulf Coast.”
“这意味着，除了血液之外，兹卡还能通过包括精液在内的其他体液传播，”美国贝勒医学院国家热带疾病学院(National School of Tropical Medicine at Baylor College of Medicine)院长彼得·J·霍特博士(Peter J. Hote)说。“所有怀孕和生活在兹卡病毒传播区域的人，都需要让她的男性伴侣使用安全套。接下来几周，这个范围可能会扩大到美国的墨西哥湾沿岸地区。”
Testing of semen may be difficult. Patients at real risk in the United States need to be first tested by standard blood testing before the testing of semen would even be considered, said Dr. Gary W. Procop, a professor of pathology at the Cleveland Clinic. Only the C.D.C. and state laboratories do such testing, and only for people determined to be at high risk, he said.
做精液检测可能会有些困难。克利夫兰诊所(Cleveland Clinic)的病理学教授、加里·W·普罗科普博士(Gary W. Procop)表示，美国面临真实风险的病人应该首先进行标准的血液检测，之后再考虑做精液检测。他还表示，只有CDC和州级实验室能做此类检测，而且只为被确定是高风险人群的人做。