兹卡病毒或可增加精神疾病风险

A baby with a shrunken, misshapen head is surely a heartbreaking sight. But reproductive health experts are warning that microcephaly may be only the most obvious consequence of the spread of the Zika virus.

生出一个头部萎缩、畸形的婴儿肯定是让人伤心的情景。但生育卫生专家警告称，小头畸形症可能只是兹卡(Zika)病毒蔓延最为明显的一个后果。

Even infants who appear normal at birth may be at higher risk for mental illnesses later in life if their mothers were infected during pregnancy, many researchers fear.

许多研究人员担心，即使是出生时看来正常的婴儿，如果他们的母亲在妊娠期间感染了兹卡病毒，他们一生中患上精神疾病的风险也更高。

The Zika virus, they say, closely resembles some infectious agents that have been linked to the development of autism, bipolar disorder and schizophrenia.

他们表示，兹卡病毒与一些经研究与自闭症、双相情感障碍、精神分裂症的发展有关的致病因子，存在紧密的相似性。

Schizophrenia and other debilitating mental illnesses have no single cause, experts emphasized in interviews. The conditions are thought to arise from a combination of factors, including genetic predisposition and traumas later in life, such as sexual or physical abuse, abandonment or heavy drug use.

专家在采访中强调，精神分裂症及其他严重影响生活的精神疾病，并非只有单一的原因。这些病情被认为是由一系列因素引发的，包括遗传特质和生活中的创伤，例如性虐待、生理虐待、遭到遗弃或大量用药。

But illnesses in utero, including viral infections, are thought to be a trigger.

但子宫中的疾病，包括病毒感染，被认为是一个触发条件。

“The consequences of this go way beyond microcephaly,” said Dr. W. Ian Lipkin, who directs The Center for Infection and Immunity at Columbia University.

“它的后果远远超出了小头畸形，”哥伦比亚大学感染与免疫研究中心主任W·伊恩·李普金(W. Ian Lipkin)说。

Among children in Latin America and the Caribbean, “I wouldn’t be surprised if we saw a big upswing in A.D.H.D., autism, epilepsy and schizophrenia,” he added. “We’re looking at a large group of individuals who may not be able to function in the world.”

在拉丁美洲和加勒比地区的儿童中，“如果看到注意力缺陷多动障碍(ADHD)、自闭症、癫痫和精神分裂症大幅增多，我不会感到惊讶的，”他补充道。“我们谈的是一大群可能在世界上无法正常生活工作的个人。”

Researchers in Brazil are investigating thousands of reports of microcephalic births. While there is no solid proof that Zika virus is the cause, virologists studying the outbreak strongly suspect it.

巴西的研究人员正在研究数千份小头畸形新生儿的报告。尽管还没有确凿的证据，但是研究疫情的病毒专家强烈怀疑起因就是兹卡病毒。

Although the virus was discovered in 1947, there has been no research into its long-term consequences. Scientists are left to draw inferences from what is known of similar infections.

尽管这种病毒是在1947年发现的，但其长期后果并没有得到过研究。科学家只能借助其他相似传染病的已知情况来进行推论。

In interviews, psychiatric researchers specializing in fetal development agreed with Dr. Lipkin’s pessimistic prognosis.

在采访中，专门研究胎儿发育的精神病学研究人员认同了李普金的悲观预测。

A viral attack early in pregnancy can kill a fetus or stunt the growing brain, producing microcephaly, they explained. An infection later in the fetus’s development, when the brain is nearly fully formed, can do damage that is less obvious but still significant.

他们解释道，妊娠早期受到病毒感染，可能会扼杀胚胎或抑制生长中的大脑，从而导致小头畸形。如果在胚胎发育后期，大脑几乎完全形成时感染，可能会造成没那么明显但仍然很严重的损害。

“It is pretty scary,” said Dr. Urs Meyer, a behavioral neurobiologist at the Swiss Federal Institute of Technology in Zurich who studies the consequences of fetal infections in lab animals. “These problems are on a continuous scale, and whether you end up with autism or schizophrenia is complex — and we really can’t predict it.”

“挺吓人的，”瑞士苏黎世联邦工学院(Swiss Federal Institute of Technology in Zurich)行为神经生物学家于尔·梅耶(Urs Meyer)说。“这些问题在一个连续的量表上，你最终是不是会患上自闭症或精神分裂症是很复杂的问题——我们实际上也并不能预测。”梅耶研究的是实验室动物胚胎感染的后果。

Evidence has increased for years that mental illnesses may be linked to exposure during pregnancy to viruses like rubella, herpes and influenza, and to parasites like Toxoplasma gondii.

多年来，有越来越多的证据显示，精神疾病或许与妊娠期间暴露于风疹、疱疹、流感等病毒，以及弓形虫等寄生虫有关。

The effects of Zika mimic those of rubella, some experts noted: Both cause only a mild rash in adults, but can cause stillbirths, microcephaly and eye malformations in newborns.

一些专家注意到，兹卡造成的效果与风疹相似。两者对成年人都只会带来轻微的皮疹症状，但却可能会造成死胎，以及新生儿的小头畸形和眼部畸形。

In the 1964-65 rubella epidemic, about 20,000 newborns suffered consequences, including 11,000 born deaf, 3,500 born blind — and at least 1,800 in whom mental problems were later diagnosed.

在1964年至1965年风疹疫情爆发期间，大约有2万名新生儿承受了后果，其中包括1.1万个婴儿出生时即耳聋，3500个出生时即眼盲，他们当中至少有1800人后来被诊断出精神问题。

That epidemic infected an estimated 12 million Americans. More than 500 million people live in the countries of Latin America and the Caribbean to which the World Health Organization has predicted that Zika will spread.

那次的疫情大约影响了1200万美国人。世界卫生组织预计兹卡病毒将会在拉美和加勒比海国家传播，那里的总人口超过5亿。

Pathologists in Ljubljana, Slovenia, who dissected a microcephalic fetus aborted at 32 weeks by a European woman who had become pregnant in Brazil reported last week that they found “severe fetal brain injury associated with ZIKV infection with vertical transmission” — meaning the Zika virus had come from the mother’s infection.

斯洛文尼亚卢布尔雅那的病理学家解剖了一名欧洲妇女在妊娠32周时堕胎的胎儿遗体。这名妇女是在巴西怀孕的。专家们报告，他们发现了“与垂直传播的ZIKV感染相关的严重胎儿脑损伤”，这意味着兹卡病毒是由于母亲感染而传给胎儿的。

But a pathogen may not even have to reach the fetus to cause damage.

但即使病原体不接触到胎儿，也能造成损害。

Flu viruses do not cross the placenta, Dr. Meyer of the Swiss Institute noted, but the mother’s immune reaction creates a storm of cytokines, some of which do. Cytokines are small “signaling” proteins that can cause cells to stop growing.

流感病毒并不能穿透胎盘，瑞士联邦工学院的梅耶说道，但是母亲的免疫反应会催生大量的细胞激素，其中有一部分会进入胎盘。细胞激素是“传导信号”的微小蛋白质，可能会导致细胞停止生长。

Reports suggest that Brazil, which was facing economic crises even before the Zika outbreak, has little capacity to cope with a surge of mentally disabled children.

报告显示，在兹卡疫情爆发前就已经面临经济危机的巴西，几乎没有应对精神病儿童激增的能力。

European researchers initially paid little attention to the South American outbreak, Dr. Meyer said. But that has changed.

欧洲研究人员最初对南美洲的疫情爆发没有给予多大的关注，梅耶说。但这一点已经发生了转变。

“The information we’re hearing now is just overwhelming,” he said. “A whole generation of children might be affected.”

“我们现在听到的信息让人难以承受，”他说。“整整一代人可能会受到影响。”