茲卡病毒或可增加精神疾病風險

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.

生出一個頭部萎縮、畸形的嬰兒肯定是讓人傷心的情景。但生育衛生專家警告稱，小頭畸形症可能只是茲卡(Zika)病毒蔓延最爲明顯的一個後果。

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.

許多研究人員擔心，即使是出生時看來正常的嬰兒，如果他們的母親在妊娠期間感染了茲卡病毒，他們一生中患上精神疾病的風險也更高。

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

他們表示，茲卡病毒與一些經研究與自閉症、雙相情感障礙、精神分裂症的發展有關的致病因子，存在緊密的相似性。

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.

專家在採訪中強調，精神分裂症及其他嚴重影響生活的精神疾病，並非只有單一的原因。這些病情被認爲是由一系列因素引發的，包括遺傳特質和生活中的創傷，例如性虐待、生理虐待、遭到遺棄或大量用藥。

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

但子宮中的疾病，包括病毒感染，被認爲是一個觸發條件。

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

“它的後果遠遠超出了小頭畸形，”哥倫比亞大學感染與免疫研究中心主任W·伊恩·李普金(W. Ian Lipkin)說。

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區的兒童中，“如果看到注意力缺陷多動障礙(ADHD)、自閉症、癲癇和精神分裂症大幅增多，我不會感到驚訝的，”他補充道。“我們談的是一大羣可能在世界上無法正常生活工作的個人。”

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.

巴西的研究人員正在研究數千份小頭畸形新生兒的報告。儘管還沒有確鑿的證據，但是研究疫情的病毒專家強烈懷疑起因就是茲卡病毒。

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.

儘管這種病毒是在1947年發現的，但其長期後果並沒有得到過研究。科學家只能藉助其他相似傳染病的已知情況來進行推論。

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

在採訪中，專門研究胎兒發育的精神病學研究人員認同了李普金的悲觀預測。

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.

他們解釋道，妊娠早期受到病毒感染，可能會扼殺胚胎或抑制生長中的大腦，從而導致小頭畸形。如果在胚胎髮育後期，大腦幾乎完全形成時感染，可能會造成沒那麼明顯但仍然很嚴重的損害。

“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.”

“挺嚇人的，”瑞士蘇黎世聯邦工學院(Swiss Federal Institute of Technology in Zurich)行爲神經生物學家於爾·梅耶(Urs Meyer)說。“這些問題在一個連續的量表上，你最終是不是會患上自閉症或精神分裂症是很複雜的問題——我們實際上也並不能預測。”梅耶研究的是實驗室動物胚胎感染的後果。

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.

多年來，有越來越多的證據顯示，精神疾病或許與妊娠期間暴露於風疹、皰疹、流感等病毒，以及弓形蟲等寄生蟲有關。

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.

一些專家注意到，茲卡造成的效果與風疹相似。兩者對成年人都只會帶來輕微的皮疹症狀，但卻可能會造成死胎，以及新生兒的小頭畸形和眼部畸形。

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年風疹疫情爆發期間，大約有2萬名新生兒承受了後果，其中包括1.1萬個嬰兒出生時即耳聾，3500個出生時即眼盲，他們當中至少有1800人後來被診斷出精神問題。

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.

那次的疫情大約影響了1200萬美國人。世界衛生組織預計茲卡病毒將會在拉美和加勒比海國家傳播，那裏的總人口超過5億。

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.

斯洛文尼亞盧布爾雅那的病理學家解剖了一名歐洲婦女在妊娠32周時墮胎的胎兒遺體。這名婦女是在巴西懷孕的。專家們報告，他們發現了“與垂直傳播的ZIKV感染相關的嚴重胎兒腦損傷”，這意味着茲卡病毒是由於母親感染而傳給胎兒的。

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

但即使病原體不接觸到胎兒，也能造成損害。

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.

流感病毒並不能穿透胎盤，瑞士聯邦工學院的梅耶說道，但是母親的免疫反應會催生大量的細胞激素，其中有一部分會進入胎盤。細胞激素是“傳導信號”的微小蛋白質，可能會導致細胞停止生長。

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.

報告顯示，在茲卡疫情爆發前就已經面臨經濟危機的巴西，幾乎沒有應對精神病兒童激增的能力。

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

歐洲研究人員最初對南美洲的疫情爆發沒有給予多大的關注，梅耶說。但這一點已經發生了轉變。

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

“我們現在聽到的信息讓人難以承受，”他說。“整整一代人可能會受到影響。”