A Debilitating Virus Surges Globally as Mosquitoes Move With Warming Climate

A mosquito-borne virus that can leave infected people debilitated for years is spreading to more regions of the world, as climate change creates new habitats for the insects that carry it.

隨著氣候變化為攜帶病毒的昆蟲創造了新的棲息地，一種通過蚊子傳播的病毒正擴散到世界更多地區。感染該病毒的人可能會多年身體虛弱。

More than 240,000 cases of the virus, chikungunya, have been reported around the world so far this year, including 200,000 cases in Latin America and 8,000 in China. Chinese authorities have launched an urgent effort to try to stifle the virus with public health measures that evoke the response to Covid-19.

今年到目前為止，全球已報告超過24萬例基孔肯雅熱病例，其中拉丁美洲20萬例，中國有8000例。中國有關部門已啟動緊急行動，採取讓人聯想到應對新冠疫情的公共衛生措施，試圖遏制該病毒。

Chikungunya is not circulating in the United States or Canada, but cases have been reported in France and Italy. The disease is endemic in Mexico.

目前基孔肯雅熱尚未在美國和加拿大傳播，但法國和義大利已報告病例。在墨西哥已經形成流行病疫情。

The World Health Organization is warning that current transmission patterns resemble a global outbreak that infected 500,000 people 20 years ago, contributing to a surge of new disabilities.

世界衛生組織警告稱，當前的傳播模式與20年前的全球疫情相似，那次疫情感染了50萬人，導致新的殘疾人數激增。

Although it is rarely fatal, chikungunya causes excruciating and prolonged joint pain and weakness.

雖然很少致命，這種病毒會引發劇烈且持續的關節疼痛和身體虛弱。

“You have people who were working, with no disabilities, and from one day to the next, they cannot even type on a phone, they can’t hold a pen, a woman cannot even hold a knife to be able to cook for her family,” said Dr. Diana Rojas Alvarez, who leads chikungunya work at the W.H.O. “It really impacts quality of life and also the economy of the country.”

「有些人原本在工作，沒有任何殘疾，一夜之間連能用手機打字、拿筆都不行了，女性甚至無法拿起菜刀為家人做飯，」世衛組織基孔肯雅熱工作負責人戴安娜·羅哈斯·阿爾瓦雷斯博士說，「這確實會影響生活質量，也會對國家經濟造成影響。」

What is chikungunya, and how dangerous is it?

什麼是基孔肯雅熱？它有多危險？

Chikungunya is a virus from the same family as Zika and dengue fever. Two different species of mosquitoes, Aedes aegypti and Aedes albopictus, transmit chikungunya. Between four and eight days after a bite, a person can develop symptoms including fever, joint pain and a rash.

基孔肯雅病毒與寨卡病毒、登革熱病毒同屬一個家族。埃及伊蚊和白紋伊蚊這兩種不同種類的蚊子都會傳播基孔肯雅病毒。被叮咬後四至八天內，人可能會出現發燒、關節疼痛和皮疹等癥狀。

Unlike dengue and Zika infections, the majority of which are asymptomatic, chikungunya sickens most people it infects. In rare instances, chikungunya can kill young children and older adults.

大多數感染基孔肯雅病毒的人都會發病，這與多數為無癥狀感染的登革熱和寨卡病毒感染不同。在極少數情況下，基孔肯雅熱可能導致幼兒和老年人死亡。

“Fatality levels are low, but we really care about chikungunya because it leaves people with months or potentially years of debilitating pain,” said Scott Weaver, an expert and the scientific director of the Galveston National Laboratory in Texas.

「死亡率較低，但我們之所以高度關注基孔肯雅熱，是因為它會讓患者遭受數月甚至數年的虛弱性疼痛，」這方面的專家、得克薩斯州加爾維斯頓國家實驗室科學主任史考特·韋弗說。

He added: “That has not only an individual toll but also a social one, with strain on health care systems, economic impact, the demand on caregivers, a lot of things.”

他還說：「這不僅會給個人帶來損失，還會產生社會影響，比如給醫療系統帶來壓力，造成經濟影響，增加護理人員的負擔等等。」

Chikungunya is often misdiagnosed as dengue, which causes the same symptoms at first.

基孔肯雅熱常被誤診為登革熱，因為兩者初期癥狀相同。

布宜諾斯艾利斯寄生蟲和病媒研究中心實驗室裡的埃及伊蚊，這是傳播基孔肯雅病的兩種蚊子之一。 Luis Robayo/Agence France-Presse — Getty Images

Dengue symptoms usually clear up in a week or two; chikungunya symptoms become chronic in as high as 40 percent of people infected, with debilitating joint pain lasting for months or years.

登革熱癥狀通常在一兩週內消退；而在40%的基孔肯雅熱感染者中，癥狀會轉為慢性，劇烈的關節疼痛會持續數月甚至數年。

Between 2005 and 2007, more than two-thirds of all the disabilities — including that caused by cancer, arthritis and diabetes — reported in India was the result of a chikungunya outbreak that was sweeping through the country.

2005至2007年間，印度報告的所有殘疾病例中（包括由癌症、關節炎和糖尿病引起的殘疾），有超過三分之二是由當時席捲全國的基孔肯雅熱疫情導致的。

Who is at risk?

哪些人面臨風險？

By the end of 2024, transmission of the virus had been reported in 199 countries, on every continent except Antarctica.

截至2024年底，已有199個國家報告了該病毒的傳播，涉及除南極洲以外的所有大洲。

The W.H.O. estimates that 5.6 billion people live in areas where the mosquitoes that transmit the virus can live. These mosquitoes are daytime biters, feeding on people who are at work, at school or on a bus.

世衛組織估計，有56億人生活在傳播病毒的蚊子可以生存的地區。這些蚊子在白天叮咬人類，目標包括上班、上學或乘坐大巴的人。

Climate change is driving the spread of chikungunya-carrying mosquitoes in two ways. A warmer, wetter world provides more suitable habitat. And extreme weather events can cause more breeding in floods — or displace people, who cluster in areas with poor water and sanitation supply.

氣候變化通過兩種方式推動攜帶基孔肯雅病毒的蚊子擴散。氣候變暖、濕潤為蚊子提供了更適宜的棲息地。極端天氣事件可能帶來洪水，從而導致蚊子更多繁殖，或者使人們流離失所，聚集在供水和衛生設施較差的地區。

The Aedes albopictus mosquito has markedly expanded its presence in Europe in recent years: The insect has been found in Amsterdam and Geneva. In South America, Aedes aegypti carries the virus and thrives in low-income neighborhoods in rapidly growing cities with patchy water systems.

近年來，白紋伊蚊在歐洲的活動範圍顯著擴大：在阿姆斯特丹和日內瓦都發現了這種蚊子。在南美洲，埃及伊蚊攜帶該病毒，在供水系統不完善、快速發展的城市的低收入社區大量滋生。

“In the U.S. I don’t think we’re going to see massive outbreaks of chikungunya” because people in warm areas use air-conditioning and spend a lot of time indoors, Dr. Weaver said. “But in places like China and the Southern Cone of South America, the warming temperatures are going to have a big impact because people don’t stay inside with air-conditioners in their houses or their workplaces. They don’t even like to screen their windows in many parts of Asia and South America.”

「在美國，我認為不會出現大規模的基孔肯雅熱疫情，」韋弗說，因為溫暖地區的人們使用空調，大量時間是在室內度過。「但在像中國和南美洲的南錐體地區，氣溫升高將產生重大影響，因為這些地方的人不是一直待在有空調的家宅或工作場所裡。在亞洲和南美洲的許多地方，人們甚至不喜歡給窗戶裝紗窗。」

People seem to become immune to chikungunya after an infection and so, if it sweeps through an area, it can be a couple of decades before there are enough immunologically vulnerable people to sustain another outbreak. But in places such as India and Brazil, populations are so large that the virus is circulating constantly.

感染基孔肯雅熱後似乎會產生免疫力，因此，如果病毒席捲某個地區，可能需要幾十年才會有足夠多的易感人群再次引發疫情。但在印度和巴西等人口眾多的國家，該病毒一直在持續傳播。

Many countries in Africa that did not have circulating chikungunya, such as Chad and Mali, have reported cases in the past few years.

過去幾年，乍得和馬利等許多原本沒有基孔肯雅熱傳播的非洲國家也報告了病例。

一劑基孔肯雅疫苗。 Richard Bouhet/Agence France-Presse — Getty Images

Is there a vaccine?

有疫苗嗎？

There are two vaccines for chikungunya, but they are produced in limited quantities for use mainly by travelers from industrialized countries. The newest vaccine, made by Bavarian Nordic, sells for about $270 per shot in the United States, a price well beyond the reach of a country such as Paraguay, which has had huge chikungunya outbreaks and would ideally vaccinate much of the population. Brazil’s Butantan Institute is working on making a lower-cost version of another vaccine.

目前有兩種基孔肯雅熱疫苗，但產量有限，主要供工業化國家的旅行者使用。由巴伐利亞北歐公司生產的最新疫苗在美國每劑售價約270美元，這個價格遠遠超出了像巴拉圭這樣國家的承受能力——該國爆發了大規模的基孔肯雅熱疫情，理想情況下需要為大部分人口接種疫苗。巴西的布坦坦研究所正致力於研發另一種更便宜的疫苗。

Neither vaccine currently has the kind of W.H.O. recommendation that might lead to accelerated development of an affordable product. Doing a clinical trial of the kind the agency requires is difficult: Chikungunya outbreaks happen so fast that they’re over before the research can begin. Dr. Rojas said the W.H.O.’s vaccine committee was reviewing chikungunya outbreak data to consider options for a possible recommendation.

這兩種疫苗目前都沒有獲得世衛組織的推薦，而這樣的推薦本可以加速研發價格親民的產品。開展世衛組織要求的那種臨床試驗很困難：基孔肯雅熱疫情暴發得太快，往往在研究開始前就已經結束了。羅哈斯表示，世衛組織疫苗委員會正在審查基孔肯雅熱疫情數據，以考慮可能的推薦方案。

What else can be done?

還能採取哪些措施？

The best protection against chikungunya is not to get bitten.

預防基孔肯雅熱的最佳方法是避免被蚊子叮咬。

The next step is to reduce mosquito breeding sites. In China, public health officials are going house to house to look for stagnant water.

其次是減少蚊子的滋生地。在中國，公共衛生官員正在挨家挨戶排查積水。

Surveillance for chikungunya is still weak. Dr. Rojas said the W.H.O. was trying to untangle how much of the current surge was new cases and how much was transmission that was already occurring but poorly tracked or reported. There is a molecular diagnostic test that screens for Zika, dengue and chikungunya at the same time, but more countries need to adopt it.

基孔肯雅熱的監測工作仍然薄弱。羅哈斯說，世衛組織正試圖弄清楚當前的病例激增中有多少是新增病例，有多少是已經存在但跟蹤或報告不力的傳播病例。有一種分子診斷測試可以同時篩查寨卡、登革熱和基孔肯雅熱病毒，但需要更多國家採用這種測試。

Disease surveillance globally has been weakened by the abrupt cuts in funding from the U.S. government, which was supporting much of this work in low-income countries.

美國政府突然削減了對低收入國家相關工作的大部分資金支持，削弱了全球的疾病監測能力。

Is this a new virus?

這是一種新病毒嗎？

No. Chikungunya was first identified in Tanzania in the 1950s, and caused sporadic outbreaks in Africa and Asia in the next decades.

不是。基孔肯雅熱病毒於20世紀50年代在坦尚尼亞首次被發現，在接下來的幾十年裡，在非洲和亞洲引發過零星疫情。

But the virus didn’t attract much attention from public health specialists until 2004. That year, an outbreak in Kenya spread to La Réunion, a French territory in the Indian Ocean. There, chikungunya raged through the population: A third of the people on the island were infected.

但直到2004年，這種病毒才引起公共衛生專家的廣泛關注。那一年，肯亞的一場疫情蔓延到了印度洋上的法國屬地留尼汪島。在那裡，基孔肯雅熱肆虐，島上三分之一的人被感染。

That same strain of the virus made its way to South Asia, and caused huge outbreaks in India from 2005 to 2007. And from there travelers took chikungunya around the world.

同一毒株的病毒傳播到了南亞，並在2005至2007年間在印度引發了大規模疫情。從那以後，旅行者將基孔肯雅熱帶到了世界各地。

By late 2013, the virus had made its way to the Caribbean and once again began to tear through a population that lacked immunity. There were 1.8 million reported infections in the region by the end of 2015. Chikungunya then made its way down through South America — and a new strain from Angola was introduced to Brazil at the same time — and the two have been circulating since then. Chikungunya cases in South America have risen steadily since 2023, alongside a surge in dengue cases.

到2013年底，該病毒傳入加勒比地區，再次在缺乏免疫力的人群中肆虐。截至2015年底，該地區報告的感染病例達180萬例。隨後，基孔肯雅熱向南蔓延至南美洲——同時，一種來自安哥拉的新毒株傳入巴西，從那以後，這兩種毒株一直在當地傳播。2023年以來，南美洲的基孔肯雅熱病例穩步上升，登革熱病例也同時激增。