Caixin
Sep 01, 2021 06:45 PM
CHINA

In Depth: How China Won Its 70-Year Battle With Malaria

The deadly flooding in Central China’s Henan province this summer made Shang Leyuan worry about an impact that was less visible than the water rushing through the province’s streets.

All the floodwater could provide ideal breeding grounds for mosquitoes, the former official in the province’s disease control center thought. That might boost the insect’s population and maybe lead to a resurgence of malaria.

Gao Qi remembers when the disease was commonplace. The Zhejiang-based researcher recalls one case, decades ago, in which nearly all of a village’s men were stricken by the disease, leaving them bedbound while their rice crops rotted.

But those days are in the past.

On June 30, China was certified malaria-free by the World Health Organization (WHO), crowning the success of a 70-year disease control effort.

So far, only 40 countries and regions in the world have been granted the certification, and in the WHO Western Pacific Region, China is the first country to be certified in more than three decades.

To finally stamp out the disease, the country devoted resources to developing new treatments and developed targeted strategies to stop outbreaks as soon as they appear. These decades of work have provided experience that can help countries still struggling with their own persistent malaria problems.

MALARIA

The specimens of the Chinese malaria vector Anopheles mosquitoes sit on display at the China CDC’s National Institute of Parasitic Diseases. Photo: Ma Danmeng/Caixin

A 70-year campaign

Malaria is an infectious disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes, according to the WHO. Patients experience symptoms such as fever, chills and uncontrollable shaking. The disease killed an estimated 409,000 people worldwide in 2019, mostly children and mostly in Africa.

During the height of its malaria problem in the 1940s, China reported 30 million cases (link in Chinese) and 300,000 deaths every year, according to official figures.

China’s malaria elimination campaign dates back to 1949, when the disease spread across large parts of the country. In 1956, it was listed as a notifiable infectious disease, followed by the establishment of a national malaria reporting mechanism.

Henan’s disease control history mirrors that of the country as a whole, Shang said. Due to a lack of resources and drugs, local health authorities in the late 1950s prevented the spread of the disease by cultivating residents’ hygiene awareness and encouraging them to take simple measures, which later proved ineffective, such as lighting a fire to smoke out mosquitoes.

From 1959 to 1961, China suffered three years of mass famine, making it more difficult to find drugs to treat the disease, Shang said. The human migrations that came with the disaster contributed to malaria transmission.

The Cultural Revolution that followed a few years later disrupted professional institutions at all levels, including institutes for disease prevention and control, meaning that no one was organizing and carrying out control measures, he said.

The country reported more than 20 million local malaria infections for three straight years starting in 1970, half of which were found in Henan.

MALARIA

Mosquitoes fly in a cage at the Jiangsu Institute of Parasitic Diseases in Wuxi, East China’s Jiangsu province. Photo: Ma Danmeng/Caixin

The turning point was in 1967 when the central government launched the “523 Project,” aiming to find new treatments for malaria. The program involved more than 500 scientists from 60 institutions. During the project, Tu Youyou discovered artemisinin in the early 1970s, the core compound of artemisinin-based combination therapies (ACTs) — the most effective antimalarial drugs used today. In 2015, Tu won the Nobel Prize for medicine for “her discoveries concerning a novel therapy against malaria.”

In the 1970s, the State Council, China’s cabinet, kicked off a campaign during which five seriously affected provinces — including Henan, Jiangsu and Anhui — worked together to battle malaria.

In the following decades, the number of malaria cases in the country continued to decline. This was due in part to rapid economic development which resulted in improved sanitation, said Xiao Ning, deputy director of National Institute of Parasitic Diseases (NIPD) at the Chinese Center for Disease Control and Prevention (China CDC).

In 2020, Beijing applied to the WHO for malaria elimination certification after reporting no local cases for four straight years. In May, members of the Malaria Elimination Certification Panel — an independent WHO advisory body — travelled to China, verifying the country had become malaria free.

Elimination

While better treatments and improved sanitation were the key to reducing the disease’s impact, it was a campaign of rapid, targeted measures known as “1-3-7” that eliminated the disease.

The main measure Chinese authorities used from 1960 to 1979 was “mass prevention and treatment.” All residents in high-risk areas were ordered to take preventive drugs in the summer and autumn — the major malaria transmission seasons — and to take drugs again before spring plowing next year.

This suppressed outbreaks, but they persisted. In 2006, a bad malaria outbreak infected nearly 35,000 people in the eastern province of Anhui, forcing local authorities to again force about 1.7 million residents in affected regions to take antimalarial medications and exterminate mosquitoes, said Wang Jianjun, deputy director of the province’s disease control center.

MALARIA

In Bozhou, East China’s Anhui province, a medical worker stands in a hospital laboratory, where microscopic examination of a parasite that potentially causes malaria in humans can be carried out. Photo: Ma Danmeng/Caixin

Under that situation, a new malaria surveillance and response approach, called “1-3-7,” was launched by Jiangsu authorities in 2012 and later adopted widely across the country. The strategy, which was included in a 2018 WHO manual for tackling the disease, requires grassroots health institutions to report suspected cases within a day, investigate and confirm cases within three days, and evaluate the risks of local transmission within seven days.

The strategy focuses on tracing cases to confirm where a malaria outbreak emerged and tackling the disease at its source, NIPD director Zhou Xiaonong said at a meeting of the Boao Forum for Asia in Beijing in early June.

Using this approach doesn’t mean people have to strictly hit the deadlines. The times can be flexible based on local conditions, said Cao Jun, a Jiangsu-based researcher. According to the WHO manual, countries can adopt the “1-3-7” approach by achieving the “3Ts,” namely testing, treating and tracking.

Malaria_chart_0901

Risk of return

Although China was certified malaria-free, the country still faces challenges in preventing the disease from reemerging.

“As the vector mosquitoes remain, imported cases are like sparks. Once a spark comes in, it might start a wild fire, leading malaria to become prevalent again,” Xiao said.

Almost every Chinese province faces the risk of imported cases, Zhou said. Though China recorded no new local cases starting from 2017, the country had 2,600 to 3,000 imported cases every year, 90% of which were found in people who had recently been in Africa.

WHO Regional Director for Africa Matshidiso Moeti said in a statement that the agency’s African region accounts for 94% of global malaria cases and deaths. The disease contributes to social and economic instability in Africa and hampers its economic development.

In order to guard against this danger, China monitors people who enter from at-risk countries, and has rolled out specific measures in places which have previously reported large numbers of imported cases.

For example, in Yongcheng, Central China’s Henan province, people who are planning to work in Africa or Southeast Asia will be sent materials educating them about malaria risks and measures they can take to protect themselves, said Chen Chuanwei, director of the city’s disease control center.

However, the best strategy is to promote global cooperation to control the epidemic worldwide, so as to “naturally” reduce the imported cases in China, the NIPD’s Xiao said.

In 2015, a China-Tanzania pilot program was launched, aiming to help the eastern African country to strengthen its malaria surveillance and control capacity. Unlike previous anti-malaria projects, which focused on sharing medical staff and building facilities, the program developed a model in which Chinese public health experts worked with Tanzanian medical workers to jointly design control measures in affected regions.

Additionally, China introduced its “1-3-7” approach to southern Tanzania and adjusted it to “1-7” to suit local circumstances. The “1” stage requires local health workers or volunteers to conduct daily screenings on locals, quickly test patients suffering from fever, and analyze the test results in the evening. If an area persistently reports a high number of cases, targeted mass treatment will be carried out within seven days, Gao said.

These measures, customized to the Tanzanian context, showed results. From 2015 to 2018, the malaria incidence in one community of 200,000 people dropped more than 80%, Zhou said.

Contact reporter Wang Xintong (xintongwang@caixin.com) and editor Joshua Dummer (joshuadummer@caixin.com)

Download our app to receive breaking news alerts and read the news on the go.

Get our weekly free Must-Read newsletter.

You've accessed an article available only to subscribers
VIEW OPTIONS
Share this article
Open WeChat and scan the QR code