Behind becoming a malaria-free country is China's scientific understanding of malaria and precise prevention and control policies.
▲The picture is from the WeChat public account of the World Health Organization.
On June 30, the World Health Organization issued a press release saying that China had officially obtained the organization's malaria elimination certification. The communiqué considers that the reduction in malaria infection cases in China from 30 million in the 1940s to zero is a remarkable feat.
Malaria had a long history of epidemics in our country before it was eliminated
To date, 87 countries in the world have endemic malaria, and China is one of only 12 countries certified by the World Health Organization to eliminate malaria.
China is a country with a large population, a vast territory, and a large number of malaria-endemic areas, and only the geographical and climatic characteristics make China a malaria-prone country. From a historical point of view, China's elimination of malaria has gone through a long era and a difficult process.
Malaria existed in the world 30 million years ago. Researchers have found mosquitoes carrying malaria parasites in a Paleogene amber fossil, and modern science has confirmed that malaria parasites are the causative agents of malaria, mainly transmitted by mosquitoes.
Malaria is accurately recorded in China during the Warring States period (403-221 BC), when the Book of Rites was written with records such as "Meng Qiu Xing Summer Order, Minduo Malaria" and "Malaria and Cold Disease in Autumn". At the same time, the "Yellow Emperor's Inner Classic" recorded more than 40 characters for "malaria", and there were special articles on "Thorn Malaria" and "Malaria Theory".
The later Twenty-Four Histories recorded malaria in southern China and elsewhere, but malaria was not the only name for the disease, miasma and miasma were other names for malaria. When Emperor Wu of the Han Dynasty conquered Minyue, "miasma is more, and the soldiers are not bloodied and sick and die twelve or thirteen". The Eastern Han Dynasty Ma Yuan led 8,000 people to march to Jiaotong (Vietnam), "military officials through the miasma of the dead of the fourteenth five-year plan".
During the Three Kingdoms period, Zhuge Liang "drove the troops into the barren in May, and the miasma of the Moon Ming Lu was high." Swear to reward the male slightly, and be afraid to enlist the seven indulgences. Zhuge Liang led his troops to overcome the miasma and pacify the south from the end of March 225 to the middle of February 226.
Miasma has multiple meanings, one refers to a large number of mosquitoes and parasites (such as schistosomiasis) that breed in dense water networks, and infectious diseases such as malaria and dysentery that they transmit. In ancient times, when malaria was not well understood, malaria was also called "yin wind" in Italian.
In the Tang Dynasty, Du Fu's "Fifty Rhymes of the Old Fifty Rhymes of the Eight Ambassadors of Yan Eight Envoys in Jiasima Liuzhang Bazhou" of the Tang Dynasty has: "The land is secluded and miasma, and the mountains are thick and narrow and stone springs." The "Song Shi Xu Zhong Propaganda" said, "It will be conscripted into the state, and its land is inflamed, and the soldiers and soldiers are dead. ”
Xu Hongzu of the Ming Dynasty wrote in xu hongzu's "Xu Xiake Travels and Dianyou Diary IX", "Brothers advised Yu not to act immediately, saying that the miasma was poisonous, but why not throw it lightly." "The Qing Dynasty expedition to Burma, "and before the war, the soldiers and soldiers died 78 times."
In modern times, malaria has caused some major disasters in China. Mangshi, Yunnan, is a well-known malaria area with 5,000 Dai residents, but by 1949 only about 1,800 were left due to the invasion of the disease. However, it is now a new industrial town with a population of tens of thousands.
The other is that at the end of the Qing Dynasty, Simao in Yunnan began to circulate malaria, and the original population of Simao City, which was 70,000 or 80,000, had only 944 people left by 1949. A folk song in Xishuangbanna, China, says: "Ten people go to Mengla, and nine people are difficult to go home; to go to Chefunan, first buy a coffin board; to go to Bodhisattva Dam, first marry the wife", vividly describing the harm of malaria to people.
Ancient China did not have a good understanding of malaria, for example, miasma in ancient times refers to a variety of different diseases, but miasma mainly refers to malaria, especially falciparum malaria.
▲ Tu Youyou artemisinin laboratory, researchers do experiments in the laboratory. Beijing News reporter Hou Shaoqing photographed
The prevention and control of malaria has become increasingly precise, starting after the founding of new China
After 1949, the scientific research and prevention of malaria was put on the agenda, and more human, material and financial resources were invested, and Since then, China's understanding and prevention of malaria have become more and more accurate.
Statistics at the end of the 1940s were that there were 1,829 malaria-endemic districts in the country at that time, accounting for about 80% of the number of districts and counties at that time, about 30 million cases of infection, and a mortality rate of about 1%.
Since then, researchers have scientifically understood malaria from pathology and pathogens. Malaria is caused by plasmodium, mainly transmitted by Anopheles mosquitoes, with periodic hot and cold hair as the most important feature, resulting in splenomegaly, anemia and various syndromes caused by damage to the brain, liver, kidneys, heart, intestines, stomach and so on, and in severe cases, causing death.
Malaria is widely distributed, found between 60 degrees north latitude and 30 degrees south latitude, parasitic body and cause malaria parasites include Plasmodium vivax, Plasmodium trinadum, Plasmodium ovoid, Plasmodium falciparum 4 species, malaria is rampant, affecting more than 1.6 billion people worldwide.
▲ In 2019, in the isolation ward of the Mohan Town Center Health Center in Mengla County, Xishuangbanna Prefecture, Yunnan Province, there were mosquito nets, screens and other facilities. Previously, a large number of malaria patients had been isolated here. The picture is from the Beijing News network.
In China, Vivax malaria is the most widely distributed, except for the Qinghai-Tibet Plateau, throughout the country. Malignant malaria is the second most distributed in the Qinling Mountains and south of the Huai River, with Yungui, Liangguang and Hainan as the most. Three-day malaria has scattered cases in the provinces of the north and south of the Yangtze River. Only a few cases of ovate malaria have been reported in Yunnan and Guangdong.
With a scientific understanding of malaria, China's efforts to eliminate malaria are steadily advancing. In 2006, the former Ministry of Health formulated the National Malaria Prevention and Control Plan (2006-2015), which made clear provisions on malaria prevention and control strategies, main technical measures, and the principles for the use of antimalarial drugs.
In May 2010, the former Ministry of Health, together with the National Development and Reform Commission, the Ministry of Education, the Ministry of Finance and 12 other departments, formulated and issued the "China Malaria Elimination Action Plan (2010-2020)", which put forward the goal of "by 2015, there will be no local cases of malaria infection in all regions except some border areas in Yunnan; by 2020, the whole country will eliminate malaria". Among them, the key action plan is the "1-3-7" strategy, that is, the case is reported within 1 day, the investigation is completed within 3 days, whether there are other cases and transmission risks are confirmed, and measures such as mosquito control are taken within 7 days to ensure that the epidemic does not spread.
For malaria control, this is mainly reflected in the spraying of insecticides and the use of impregnated mosquito nets, as well as the simultaneous anti-mosquito and mosquito avoidance operations.
Beginning in the 1980s, long before the World Health Organization recommended insecticide-treated nets as an intervention for malaria control, China had used them on a large scale, mainly in provinces such as Sichuan, Guangdong, Henan and Jiangsu, significantly reducing the incidence of malaria in these areas.
Malaria elimination is also inseparable from medicines. In 1967, the Chinese government launched Project 523 to find new treatments for malaria. The nationwide effort involved more than 500 scientists from 60 institutions led to the discovery in the 1970s of artemisinin-artemisinin combination therapy, the most effective antimalarial drug available today.
▲ On May 29, 2019, Dong Xueshu, an expert from the Yunnan Provincial Malaria Control Institute, was in the mosquito specimen room of the Yunnan Provincial Institute for Parasitic Disease Control. The picture is from the Beijing News network.
The invention of artemisinin has contributed to both China and other countries that eliminate malaria, and China's main inventor, Tu Youyou, also won the 2015 Nobel Prize in Physiology or Medicine.
In 2017, China achieved for the first time that there were no local malaria cases reported throughout the year, with 99.5% of districts and counties and 83.3% of prefectures and cities passing the malaria elimination assessment, and Shanghai became the first place to pass the provincial malaria elimination assessment.
To obtain malaria-free certification, there are strict criteria, that is, a country or region has no indigenous malaria cases for 3 consecutive years, and an effective malaria rapid detection and monitoring system is established to develop malaria prevention and control programs.
Now, China has received the World Health Organization's malaria elimination certification, indicating that China has contributed to world health and that the public's health and lives are no longer endangered by malaria. This is a remarkable achievement, and of course we also need to remain vigilant to prevent the resurgence of malaria.
□ Zhang Tiankan (columnist)
Editor: Chen Jing Proofreader: Wu Xingfa