In the process of the 60-year control and 10-year elimination programs, China has accumulated several experiences and the lessons, and the latter could be particularly useful in coping with future challenges. China is approaching the last steps to reach nationwide malaria elimination. If the challenges are addressed properly, China will become sustainably free of indigenous malaria cases. If not, however, all efforts made for the elimination would be lost. The painful lessons taken from repeated emergence in a few countries remind us that we should be vigilant.
Country ownership: Some of the key drivers and sustainable factors contributing to China’s success in effectively controlling and eliminating malaria have been country ownership and government leadership. Other factors also involve multi-sectoral cooperation, constant investment, international collaboration, and the combined efforts of disease control agencies, healthcare facilities, and customs implementing quarantine control. Moreover, adequate funding has shown the impact of country ownership in eliminating malaria. In the transition from the control phase to elimination phase, the GFFATM did provide key funding to assist China in containing malaria transmission, strengthening capacity, and initiating the campaign for malaria elimination, but the Chinese government also simultaneously increased investments in malaria control and elimination. When the GFFATM’s funding stopped in mid-2012, the central government quickly filled in the gap by means of the Central Transfer Payment (CTP), which ensured that required funding to support the elimination was sustained (13) (Figure 2).
Trend of the investment and indigenous cases in China since 2011.
Moreover, funding resources will be one of fundamental pillars at post-elimination. After a country declares elimination of malaria, governmental financial support or investment on malaria surveillance may decline or be reduced, and human resources will be adjusted and transferred to other more urgent posts. To avoid such a risky situation, it is necessary to request the governments to recognize the potential threat of reemerging malaria outbreaks and keep their commitment and continuous support to the functioning of the surveillance system and vital human resources.
Note: GFFATM stands for the funding from the Global Fund to Fight AIDS, Tuberculosis and Malaria. CG stands for the funding from the Chinese Central Government by Central Transfer Payment (CTP). IC stands for indigenous cases of malaria. Since 2016, a novel funding mechanism called the factor-based CTP has been introduced into the program management to replace previous malaria-specific CTP. So it becomes difficult to obtain an exact amount of funding because this funding mechanism is dependent on the priority-oriented consideration at the provincial level.
Capacity building: As an obligatory task, a variety of training every year has been organized at different levels from national, provincial, prefectural, and county-level with a focus on the key knowledge and skills to cover control strategy, implementation measures, epidemiological investigation, use of detection tools, risk assessment, and information and program management. Since 2010, a surveillance network consisting of well-distributed sentinel sites has been established. At nearly the same time, a laboratory network from the national and provincial reference laboratories for malaria diagnosis has been established and extended to county-level malaria-testing laboratories. Since 2011, the National Technical Competition, which is regarded as the Olympics for China’s parasitic diseases control and prevention field, has been held annually for 9 years.
All of these efforts aim to maintain an essential human resource and an efficient disease control and prevention system to quickly identify and respond to any potential risks of transmission, outbreak, importation, and re-transmission of malaria.
Cross-border issues: Yunnan Province borders three malaria-endemic countries, the Lao People’s Democratic Republic, Myanmar, and Vietnam, and has been the high risk area and a frontline of malaria control and elimination in China because Yunnan is subject to frequent cross-border migration. Currently Yunnan remains vigilant in detecting imported malaria cases. To effectively detect infected persons near the border, 68 malaria posts have been established as a defense line and are equipped with microscopes and rapid diagnostic tests (RDTs) to rapidly do blood sample tests and report cases. In addition, China has also been providing technical assistance to the bordering countries to help them reduce malaria transmission and burden of disease (1-2).
Imported malaria: Globalization has increasingly created a huge of migration flow and mobile populations, which causes a high risk of disease spreading. Consequently, the threat of imported malaria will remain for a long time. Cases with Plasmodium infections may come from neighboring countries by border crossings or from other continents by flights or ship. If current efforts on surveillance and response cannot be maintained, malaria may come back and retransmit in previously endemic areas where anopheline mosquitos, the primary carriers of Plasmodium, still exist. It has been reported that, from 2010 to 2018, a total of 33,729 cases of malaria were detected nationwide, of these 5,998 were local infections (17.8%) and 27,719 were imported cases (82.2%) (3). Therefore, the sensitivity and effectiveness of the surveillance and response system against malaria are crucial in the past, present, and future, and the clinicians’ awareness and ability on identifying, treating, and reporting malaria may play the most important role because infected persons with symptoms usually go to clinics or hospitals to get medical help first.
In 2013, an emergency event took place, in which 874 cases of malaria were detected in 4,052 workers returning from overseas and were reported within 4 months, from May to August in Shanglin County, Guangxi Province, China (14). By taking prompt measures including health education, massive screening, rapid clinical treatment and vector control, no deaths or secondary transmission were reported. However, it is a warning signal that such an event may happen again in future and the surveillance system has to be prepared to respond to emergency situations like the Shanglin case.
In recent years, a few PLADs have occasionally reported non-imported malaria cases sporadically including the cases that were isolated or some that were separated at a distance. Four cases reported in Hunan Province were an example of the cases thought to be indigenous but eventually confirmed to be introduced. These infections share common characteristics such as no local indigenous malaria for years and no recorded evidence of history of traveling to the endemic areas. Due to these unknown factors, therefore, inferences should be made on the origins of infections based on molecular tracking technology for cases where epidemiology alone is not sufficient. These phenomena might partly be due to unknown biological features of species of Plasmodium or vectors, and more studies are necessary to explore the mechanisms.
Global public health cooperation: China has proposed an initiative to build a global community with a shared future and actively assist other highly endemic countries in Africa and the Southeast Asia to control malaria. Through international cooperation, China aims to share its lessons in malaria control and elimination and eventually contribute to the goal of making a healthier world. This effort will be able to benefit and impact a healthier world on at least the following points: 1) the sustained ability of malaria control and surveillance of Chinese experts can provide technical support to other endemic countries; 2) supporting malaria control in endemic countries will make a great contribution to the local peoples’ health and global malaria elimination process; 3) the efforts will reduce the pressure of imported malaria from highly endemic areas to lower or non-endemic areas (15-16).
Conflict of interest: The authors declare no competing interests.