[Malaria situation in the People's Republic of China in 2002].

This summary was made on the basis of the annual reports of malaria control from the professional institutions in the 21 Provinces/Municipality/Autonomous Region (P/M/A). The number of malaria cases reported in the country was 35,298 in the year 2002 and the incidence rate was 0.348/10,000, an increase of 68.2% than that of the last year and the largest increase since 1994. The total number of suspected cases was 136,902, and the death toll due to malaria was 42. Based on the numbers of malaria cases and suspected cases from the case reporting system of P/M/A, and on the field investigations of the cases missed (failed to report), the estimated total number of malaria cases was 387,000 in 2002. In the South, the provinces of Yunnan and Hainan have been the major area of malaria historically. About 50% of the reported cases in the country were from the two provinces in 2002. There were 12,218 cases reported from Yunnan with 33 deaths, the incidence was 3.026/10,000, 31.6% increase than that in the last year. Among the reported cases, 2,922 were cases of falciparum malaria. The estimated number of malaria cases was 18 times more than that reported. The number of reported cases in Hainan was 5,354 with an incidence of 6.645/10,000, 15.5% increase than that of the last year; there were 1,210 cases of falciparum malaria, and 1 death. The estimated number of malaria cases was 100,000. Covered were also the other P/M/A in the South: Fujian, Guizhou, Guangxi, Guangdong, Sichuan and Chongqing. In Fujian province, 92 malaria cases were reported, all imported, with an incidence of 0.028/10,000 which increased by 272.8% than that in the last year. There were 713 cases reported in Guizhou with an incidence of 0.193/10,000, increased by 17.1%. The number of reported malaria cases was 392 in Guangxi, with an incidence rate of 0.082/10,000, increased by 14.0%. The incidence slightly decreased in Sichuan, Guangdong and Chongqing, and the case number was 443, 403 and 130 respectively. The cases from the 6 provinces/municipality occupied 6.2% of all cases reported from the country. The 5 provinces in central China were also important in malaria control program. Hubei province reported 5,101 malaria cases (incidence 0.895/10,000), increased by 161.6% than that of the last year; plus suspected cases of 5,614, the total number of malaria cases was estimated to be 11,000. The number of reported cases in Anhui province was 5,999 (0.958/10,000), second largest to that of Yunnan province, increased by 123.6%; with 22,615 suspected cases, the total number of malaria cases was estimated to be 28,000. The case number reported in Henan and Jiangsu provinces was 2,921 and 686 respectively, the incidence decreased by 35.1% and 41.7% respectively, but in Shandong province, 52 cases reported with an increase of 23.8%. Focal outbreaks occurred in 81 villages of 17 counties in the provinces of Hubei, Anhui, Henan and Jiangsu, where Anopheles sinensis is the principal transmitting vector. Malaria cases reported from the 5 provinces in central China accounted for 42% of the national figure. Three hundred and thirteen and 229 cases respectively reported from Hunan and Zhejiang provinces, the incidence increased by 44.2% and 288.1% with 3 and 1 death respectively. There were 28 cases in Jiangxi province with a little fluctuation situation. In Shanghai, 135 cases were recorded with an increase of incidence by 66.7%; 16 were infected locally and others all imported. In the provinces of Shaanxi, Shanxi, Liaoning and Gansu, sporadical malaria cases were still reported. The number of Plasmodium falciparum malaria cases was 4,319, accounting for 12.2% of the total cases; of which 13.4% (556) were imported cases. The locally infected falciparum malaria was found in 61 counties/cities of Hainan, Yunnan, Guangxi, and Shaanxi; of which 42 counties/cities were in Yunnan, increased by 11, 16 counties/cities in Hainan, increased by 5, 2 counties in Guangxi and 1 county in Shaanxi. Imported falciparum malaria cases were reported in 114 counties of 14 P/M/A, 2 provinces less but 6 counties more than that in 2001. Due to the strengthening of surveillance and effective management of dubious epidemic conditions, there was no local transmission of falciparum malaria in the above provinces except 2 locally infected cases in Guangxi and 1 in Shaanxi. In areas where the transmission of falciparum malaria has been interrupted but vectors and transmission conditions exist, it is of great importance to prevent the transmission of falciparum malaria by imported source of infection. The main reasons for the considerable increase of malaria transmission in 2002 were as follows: the provinces of Yunnan and Hainan still faced a severe situation of malaria epidemic with a spread of Plasmodium falciparum, especially in the mountainous area of Hainan and the 25 frontier counties in the south and west of Yunnan. Following the development of economy and trade, more frequent population movement occurred among the provinces and between Yunnan and bordering countries, malaria situation becomes more challenging. In central part of the country including Hubei, Anhui, Henan and Jiangsu, where Anopheles sinensis was the principal vector, the malaria situation was highly unstable and local outbreaks took place from time to time. Meanwhile, the increase of the floating population brought more imported cases into Guangdong, Guangxi, Guizhou, Hunan, Fujian, Jiangxi, Chongqing, Shangdong, Zhejiang, and Shanghai, which accounted for 47%-100% of the cases reported in the P/M/A. Furthermore, because of the faultiness in the public health system and the network of the case reporting system, more malaria cases failed to be reported and it is therefore a challenge in implementing the program of malaria control and prevention.