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@#Abstract: Objective To compare the screening effects of RDT, microscopy and PCR for malaria among residents in low malaria areas and elimination areas, and to investigate the presence of malaria in residents of border Villages in Cangyuan Va County and asymptomatic infections in surrounding areas, providing a basis for preventing re-introduction of malaria after elimination. Methods From August 2020 to March 2021, the fingertip blood of the investigated subjects was collected from three survey sites in the border area between China and Myanmar, namely Banlao Township in Cangyuan Va Autonomous County of Lincang City, Banwai District, Mengmao County, the Second Special Zone of Shan State, Myanmar, Yongmo and Dayan Township, Nandeng Special Zone, the Second Special Zone of Shan State, Myanmar. The malaria parasite antigen detection test kit, malaria parasite microscopic examination, fluorescent quantitative PCR and nested PCR were used to detect the asymptomatic infection of malaria parasites. Results A total of 1 040 blood samples were collected, including 606 from China and 434 from Myanmar, with 506 males and 534 females. Among them, , there were 51 individuals aged 0 to <5 years, 283 aged 5 to < years, 187 aged 15 to < years, 232 aged 30 to <45 years, 205 aged 45 to < years, and 82 aged ≥60 years. All 1 040 people tested negative for plasmodium antigen detection kit. One case of Plasmodium vivax detected by plasmodium microscopic etiology, with a detection rate of 0.10%. One case of P. vivax was also detected by fluorescent quantitative PCR and nested PCR, with a detection rate of 0.10%. Among them, one case of P. vivax was detected in Banwai District, Mengmao County, the Second Special Zone of Shan State, Myanmar, with a detection rate of 0.35%. The detection rates of malaria parasites in Banlao Township in Cangyuan Va Autonomous County of Lincang City, Yunnan Province and Yongmo Township and Dayan Township, Nandeng Special District, the Second Special Zone of Shan State, Myanmar were both 0. The difference in the detection rate of malaria parasites among the three survey sites was not statistically significant (χ2 =2.682, P>0.05). The asymptomatic P. vivax infection was detected in a 6-year-old girl from Banwai District, Mengmao County, the Second Special Zone of Shan State, Myanmar. Conclusions RDT is not suitable for malaria screening in low malaria area and elimination area. Microscopic examination and PCR can be used for malaria screening, but PCR operation is complex and costly. In surrounding areas outside of China, malaria is still prevalent, while there is no source of malaria infection in border villages of Cangyuan Va County. However, there is a risk of importation, and timely and effective measures should be taken to prevent reintroduction and transmission.
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Objective To investigate the awareness of malaria-related knowledge, the use of mosquito nets and their influencing factors among residents in Banlao Township, Cangyuan County, Yunnan Province.. Methods In August 2020, 19 settlement sites in Banlao Township, Cangyuan County, Lincang City, Yunnan Province were selected as study areas, and permanent residents at ages of 10 years and older were enrolled for a questionnaire survey, including residents’ demographics, family economic status, malaria control knowledge and use of mosquito nets. In addition, the factors affecting the use of mosquito nets in the night prior to the survey were identified using multivariate logistic regression analysis. Results A total of 320 questionnaires were allocated, and all were recovered (a 100% recovery rate). There were 316 valid questionnaires, with an effective recovery rate of 98.75%. The 316 respondents included 152 men and 164 women and 250 Chinese respondents and 66 foreign respondents. The awareness of clinical syndromes of malaria was significantly higher among Chinese residents (71.60%) than among foreign residents (50.00%) (χ2 = 11.03, P < 0.01), and the proportions of Chinese and foreign residents sleeping under mosquito nets were 46.00% and 69.70% on the night prior to the survey, respectively (χ2 = 11.73, P < 0.01). Multivariate logistic regression analysis identified ethnicity group and type of residence as factors affecting the use of mosquito nets in the night prior to the survey. Conclusions The awareness of malaria control knowledge, the coverage and the use of mosquito nets were low among residents in Banlao Township, Cangyuan County, Yunnan Province. Targeted health education is recommended to improve the awareness of malaria control knowledge and self-protection ability. In addition, improving the allocation of long-lasting mosquito nets and health education pertaining to their uses and increasing the proportion of using mosquito nets correctly is needed to prevent re-establishment of imported malaria.
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@#Abstract: Objective To detect the polymorphisms of drug resistance-related genes pvcrt-o and pvmdr1 of Plasmodium vivax in lazan city in the China-Myanmar border, in order to guide the treatment plan of Plasmodium vivax. Methods A total of 48 Plasmodium vivax samples were collected from Lazan in the China-Myanmar border in 2007, and fragments of pvcrt-o and pvmdr1 genes were amplified by PCR and sequenced. The sequences were aligned with the Salvador I (Sal-I) strain reference genome sequences to determine the presence of SNPs. Results The target fragments of pvcrt-o gene were amplified from 39 Plasmodium vivax samples, while pvmdr1 genes were amplified from 40 samples. Amongst them, 25 samples had AAG insertion before the 10th amino acid (K10 insertion) of pvcrt-o gene, accounting for 64.1%. Non-synonymous mutations were detected at three loci of pvmdr1 gene (T958M, Y976F, and F1076L), the mutation rates were 100%, 22.5%, and 55.0%, respectively. There were three haplotypes of pvmdr1 gene, of which the triple mutant 958M/976F/1076L accounted for 22.5% (9/40), the double mutant 958M/Y976/1076L accounted for 32.5% (13/40), and the single mutant 958M/Y976/F1076 accounted for 45.0% (18/40). The proportion of strains with pvcrt-o and pvmdr1 gene mutation is 63.16%, which is significantly different from those only with pvmdr1 mutation. Conclusions The proportion of pvcrt-o and pvmdr1 gene mutation of 48 Plasmodium vivax isolates is high in the China-Myanmar border, and there is a certain degree of correlation between the two gene mutations. To assess changes in Plasmodium vivax drug resistance in this region, it is required to improve the surveillance of these two molecular markers.
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China was certificated malaria-free by WHO in 2021 and has continued to maintain malaria elimination. However, there are still huge challenges in malaria control in the border regions between Yunnan Province, China and Myanmar due to lack of geographic barriers and frequent cross-border travel. Hereby, we review the direction contributions of the Global Fund Malaria Program implemented by Health Poverty Action (HPA), an international non-governmental organization (NGO), to malaria elimination in China, and analyze the challenges of malaria control caused by external environmental factors, such as COVID-19, in regions where the Global Fund Malaria Program is implemented. In addition, some suggestions are proposed for cross-border collaboration on malaria control.