[Polymorphism analysis of microsatellite marker loci of Plasmodium falciparum from different geographical origins].

OBJECTIVE: To compare the genetic diversity of imported Plasmodium falciparum by Polyα and TAA87 microsatellite markers in Southeast Asian and African geographical isolates. METHODS: Ninety-two and 126 filter paper samples from patients infected with P. falciparum from Southeast Asia (Myanmar) and Africa (Ghana) were collected, respectively. Two neutral microsatellite loci, Polyα and TAA87 were amplified by PCR. The length of PCR fragments was detected by capillary electrophoresis. The allele frequency and expected heterozygosity (He) were calculated by Excel 2010 and GenALEx 6.0 software. RESULTS: A total of 146 P. falciparum samples were analyzed as single infection samples with a total of 26 alleles in locus Polyα and 12 alleles in locus TAA87. The mean He value of the two loci was 0.86 ± 0.02. Ten alleles in locus Polyα and 8 alleles in locus TAA87 were distributed in Myanmar isolates, with the He values of 0.86 and 0.81 respectively. Fifteen alleles in locus Polyα and 11 in locus TAA87 were detected in Ghana isolates, with the He values of 0.91 and 0.86 respectively. In addition, the haplotype of 174 bp (Polyα) and 113 bp (TAA87) were only detected in Myanmar isolates with more than 17% gene frequency, whereas they were absent in Ghana isolates. CONCLUSIONS: The two different geographical sources of imported P. falciparum strains have different allele frequencies and haplotypes at the two neutral microsatellite markers, Polyα and TAA87. Therefore, these two microsatellite loci may be considered as the potential molecular marker candidates for identifying P. falciparum strains with different geographical sources.

[Tracking evaluation on implementation of Criteria for Control and Elimination of Malaria (GB 26345-2010) in Yunnan Province].

OBJECTIVE: To understand the knowledge, usage, applicability of the standard and the suggestions on the implementation of Criteria for Control and Elimination of Malaria (GB 26345-2010) among malaria prevention and control staff of disease control and medical institutions at all levels in Yunnan Province, so as to provide the evidence for the implementation and revision of the standard. METHODS: Malaria prevention and control workers at 192 institutions in 16 prefectures and cities of Yunnan Province were surveyed. The malaria prevention and treatment workers at county-level center for disease control and prevention (CDCs), county-level medical institutions and township hospitals in Tengchong City and Yingjiang County of Yunnan Province were investigated on the spot. The knowledge and usage, problems and recommendations encountered in the implementation of the standard were collected. RESULTS: Totally 444 questionnaires were collected, of which 428 were valid and the valid rate of questionnaires was 96.4%. Among them, the proportion of those who knew the standard was 86.7% (371/428), and the channel of knowledge acquirement was mainly the education and training, accounting for 50.7% (188/371). The total awareness rate of objective indicators in the standard content was 65.9% (282/428). Among the frequency of utilization, the "occasional use" of this standard was the majority, accounting for 33.6% (144/428). Among the applications, the highest proportion of applying to the "regular malaria prevention and control work" was 59.3% (191/322), and only 19.3% (62/322) applied to the "assessment for malaria elimination". In the standard suitability assessment, the proportion of considering the standard to be fully applicable was 91.3% (391/428), and the proportion of considering the standard to be revised was 8.7% (37/428). The agencies where the respondents were located have taken corresponding measures to promote the implementation of the standard. A total of 43 proposals for the implementation of the standard were collected, relating to personnel and supporting conditions. CONCLUSIONS: Combined with the actual situation, the standard should be strengthened practically. At the same time, the standard learning, training, and publicity should be strengthened to raise the implementation level. Its implementation in Yunnan Province should be sequentially consolidated and steadily promoted.

Polymorphism analysis of microsatellite marker loci of Plasmodium falciparum from different geographical origins / 中国血吸虫病防治杂志

Objective To compare the genetic diversity of imported Plasmodium falciparum by Polyα and TAA87 microsatellite markers in Southeast Asian and African geographical isolates. Methods Ninety-two and 126 filter paper samples from patients infected with P. falciparum from Southeast Asia (Myanmar) and Africa (Ghana) were collected, respectively. Two neutral microsatellite loci, Polyα and TAA87 were amplified by PCR. The length of PCR fragments was detected by capillary electrophoresis. The allele frequency and expected heterozygosity (He) were calculated by Excel 2010 and GenALEx 6.0 software. Results A total of 146 P. falciparum samples were analyzed as single infection samples with a total of 26 alleles in locus Polyα and 12 alleles in locus TAA87. The mean He value of the two loci was 0.86 ± 0.02. Ten alleles in locus Polyα and 8 alleles in locus TAA87 were distributed in Myanmar isolates, with the He values of 0.86 and 0.81 respectively. Fifteen alleles in locus Polyα and 11 in locus TAA87 were detected in Ghana isolates, with the He values of 0.91 and 0.86 respectively. In addition, the haplotype of 174 bp (Polyα) and 113 bp (TAA87) were only detected in Myanmar isolates with more than 17% gene frequency, whereas they were absent in Ghana isolates. Conclusions The two different geographical sources of imported P. falciparum strains have different allele frequencies and haplotypes at the two neutral microsatellite markers, Polyα and TAA87. Therefore, these two microsatellite loci may be considered as the potential molecular marker candidates for identifying P. falciparum strains with different geographical sources.

Polymorphism analysis of microsatellite marker loci of Plasmodium falciparum from different geographical origins / 中国血吸虫病防治杂志

Objective To compare the genetic diversity of imported Plasmodium falciparum by Polyα and TAA87 microsatellite markers in Southeast Asian and African geographical isolates. Methods Ninety-two and 126 filter paper samples from patients infected with P. falciparum from Southeast Asia (Myanmar) and Africa (Ghana) were collected, respectively. Two neutral microsatellite loci, Polyα and TAA87 were amplified by PCR. The length of PCR fragments was detected by capillary electrophoresis. The allele frequency and expected heterozygosity (He) were calculated by Excel 2010 and GenALEx 6.0 software. Results A total of 146 P. falciparum samples were analyzed as single infection samples with a total of 26 alleles in locus Polyα and 12 alleles in locus TAA87. The mean He value of the two loci was 0.86 ± 0.02. Ten alleles in locus Polyα and 8 alleles in locus TAA87 were distributed in Myanmar isolates, with the He values of 0.86 and 0.81 respectively. Fifteen alleles in locus Polyα and 11 in locus TAA87 were detected in Ghana isolates, with the He values of 0.91 and 0.86 respectively. In addition, the haplotype of 174 bp (Polyα) and 113 bp (TAA87) were only detected in Myanmar isolates with more than 17% gene frequency, whereas they were absent in Ghana isolates. Conclusions The two different geographical sources of imported P. falciparum strains have different allele frequencies and haplotypes at the two neutral microsatellite markers, Polyα and TAA87. Therefore, these two microsatellite loci may be considered as the potential molecular marker candidates for identifying P. falciparum strains with different geographical sources.

Tracking evaluation on implementation of Criteria for Control and Elimina-tion of Malaria(GB 26345-2010)in Yunnan Province / 中国血吸虫病防治杂志

Objective To understand the knowledge,usage,applicability of the standard and the suggestions on the imple-mentation of Criteria for Control and Elimination of Malaria(GB 26345-2010)among malaria prevention and control staff of disease control and medical institutions at all levels in Yunnan Province,so as to provide the evidence for the implementation and revision of the standard.Methods Malaria prevention and control workers at 192 institutions in 16 prefectures and cities of Yunnan Province were surveyed.The malaria prevention and treatment workers at county-level center for disease control and pre-vention(CDCs),county-level medical institutions and township hospitals in Tengchong City and Yingjiang County of Yunnan Province were investigated on the spot.The knowledge and usage,problems and recommendations encountered in the implemen-tation of the standard were collected.Results Totally 444 questionnaires were collected,of which 428 were valid and the valid rate of questionnaires was 96.4％.Among them,the proportion of those who knew the standard was 86.7％(371/428),and the channel of knowledge acquirement was mainly the education and training,accounting for 50.7％(188/371).The total awareness rate of objective indicators in the standard content was 65.9％(282/428).Among the frequency of utilization,the "occasional use" of this standard was the majority,accounting for 33.6％(144/428).Among the applications,the highest proportion of ap-plying to the "regular malaria prevention and control work" was 59.3％(191/322),and only 19.3％(62/322)applied to the "as-sessment for malaria elimination".In the standard suitability assessment,the proportion of considering the standard to be fully applicable was 91.3％(391/428),and the proportion of considering the standard to be revised was 8.7％(37/428).The agen-cies where the respondents were located have taken corresponding measures to promote the implementation of the standard.A to-tal of 43 proposals for the implementation of the standard were collected,relating to personnel and supporting conditions.Con-clusions Combined with the actual situation,the standard should be strengthened practically.At the same time,the standard learning,training,and publicity should be strengthened to raise the implementation level.Its implementation in Yunnan Prov-ince should be sequentially consolidated and steadily promoted.

[Epidemiological analysis of imported malaria cases in 20 counties at border region of Yunnan Province from 2012 to 2014].

OBJECTIVE: To analyze the epidemiological characteristics of the imported malaria cases in 20 counties at the border region of Yunnan Province from 2012 to 2014, so as to provide the evidence-based proof for adjusting the strategies in the elimination stage. METHODS: The malaria epidemic data of the 20 border counties in Yunnan Province from 2012 to 2014 were collected and analyzed by using Microsoft Excel 2010. RESULTS: From 2012 to 2014, a total of 1 558 malaria cases were reported in the 20 border counties in Yunnan Province, among which, 1 336 were imported cases, accounting for 85.75% (1 336/1 558), and 222 were indigenous cases, accounting for 14.25% (222/1 558). The number of the imported cases in the above years took up 80.00% (544/680), 89.10% (425/477) and 91.52% (367/401) of the total reported cases in the whole year, respectively. Among all the 1 336 imported cases, 1 045 (78.22%) were infected with Plasmodium vivax, 284 (21.26%) were infected with P. falciparum, 3 were infected with P. malariae, 3 were mixed infection and 1 was an unclassified case; 2 patients died. And 95.58% of the cases were mainly infected in Myanmar (1 277 cases). Young and middle-aged adult of 20-40 years who worked overseas were the predominant (802 cases, 60.03%) and most of the cases occurred from April to June of the year (679 cases, 50.82%). Those cases mainly distributed in Tengchong (459 cases), Ruili (366 cases), Yingjiang (191 cases) and Mangshi (78 cases). CONCLUSIONS: The epidemic situation of imported malaria is serious in the border region of Yunnan Province. Therefore, the surveillance system of malaria control needs to be well planned and managed to ensure timely case detection and prompt response at the elimination and post-elimination stage.

Evaluation on current malaria prevalence using capture-recapture method in national sentinel surveillance points malaria / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the feasibility of using the capture-recapture method (CRM) for national malaria sentinel surveillance program and to evaluate the malaria prevalence at those points.</p><p><b>METHODS</b>By CRM to compare data on malaria cases reported from national sentinel surveillance program and those from the registration of case report system (CRS). Analysis was made to express the difference regarding the number of cases in order to get the estimates and the incidence rate.</p><p><b>RESULTS</b>The incidence in the relative higher epidemic area, unstable epidemic area and relative lower epidemic area were 1247.30/100000, 171.50/100000 and 46.10/100000, respectively. The rate of miss-reporting malaria cases in these areas were 65.20% ,45.32% and 66.67%, respectively.</p><p><b>CONCLUSION</b>The situation of the malaria cases in the national sentinel surveillance points could be estimated,using the CRM.</p>