Monitoring Plasmodium falciparum chloroquine resistance in Yunnan Province, China, 1981–2006

Yang, Henglin; Yang, Yaming; Yang, Ping; Li, Xingliang; Gao, B H; Zhang, Zhiyong; Yang, Zhaoqing; Cui, Liwang

doi:10.1016/j.actatropica.2008.08.010

Cited by 21 publications

(19 citation statements)

References 29 publications

(34 reference statements)

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“…Interestingly, the overall rate of resistant clinical cases decreased from 97% between 1981 and 1983 to 40% between 2005 and 2006. 38 This decline is consistent with the decrease of malaria deaths in Yunnan. In contrast, an association between the emergence of chloroquine resistance and increases in malaria mortality has been observed in Senegal.…”

Section: Discussionsupporting

confidence: 70%

Spatial Patterns of Malaria Reported Deaths in Yunnan Province, China

Bi¹,

Hu²,

Yang³

et al. 2013

The American Society of Tropical Medicine and Hygiene

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Abstract. Malaria has been a heavy social and health burden in the remote and poor areas in southern China. Analyses of malaria epidemic patterns can uncover important features of malaria transmission. This study identified spatial clusters, seasonal patterns, and geographic variations of malaria deaths at a county level in Yunnan, China, during 1991-2010. A discrete Poisson model was used to identify purely spatial clusters of malaria deaths. Logistic regression analysis was performed to detect changes in geographic patterns. The results show that malaria mortality had declined in Yunnan over the study period and the most likely spatial clusters (relative risk [RR] = 23.03-32.06, P 0.001) of malaria deaths were identified in western Yunnan along the China-Myanmar border. The highest risk of malaria deaths occurred in autumn (RR = 58.91, P 0.001) and summer (RR = 31.91, P 0.001). The results suggested that the geographic distribution of malaria deaths was significantly changed with longitude, which indicated there was decreased mortality of malaria in eastern areas over the last two decades, although there was no significant change in latitude during the same period. Public health interventions should target populations in western Yunnan along border areas, especially focusing on floating populations crossing international borders.

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Section: Discussionsupporting

confidence: 70%

Spatial Patterns of Malaria Reported Deaths in Yunnan Province, China

Bi¹,

Hu²,

Yang³

et al. 2013

The American Society of Tropical Medicine and Hygiene

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“…The withdrawal of CQ as a first-line treatment led to some regression of CQ resistance in certain areas in Africa, such as Malawi and Kenya (19,20), and also in Far East regions, such as China and Vietnam (21)(22)(23). Nevertheless, in Cameroon, high prevalences of the 76T (83%) and 86Y (93%) mutations were observed after the replacement of CQ by AQ monotherapy in 2002 and by ACT (ASϩAQ) in 2004 (24).…”

Section: Discussionmentioning

confidence: 99%

Plasmodium falciparum Genetic Diversity in Continental Equatorial Guinea before and after Introduction of Artemisinin-Based Combination Therapy

Guerra

Neres

Salgueiro

et al. 2017

Antimicrob Agents Chemother

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Efforts to control malaria may affect malaria parasite genetic variability and drug resistance, the latter of which is associated with genetic events that promote mechanisms to escape drug action. The worldwide spread of drug resistance has been a major obstacle to controlling Plasmodium falciparum malaria, and thus the study of the origin and spread of associated mutations may provide some insights into the prevention of its emergence. This study reports an analysis of P. falciparum genetic diversity, focusing on antimalarial resistance-associated molecular markers in two socioeconomically different villages in mainland Equatorial Guinea. The present study took place 8 years after a previous one, allowing the analysis of results before and after the introduction of an artemisinin-based combination therapy (ACT), i.e., artesunate plus amodiaquine. Genetic diversity was assessed by analysis of the Pfmsp2 gene and neutral microsatellite loci. Pfdhps and Pfdhfr alleles associated with sulfadoxine-pyrimethamine (SP) resistance and flanking microsatellite loci were investigated, and the prevalences of drug resistance-associated point mutations of the Pfcrt, Pfmdr1, Pfdhfr, and Pfdhps genes were estimated. Further, to monitor the use of ACT, we provide the baseline prevalences of K13 propeller mutations and Pfmdr1 copy numbers. After 8 years, noticeable differences occurred in the distribution of genotypes conferring resistance to chloroquine and SP, and the spread of mutated genotypes differed according to the setting. Regarding artemisinin resistance, although mutations reported as being linked to artemisinin resistance were not present at the time, several single nucleotide polymorphisms (SNPs) were observed in the K13 gene, suggesting that closer monitoring should be maintained to prevent the possible spread of artemisinin resistance in Africa.

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“…In the China-Myanmar border area, artemisinins have been used for more than 30 years, mostly as monotherapies prior to 2005. Earlier in vitro assays had already detected a trend of declining sensitivity to artemisinins in the border area of Yunnan province (23,24). Therefore, an understanding of whether artemisinin-resistant parasites have spread to the neighboring regions or emerged elsewhere in this area is essential for coordinating containment efforts.…”

Section: Discussionmentioning

confidence: 99%

Amplification of pfmdr1 , pfcrt , pvmdr1 , and K13 Propeller Polymorphisms Associated with Plasmodium falciparum and Plasmodium vivax Isolates from the China-Myanmar Border

Feng

Zhou

Lin

et al. 2015

Antimicrob Agents Chemother

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bMalaria in the China-Myanmar border region is still severe; local transmission of both falciparum and vivax malaria persists, and there is a risk of geographically expanding antimalarial resistance. In this research, the pfmdr1, pfcrt, pvmdr1, and K13-propeller genotypes were determined in 26 Plasmodium falciparum and 64 Plasmodium vivax isolates from Yingjiang county of Yunnan province. The pfmdr1 (11.5%), pfcrt (34.6%), and pvmdr1 (3.1%) mutations were prevalent at the China-Myanmar border. The indigenous samples exhibited prevalences of 14.3%, 28.6%, and 14.3% for pfmdr1 N86Y, pfcrt K76T, and pfcrt M74I, respectively, whereas the samples from Myanmar showed prevalences of 10.5%, 21.1%, and 5.3%, respectively. The most prevalent genotypes of pfmdr1 and pfcrt were Y 86 Y 184 and M 74 N 75 T 76 , respectively. No pvmdr1 mutation occurred in the indigenous samples but was observed in two cases coming from Myanmar. In addition, we are the first to report on 10 patients (38.5%) with five different K13 point mutations. The F446I allele is predominant (19.2%), and its prevalence was 28.6% in the indigenous samples of Yingjiang county and 15.8% in samples from Myanmar. The present data might be helpful for enrichment of the molecular surveillance of antimalarial resistance and useful for developing and updating guidance for the use of antimalarials in this region. Malaria is a serious public health problem in the Greater Mekong Subregion (GMS), which includes Cambodia, Laos, Thailand, Vietnam, Myanmar, and Yunnan province of China (1). Within this region, malaria transmission is particularly intense in international border areas. The malaria prevalence along the China-Myanmar border is particularly high, and malaria outbreaks have occurred frequently (2). In 2010, China initiated the National Malaria Elimination Action Plan, which aims to eliminate local malaria transmission nationwide by 2015 with the exception of the border region in Yunnan province and to completely eliminate malaria from China by 2020 (3). Despite a great reduction in the number of local malaria cases recently, both Plasmodium falciparum and Plasmodium vivax infections persist in the counties at the China-Myanmar border.Effective chemotherapy is essential for malaria control, but the emergence and spread of multidrug-resistant (MDR) P. falciparum strains have led to the adoption of artemisinin-based combination therapies (ACTs) as the first-line treatment for uncomplicated falciparum malaria in the GMS. However, the confirmed emergence of artemisinin resistance in western Cambodia is a major threat for malaria control and elimination (4). Artemisinin resistance has since spread or emerged independently or both in other areas of mainland Southeast Asia (5). Because this area has been the origin of both chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) resistance (6, 7), the consequences of a similar spread of artemisinin resistance will be catastrophic. Therefore, the World Health Organization (WHO) is coordinating a largescale elimination campa...

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Monitoring Plasmodium falciparum chloroquine resistance in Yunnan Province, China, 1981–2006

Cited by 21 publications

References 29 publications

Spatial Patterns of Malaria Reported Deaths in Yunnan Province, China

Spatial Patterns of Malaria Reported Deaths in Yunnan Province, China

Plasmodium falciparum Genetic Diversity in Continental Equatorial Guinea before and after Introduction of Artemisinin-Based Combination Therapy

Amplification of pfmdr1 , pfcrt , pvmdr1 , and K13 Propeller Polymorphisms Associated with Plasmodium falciparum and Plasmodium vivax Isolates from the China-Myanmar Border

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