A molecular survey of febrile cases in malaria-endemic areas along China-Myanmar border in Yunnan province, People’s Republic of China

Zhou, Xiao‐Nong; Huang, Ji-Lei; Njuabe, Metoh Theresia; Li, Shengguo; Chen, Jun-Hu

doi:10.1051/parasite/2014030

Cited by 28 publications

(33 citation statements)

References 29 publications

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“…In this border region, malaria is seasonal with all four human malaria parasites. While P. vivax has become the predominant parasite species followed by P. falciparum [16, 53], the two minor parasite species P. malariae and P. ovale spp. were detected at very low frequencies in patients presenting in hospitals and clinics with acute febrile illness.…”

Section: Discussionmentioning

confidence: 99%

“…In contrast, other parasite species have been detected at much lower prevalence. Plasmodium malariae infections have been described in Cambodia [20–22], China [16, 23], Laos [19], Myanmar [24, 25], Thailand [11, 26–28], and Vietnam [19, 29, 30]. The detection of field isolates with variations in both morphology and the SSU rRNA gene suggests that P. malariae may exhibit high genetic diversity [23, 24].…”

Section: Introductionmentioning

confidence: 99%

“…Similarly, P. ovale spp. have been found in all nations of the GMS including Cambodia [21, 22], Laos [31, 32], Myanmar [16, 33, 34], Thailand [11, 26, 27], and Vietnam [30, 35]. Although a P. ovale -like case was described in 1941 in Yunnan [36], most, if not all, P. ovale spp.…”

Section: Introductionmentioning

confidence: 99%

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Plasmodium malariae and Plasmodium ovale infections in the China–Myanmar border area

Li¹,

Zhao²,

Hua

et al. 2016

Malar J

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BackgroundThe Greater Mekong Subregion is aiming to achieve regional malaria elimination by 2030. Though a shift in malaria parasite species predominance by Plasmodium vivax has been recently documented, the transmission of the two minor Plasmodium species, Plasmodium malariae and Plasmodium ovale spp., is poorly characterized in the region. This study aims to determine the prevalence of these minor species in the China–Myanmar border area and their genetic diversity.MethodsEpidemiology study was conducted during passive case detection in hospitals and clinics in Myanmar and four counties in China along the China–Myanmar border. Cross-sectional surveys were conducted in villages and camps for internally displaced persons to determine the prevalence of malaria infections. Malaria infections were diagnosed initially by microscopy and later in the laboratory using nested PCR for the SSU rRNA genes. Plasmodium malariae and P. ovale infections were confirmed by sequencing the PCR products. The P. ovale subtypes were determined by sequencing the Pocytb, Pocox1 and Pog3p genes. Parasite populations were evaluated by PCR amplification and sequencing of the MSP-1 genes. Antifolate sensitivity was assessed by sequencing the dhfr-ts and dhps genes from the P. malariae and P. ovale isolates.ResultsAnalysis of 2701 blood samples collected from the China–Myanmar border by nested PCR targeting the parasite SSU rRNA genes identified 561 malaria cases, including 161 Plasmodium falciparum, 327 P. vivax, 66 P. falciparum/P. vivax mixed infections, 4 P. malariae and 3 P. ovale spp. P. vivax and P. falciparum accounted for >60 and ~30% of all malaria cases, respectively. In comparison, the prevalence of P. malariae and P. ovale spp. was very low and only made up ~1% of all PCR-positive cases. Nevertheless, these two species were often misidentified as P. vivax infections or completely missed by microscopy even among symptomatic patients. Phylogenetic analysis of the SSU rRNA, Pocytb, Pocox1 and Pog3p genes confirmed that the three P. ovale spp. isolates belonged to the subtype P. ovale curtisi. Low-level genetic diversity was detected in the MSP-1, dhfr and dhps genes of these minor parasite species, potentially stemming from the low prevalence of these parasites preventing their mixing. Whereas most of the dhfr and dhps positions equivalent to those conferring antifolate resistance in P. falciparum and P. vivax were wild type, a new mutation S113C corresponding to the S108 position in pfdhfr was identified in two P. ovale curtisi isolates.ConclusionsThe four human malaria parasite species all occurred sympatrically at the China–Myanmar border. While P. vivax has become the predominant species, the two minor parasite species also occurred at very low prevalence but were often misidentified or missed by conventional microscopy. These minor parasite species displayed low levels of polymorphisms in the msp-1, dhfr and dhps genes.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-016-1605-y) contains ...

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Plasmodium malariae and Plasmodium ovale infections in the China–Myanmar border area

Li¹,

Zhao²,

Hua

et al. 2016

Malar J

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“…In the Greater Mekong Subregion (GMS) where countries are pursuing regional malaria elimination (www.apmen.org), P. vivax is often sympatric with P. falciparum , P. ovale and P. malariae [2], although P. vivax has become the predominant species in recent years [3]. With the ability to form hypnozoites that are responsible for relapses, P. vivax presents a major challenge for malaria elimination.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Pvama1 genes from China-Myanmar border reveals little regional genetic differentiation of Plasmodium vivax populations

et al. 2016

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BackgroundWith the premise of diminishing parasite genetic diversity following the reduction of malaria incidence, the analysis of polymorphic antigenic markers may provide important information about the impact of malaria control on local parasite populations. Here we evaluated the genetic diversity of Plasmodium vivax apical membrane antigen 1 (Pvama1) gene in a parasite population from the China-Myanmar border and compared it with global P. vivax populations.MethodsWe performed evolutionary analysis to examine the genetic diversity, natural selection, and population differentiation of 73 Pvama1 sequences acquired from the China-Myanmar border as well as 615 publically available Pvama1 sequences from seven global P. vivax populations.ResultsA total of 308 Pvama1 haplotypes were identified among the global P. vivax isolates. The overall nucleotide diversity of Pvama1 gene among the 73 China-Myanmar border parasite isolates was 0.008 with 41 haplotypes being identified (Hd = 0.958). Domain I (DI) harbored the majority (26/33) of the polymorphic sites. The McDonald Kreitman test showed a significant positive selection across the ectodomain and the DI of Pvama1. The fixation index (F ST) estimation between the China-Myanmar border, Thailand (0.01) and Myanmar (0.10) showed only slight geographical genetic differentiation. Notably, the Sal-I haplotype was not detected in any of the analyzed global isolates, whereas the Belem strain was restricted to the Thai population. The detected mutations are mapped outside the overlapped region of the predicted B-cell epitopes and intrinsically unstructured/disordered regions.ConclusionsThis study revealed high levels of genetic diversity of Pvama1 in the P. vivax parasite population from the China-Myanmar border with DI displaying stronger diversifying selection than other domains. There were low levels of population subdivision among parasite populations from the Greater Mekong Subregion.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1899-1) contains supplementary material, which is available to authorized users.

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“…PCR-based assay has been shown to be more sensitive and specific in the detection and identification of Plasmodium species, and they more readily detect mixed infections [23][24][25][26][27]. They are therefore, useful for epidemiological studies in addition to being an assay of choice in critical situations where confirmatory diagnosis is required.…”

Section: Objectivementioning

confidence: 99%

Molecular investigation of sub-microscopic and mixed Plasmodium species infection in North-Central Nigeria

Oyedeji¹,

Awobode²,

Bassi³

2017

APJTD

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A molecular survey of febrile cases in malaria-endemic areas along China-Myanmar border in Yunnan province, People’s Republic of China

Cited by 28 publications

References 29 publications

Plasmodium malariae and Plasmodium ovale infections in the China–Myanmar border area

Plasmodium malariae and Plasmodium ovale infections in the China–Myanmar border area

Analysis of Pvama1 genes from China-Myanmar border reveals little regional genetic differentiation of Plasmodium vivax populations

Molecular investigation of sub-microscopic and mixed Plasmodium species infection in North-Central Nigeria

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