Absence of association between Pfnfs1 mutation and in vitro susceptibility to lumefantrine in Plasmodium falciparum.

Artemether-lumefantrine (AL) is the most widely used antimalarial drug for treating uncomplicated falciparum malaria. This study evaluated whether the K65Q mutation in the Plasmodium falciparum cysteine desulfurase IscS (Pfnfs1) gene was associated with alternated susceptibility to lumefantrine using clinical parasite samples from Ghana and the China-Myanmar border area. Parasite isolates from the China-Myanmar border had significantly higher IC50 values to lumefantrine than parasites from Ghana. In addition, the K65 allele was significantly more prevalent in the Ghanaian parasites (34.5%) than in the China-Myanmar border samples (6.8%). However, no difference was observed in the lumefantrine IC50 value between the Pfnfs1 reference K65 allele and the non reference 65Q allele in parasites from the two regions. These data suggest that the Pfnfs1 K65Q mutation may not be a reliable marker for reduced susceptibility to lumefantrine.

An imported malaria case with repeated episodes of neurological syndromes resulting from different Plasmodium species.

BACKGROUND: Imported cerebral malaria (CM) cases in non-endemic areas are often misdiagnosed, which delays treatment. Post-malaria neurological syndrome (PMNS) after recovery from severe malaria can also complicate diagnosis. CASE: We report an imported malaria case from West Africa with two sequential episodes with neurological syndromes within about a month. The first episode was diagnosed as CM with microscopy-positive Plasmodium falciparum infection. The second episode, occurring a month after the recovery from the first CM episode, was consistent with PMNS, since malaria parasites were not detected by microscopy in peripheral blood smears. However, this diagnosis was complicated by the detection of Plasmodium vivax in peripheral blood by PCR, suggesting a potential cause of the second episode by P. vivax. CONCLUSION: This study suggests that PMNS often occurs after severe falciparum malaria. Concurrent P. vivax infection with pathogenic biomass being predominantly extravascular further complicates accurate diagnosis.

Post-marital residence patterns and the timing of reproduction: evidence from a matrilineal society.

Humans exhibit a broad range of post-marital residence patterns and there is growing recognition that post-marital residence predicts women's reproductive success; however, the nature of the relationship is probably dependent on whether co-resident kin are cooperators or competitors. Here, we explore this relationship in a Tibetan population, where couples practice a mixture of post-marital residence patterns, co-residing in the same village with the wife's parents, the husband's parents or endogamously with both sets of parents. Using detailed demographic data from 17 villages we find that women who live with only their own parents have an earlier age at first birth (AFB) and age at last birth (ALB) than women who live with only their parents-in-law. Women who co-reside with both sets of parents have the earliest AFB and ALB. However, those with co-resident older siblings postponed reproduction, suggestive of competition-related delay. Shifts to earlier reproductive timing were also observed in relation to the imposition of family planning policies, in line with Fisherian expectations. Our study provides evidence of the costs and benefits to women's direct fitness of co-residing with different kin, against a backdrop of adaptive responses to cultural constraints on completed fertility.

Application of a low-cost, specific, and sensitive loop-mediated isothermal amplification (LAMP) assay to detect Plasmodium falciparum imported from Africa.

BACKGROUND: Chinese citizens traveling abroad bring back imported malaria cases to China. Current malaria diagnostic tests, including microscopy and antigen-detecting rapid tests, cannot reliably detect low-density infections. To complement existing diagnostic methods, we aimed to develop a new loop-mediated isothermal amplification (LAMP) assay to detect and identify Plasmodium falciparum in Chinese travelers returning from Africa. METHODS: We developed a miniaturized LAMP assay to amplify the actin I gene of P. falciparum. Each reaction consumed only 25% of the reagents used in a conventional LAMP assay and the same amount of DNA templates used in nested PCR. We evaluated this LAMP assay's performance and compared it to microscopy and a nested PCR assay using 466 suspected malaria cases imported from Africa. We assessed the sensitivity of the new LAMP assay using cultured P. falciparum, clinical samples, and a plasmid construct, allowing unprecedented precision when quantifying the limit of detection. RESULTS: The new LAMP assay was highly sensitive and detected two more malaria cases than nested PCR. Compared to nested PCR, the sensitivity and specificity of the novel LAMP assay were 100% [95% confidence interval (CI) 98.5-100%] and 99.1% (95% CI 96.7-99.9%), respectively. When evaluated using serial dilutions of the plasmid construct, the detection limit of the new LAMP was as low as 102 copies/µL, 10-fold lower than PCR. The LAMP assay detected 0.01 parasites/µL of blood (equal to 0.04 parasites/µL of DNA) using cultured P. falciparum and 1-7 parasites/µL of blood (4-28 parasites/µL of DNA) in clinical samples, which is as good as or better than previously reported and commercially licensed assays. CONCLUSION: The novel LAMP assay based on the P. falciparum actin I gene was specific, sensitive, and cost-effective, as it consumes 1/4 of the reagents in a typical LAMP reaction.

In vitro susceptibility profile of Plasmodium falciparum clinical isolates from Ghana to antimalarial drugs and polymorphisms in resistance markers.

Drug resistance in Plasmodium falciparum compromises the effectiveness of antimalarial therapy. This study aimed to evaluate the extent of drug resistance in parasites obtained from international travelers returning from Ghana to guide the management of malaria cases. Eighty-two clinical parasite isolates were obtained from patients returning from Ghana in 2016-2018, of which 29 were adapted to continuous in vitro culture. Their geometric mean IC50 values to a panel of 11 antimalarial drugs, assessed using the standard SYBR Green-I drug sensitivity assay, were 2.1, 3.8, 1.0, 2.7, 17.2, 4.6, 8.3, 8.3, 19.6, 55.1, and 11,555 nM for artemether, artesunate, dihydroartemisinin, lumefantrine, mefloquine, piperaquine, naphthoquine, pyronaridine, chloroquine, quinine, and pyrimethamine, respectively. Except for chloroquine and pyrimethamine, the IC50 values for other tested drugs were below the resistance threshold. The mean ring-stage survival assay value was 0.8%, with four isolates exceeding 1%. The mean piperaquine survival assay value was 2.1%, all below 10%. Mutations associated with chloroquine resistance (pfcrt K76T and pfmdr1 N86Y) were scarce, consistent with the discontinuation of chloroquine a decade ago. Instead, the pfmdr1 86N-184F-1246D haplotype was predominant, suggesting selection by the extensive use of artemether-lumefantrine. No mutations in the pfk13 propeller domain were detected. The pfdhfr/pfdhps quadruple mutant IRNGK associated with resistance to sulfadoxine-pyrimethamine reached an 82% prevalence. In addition, five isolates had pfgch1 gene amplification but, intriguingly, increased susceptibilities to pyrimethamine. This study showed that parasites originating from Ghana were susceptible to artemisinins and the partner drugs of artemisinin-based combination therapies. Genotyping drug resistance genes identified the signature of selection by artemether-lumefantrine. Parasites showed substantial levels of resistance to the antifolate drugs. Continuous resistance surveillance is necessary to guide timely changes in drug policy.

Characteristics and Mechanism of Crayfish Myofibril Protein Gel Deterioration Induced by Autoclaving.

Crayfish myofibril protein (CMP) gel deterioration induced by autoclaving was investigated. A series of CMP gels were obtained through treating CMP solutions at different autoclaving conditions from 100 °C/0.1 MPa to 121 °C/0.21 MPa, and then characteristics and the mechanism of gel texture deterioration along with the intensification of autoclaving were explored through determining appearance, texture, protein composition, cross-linking forces, degree of hydrolysis, water state, microstructure of the gels, and average particle size of aggregates. When autoclaving was at above 105 °C/0.103 MPa, texture of CMP gel showed a tendency to severely weaken with the intensification of autoclaving (p < 0.05), hydrophobic interaction and aggregation between proteins weakened gradually (p < 0.05), and moderately bound water in the gel decreased and T22 relaxation time significantly increased (p < 0.05). After heating for 30 min at above 105 °C/0.103 MPa, pores in the microstructure of CMP gel enlarged obviously, and myosin heavy chain (MHC) degraded. It can be concluded that CMP gel deterioration induced by autoclaving was associated with the degradation of MHC and 105 °C might be the critical temperature to ensure good texture of crayfish products.

First Detection in West Africa of a Mutation That May Contribute to Artemisinin Resistance Plasmodium falciparum.

Background: The spread of drug resistance has seriously impacted the effective treatment of infection with the malaria parasite, Plasmodium falciparum. Continuous monitoring of molecular marker polymorphisms associated with drug resistance in parasites is essential for malaria control and elimination efforts. Our study describes mutations observed in the resistance genes Pfkelch13, Pfcrt, and Pfmdr1 in imported malaria and identifies additional potential drug resistance-associated molecular markers. Methods: Chinese patients infected in Africa with P. falciparum were treated with intravenous (IV) injections of artesunate 240-360 mg for 3-5 days while hospitalized and treated with oral dihydroartemisinin-piperaquine (DHP) for 3 days after hospital discharge. Blood samples were collected and PCR sequencing performed on genes Pfkelch13, Pfcrt, and Pfmdr1 from all isolates. Results: We analyzed a total of 225 patients from Guangxi, China with P. falciparum malaria acquired in Africa between 2016 and 2018. All patients were cured completely after treatment. The F446I mutation of the Pfkelch13 gene was detected for the first time from samples of West African P. falciparum, with a frequency of 1.0%. Five haplotypes of Pfcrt that encode residues 72-76 were found, with the wild-type CVMNK sequence predominating (80.8% of samples), suggesting that the parasites might be chloroquine sensitive. For Pfmdr1, N86Y (13.1%) and Y184F (58.8%) were the most prevalent, suggesting that artemether-lumefantrine may not, in general, be a suitable treatment for the group. Conclusions: For the first time, this study detected the F446I mutation of the Pfkelch13 gene from Africa parasites that lacked clinical evidence of resistance. This study provides the latest data for molecular marker surveillance related to antimalarial drug resistance genes Pfkelch13, Pfcrt, and Pfmdr1 imported from Africa, in Guangxi, China from Chinese migrate workers. Clinical Trial Registration: ChiCTROPC17013106.

Unraveling the Complexity of Imported Malaria Infections by Amplicon Deep Sequencing.

Imported malaria and recurrent infections are becoming an emerging issue in many malaria non-endemic countries. This study aimed to determine the molecular patterns of the imported malaria infections and recurrence. Blood samples were collected from patients with imported malaria infections during 2016-2018 in Guangxi Zhuang Autonomous Region, China. Next-generation amplicon deep-sequencing approaches were used to assess parasite genetic diversity, multiplexity of infection, relapse, recrudescence, and antimalarial drug resistance. A total of 44 imported malaria cases were examined during the study, of which 35 (79.5%) had recurrent malaria infections within 1 year. The majority (91.4%) had one recurrent malaria episode, whereas two patients had two recurrences and one patient had three recurrences. A total of 19 recurrence patterns (the species responsible for primary and successive clinical episodes) were found in patients returning from malaria epidemic countries. Four parasite species were detected with a higher than usual proportion (46.2%) of non-falciparum infections or mixed-species infections. An increasing trend of recurrence infections and reduced drug treatment efficacy were observed among the cases of imported malaria. The high recurrence rate and complex patterns of imported malaria from Africa to non-endemic countries have the potential to initiate local transmission, thereby undermining efforts to eliminate locally acquired malaria. Our findings highlight the power of amplicon deep-sequencing applications in molecular epidemiological studies of the imported malaria recurrences.

Increasing proportions of relapsing parasite species among imported malaria in China's Guangxi Province from Western and Central Africa.

BACKGROUND: Travel-related malaria in non-endemic areas returning from endemic areas presents important challenges to diagnosis and treatment. Imported malaria to newly malaria-free countries poses further threats of malaria re-introduction and potential resurgence. For those traveling to places with high Plasmodium falciparum prevalence, prophylaxis against this parasite is recommended, whereas causal prophylaxis against relapsing malaria is often overlooked. METHODS: We analyzed a cluster of imported malaria among febrile patients in Shanglin County, Guangxi Province, China, who had recent travel histories to Western and Central Africa. Malaria was diagnosed by microscopy and subsequently confirmed by species- and subspecies-specific PCR. Plasmodium vivax was genotyped using a barcode consisting of 42 single nucleotide polymorphisms. RESULTS: Investigations of 344 PCR-confirmed malaria cases revealed that in addition to Plasmodium falciparum being the major parasite species, the relapsing parasites Plasmodium ovale and P. vivax accounted for ~40% of these imported cases. Of the 114 P. ovale infections, 65.8% and 34.2% were P. ovale curtisi and P. ovale wallikeri, respectively, with the two subspecies having a ~2:1 ratio in both Western and Central Africa. Phylogenetic analysis of 14 P. vivax isolates using a genetic barcode demonstrated that 11 formed a distinct clade from P. vivax populations from Eastern Africa. CONCLUSION: This study provides support for active P. vivax transmission in areas with the predominant Duffy-negative blood group. With relapsing malaria making a substantial proportion of the imported malaria, causal prophylaxis should be advocated to travelers with a travel destination to Western and Central Africa.

Loop-mediated isothermal amplification (LAMP) assays targeting 18S ribosomal RNA genes for identifying P. vivax and P. ovale species and mitochondrial DNA for detecting the genus Plasmodium.

BACKGROUND: Loop-mediated isothermal amplification (LAMP) has been widely used to diagnose various infectious diseases. Malaria is a globally distributed infectious disease attributed to parasites in the genus Plasmodium. It is known that persons infected with Plasmodium vivax and P. ovale are prone to clinical relapse of symptomatic blood-stage infections. LAMP has not previously been specifically evaluated for its diagnostic performance in detecting P. ovale in an epidemiological study, and no commercial LAMP or rapid diagnostic test (RDT) kits are available for specifically diagnosing infections with P. ovale. METHODS: An assay was designed to target a portion of mitochondrial DNA (mtDNA) among Plasmodium spp., the five human Plasmodium species and two other assays were designed to target the nuclear 18S ribosomal DNA gene (18S rDNA) of either P. vivax or P. ovale for differentiating the two species. The sensitivity of the assays was compared to that of nested PCR using defined concentrations of plasmids containing the target sequences and using limiting dilutions prepared from clinical isolates derived from Chinese workers who had become infected in Africa or near the Chinese border with Myanmar. RESULTS: The results showed that 102 copies of the mitochondrial target or 102 and 103 copies of 18S rDNA could be detected from Plasmodium spp., P. vivax and P. ovale, respectively. In 279 clinical samples, the malaria Pan mtDNA LAMP test performed well when compared with a nested PCR assay (95% confidence interval [CI] sensitivity 98.48-100%; specificity 90.75-100%). When diagnosing clinical cases of infection with P. vivax, the 18S rDNA assay demonstrated an even great sensitivity (95.85-100%) and specificity (98.1-100%). The same was true for clinical infections with P. ovale (sensitivity 90.76-99.96%; specificity 98.34-100%). Using plasmid-positive controls, the limits of detection of Malaria Pan, 18S rDNA P. vivax and 18S rDNA P. ovale LAMP were 100-, 100- and tenfold lower than those of PCR, respectively. CONCLUSION: The novel LAMP assays can greatly aid the rapid, reliable and highly sensitive diagnosis of infections of Plasmodium spp. transmitted among people, including P. vivax and P. ovale, cases of which are most prone to clinical relapse.

The Inhibitory Activities and Antiviral Mechanism of Medicinal Plant Ingredient Quercetin Against Grouper Iridovirus Infection.

Singapore grouper iridovirus (SGIV) causes high mortality rates in mariculture, and effective treatments against SGIV infection are urgently required. Illicium verum Hook. f. (I. verum) is a well-known medicinal plant with a variety of biological activities. The natural ingredient quercetin isolated from I. verum could effectively inhibit SGIV infection in a dose-dependent manner. The possible antiviral mechanism of quercetin was further analyzed in this study. It showed that quercetin did obvious damages to SGIV particles. Furthermore, quercetin could interfere with SGIV binding to targets on host cells (by 76.14%), disturb SGIV invading into host cells (by 56.03%), and effect SGIV replication in host cells (by 52.73%), respectively. Quercetin had the best antiviral effects during the SGIV life cycle of binding to the receptors on host cells' membranes. Overall, the results suggest that quercetin has direct and host-mediated antiviral effects against SGIV and holds great potential for developing effective drugs to control SGIV infection in aquaculture.

Antiviral activity of Illicium verum Hook. f. extracts against grouper iridovirus infection.

Grouper iridovirus causes high mortality rates in cultured groupers, and effective treatment for grouper iridovirus infection is urgently required. Illicium verum Hook. f. is a well-known medicinal plant with a variety of biological activities. The aim of this study was to analyse the use of I. verum extracts to treat grouper iridovirus infection. The safe working concentration of each I. verum extract was identified both in vitro and in vivo as follows: I. verum aqueous extract (IVAE) ≤ 500 µg/ml; I. verum ethanol extract (IVEE) ≤ 250 µg/ml; shikimic acid (SKA) ≤ 250 µg/ml; trans-anethole (TAT) ≤ 800 µg/ml; 3,4-dihydroxybenzoic acid (DDBA) ≤ 400 µg/ml; and quercetin (QCE) ≤ 50 µg/ml. The inhibitory activity of each I. verum extract against grouper iridovirus infection was analysed using aptamer (Q2)-based fluorescent molecular probe (Q2-AFMP) and RT-qPCR. All of the I. verum extracts displayed dose-dependent antiviral activities against grouper iridovirus. Based on the achieved per cent inhibition, IVAE, IVEE, DDBA and QCE were associated with the greatest antiviral activity (all > 90%). Together, our results indicate that I. verum extracts have effective antiviral properties, making it an excellent potential source material for the development of effective treatment for grouper iridovirus infection.

Widespread resistance mutations to sulfadoxine-pyrimethamine in malaria parasites imported to China from Central and Western Africa.

BACKGROUND: Imported cases of infectious disease provide invaluable information about epidemiological conditions abroad, and should guide treatment decisions at home and abroad. Here, we examined cases of malaria imported from Africa to China for mutations eroding the efficacy of sulfadoxine-pyrimethamine (SP), sometimes used as an intermittent preventive treatment during for pregnant women and infants. METHODS: A total of 208 blood samples were collected from P. falciparum-infected workers who had returned from Western and Central Africa to Guangxi Province Frequency distribution. Samples were analyzed for the mutations in dhfr and dhps genes by PCR -sequencing. The prevalence of dhfr and dhps polymorphisms was analyzed. Among the isolates, polymorphisms were detected in mutants N51I, C59R, S108N and I164L of Pfdhfr and I431V, S436 A/F, A437G, K540 E/N, A581G and A613T of pfdhps. RESULTS: Mutations promoting drug resistance were widespread in this cohort. For pfdhfr and pfdhps, wild types were equally rare among patients returned from Western Africa and Central Africa. A triple-mutant dhfr haplotype was most prevalent (>70%). We report for the first time mutation I164L-dhfr and I431V-dhps in Ghana, and for the first time we found A581G to exceed a clinically-relevant threshold that may counter-indicate current clinical practices. For Pfdhps, the double-mutant IAGKAA was high prevalent haplotype in Ghana, Western Africa. The single-mutant ISGKAA was a majority haplotype in Cameroon. Alarmingly, a "super resistance" quintuple mutant was detected, for the first time, in parasites of West African origin (defined by IAGKAA/IRNI in combination with pfdhps 581G and dhfr I164L). This may limit the efficacy of this drug combination for even intermittent clinical applications. CONCLUSIONS: These data are cause for great concern and call for continued surveillance of the efficacy of SP in source and recipient populations, and should be considered when developing treatment policy for imported malaria cases in China and elsewhere.

Multiple relapses of Plasmodium vivax malaria acquired from West Africa and association with poor metabolizer CYP2D6 variant: a case report.

BACKGROUND: Plasmodium vivax transmission in West Africa, dominant for the Duffy-negative blood group, has been increasingly recognized from both local residents as well as international travelers who contracted P. vivax malaria there. However, the relapsing pattern and sensitivity to antimalarial treatment of P. vivax strains originated from this region are largely unknown. There is evidence that the efficacy of primaquine for radical cure of relapsing malaria depends on host factors such as the hepatic enzyme cytochrome P450 (CYP) 2D6. CASE PRESENTATION: A 49-year-old Chinese man was admitted to the Shanglin County Hospital in Guangxi Province, China, on December 19, 2016, 39 days after he returned from Ghana, where he stayed for one and a half years. He was diagnosed by microscopy as having uncomplicated P. vivax malaria. Treatment included 3 days of intravenous artesunate (420 mg total), and 3 days of chloroquine (1550 mg total), and 8 days of primaquine (180 mg total). Although parasites and symptoms were cleared rapidly and he was malaria-negative for almost two months, he suffered four relapses with relapse intervals ranging from 58 to 232 days. The last relapse occurred at 491 days from his first vivax attack. For the first three relapses, he was treated similarly with chloroquine and primaquine, sometimes supplemented with additional artemisinin combination therapies (ACTs). For the last relapse, he was treated with intravenous artesunate, 3 days of an ACT, and 7 days of azithromycin, and had remained healthy for 330 days. Molecular studies confirmed P. vivax infections for all the episodes. Although this patient was diagnosed to have normal glucose-6-phosphate dehydrogenase (G6PD) activity, his CYP2D6 genotype corresponded to a *2A/*36 allele variant suggesting of an impaired primaquine metabolizer phenotype. CONCLUSIONS: This clinical case suggests that P. vivax malaria originating from West Africa may produce multiple relapses extending beyond one year. The failures of primaquine as an anti-relapse therapy may be attributed to the patient's impaired metabolizer phenotype of the CYP2D6. This highlights the importance of knowing the host G6PD and CYP2D6 activities for effective radical cure of relapsing malaria by primaquine.

Malaria in the Guangxi Zhuang Autonomous Region in China: A Twelve-Year Surveillance Data Study.

The incidence of an indigenous malaria, defined as malaria acquired by a local mosquito transmission, declined from 2004 to 2015 in the Guangxi Zhuang Autonomous Region. However, imported malaria, defined as malaria acquired from other endemic regions outside of China, has been increasing in the region, as in the rest of the country, particularly the disease caused by Plasmodium falciparum. A retrospective study was conducted to explore malaria-endemic characteristics in Guangxi during the 2004-2015 timeframe; a total of 2,726 confirmed malaria cases were reported, and the majority (90.3%) were due to P. falciparum (N = 1,697 [62.2%]) and Plasmodium vivax (N = 765 [28.1%]). Thirty-four indigenous cases (1.2%) were observed, with no cases of transmission recorded since 2012. Imported P. vivax and Plasmodium ovale infections increased since 2013. The interval between returning to China and the onset of illness was longer for P. vivax and P. ovale infections than for P. falciparum and Plasmodium malariae infections. The difference interval among the species is likely because of the relapse of P. vivax and P. ovale caused by the activation of the latent hypnozoites. Therefore, health clinics should raise awareness and carry out epidemiological studies and follow-up surveys on migrant workers to avoid misdiagnosis and mistreatment. The evaluation of radical treatment should be carried out using a genotyping technology based on glucose-6-phosphate dehydrogenase deficiency levels, and some new drugs active against the hypnozoites should be developed to mitigate malaria in the region.

[Analysis of population genetic structure of Anopheles sinensis based on mitochondrial DNA cytochrome oxidase subunit I gene fragment].

OBJECTIVE: To study the population genetic variation, genetic diversity and phylogenesis of Anopheles sinensis in China. METHODS: Anopheles sinensis samples collected from Shandong, Anhui, Jiangsu, Guizhou, and Yunnan Provinces and Guangxi Zhuang Autonomous Region with different geographical conditions between 2010 and 2012 were analyzed by mitochondrial DNA cytochrome oxidase subunit I (mtDNA-COI) gene amplification and sequencing. Bioedit 7.0 and DnaSP 5.0 software was used to compare the gene sequences and analyze the population genetic structure, respectively. Arlequin 3.1 was used to calculate the genetic distance and parameters of population differentiation. The relationship between the geographic and genetic distances was analyzed using IBD Web Service. PHYLIP 3.6 was used to construct the phylogenetic tree. RESULTS: PCR amplification and sequencing was performed successfully for 6 Anopheles sinensis populations containing 123 female mosquitoes. The length of mtDNA-COI gene fragment was 841 bp with an average A+T content of 71.2% and G+C content of 28.8%. High nucleotide diversity and genetic differentiation were observed among the Anopheles sinensis populations based on mtDNA-COI gene. Analysis of the molecular variance revealed a greater variation between populations than that within populations with isolation by distance between the populations. The Anopheles sinensis populations appeared to have undergone expansion, but the Yunnan population constituted an isolated branch in the phylogenetic tree. CONCLUSION: mtDNA-COI can serve as the molecular marker to analyze population genetic variation and phylogenesis of Anopheles sinensis. The Yunnan population shows a phylogenetic difference from the other populations analyzed in this study.

[A case of neonatal congenital malaria accompanied with severe thrombocytopenia].

This article reports the process of diagnosis and treatment of one case of neonatal congenital malaria accompanied with severe thrombocytopenia.

[Status of malaria epidemic and feasibility of malaria elimination in Guangxi Zhuang Autonomous Region].

OBJECTIVE: To analyze the status of malaria epidemic and discuss the feasibility of malaria elimination in Guangxi Zhuang Autonomous Region. METHODS: The data of blood smear examinations of febrile patients among local residents, focus residents and mobile population in Guangxi Zhuang Autonomous Region were collected, described and analyzed statistically from 2001 to 2011. RESULTS: A total of 4 916 343 blood smear slides of local residents who had fever, 195 967 slides of focus residents, 282 461 slides of returned emigrants, and 228 341 slides of immigrants were examined, and the average positive rates of blood examinations were 0.004 8%, 0.007 7%, 0.480% and 0.127%, respectively. The indigenous malaria cases reduced from 51 in 2001 to 1 in 2009. There were no indigenous malaria cases during the period of 2010-2011. The malaria incidence has been under 1/100 000 for 11 years. The imported malaria cases were dominated in the whole region. CONCLUSIONS: Malaria situation in this region has entranced the consolidating phase of elimination according to the WHO criteria of malaria elimination. The goal of malaria elimination in Guangxi would be achieved in 2018 as long as the government and other departments pay enough attention to the imported malaria control, and the technical measures are further strengthened.

[Surveillance of malaria in Global Fund Malaria Project counties of Guangxi Zhuang Autonomous Region in 2011].

OBJECTIVE: To analyze the monitoring results and epidemic trend of malaria in the Global Fund Malaria Project counties of Guangxi Zhuang Autonomous Region in 2011, so as to provide the evidence for improving the preventive measures. METHODS: The data about malaria surveillance were collected and statistically analyzed in 7 Global Fund Malaria Project counties of Guangxi in 2011. RESULTS: A total of 8 cases of malaria were reported in the Global Fund Malaria Project counties of Guangxi in 2011, the average annual incidence rate was 0.04 per 10000 which increased by 100% compared with that in 2010, accounting for 7.14% (8/112) of the total number of cases in Guangxi. Totally 42 064 residents with fever were examined with blood tests and no case was found; 3 867 floating people were examined with blood tests and 8 cases of malaria were found (0.21%), including 5 cases of vivax malaria and 3 cases of falciparum malaria. The 8 malaria cases distributed in Longlin, Tiane, Nandan, Youjiang counties (district), and they all had ever worked in Africa or Southeast Asia. There were no input secondary cases or deaths throughout the year. CONCLUSIONS: The preventive measures of malaria are effective in the Global Fund Malaria Project counties of Guangxi, and the malaria epidemic situation is stable. It is the key to strengthen the malaria surveillance of the floating population who returned from Africa or Southeast Asia for consolidating the achievement of malaria prevention and control.

Plasmodium vivax populations revisited: mitochondrial genomes of temperate strains in Asia suggest ancient population expansion.

BACKGROUND: Plasmodium vivax is the most widely distributed human malaria parasite outside of Africa, and its range extends well into the temperate zones. Previous studies provided evidence for vivax population differentiation, but temperate vivax parasites were not well represented in these analyses. Here we address this deficit by using complete mitochondrial (mt) genome sequences to elucidate the broad genetic diversity and population structure of P. vivax from temperate regions in East and Southeast Asia. RESULTS: From the complete mtDNA sequences of 99 clinical samples collected in China, Myanmar and Korea, a total of 30 different haplotypes were identified from 26 polymorphic sites. Significant differentiation between different East and Southeast Asian parasite populations was observed except for the comparison between populations from Korea and southern China. Haplotype patterns and structure diversity analysis showed coexistence of two different groups in East Asia, which were genetically related to the Southeast Asian population and Myanmar population, respectively. The demographic history of P. vivax, examined using neutrality tests and mismatch distribution analyses, revealed population expansion events across the entire P. vivax range and the Myanmar population. Bayesian skyline analysis further supported the occurrence of ancient P. vivax population expansion. CONCLUSIONS: This study provided further resolution of the population structure and evolution of P. vivax, especially in temperate/warm-temperate endemic areas of Asia. The results revealed divergence of the P. vivax populations in temperate regions of China and Korea from other populations. Multiple analyses confirmed ancient population expansion of this parasite. The extensive genetic diversity of the P. vivax populations is consistent with phenotypic plasticity of the parasites, which has implications for malaria control.