Yingjiang County Research Articles

Prevalence of molecular markers associated with drug resistance of Plasmodium vivax isolates in Western Yunnan Province, China

BackgroundPlasmodium vivax is the most widely distributed malaria parasite, and its drug resistance poses unique challenges to malaria elimination. The Greater Mekong Subregion (GMS) is known as the global epicenter of multidrug resistance. Surveillance of molecular markers associated with drug resistance in this area will help to inform drug policy.MethodsDry blood spots from 58 patients out of 109 with P. vivax infection between 2017, December and 2019, March were obtained from Yingjiang County, Yunnan Province, along the China–Myanmar border. Pvdhfr, Pvdhps, Pvmdr1 and Pvcrt-o were amplified and sequenced to assess gene mutations. The polymorphism and prevalence of these molecular markers were analyzed.ResultsMutations in Pvdhfr at codons 57, 58, 61, 99 and 117 were detected in 27.59, 48.28, 27.59, 32.76 and 48.28% of the isolates, respectively. Single mutant haplotype (I13F57S58T61S99S117I173) was the most frequent (29.31%, 17/58), followed by double mutant haplotype (20.69%, 12/58). Of three types of tandem repeat variations of Pvdhfr, deletion type was the most common. Pvdhps showed a lower prevalence among mutation genotypes. Single mutant was dominant and accounted for 34.48% (20/58). Prevalence of Pvmdr1 mutations at codons 958 and 1076 were 100.00% and 84.48%, respectively. The proportion of double and single mutant types was 84.48% (49/58) and 15.52% (9/58), respectively. Eleven samples (18.97%, 11/58) showed K10 “AAG” insertion in chloroquine resistance transporter gene Pvcrt-o.ConclusionsThere was moderate diversity of molecular patterns of resistance markers of Pvdhfr, Pvdhps, Pvmdr1 and Pvcrt-o in imported P. vivax cases to Yingjiang county in Western Yunnan, along the China–Myanmar border. Prevalence and molecular pattern of candidate drug resistance markers Pvdhfr, Pvdhps, Pvmdr1 and Pvcrt-o were demonstrated in this current study, which would help to update drug policy.

Agapetes yingjiangensis (Ericaceae), a new epiphytic species of A. ser. Longifiles from Yunnan, China

Agapetes yingjiangensis (Ericaceae), a new species from Yingjiang County, Yunnan Province, China is described and illustrated. This new species is somewhat similar to A. mannii Hemsl., but differs in having brown‐hirsute young branches, acute mucronate apex of the leaf blade and sparsely hirsute pedicel, calyx tube and corolla. A key to Chinese species with small (less than 2.5 cm) entire leaves in Agapetes sect. Agapetes ser. Longifiles is included.

A New Species of the GenusCalamaria(Squamata: Colubridae) from Yunnan Province, China

A new reed snake of the genus Calamaria Boie, 1827, Calamaria andersoni, new species, is described on the basis of a single male specimen collected from Yingjiang County, Yunnan Province, China. The new species can be distinguished from other congeners by the unique combination of the following morphological characters: nine modified maxillary teeth; four supralabials, second and third supralabials entering orbit; one preocular; mental not touching anterior chin shields; six shields and scales surrounding the paraparietal; dorsal scales in 13:13:13 rows; 171 ventral scales; 23 subcaudals; tail slowly tapering anteriorly, then abruptly tapering at tip; dorsal scales reduced to four rows on tail at last two subcaudals; dorsum of body and tail brownish with indistinct narrow black stripes on sides; dark collar on neck absent; light rings/blotches on neck and tail absent; and ventral scales with dark outermost corners. Calamaria andersoni, new species, is the fourth species of the genus recorded from China.

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

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. 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. 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. 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.

Mobile population dynamics and malaria vulnerability: a modelling study in the China-Myanmar border region of Yunnan Province, China

BackgroundThe China-Myanmar border region presents a great challenge in malaria elimination in China, and it is essential to understand the relationship between malaria vulnerability and population mobility in this region.MethodsA community-based, cross-sectional survey was performed in five villages of Yingjiang county during September 2016. Finger-prick blood samples were obtained to identify asymptomatic infections, and imported cases were identified in each village (between January 2013 and September 2016). A stochastic simulation model (SSM) was used to test the relationship between population mobility and malaria vulnerability, according to the mechanisms of malaria importation.ResultsThirty-two imported cases were identified in the five villages, with a 4-year average of 1 case/year (range: 0–5 cases/year). No parasites were detected in the 353 blood samples from 2016. The median density of malaria vulnerability was 0.012 (range: 0.000–0.033). The average proportion of mobile members of the study population was 32.56% (range: 28.38–71.95%). Most mobile individuals lived indoors at night with mosquito protection. The SSM model fit the investigated data (χ2 = 0.487, P = 0.485). The average probability of infection in the members of the population that moved to Myanmar was 0.011 (range: 0.0048–0.1585). The values for simulated vulnerability increased with greater population mobility in each village.ConclusionsA high proportion of population mobility was associated with greater malaria vulnerability in the China-Myanmar border region. Mobile population-specific measures should be used to decrease the risk of malaria re-establishment in China.

A new species of the genus Megophrys (Anura: Megophryidae) from Yunnan Province, China.

We describe a new horned toad species of the genus Megophrys from Yingjiang County of Yunnan Province, China. The new species, Megophrys feii sp. nov., can be distinguished from its congeners by a combination of the following characters: (1) body slender and small (SVL 24.3-25.1 mm in four males, 28.2-28.9 mm in two females); (2) head length about equal to head width (HDL/HDW 0.97-0.99); (3) tympanum circular and distinct; (4) maxillary teeth present; (5) vomerine ridges and vomerine teeth absent; (6) tongue round, slightly notched posteriorly; (7) tibia long (TIB/SVL 0.48-0.52 in four males, 0.54-0.55 in two females), shanks overlapping when thighs are held at right angles to the body; (8) dorsal skin distinctly granular and densely covered with small tubercles; (9) lower flanks and lateral sides of belly scattered with small but prominent, white, tubercles; (10) webbing between toes rudimentary; (11) lateral fringes on toes moderate to wide; (12) breeding males without nuptial pads and spines on fingers; (13) protruding projection posterior to cloaca present in both sexes; (14) groin and ventral thigh coloration in life not contrasting with surrounding regions; (15) the presence of an indistinct and small horn-like tubercle at the edge of the eyelid; and (16) an advertisement call with a dominant frequency of 4.74-4.91 kHz (at 18 ˚C). To date, the new species has only been found at its type locality in stream areas in montane evergreen broadleaf forests between 700-1200 m elevation.

Description of two new sympatric species of the genus Leptolalax (Anura: Megophryidae) from western Yunnan of China.

The Asian leaf litter toads of the genus Leptolalax represent a highly diverse species group and currently contain 53 recognized species. During herpetological surveys in Yingjiang County, western Yunnan of China, we collected series of Leptolalax specimens from an isolated small fragment of montane evergreen forest. Subsequent study based on acoustic, morphological and molecular data reveals that there were three different species among the specimens sampled: while one of them belongs to Leptolalax ventripunctataus, the other two species represent unknown taxa and are described herein: Leptolalax purpurus sp. nov. and Leptolalax yingjiangensis sp. nov. The two new species can be distinguished from other congeners by the molecular divergences, acoustic data, and by a combination of morphological characters including: body size, dorsal and ventral patterns, dorsal skin texture, sizes of pectoral and femoral glands, degree of webbing and fringing on the toes and fingers, dorsum coloration and iris coloration in life. Our results further reveal that species diversity of the genus Leptolalax still remains highly underestimated and warrants further attention.

A new phytotelm-breeding treefrog of the genus Nasutixalus (Rhacophoridae) from western Yunnan of China.

A new treefrog of the genus Nasutixalus is described from montane evergreen forest in Yingjiang County, in western Yunnan, China. The new species, Nasutixalus yingjiangensis sp. nov., can be distinguished from its congeners by a combination of the following characters: medium body size (SVL 39.5-40.0 mm in adult males, 47.5 mm in a single female); tympanum indistinct and covered with tubercles; disc diameter of third finger greater than tympanum diameter; dorsal skin relatively smooth, scattered with small tubercles, those on head and anterior dorsum of body more dense and more prominent; light brown above with a dark brown marking between eyes and two broad dark brown lateral strips on the dorsum; iris with a weak "X"-shaped, light colored marking; interorbital distance shorter than the upper eyelid width; comparatively short foot (mean TFL/SVL ratio 67.0% and 62.9% in males and female respectively). The new species appears to be forest-dependent and was found in well-preserved montane rainforest; it inhabits the canopy and breeds in tree holes during the rainy season. The type locality of the new species is an isolated forest fragment surrounded by degraded landscape and efforts are already underway to protect the site. Nasutixalus yingjiangensis sp. nov. represents the third known species of the newly established genus Nasutixalus.

Yunnanosticta gen. nov., from Yunnan, a new genus from the Sinostictinae, with the description of two new species (Odonata: Zygoptera: Platystictidae).

Yunnanosticta gen. nov. in the platystictid subfamily Sinostictinae is described from Yunnan, China. The genotype is Yunnanosticta wilsoni sp. nov., described here (holotype ♂ from Tongbiguan, Yingjiang County, Dehong Dai Jingpo Autonomous Prefecture, Yunnan, China, 23 vi 2015, leg. H.M. Zhang, to be deposited in the Natural History Museum, London). Yunnanosticta cyaneocollaris sp. nov. (holotype ♂ from Tongbiguan, Yingjiang County, Dehong Dai Jingpo Autonomous Prefecture, Yunnan, China, 23 vi 2015, leg. H.M. Zhang, to be deposited in the Natural History Museum, London) is also described.

Evaluating medical convenience in ethnic minority areas of Southwest China via road network vulnerability: a case study for Dehong autonomous prefecture

BackgroundSouthwest China is home to more than 30 ethnic minority groups. Since most of these populations reside in mountainous areas, convenient access to medical services is an important metric of how well their livelihoods are being protected.MethodsThis paper proposes a medical convenience index (MCI) and computation model for mountain residents, taking into account various conditions including topography, geology, and climate. Data on road networks were used for comprehensive evaluation from three perspectives: vulnerability, complexity, and accessibility. The model is innovative for considering road network vulnerability in mountainous areas, and proposing a method of evaluating road network vulnerability by measuring the impacts of debris flows based on only links. The model was used to compute and rank the respective MCIs for settlements of each ethnic population in the Dehong Dai and Jingpo Autonomous Prefecture of Yunnan Province, in 2009 and 2015. Data on the settlements over the two periods were also used to analyze the spatial differentiation of medical convenience levels within the study area.ResultsThe medical convenience levels of many settlements improved significantly. 80 settlements were greatly improved, while another 103 showed slight improvement.Areas with obvious improvement were distributed in clusters, and mainly located in the southwestern part of Yingjiang County, northern Longchuan County, eastern Lianghe County, and the region where Lianghe and Longchuan counties and Mang City intersect.ConclusionsDevelopment of the road network was found to be a major contributor to improvements in MCI for mountain residents over the six-year period.

Receptivity to malaria in the China\u2013Myanmar border in Yingjiang County, Yunnan Province, China

BackgroundThe re-establishment of malaria has become an important public health issue in and out of China, and receptivity to this disease is key to its re-emergence. Yingjiang is one of the few counties with locally acquired malaria cases in the China–Myanmar border in China. This study aimed to understand receptivity to malaria in Yingjiang County, China, from June to October 2016.MethodsLight-traps were employed to capture the mosquitoes in 17 villages in eight towns which were categorized into four elevation levels: level 1, 0–599 m; level 2, 600–1199 m; level 3, 1200–1799 m; and level 4, > 1800 m. Species richness, diversity, dominance and evenness were used to picture the community structure. Similarity in species composition was compared between different elevation levels. Data of seasonal abundance of mosquitoes, human biting rate, density of light-trap-captured adult mosquitoes and larvae, parous rate, and height distribution (density) of Anopheles minimus and Anopheles sinensis were collected in two towns (Na Bang and Ping Yuan) each month from June to October, 2016.ResultsOver the study period, 10,053 Anopheles mosquitoes were collected from the eight towns, and 15 Anopheles species were identified, the most-common of which were An. sinensis (75.4%), Anopheles kunmingensis (15.6%), and An. minimus (3.5%). Anopheles minimus was the major malaria vector in low-elevation areas (< 600 m, i.e., Na Bang town), and An. sinensis in medium-elevation areas (600–1200 m, i.e., Ping Yuan town). In Na Bang, the peak human-biting rate of An. minimus at the inner and outer sites of the village occurred in June and August 2016, with 5/bait/night and 15/bait/night, respectively. In Ping Yuan, the peak human-biting rate of An. sinensis was in August, with 9/bait/night at the inner site and 21/bait/night at the outer site. The two towns exhibited seasonal abundance with high density of the two adult vectors: The peak density of An. minimus was in June and that of An. sinensis was in August. Meanwhile, the peak larval density of An. minimus was in July, but that of An. sinensis decreased during the investigation season; the slightly acidic water suited the growth of these vectors. The parous rates of An. sinensis and An. minimus were 90.46 and 93.33%, respectively.ConclusionsThe Anopheles community was spread across different elevation levels. Its structure was complex and stable during the entire epidemic season in low-elevation areas at the border. The high human-biting rates, adult and larval densities, and parous rates of the two Anopheles vectors reveal an exceedingly high receptivity to malaria in the China–Myanmar border in Yingjiang County.

Assessment of malaria control consultation and service posts in Yunnan, P. R. China.

BackgroundThis paper seeks to assess the function of malaria control consultation and service posts (MCCSPs) that are located on the border areas of Yunnan province, P.R. China, as a strategy for eliminating malaria among the mobile and migrant population in these areas.MethodsA retrospective descriptive analytical study was conducted. Blood smear examinations conducted at all MCCSPs in Yunnan from 2008 to 2014 were analysed. A cross-sectional survey was conducted in 2014 to understand how the MCCSPs function and to elucidate the quality of the blood smear examinations that they conduct.ResultsOut of the surveyed MCCSPs, 66 % (39/59), 22 % (13/59), and 12 % (7/59) were attached to local township hospitals, village health clinics, and the county centre for disease control and prevention or private clinics, respectively. More than 64 % (38/59) of the posts’ staff were part-time workers from township hospitals and village health facilities. Less than 31 % (18/59) of the posts’ staff were full-time workers. A total of 35 positive malaria cases were reported from seven MCCSPs in 2014. Four MCCSPs were unable to perform their functions due to under staffing in 2014. There was a small fluctuation in blood smear examinations from January 2008 to June 2009, with two peaks during the period from July 2009 to October 2010. The number of blood smear examinations has been increasing since 2011. The yearly mean number of blood smear examinations in each post increased from 44 per month in 2011 to 109 per month in 2014, and the number of positive malaria cases detected by blood smear examinations has declined (χ2 = 90.67, P = 0.000). The percentage of people from Yingjiang county getting blood smear examinations increased between 2008 and 2014, while percentages of the mobile population including Myanmar people, people from other provinces, and people from other Yunnan counties getting blood smear examinations decreased.ConclusionMCCSPs face challenges in the phase of malaria elimination in Yunnan, China. New case detection strategies should be designed for MCCSPs taking into account the current trends of migration.Electronic supplementary materialThe online version of this article (doi:10.1186/s40249-016-0185-y) contains supplementary material, which is available to authorized users.

Study on drop-out from antiretroviral therapy among adult HIV-infected individuals in Dehong prefecture, Yunnan province

To examine the proportion and reasons of drop-out from antiretroviral therapy (ART) among 8 367 adult HIV-infected individuals in Dehong prefecture, Yunnan province. All adult HIV-infected patients receiving ART before September 30 of 2014 were examined for the situation of drop-out from ART. The proportion of drop-out from ART among adult HIV-infected patients in Dehong prefecture was 14.4% (1 202/8 367). Results from the univariate logistic regression analyses indicated that drop-out from ART was significantly correlated with factors as: living area, gender, age, marital status, HIV transmission route, baseline CD4⁺ T cell counts and initial treatment regimen of the patients. After adjusted for potential confounding variables by multiple logistic regression model, drop-out from ART was significantly correlated with residential area, marital status, HIV transmission route, baseline CD4⁺ T cell count and initial treatment regimen of the patients. HIV-infected patients who were living in Mangshi city, Lianghe county or Yingjiang County, being married or living with partner, HIV infection through sexual contact, with baseline CD4⁺ T cell counts ≤ 200 cells/mm³, and ART included in the initial treatment regimen etc., were less likely to drop out from ART. The proportion of drop out from ART was significantly decreasing along with the increasing time of ART. Data from specific investigation revealed that among the 1 202 patients who dropped out from ART, 704 (58.6%) were lost to follow-up, 303 (25.2%) did not adhere to treatment, 74 (6.2%) moved out the region, 64 (5.3%) were Burmese that had returned to Burma, 29 (2.4%) stopped the treatment according to doctors' advice, 18 (1.5%) were incarcerated and 10 (0.8%) were under other reasons. Reasons for the drop-out varied, according to the situation of patients. The proportion of drop-out from ART varied significantly according to the characteristics of HIV-infected patients in Dehong prefecture that underscoring the needs for tailored responses to reduce drop-out of ART. Focus should be targeted on reducing the loss to follow-up and improving the treatment adherence.

Amplification of pfmdr1, pfcrt, pvmdr1, and K13 propeller polymorphisms associated with Plasmodium falciparum and Plasmodium vivax isolates from the China-Myanmar border.

Malaria 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 Y86Y184 and M74N75T76, 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.

Proportion and related influencing factors of HIV-infected individuals that rejecting the antiretroviral therapy among all the HIV infections, Dehong prefecture, Yunnan province

To examine the proportion and influencing factors on HIV-infected individuals who rejecting the antiretroviral therapy among all the HIV positives, in Dehong prefecture, Yunnan province. A cross-sectional analysis was conducted on all the local HIV-infected survivals aged over 16 year old who refused to receive antiretroviral therapy (ART) by the end of 2013 in Dehong prefecture. The proportion of those rejecting the ART among HIV-infected survivals and aged over 16 years old in Dehong prefecture, was 7.4% (605/8 136). Factors related to the 'rejection' among the 605 refusals would include: being male (72.9%), aged 31-45 years (57.2%), peasants (75.4%), married (52.2%), with minor ethnicity (41.3%), illiterate or only having primary school education (58.7%), infected through sexual contacts (61.2%), and with CD4(+)T cell counts >350 cells/mm(3) (66.6%). Data from the multiple logistic regression analysis indicated that rejecting the ART was significantly associated with areas, gender, age, ethnicity and CD4(+)T cell counts of the HIV patients. Those who were from Yingjiang county, female, aged 31-45 years old had lower proportions of ART refusals than those who were from Ruili city, male, aged ≤30 year old. Those who were of Dai minority and had no records on CD4(+)T cell counts, had higher proportions of ART refusals than those who were of Han ethnicity and had CD4(+)T cell counts ≤350 cells/mm(3). Reasons for the 605 HIV-infected patients with rejection to the ART would include fear of disclosure of HIV infection status (84, 13.9%), misunderstandings of the effectiveness and side effects of ART (111, 18.3%), self-realized wellness(340, 56.2%) and others (70, 11.6%). Of them, reasons for the 181 patients with CD4(+)T cell counts ≤350 cells/mm(3) that rejecting ART would include fearfulness on the disclosure of HIV infection status(40, 22.1%), misunderstandings of the effectiveness and side effects of ART (36, 19.9%), self-realized wellness (84, 46.4%) and others (21, 11.6%). Among those who rejected ART, reasons for that would vary by areas, gender, age, marital status and routes of HIV transmission, according to the results from Chi-squared tests. A substantial proportion of HIV-infected individuals rejected ART in Dehong prefecture of Yunnan province. It was urgently needed to enhance health education programs of ART tailored for those HIV-infected patients, according to different characteristics and reasons for rejection, so as to promote the ART in this prefecture.

Schistura megalodon species nova, a new river loach from the Irra-waddy basin in Dehong, Yunnan, China (Teleostei: Cypriniformes: Nemacheilidae).

A new species of river loach, Schistura megalodon sp. nov., is described from the Irrawaddy basin in Yingjiang County, Dehong Autonomous Prefecture, Yunnan Province, China. The following combination of diagnostic characters serve to distinguish it from all other congeners in the given zoogeographical region: a large processus dentiformes in the upper jaw, a short pre-anus length of 65.4%-66.3% of SL, long paired fins (pectoral: 20.8%-24.2% of SL; pelvic: 17.9%-20.6% of SL), a wide body of 9.7%-11.3% of SL at anal fin origin, an incomplete lateral line, the absence of an orbital lobe, and a oad and distinct basicaudal bar with forward extensions.

Therapeutic efficacy of artesunate in the treatment of uncomplicated Plasmodium falciparum malaria and anti-malarial, drug-resistance marker polymorphisms in populations near the China-Myanmar border

BackgroundThe aim of this study was to evaluate the clinical outcome after seven-day artesunate monotherapy for uncomplicated Plasmodium falciparum malaria in Yingjiang County along the China-Myanmar border and investigate genetic polymorphisms in the P. falciparum chloroquine-resistance transporter (pfcrt), multidrug resistance 1 (pfmdr1), dihydrofolate reductase (pfdhfr), dihydropteroate synthase (pfdhps) and ATPase (pfatp6) genes.MethodsPatients ≥ one year of age with fever (axillary temperature ≥37.5°C) or history of fever and P. falciparum mono-infection were included. Patients received anti-malarial treatment with artesunate (total dose of 16 mg/kg over seven days) by directly observed therapy. After a 28-day follow-up, treatment efficacy and effectiveness were assessed based on clinical and parasitological outcomes. Treatment failure was defined as recrudescence of the original parasite and distinguished with new infection confirmed by PCR. Analysis of gene mutation and amplification were performed by nested polymerase chain reaction.ResultsSixty-five patients were enrolled; 10 withdrew from the study, and six were lost to follow-up. All but two patients demonstrated adequate clinical and parasitological response; 12 had detectable parasitaemia on day 3. These two patients were confirmed to be new infection by PCR. The efficacy of artesunate was 95.9%. The pfcrt mutation in codon 76 was found in all isolates (100%), and mutations in codons 71 and 72 were found in 4.8% of parasite isolates. No mutation of pfmdr1 (codons 86 or 1246) was found. Among all samples, 5.1% were wild type for pfdhfr, whereas the other samples had mutations in four codons (51, 59, 108 and 164), and mutations in pfdhps (codons 436, 437, 540 and 581) were found in all isolates. No samples had mutations in pfatp6 codons 623 or 769, but two new mutations (N683K and R756K) were found in 4.6% and 9.2% of parasite isolates, respectively.ConclusionPlasmodium falciparum infection was associated with slow parasite clearance and suspected artemisinin resistance at the China-Myanmar border area. The prevalence of pfcrt 76 T and markers for SP resistance are still high. It should be strengthened further on parasite clearance time or clearance half life to confirm the resistance status, and molecular epidemiology should provide complementary information to assess the appropriateness of current policies based on artemisinin derivatives.

Relocation of the 10 March 2011 Yingjiang, China, earthquake sequence and its tectonic implications

An earthquake with MS5.8 occurred on 10 March 2011 in Yingjiang county, western Yunnan, China. This earthquake caused 25 deaths and over 250 injuries. In order to better understand the seismotectonics in the region, we collected the arrival time data from the Yunnan seismic observational bulletins during 1 January to 25 March 2011, and precisely hand-picked the arrival times from high-quality seismograms that were recorded by the temporary seismic stations deployed by our Institute of Crustal Dynamics, China Earthquake Administration. Using these arrival times, we relocated all the earthquakes including the Yingjiang mainshock and its aftershocks using the double-difference relocation algorithm. Our results show that the relocated earthquakes dominantly occurred along the ENE direction and formed an upside-down bow-shaped structure in depth. It is also observed that after the Yingjiang mainshock, some aftershocks extended toward the SSE over about 10 km. These results may indicate that the Yingjiang mainshock ruptured a conjugate fault system consisting of the ENE trending Da Yingjiang fault and a SSE trending blind fault. Such structural features could contribute to severely seismic hazards during the moderate-size Yingjiang earthquake.

Incidence and risk factors of HIV infection among sero-negative spouses of HIV patients in Dehong prefecture of Yunnan province

To study the HIV incidence and risk factors among sero-negative spouses of HIV patients in Dehong prefecture of Yunnan province. A cohort of sero-negative spouses of the HIV patients had been developed and followed up since November, 2005. HIV new infections and related behaviors had been investigated every six months. By the end of June, 2008, 790 sero-negative spouses of HIV patients had been recruited, of whom 702 were followed-up for at least one time. During the total 1202.35 person-years, 31 new HIV infections were identified, with an overall incidence of 2.58/100 person-years. The HIV incidence rates were 2.22/100 person-years in 2006, 2.95/100 person-years in 2007 and 2.74/100 person-years in 2008. Data from the Cox proportional hazard regression model indicated that those who resided in Yingjiang county [hazard ratio (HR) = 4.37, 95%CI: 1.48 - 12.90, P = 0.008], ever using drugs (HR = 3.49, 95%CI: 1.09 - 11.18, P = 0.035), or having an HIV-infected spouse who never exposed to antiretroviral treatment (HR = 3.60, 95%CI: 1.41 - 9.16, P = 0.007) were at higher risk for HIV infection. Sero-negative spouses of HIV patients in Dehong prefecture of Yunnan province had a relatively high incidence of HIV new infection during 2006-2008. More efforts should put on those people living in these areas, having a history of drug use or having an HIV-infected spouse who had never been exposed to antiretroviral treatment.

A new species of the genus Sanmenia Song &amp;amp; Kim, 1992 (Araneae, Thomisidae) from Yunnan Province, China

A new species, Sanmenia gongshan sp. nov., is described based on five males and eight females collected from Gongshan County of the Gaoligong Mountains National Nature Reserve and three males from Yingjiang County of Yunnan Province, China. A revised diagnosis and distribution for the genus Sanmenia are given.