China-Myanmar Border Region Research Articles

Characterizing HIV-1 transmission by genetic cluster analysis among newly diagnosed patients in the China-Myanmar border region from 2020 to 2023

ABSTRACT Cluster analysis of HIV sequence can provide insights into viral transmission patterns in border regions. This study aims to illuminate the HIV-1 subtype distribution and transmission dynamics among newly diagnosed individuals in Dehong prefecture, a region along the China-Myanmar border. Among 948 participants with pol gene sequences, 36 HIV-1 subtypes were identified, with URFs (18.8%, 178/948) being the dominant strain, followed by CRF01_AE (18.5%, 175/948) and CRF07_BC (10.9%, 103/948). Additionally, 287 sequences (30.3%, 287/948) were grouped into 91 clusters, 31 of which contained both Chinese and Burmese individuals. Multivariable logistic regression indicated that men who have sex with men (MSM), CD4 + cell count of 200∼499 cells/μl, and 500 cells/μl and above, and CRF01_AE were risk factors for entering the network. Through Chord diagram, we found frequent transmission relationships among heterosexual China male group, especially those over 35 years of age. Additionally, the correlation between heterosexual Myanmar female group and heterosexual China male group among cross-risk groups deserved to be emphasized. Furthermore, the network exhibited a growing trend over time, with the largest active transmission cluster identified in Ruili county. In conclusion, the HIV-1 subtype landscape in Dehong has become increasingly complex, and the region has faced risks of transmission from both domestic and international sources. Targeted intervention strategies should be implemented for MSM, heterosexual Chinese middle-aged and elderly men, and heterosexual Burmese young adults to mitigate these risks. These findings provided evidence-based insights for local government to formulate coordinated transnational intervention approaches.

A new multivariate index for ecological security assessment in the China-Myanmar border region

The coordination of development efforts and ecological conservation in China's border regions is a significant challenge due to the overlap of biodiversity hotspots, ecologically fragile zones, and impoverished areas. Achieving the harmonious integration of ecological preservation and economic development relies on the fundamental assessment of ecological security (ES). However, comprehensive assessments of ES in border regions remain limited. This study introduces a new index, the multivariate ecological security index (MESI), which integrates ecosystem vigor, organization, elasticity, services and risk. Here, the MESI was utilized to assess the temporal and spatial changes in ES and its associated impact factors in the China-Myanmar border region (CMBR) from 2000 to 2020. The MESI provides a clear representation of the actual ES status in the CMBR, exhibiting a significant correlation with the eco-environmental quality index (EEQI; p < 0.01). The ES status exhibited notable spatial heterogeneity in the CMBR, consisting primarily of both relatively safe and safe levels, which accounted for approximately 85% of the total area. From 2000 to 2020, the CMBR experienced a gradual improvement in ES status, with the area experiencing an increase in the ES level accounting for 23.41% of the total area, which exceeded the proportion of the area experiencing a decrease in the ES level (4.71%). The combined impact of multiple factors exerted a greater influence on ES than did individual factors alone. Notably, human factors increasingly influenced the ES status during the study period. The results of this study provide valuable insights for ecological preservation and sustainable management in the CMBR, and the MESI can be extended to assess the ES of other regions.

Genetic Diversity and Natural Selection of Plasmodium vivax Merozoite Surface Protein 8 in Global Populations

Plasmodium vivax Merozoite Surface Protein 8 (PvMSP8) is a promising candidate target for the development of multi-component vaccines. Therefore, determining the genetic variation pattern of Pvmsp8 is essential in providing a reference for the rational design of the P. vivax malaria vaccines. This study delves into the genetic characteristics of the Pvmsp8 gene, specifically focusing on samples from the China-Myanmar border (CMB) region, and contrasts these findings with broader global patterns. The study uncovers that Pvmsp8 exhibits a notable level of conservation across different populations, with limited polymorphisms and relatively low nucleotide diversity (0.00023–0.00120). This conservation contrasts starkly with the high polymorphisms found in other P. vivax antigens such as Pvmsp1. A total of 25 haplotypes and 14 amino acid mutation sites were identified in the global populations, and all mutation sites were confined to non-functional regions. The study also notes that most CMB Pvmsp8 haplotypes are shared among Burmese, Cambodian, Thai, and Vietnamese populations, indicating less geographical variance, but differ notably from those found in Pacific island regions or the Panama. The findings underscore the importance of considering regional genetic diversity in P. vivax when developing targeted malaria vaccines. Non departure from neutral evolution were found by Tajima's D test, however, statistically significant differences were observed between the kn/ks rates. The study's findings are crucial in understanding the evolution and population structure of the Pvmsp8 gene, particularly during regional malaria elimination efforts. The highly conserved nature of Pvmsp8, combined with the lack of mutations in its functional domain, presents it as a promising candidate for developing a broad and effective P. vivax vaccine. This research thus lays a foundation for the rational development of multivalent malaria vaccines targeting this genetically stable antigen.

Pyrethroid resistance status and co-occurrence of V1016G, F1534C and S989P mutations in the Aedes aegypti population from two dengue outbreak counties along the China-Myanmar border

BackgroundOver the past two decades, dengue fever (DF) has emerged as a significant arboviral disease in Yunnan province, China, particularly in the China-Myanmar border area. Aedes aegypti, an invasive mosquito species, plays a crucial role in transmitting the dengue virus to the local population. Insecticide-based vector control has been the primary tool employed to combat DF, but the current susceptibility status of Ae. aegypti to commonly used insecticides is unknown. Assessment of Ae. aegypti resistance to pyrethroid insecticides and an understanding of the underlying mechanisms of this resistance in the China-Myanmar border region is of significant strategic importance for effectively controlling the DF epidemic in the area.MethodsAedes aegypti larvae collected from Ruili and Gengma counties in Yunnan Province were reared to adults in the laboratory and tested for susceptibility to three pyrethroid insecticides (3.20% permethrin, 0.08% lambda-cyhalothrin and 0.20% deltamethrin) by the standard WHO susceptibility bioassay. Genotyping of mutations in the knockdown gene (kdr), namely S989P, V1016G and F1534C, that are responsible for resistance to pyrethroid insecticides was performed using allele-specific PCR methods. A possible association between the observed resistant phenotype and mutations in the voltage-gated sodium channel gene (VGSC) was also studied.ResultsAedes aegypti mosquitoes collected from the two counties and reared in the laboratory were resistant to all of the pyrethroids tested, with the exception of Ae. aegypti from Gengma County, which showed sensitivity to 0.20% deltamethrin. The mortality rate of Ae. aegypti from Ruili county exposed to 3.20% permethrin did not differ significantly from that of Ae. aegypti from Gengma County (χ2 = 0.311, P = 0.577). By contrast, the mortality rate of Ae. aegypti from Ruili County exposed to 0.08% lambda-cyhalothrin and 0.20% deltamethrin, respectively, was significantly different from that of Ae. aegypti from Gengma. There was no significant difference in the observed KDT50 of Ae. aegypti from the two counties to various insecticides. Four mutation types and 12 genotypes were detected at three kdr mutation sites. Based on results from all tested Ae. aegypti, the V1016G mutation was the most prevalent kdr mutation (100% prevalence), followed by the S989P mutation (81.6%) and the F1534C mutation (78.9%). The constituent ratio of VGSC gene mutation types was significantly different in Ae. aegypti mosquitoes from Ruili and those Gengma. The triple mutant S989P + V1016G + F1534C was observed in 274 Ae. aegypti mosquitoes (60.8%), with the most common genotype being SP + GG + FC (31.4%). The prevalence of the F1534C mutation was significantly higher in resistant Ae. aegypti from Ruili (odds ratio [OR] 7.43; 95% confidence interval [CI] 1.71–32.29; P = 0.01) and Gengma (OR 9.29; 95% CI 3.38–25.50; P = 0.00) counties than in susceptible Ae. aegypti when exposed to 3.20% permethrin and 0.08% lambda-cyhalothrin, respectively. No significant association was observed in the triple mutation genotypes with the Ae. aegypti population exposed to 3.20% permethrin and 0.20% deltamethrin resistance (P > 0.05), except for Ae. aegypti from Gengma County when exposed to 0.08% lambda-cyhalothrin (OR 2.86; 95% CI 1.20–6.81; P = 0.02).ConclusionsAedes aegypti from Ruili and Gengma counties have developed resistance to various pyrethroid insecticides. The occurrence of multiple mutant sites in VGSC strongly correlated with the high levels of resistance to pyrethroids in the Ae. aegypti populations, highlighting the need for alternative strategies to manage the spread of resistance. A region-specific control strategy for dengue vectors needs to be implemented in the future based on the status of insecticide resistance and kdr mutations.Graphical

Implementing a novel capture and ligation probe-PCR method in mass screen and treatment to support malaria elimination efforts in the China-Myanmar border region

BackgroundMass screening and treatment (MSAT) for malaria elimination lacks an ideal diagnostic tool to allow sensitive and affordable test of the target population in the field. This study evaluated whether Capture and Ligation Probe-PCR (CLIP-PCR) could be used in a field MSAT in Laiza City, Myanmar.MethodsOn day 0, two dried blood spots were collected from each participant. On day 1, all samples were screened for Plasmodium in a 20 m2 laboratory with workbench, a biosafety cabinet, a refrigerator, a benchtop shaking incubator and a qPCR machine, by four technicians using CLIP-PCR with sample pooling, at a health clinic of the Chinese bordering town of Nabang. On day 2, all positives were followed up and treated.ResultsOf 15,038 persons (65% of the total population) screened, 204 (1.36%) were CLIP-PCR positives. Among them, 188, 14, and 2 were infected with Plasmodium vivax, Plasmodium falciparum, and P. vivax/P. falciparum mix, respectively. The testing capacity was 538 persons/day, with a cost of US$0.92 /person. The proportion of submicroscopic infection was 64.7%. All positive individuals received treatment within 72 h after blood collection.ConclusionUsing CLIP-PCR in MSAT in low transmission settings can support the malaria elimination efforts in the China-Myanmar border region.

Oscillating Border Policy: Is It a Triumph for the Government or for the Myanmar IDPs in China?

In recent years, several large-scale internal military conflicts in Myanmar, represented by the “8.08 Kokang Incident”, have led to an influx of Burmese into Yunnan, a border area between China and Myanmar. China’s border management has faced serious challenges, most directly reflected in a change in its border policy. China has not used enforced power to directly stop the influx of Burmese, such as building walls or barbed wire. But neither has it recognized the status of these people as refugees. China’s new border management policy is more about blurring their official status, in practice, allowing them to enter easily to the Chinese border city (Ruili) for work. But it also restricts them to the southeast coast of China in search of better income. This seemingly contradictory attitude of the Chinese government reflects the complexity of a multi-actor participation in governance in the China-Myanmar border region. Using Gramsci’s “hegemony theory” and Ho’s affinity ties theory, this paper explores how IDPs can flexibly use affinity ties networks to proactively influence the Chinese government’s new border governance policy from the bottom up by interacting with grassroots multi-actor border practices.

Making markets ‘decisive’: a firm-level evaluation of state-led development in the China–Myanmar border region

This article critically assesses state–market relations through a comparative firm-level study of state-led development in the China–Myanmar border region. It develops a framework that foregrounds how market building is a contingent and multi-scalar process that underpins the reproduction of stable state rule. The framework is utilized to examine state-led attempts in Ruili, a border city in Yunnan province, to attract Yinxiang, a privately owned firm, and Beijing Automotive Industry Holding Corporation (BAIC), a state-owned enterprise (SOEs), to launch flagship manufacturing projects. The contrasting performance of these firms—Yinxiang successfully captured its target market in Myanmar while BAIC did not even commence production—foregrounds a pronounced tension in the ongoing market reforms. On the one hand, attempts at giving market actors more autonomy in resource allocation through supply-side structural reforms continue to be shaped by the institutional legacy of reciprocal accountability. On the other hand, the Chinese state’s willingness to allow BAIC’s investment to fail suggests it is serious about subjecting both local governments and SOEs to demand-side discipline. These findings collectively generate one distinct contribution to existing research on state–market relations: market activities are embedded within state-building processes in place-specific and often unpredictable ways.

Frequently Transmission and Close Relationship Among Immigrants in the China-Myanmar Border Region Indicated by Molecular Transmission Analysis From a Cross-Sectional Data.

BackgroundAccurate identification of molecular transmission clusters (MTCs) and understanding the dynamics of human immunodeficiency virus (HIV) transmission are necessary to develop targeted interventions to prevent HIV transmission. We evaluated the characteristics of antiretroviral therapy-naïve individuals who belonged to HIV-1 MTCs in the China–Myanmar border region to inform targeted effective HIV intervention.MethodsPhylogenetic analyses were undertaken on HIV-1 pol sequences to characterize subtypes or circulating recombinant forms and identify MTCs. MTCs were defined as those with 2 or more sequences having bootstrap support > 80% and a pairwise gene distance less than or equal to 0.03. Factors correlated with MTCs were evaluated using logistic regression analysis. The chi-square test was used to compare differences between Chinese and Burmese participants belonging to MTCs.ResultsA total of 900 people had their pol gene successfully sequenced. Twenty-one MTCs were identified and included 110 individuals (12.2%). Individuals in MTCs were more likely to be Burmese [aOR = 2.24 (95% CI: 1.33, 3.79), P = 0.003], be younger [aOR = 0.34 (95% CI: 0.20, 0.58), P < 0.001 for age 26–50 vs. 25 years or younger], have a lower CD4 T cell count [aOR = 2.86 (95% CI: 1.34, 6.11), P = 0.007 for < 200 vs. 350 or greater], and have subtypes CRF07_BC or C [CRF07_BC: aOR = 7.88 (95% CI: 3.55, 17.52), P < 0.001; C: aOR = 2.38 (95% CI: 1.23, 4.62), P = 0.010 compared to CRF01_AE]. In MTCs, Burmese were younger (89.7 vs. 57.7% for age 25 years or younger), had a lower education level (41.0 vs. 8.5% for illiterate), were more likely to be infected through injection drug use (35.9 vs. 12.7%), and had a higher proportion of subtype BC (33.3 vs. 15.5%) and CRF01_AE (20.5 vs. 8.5%) compared to Chinese (P < 0.05 for all).ConclusionBurmese participants were more likely to belong to MTCs, and most MTCs had both Burmese and Chinese participants. These data highlight the bidirectional transmission of HIV-1 frequently transmission and close relationship among immigrants in the China–Myanmar border region. Local health departments should pay more attention to HIV screening and intervention to immigrants Burmese with the characteristics of younger age, having lower CD4 T cell count and infected with HIV subtypes CRF07_ BC or C.

Ten-Year Molecular Surveillance of Drug-Resistant Plasmodium spp. Isolated From the China-Myanmar Border.

Antimalarial drug resistance has emerged as a major threat to global malaria control efforts, particularly in the Greater Mekong Subregion (GMS). In this study, we analyzed the polymorphism and prevalence of molecular markers associated with resistance to first-line antimalarial drugs, such as artemisinin, chloroquine, and pyrimethamine, using blood samples collected from malaria patients in the China–Myanmar border region of the GMS from 2008 to 2017, including 225 cases of Plasmodium falciparum and 194 cases of Plasmodium vivax. In artemisinin resistance, only the C580Y mutation with low frequency was detected in pfk13, and no highly frequent stable mutation was found in pvk12. In chloroquine resistance, the frequency of K76T mutation in pfcrt was always high, and the frequency of double mutations in pvmdr1 of P. vivax has been steadily increasing every year. In pyrimidine resistance, pfdhfr and pvdhfr had relatively more complex mutant types associated with drug resistance sites, and the overall mutation rate was still high. Therefore, artemisinin-based combination therapies are still suitable for use as the first choice of antimalarial strategy in the China–Myanmar border region in the future.

Educational Approaches Help Bridge Perception Gaps of Invasive Alien Species (Mikania micrantha) between Managers and Non-managers.

Invasive alien species (IAS) significantly impact biodiversity, human health, and economies, and considerable resources are often used to manage their spread. Few studies have focused on the human perception of IAS management, and little is known about approaches to improve stakeholder perception. This study examined perception gaps between managers and non-managers of a notorious weed Mikania micrantha and the preference for educational approaches to bridge those gaps. Household questionnaires and key informant interviews were conducted in the China-Myanmar Border Region (China), and ordinal logistic regressions and Wilcoxon rank sum tests were used in statistical analyses. We found a high level of perception of M. micrantha among stakeholders, and a significant influence of socio-demographic factors including gender, educational level, ethnic group, and geographical location. Scores of the identification, damage, control measure, and manual treatment of M. micrantha were significantly higher for managers than those for non-managers, indicating that there were certain perception gaps between two stakeholder groups. Nine educational approaches were identified as being effective in improving stakeholder perception of IAS, of which training workshops were mostly preferred, followed by brochures (or leaflets) and other promotional materials. Additionally, we propose that well-designed and well-conducted educational approaches would benefit stakeholder perception of IAS, and that integration of IAS management into a comprehensive rural development scheme would improve its long-term performance in marginalized rural communities.

Cross‐border market building for narcotics control: A Polanyian analysis of the China–Myanmar border region

AbstractFor decades, narcotics control has been unable to overhaul the durable and arguably self‐regulating socio‐economic networks driving heroin production and distribution in northern Myanmar, the second biggest drug production area in the world. To overcome this territorial barrier, the Chinese state introduced in 2000 an opium substitution programme that involved bringing Chinese agribusiness firms together with ex‐poppy farmers and local elites in northern Myanmar to form a formal cross‐border market. The programme raises a unique empirical puzzle: how could formal market building play a socially progressive role when it is superimposed in a border region underpinned by a well‐established informal, if also mostly illegal, market structure? This paper addresses this question through a reflexive Polanyian analytical framework that examines the “market” through its connections with non‐economic factors over time. It makes a distinct conceptual contribution by incorporating the border as a tangible anchor from which to assess how the processes of redistribution, reciprocity, and market exchange constitute the opium substitution programme as a social “countermovement.” Findings indicate Yunnanese firms negotiate border politics to engage in exchange with ex‐poppy farmers, establish reciprocal relations with local military elites, and implement the redistributive strategies of the Chinese state. Despite some success, this formal market‐building process continues to experience barriers generated by the pre‐existing informal market structure across the border region. Whether market building could further impact on economic restructuring in this border region and fully remove opium production from the border economy therefore remains an open question.

Public education improves farmers knowledge and management of invasive alien species

Research into the human dimensions of invasive alien species (IAS) management has received great attention to date. However, little is known about how public education influences stakeholders knowledge and management of IAS. Using key informant interviews and household questionnaires, we explored the role of public education in farmers knowledge and management of invasive Mikania micrantha in the China-Myanmar Border Region (China). We found ten common educational approaches that farmers were familiar with and/or adopted, and a high level of knowledge and management among farmers. We also found that public educational approaches helped to improve farmers knowledge and management, with some differences due to socio-demographic factors. We conclude that promotional materials and training workshops work better than personal experience, and that training workshops perform best. These results suggest that improving the design and implementation of public education could contribute to effective communication among stakeholders and long-term management of IAS. Our findings provide important insights for adopting public education programs in IAS management.

A new frog species of the genus Odorrana (Anura: Ranidae) from Yunnan, China.

The Chinese-Myanmar border area forms part of a long-acknowledged biodiversity hotspot. This region is characterised by dramatic topography and diverse landscapes, which support a high degree of biodiversity and endemism that remains largely understudied. Based on recent survey efforts we here describe a new frog species of the genus Odorrana from this area. Found in Dulongjiang village, Yunnan, China, the new species differs from a morphological perspective from its congeners through the combination of a grass-green dorsum with black posterior spots, absence of dorsolateral folds, a distinct pineal body, presence of supratympanic folds, absence of outer metacarpal, metatarsal and supernumerary tubercles, and a pair of external subgular vocal sacs. From a molecular perspective, pairwise genetic distances of 4.8% to 11.6% for DNA sequences of the mitochondrial gene for 16S ribosomal RNA differentiate the new species from other Odorrana. Our mitochondrial phylogeny suggests that the new species is a deeply divergent genetic lineage clustering with the clade including Odorrana wuchuanensis, and the Odorrana andersonii and Odorrana margaretae groups. The discovery of this new species emphasizes the need for further herpetological studies in the China-Myanmar border region.

Challenges of Sustaining Malaria Community Case Management in 81 Township Hospitals along the China-Myanmar Border Region - Yunnan Province, China, 2020.

What is already known on this topic? The health workforce at township hospitals in the China-Myanmar border region has played a key role in sustaining Community case management of malaria (CCMm), while few studies have investigated their performance and challenges. What is added by this report? Sustaining CCMm in the region was subject to the following major challenges: insufficient training on malaria diagnosis and testing, lacking necessary and timely treatment for patients, and risks of instability among the malaria workforce. What are the implications for public health practice? These challenges called for the national and provincial authorities to provide regular trainings and intensive supervision to strengthen malaria diagnosis and treatment capacity in the region and to set up incentive mechanisms and individual career development paths to sustain the workforce.

Molecular Surveillance and in vitro Drug Sensitivity Study of Plasmodium falciparum Isolates from the China-Myanmar Border.

The emergence and spread of resistance in Plasmodium falciparum to the frontline treatment artemisinin-based combination therapies in Southeast Asia require close monitoring of the situation. Here, we collected 36 clinical samples of P. falciparum from the China-Myanmar border in 2014-2016, adapted these parasites to continuous culture, and performed in vitro drug assays on seven antimalarial drugs. Data for 23 parasites collected in 2010 and 2012 from the same area reported in an early study were used to assess longitudinal changes in drug sensitivity. Parasites remained highly resistant to chloroquine (CQ) and pyrimethamine, whereas they were generally sensitive to mefloquine (MFQ), lumefantrine (LMF), naphthoquine (NQ), and pyronaridine (PND). Parasites showed a similar temporal trend in sensitivity to CQ, NQ, and PND, with gradual reduction in the half-maximal inhibitory concentrations (IC50s) after 2012. The IC50s to the aminoalcohol drugs MFQ, LMF, and quinine (QN) all significantly declined in 2014, followed by various degrees of increase in 2016. Pyrimethamine displayed a continuous increase in IC50 over the years. The Dd2-like P. falciparum chloroquine-resistant transporter mutations were fixed or nearly fixed in the parasite population. The P. falciparum multidrug resistance 1 F1226Y mutation was detected in 80% parasites in 2016 and associated with reduced sensitivity to LMF and QN (P < 0.05). The N51I in P. falciparum dihydrofolate reductase and K540E/N and A581G in P. falciparum dihydropteroate synthase that are associated with antifolate resistance were either fixed or were approaching fixation in recent years. This study provides an updated picture and temporal trend of antimalarial drug resistance in the China-Myanmar border region, which will serve as a reference for antimalarial treatment.

Plasmodium vivax HAP2/GCS1 gene exhibits limited genetic diversity among parasite isolates from the Greater Mekong Subregion

BackgroundAntigens expressed in sexual stages of the malaria parasites are targets of transmission-blocking vaccines (TBVs). HAP2/GCS1, a TBV candidate, is critical for fertilization in Plasmodium. Here, the genetic diversity of PvHAP2 was studied in Plasmodium vivax parasite populations from the Greater Mekong Subregion (GMS).MethodsPlasmodium vivax clinical isolates were collected in clinics from the China-Myanmar border region (135 samples), western Thailand (41 samples) and western Myanmar (51 samples). Near full-length Pvhap2 (nucleotides 13–2574) was amplified and sequenced from these isolates. Molecular evolution studies were conducted to evaluate the genetic diversity, selection and population differentiation.ResultsSequencing of the pvhap2 gene for a total of 227 samples from the three P. vivax populations revealed limited genetic diversity of this gene in the GMS (π = 0.00036 ± 0.00003), with the highest π value observed in Myanmar (0.00053 ± 0.00009). Y133S was the dominant mutation in the China-Myanmar border (99.26%), Myanmar (100%) and Thailand (95.12%). Results of all neutrality tests were negative for all the three populations, suggesting the possible action of purifying selection. Codon-based tests identified specific codons which are under purifying or positive selections. Wright’s fixation index showed low to moderate genetic differentiation of P. vivax populations in the GMS, with FST ranging from 0.04077 to 0.24833, whereas high levels of genetic differentiation were detected between the China-Myanmar border and Iran populations (FST = 0.60266), and between Thailand and Iran populations (FST = 0.44161). A total of 20 haplotypes were identified, with H2 being the abundant haplotype in China-Myanmar border, Myanmar and Thailand populations. Epitope mapping prediction of Pvhap2 antigen showed that high-score B-cell epitopes are located in the S307-G324, L429-P453 and V623-D637 regions. The E317K and D637N mutations located within S307-G324 and V623-D637 epitopes slightly reduced the predicted score for potential epitopes.ConclusionsThe present study showed a very low level of genetic diversity of pvhap2 gene among P. vivax populations in the Greater Mekong Subregion. The relative conservation of pvhap2 supports further evaluation of a Pvhap2-based TBV.

HIV-1 Drug Resistance in ART-Naïve Individuals in Myanmar.

BackgroundEstimating the prevalence and characterizing the transmission of HIV-1 drug resistance in treatment-naïve individuals are very important in the prevention and control of HIV/AIDS. As one of the areas most affected by HIV/AIDS, few data are currently available for HIV-1 drug resistance in antiretroviral therapy (ART)-naïve individuals in Myanmar, which borders Yunnan, China.MethodsHIV-1 pol sequences from ART-naïve HIV-1-infected individuals during 2008 and 2014 in Myanmar were retrieved from our previous studies. HIV-1 transmitted drug resistance (TDR) and susceptibility to antiretroviral drugs were predicted using the Stanford HIVdb program. HIV-1 transmission cluster (TC) was determined by Cluster Picker.ResultsA total of 169 partial pol sequences from ART-naïve HIV-1 positive Burmese were analyzed. The prevalence of TDR was 20.1%. CRF01_AE and BC recombinants appeared to have a higher prevalence of TDR than other subtypes. The V179D/T was found to be very common in the China–Myanmar border region and was involved in half of the transmission clusters formed by HIV-1 drug-resistance strains in this region. Comparison showed that drug-resistance mutation profile in Myanmar was very similar to that in Dehong prefecture of Yunnan. By further phylogenetic analysis with all available sequences from the China–Myanmar border region, four HIV-1 drug-resistance-related TCs were identified. Three of them were formed by Burmese long-distance truck drivers and the Burmese staying in Yunnan, and another was formed by Burmese injection drug users staying in Myanmar and Yunnan. These results suggest a potential transmission link of HIV-1 drug resistance between Myanmar and Yunnan.ConclusionGiven the high prevalence of TDR in Myanmar, and the potential risk of cross-border transmission of HIV-1 drug-resistant strains between Myanmar and Yunnan, China, ongoing monitoring of HIV-1 drug resistance in ART-naïve individuals will provide a guideline for clinical antiretroviral treatment and benefit the prevention and control of HIV/AIDS in this border region.

Measles immunity in the China-Myanmar border region, Lincang city, Yunnan province, 2017

ABSTRACT Background A recent measles importation-related outbreak in the China-Myanmar border region required outbreak response immunization to stop the outbreak, raising the question of measles immunity in the area. We conducted two measles serological surveys to develop a seroepidemiological profile of native Chinese citizens and registered Myanmar immigrants to identify strategies to promote measles elimination in the border region. Methods We conducted a clinic-based measles serosurvey of Myanmar registered immigrants (n = 300) and a population-based serosurvey of Chinese Lincang residents (n = 355). Serum samples were tested with enzyme-linked immunosorbent assays to assess immunity to measles. Results We found that Myanmar immigrants had a seropositivity rate of 85.3% (95% CI: 81.3–89.4) with a GMT of 924.9 mIU/ml, and Lincang Chinese nationals had a seropositivity rate of 94.6% (95% CI:92.3–97.0) with a GMT of 1363.3 mIU/ml. Myanmar children 2–6 years of age and 7–14 years of age were more likely to be susceptible to measles than same-aged Chinese children: odds ratios 23.00 (95% CI: 5.10–103.69, P < .001) and 7.95 (95% CI: 1.66–38.01,P = .009), respectively. Conclusions We recommend conducting a catch-up vaccination program for Myanmar children ≤15 years old.

Seroepidemiologic investigation of human Toxoplasma gondii infections in border areas of Yunnan Province, China

To ascertain the prevalence of Toxoplasma gondii infection in different genders, ages, and ethnic populations of three border regions in Yunnan Province, China, in order to provide the basic data for prevention and control of toxoplasmosis in these areas. A total of 561 serum samples were collected from the local hospitals of three border regions of Yunnan Province (222 serum samples from China-Vietnam border region, 170 serum samples from China-Laos border region, and 169 serum samples from China-Myanmar border region) from November 2015 to May 2016. The detection of IgG antibodies of T. gondii was performed by ELISA. In total, 44 (7.84%) of the 561 serum samples were anti-Toxoplasma IgG positive. The positive rates were 8.56% (19/222), 8.82% (15/170) and 5.92% (10/169) in China-Vietnam, China-Laos, and China-Myanmar border regions, respectively. The anti-Toxoplasma IgG positive rates were 5.63%(16/284) in Han, 10.96% (8/73) in Hani, 13.70% (10/73) in Dai, 4.17% (2/48) in Miao, 11.11% (1/9) in Lahu, 7.69% (1/13) in Jinuo, 12.00% (3/25) in Yao, and 11.11% (3/27) in Yi, respectively. The anti-Toxoplasma IgG positive rate in minorities was 10.11%, which was higher than that in Han significantly (χ2 = 3.884, P < 0.05), and the positive rate in Dai was higher than that in Han significantly (χ2 = 5.594, P < 0.05). The anti-Toxoplasma IgG positive rate in the 11-20-year age group was 23.53% (4/17), which was higher than that in the 0-10 [4.23% (3/71)] (χ2 = 4.593, P < 0.05) and 31-40-year groups [4.00% (3/75)] (χ2 = 4.997, P < 0.05). There are different degrees of T. gondii infection in the human population in the border areas in Yunnan Province, and the risk of infection in ethnic minorities is higher than that in Han nationality. The prevention and control of toxoplasmosis should focus on the minority population.

Identification of a New HCV Subtype 6xg Among Injection Drug Users in Kachin, Myanmar.

Characterizing hepatitis C virus (HCV) genetic diversity not only allows us to trace its origin and evolutionary history, but also provides valuable insights into diagnosis, prevention and therapy of HCV infection. Although eight HCV genotypes and 86 subtypes have been classified, there are still some HCV variants that need to be assigned. The genotype 6 is the most diverse HCV genotype and mainly prevalent in Southeast Asia. In this study, we identified a new HCV subtype 6xg from injection drug users (IDUs) in Kachin, Myanmar. A distinctive feature of 6xg from other subtypes of the genotype 6 was a Lys insertion in NS5A gene, which changes the RRKR/K motif into RRKKR/K. Bayesian analyses showed that HCV 6xg originated during 1984–1988, and experienced a rapid population expansion during 2005–2009. We characterized HCV subtype profile among IDUs in this region, and detected six HCV subtypes, including 1a (12.0%), 3a (12.0%), 3b (24.0%), 6n (16.0%), 6xa (20.0%), and 6xg (12.0%). Importantly, we found that HCV subtype distribution in Kachin was very similar to that in Dehong prefecture of Yunnan, but very distinct from those in other regions of Myanmar and Yunnan, indicating that the China–Myanmar border region shared a unique HCV subtype pattern. The appearance of 6xg and the unique HCV subtype profile among IDUs in the China–Myanmar border region have significant epidemiological and public health implications.