Application of an innovative grid-based surveillance strategy to ensure elimination and prevent reintroduction of malaria in high-risk border communities in China.

Grid management is a grassroots governance strategy widely implemented in China since 2004 to improve the government's efficiency to actively find and solve problems among populated regions. A grid-based strategy surveillancing high-risk groups, including mobile and migrant populations (MMPs), in the China-Myanmar border region has played an indispensable role in promoting and consolidating the malaria elimination efforts by tracking and timely identification of potential importation or re-establishment of malaria among MMPs. A sequential mixed methods was implementated to explore the operational mechanism and best practices of the grid-based strategy including through the focus group discussions (FGDs), comparison of before and after the implementation of a grid-based strategy in the field sites, and data collection from the local health system.This paper distills the implementation mechanism and highlights the role of the grid-based strategy in the elimination and prevention of re-establishment of malaria transmission.

Detection of novel piroplasmid species and Babesia microti and Theileria orientalis genotypes in hard ticks from Tengchong County, Southwest China.

To reveal the genetic diversity of Babesia microti and Theileria orientalis in Southwest China, we conducted a molecular survey of piroplasms in hard ticks in a China-Myanmar border county. Host infesting and questing ticks were collected from Tengchong County in 2013 and 2014. Piroplasm infection in ticks was detected by PCR, and then, phylogenetic analysis was conducted to study the genetic diversity of the pathogens identified in ticks. All in all, six piroplasm species comprising of B. microti; B. orientalis; a novel Babesia species designated Babesia sp. Tengchong, China; T. orientalis; T. luwenshuni; and an as yet undescribed piroplasmid species referred to as Piroplasmid sp. Tengchong, China, have been identified after screening goat- and cattle-attached ticks. In addition, B. bigemina has been identified by screening questing ticks. Phylogenetic analysis based on the 18S rRNA and partial ß-tubulin gene revealed two novel potentially zoonotic genotypes designated B. microti Tengchong-Type A and B. The T. orientalis genotypes identified in the present study represent the seven known genotypes 1-5, 7, and N3 as revealed by phylogenetic analysis of 18S rRNA and MPSP genes. Importantly, an additional genotype designated N4 has also been identified in this study, which brings the number of recognized T. orientalis genotypes to a total of twelve. Thus, besides the two novel species, Babesia sp. Tengchong, China, closely related to Babesia species isolated from yak and Piroplasmid sp. Tengchong, China, our study demonstrates that additional novel B. microti and T. orientalis genotypes exist in Southwest China.

Generating Defect-Rich Bismuth for Enhancing the Rate of Nitrogen Electroreduction to Ammonia.

The electrochemical N2 fixation, which is far from practical application in aqueous solution under ambient conditions, is extremely challenging and requires a rational design of electrocatalytic centers. We observed that bismuth (Bi) might be a promising candidate for this task because of its weak binding with H adatoms, which increases the selectivity and production rate. Furthermore, we successfully synthesized defect-rich Bi nanoplates as an efficient noble-metal-free N2 reduction electrocatalyst via a low-temperature plasma bombardment approach. When exclusively using 1 H NMR measurements with N2 gas as a quantitative testing method, the defect-rich Bi(110) nanoplates achieved a 15 NH3 production rate of 5.453 µg mgBi -1 h-1 and a Faradaic efficiency of 11.68 % at -0.6 V vs. RHE in aqueous solution at ambient conditions.

[An Imported Case of Vivax Malaria with Co-occurrence of Different Stages of Plasmodium vivax in Erythrocyte].

The blood sample from a case of vivax malaria in Tengchong City, Yunnan Province, was tested with CareStartTM malaria rapid diagnostic test, Giemsa staining and nested PCR in 2012. The case was determined to be infected with Plasmodium vivax, P. malariae or P. ovale other than P. falciparum by CareStartTM malaria rapid diagnostic test. Microscopic results revealed multinuclear P. vivax ring form and multi-infections with P. vivax in blood slides, with occurrence of two or more nuclei in one ring form accounting for 14.68%（188/1 280）, and parasitism of two or more P. vivax rings in one erythrocyte accounting for 22.50%（288/1 280）. In addition, co-occurrence of ring form and trophozoite, and ring form and gametophyte was found in erythrocytes. Nested PCR revealed P. vivax-specific amplification products. Combining the results with epidemiological information and clinical symptoms, this case was finally diagnosed as imported vivax malaria, and the erythrocytes of the case harbored different stages of P. vivax parasites.

[Evaluation of Measures and Achievements of Malaria Control in Tengchong City, Yunnan Province during 2010-2015].

Objective: To evaluate the measures and achievements of malaria control in Tengchong City during 2010-2015. Methods: The malaria control information on epidemiology, foci disposal, blood detection of febrile patients, and medical treatment during 2010-2015 in Tengchong City was collected and analyzed using Microsoft Excel 2010. Results: In 2010-2015, 1 654 malaria cases were reported in Tengchong City, including 18 indigenous cases, 22 domestically mobile cases, and 1 614 imported cases from abroad, of whom 1 584 cases （98.1%） were imported from Myanmar. Most of the cases were vivax malaria（76.2%, 1 261/1 654）. No indigenous malaria cases were reported from 2013 to 2015. Blood test was conducted for 80 655 febrile patients, with a positive detection rate of 2.1%（1 654/80 655）. The positive detection rate was highest in 2010 （2.8%, 700/24 861）, lowest in 2011（1.4%, 341/23 623）, and decreased from 2012 to 2015. In addition, 1 654 cases were directly reported through online system. The 24-h case report rate during 2013-2015 was 100%. A total of 1 191 cases were investigated. The 3-day case investigation rate during 2013-2015 was 100%. A total of 1 351 endemic foci were investigated. The 7-day foci disposal rate during 2014-2015 was 100%. Conclusion: No indigenous transmission has been reported for three years in Tengchong City. However, the imported malaria remains an important problem.

In vivo monitoring of dihydroartemisinin-piperaquine sensitivity in Plasmodium falciparum along the China-Myanmar border of Yunnan Province, China from 2007 to 2013.

BACKGROUND: Artemisinin-based combination therapy (ACT) is the recommended first-line treatment of falciparum malaria in all endemic countries. Artemisinin resistance in Plasmodium falciparum has been confirmed in the Greater Mekong subregion (GMS). Dihydroartemisinin-piperaquine (DAPQ) is the most commonly used ACT in China. To understand the DAPQ sensitivity of P. falciparum, DAPQ resistance was monitored in vivo along the China-Myanmar border from 2007 to 2013. METHODS: Eligible patients with mono-infections of P. falciparum were recruited to this study after obtaining full informed consent. DAPQ tablets for different categories of kg body weight ranges were given once a day for three days. Patients were followed up for 42 days. Polymerase chain reaction (PCR) was conducted to distinguish between re-infection and recrudescence, to confirm the Plasmodium species. The data were entered and analysed by the Kaplan-Meier method. Treatment outcome was assessed according to the WHO recommended standards. RESULTS: 243 patients were completed valid follow-up. The fever clearance time (FCT) and asexual parasite clearance times (APCT) were, respectively, 36.5 ± 10.9 and 43.5 ± 11.8 hours, and there was an increasing trend of both FCT (F = 268.41, P < 0.0001) and APCT (F = 88.6, P < 0.0001) from 2007 to 2013. Eight (3.3%, 95% confidence interval, 1.4-6.4%) patients present parasitaemia on day three after medication; however they were spontaneous cure on day four. 241 (99.2%; 95% CI, 97.1-99.9%) of the patients were adequate clinical and parasitological response (ACPR) and the proportions of ACPR had not changed significantly from 2007 to 2013 (X(2) = 2.81, P = 0.7288). CONCLUSION: In terms of efficacy, DAPQ is still an effective treatment for falciparum malaria. DAPQ sensitivity in P. falciparum had not significantly changed along the China-Myanmar border of Yunnan Province, China. However more attentions should be given to becoming slower fever and parasite clearance.

Monitoring Plasmodium vivax chloroquine sensitivity along China-Myanmar border of Yunnan Province, China during 2008-2013.

BACKGROUND: Plasmodium vivax is the most widespread of the malaria parasites infecting human hosts. In malaria-eliminating settings, both imported and local malaria predominantly occurs in border areas, and most of them are P. vivax. Chloroquine (CQ) is the first-line drug for P. vivax treatment in China. To understand CQ sensitivity in P. vivax, in vivo monitoring of CQ resistance was conducted along the China-Myanmar border from 2008 to 2013. METHODS: Eligible patients with mono-infections of P. vivax were recruited to this study after obtaining full informed consent. CQ tablets for different categories of kg body weight ranges were given once a day for three days. Patients were followed up for 28 days. PCR was conducted to distinguish between re-infection and recrudescence, to confirm the Plasmodium species. The data were entered and analysed by the Kaplan-Meier method. Treatment outcome and sensitivity were classified according to the WHO recommended standards. RESULTS: 603 patients were completed valid follow-up. The fever clearance time and asexual parasite clearance times were, respectively, 22.2 ± 10.2 and 38.1 ± 12.6 hours. 594 (98.5%) patients were adequate clinical and parasitological response (ACPR), and nine (1.5%) patients, who were late clinical failure (LCF) or resistant response level I (RI), were imported from the neighbouring districts of Myanmar. CONCLUSION: In terms of efficacy, CQ is still effective for vivax malaria treatment. Plasmodium vivax CQ sensitivity had not significantly changed along the China-Myanmar border of Yunnan Province, China.

Artemisinin-naphthoquine combination versus chloroquine-primaquine to treat vivax malaria: an open-label randomized and non-inferiority trial in Yunnan Province, China.

BACKGROUND: Plasmodium vivax is the main malaria parasite in China, and China is now making efforts to eliminate malaria by 2020. Radical cure of vivax malaria is one of challenges for malaria elimination. The purpose is to evaluate the efficacy and safety of artemisinin-naphthoquine (ANQ) versus chloroquine-primaquine (CQ-PQ) in treatment of vivax malaria in Yunnan Province, China. METHODS: An open-label randomized and non-inferiority design, eligible patients with monoinfections of P. vivax were randomly assigned to receive either a total target dose of ANQ 24.5 mg/kg (naphthoquine 7 mg/kg and artemisinin 17.5 mg/kg), once a day for three days, or a total CQ dose of 24 mg base/kg, once a day for three days plus a PQ dose of 0.45 mg base/kg/day, once a day for eight days. Patients were followed up for one year. The difference in efficacy between ANQ and CQ-PQ was compared via Wilson's test. RESULTS: By day 42, the number of patients free of recurrence was 125 (98.4%; 95% Confidence interval, 94.4-99.8%) for ANQ arm and 123 (96.1%; 95%CI, 91.1-98.7%) for CQ-PQ, and non-significant (P = 0.4496). By day 365, the number was 101 (79.5%; 95%CI, 71.8-85.9%) for ANQ and 106 (82.8%; 95%CI, 75.1-88.9%) for CQ-PQ, and non-significant (P = 0.610). So the proportions of patients free of recurrence had no significant difference between ANQ and CQ-PQ groups by day 28, 42 and 365; compared with CQ-PQ, the side effect of ANQ was mild. CONCLUSION: ANQ is non-inferior to CQ-PQ in terms of patients free of recurrence, and safer than CQ-PQ.

Fully exposed nickel clusters with electron-rich centers for high-performance electrocatalytic CO2 reduction to CO.

Single-atom catalysts (SACs) have attracted increasing concerns in electrocatalysis because of their maximal metal atom utilization, distinctive electronic properties, and catalytic performance. However, the isolated single sites are disadvantageous for reactions that require simultaneously activating different reactants/intermediates. Fully exposed metal cluster catalyst (FECC), inheriting the merits of SACs and metallic nanoparticles, can synergistically adsorb and activate reactants/intermediates on their multi-atomic sites, demonstrating great promise in electrocatalytic reactions. Here a facile method to regulate the atomic dispersion of Ni species from cluster to single-atom scale for efficient CO2 reduction was developed. The obtained Ni FECC exhibits high Faradaic efficiency of CO up to 99%, high CO partial current density of 347.2 mA cm-2, and robust durability under 20 h electrolysis. Theoretical calculations illuminate that the ensemble of multiple Ni atoms regulated by sulfur atoms accelerates the reaction kinetics and thus improves CO production.

Molecular epidemiology of mosquito-borne viruses at the China-Myanmar border: discovery of a potential epidemic focus of Japanese encephalitis.

BACKGROUND: Mosquito-based arbovirus surveillance can serve as an early warning in evaluating the status of mosquito-borne virus prevalence and thus prevent local outbreaks. Although Tengchong County in Yunnan Province-which borders Myanmar-is abundant and diverse in mosquitoes, very few mosquito-based arbovirus investigations have been conducted in the recent decade. Herein, this study aims to evaluate the presence and the diffusion of mosquito-borne pathogens, currently prevalent in this region. METHODS: We collected 9486 mosquitoes, representing eight species, with Culex tritaeniorhynchus and Anopheles sinensis as the dominant species, during high mosquito activity seasons (July-October) in Tengchong, in 2018. Samples collected from 342 pools were tested using reverse-transcription PCR to determine the species, distribution, and infection rates of virus and parasite, and further analyze their genotypes, phylogenetic relationships, infection rate, and potential pathogenicity. RESULTS: Fifteen Japanese encephalitis virus (JEV) strains from Cx. tritaeniorhynchus pools were detected. Seven strains of insect-specific flaviviruses (ISFVs), including two Aedes flavivirus (AeFV) and Yunnan Culex flavivirus strains each, one Culex theileri flavivirus, Yamadai flavivirus (YDFV) and Anopheles-associated flavivirus (AAFV) strains each were detected in Aedes albopictus, Cx. tritaeniorhynchus, Cx. vagans, Cx. pseudovihnui, and An. sinensis pools, respectively. The whole-genome was successfully amplified in one strain of JEV and AeFV each. Phylogenetic analysis using the E gene placed all the newly detected JEV strains into the GI-b genotype. They showed highly nucleotide identities, and were most closely related to the strain detected in Tengchong in 2010. The comparison of the E protein of JEV strains and vaccine-derived strain, showed six amino residue differences. The bias-corrected maximum likelihood estimation values (and 95% confidence interval) for JEV in Cx. tritaeniorhynchus collected in Tengchong in 2018 were 2.4 (1.4-3.9). CONCLUSIONS: A potential Japanese encephalitis epidemic focus with the abundance of host mosquitoes and high JEV infection rate was observed in Tengchong. In addition, at least five species of ISFVs co-circulate in this area. This study highlights the importance of widespread and sustained mosquito-based arbovirus surveillance in local areas to prevent the transmission of JEV, and other emerging/re-emerging mosquito-borne pathogens.

In Situ Designing a Gradient Li+ Capture and Quasi-Spontaneous Diffusion Anode Protection Layer toward Long-Life Li-O2 Batteries.

Lithium metal is the only anode material that can enable the Li-O2 battery to realize its high theoretical energy density (≈3500 Wh kg-1 ). However, the inherent uncontrolled dendrite growth and serious corrosion limitations of lithium metal anodes make it experience fast degradation and impede the practical application of Li-O2 batteries. Herein, a multifunctional complementary LiF/F-doped carbon gradient protection layer on a lithium metal anode by one-step in situ reaction of molten Li with poly(tetrafluoroethylene) (PTFE) is developed. The abundant strong polar C-F bonds in the upper carbon can not only act as Li+ capture site to pre-uniform Li+ flux but also regulate the electron configuration of LiF to make Li+ quasi-spontaneously diffuse from carbon to LiF surface, avoiding the strong Li+ -adhesion-induced Li aggregation. For LiF, it can behave as fast Li+ conductor and homogenize the nucleation sites on lithium, as well as ensure firm connection with lithium. As a result, this well-designed protection layer endows the Li metal anode with dendrite-free plating/stripping and anticorrosion behavior both in ether-based and carbonate ester-based electrolytes. Even applied protected Li anodes in Li-O2 batteries, its superiority can still be maintained, making the cell achieve stable cycling performance (180 cycles).

High genetic diversity in hard ticks from a China-Myanmar border county.

BACKGROUND: Many tick species have great morphological similarity and are thus grouped into species complexes. Molecular methods are therefore useful in the classification and identification of ticks. However, little is known about the genetic diversity of hard ticks in China, especially at the subspecies level. Tengchong is one of the epidemic foci of tick-borne diseases in China, but the tick species inhabiting the local area are still unknown. METHODS: Eighteen villages in Tengchong County, China, were selected for sampling carried out from September to October 2014. Infesting hard ticks were removed from the body surface of domestic animals and questing ticks were collected from grazing fields. After morphological identification, molecular characteristics of each tick species were analyzed based on both 16S rRNA and cytochrome c oxidase subunit 1 (cox1) gene fragments. RESULTS: Six tick species were identified based on morphology: Rhipicephalus microplus, R. haemaphysaloides, Ixodes ovatus, Haemaphysalis longicornis, H. shimoga and H. kitaokai. Phylogenetic analysis using the cox1 gene revealed that R. microplus ticks from the present study belong to clade C. For tick samples of both R. haemaphysaloides and I. ovatus, three phylogenetic groups were recognized, and the intergroup genetic distances exceeded the usual tick species boundaries. Haemaphysalis longicornis ticks were clustered into two separate clades based on the cox1 gene. For ticks from both H. shimoga and H. kitaokai, two phylogenetic groups were recognized based on the phylogenetic analysis of the 16S rRNA gene, and the intergroup genetic distances also exceeded the known boundaries for closely related tick species. CONCLUSIONS: According to molecular analyses, new species or subspecies closely related to R. haemaphysaloides, I. ovatus, H. shimoga and H. kitaokai probably exist in the China-Myanmar border Tengchong County, or these ticks form species complexes with highly divergent mitochondrial lineages. Morphological comparisons are warranted to further confirm the taxonomic status of these tick species.

Anti-hepatoma activities of ethyl acetate extract from Ampelopsis sinica root.

Ampelopsis sinica root (ASR) is a known hepatoprotective folk traditional Chinese medicine. The anti­hepatoma activity of ethyl acetate extract from A. sinica root (ASRE) in vitro and in vivo and its possible mechanism were explored. This study was designed to investigate cytotoxicity by MTT assay, induction of apoptosis via Hoechst 33258 staining, scanning electron microscopy and bivariate flow cytometric analysis (Annexin V-FITC/PI), inflammation and apoptosis related genes expression by RT-PCR and p53 protein expression by immunofluorescence assay in HepG2 cells. Then, the antitumor activity in vivo was detected by hepatoma H22 xenograft tumor in mice. The results showed that ASRE had powerful anti­hepatoma activity in vitro without obvious toxicity on normal cells and could induce HepG2 cell apoptosis. The mechanism may be associated with downregulation of inflammatory cytokines including cyclooxygenase-2, 5-lipoxygenase and FLAP, increase of the ratio of bax/bcl-2, activation caspase-3 and inhibition of survivin, and increased expression of p53 protein. Furthermore, the HPLC assay showed the main compounds of ASRE were gallic acid, catechin and gallic acid ethyl ester. In animal experiments, ASR ethanol extract decreased the tumor weights of hepatoma H22 tumor-bearing mice. Therefore, ASR may be a potential therapeutic agent in the treatment of hepatocellular carcinoma.

[Malaria surveillance in Tengchong County of Yunnan Province in 2013].

OBJECTIVE: To analyze the surveillance data of malaria in Tengchong County of Yunnan Province in 2013, so as to provide the evidence for carrying out the malaria elimination in the future. METHODS: The data of epidemic situation and surveillance of malaria in Tengchong County in 2013 were collected and analyzed for the prevalence state as well as and the monitoring indicators including the blood examination of fever patients of unknown origin, initiative detection of cases, under-reporting survey, sentinel surveillance and species and density investigation of Anopheles mosquitoes. RESULTS: Totally 138 malaria cases were reported in Tengchong County in 2013, among which 118 cases were infected with Plasmodium vivax and 20 cases with P. falciparum, and all the reported cases were imported. The completion rates of blood examinations, case reports and case investigations all reached 100%. A total of 57 cases were involved in initiative detection, but no positive cases were found. The twice under-reporting of malaria case surveys were conducted and 1 case had been under-reported. The sentinel surveillance was carried out both in the domestic and overseas sites at the same time to detect the suspected malaria cases, 172 cases were screened totally, and 15 ones were detected as positives. Totally 528 returnees were screened, and there were no positive case found. A. sinensis and A. liangshanensis were the dominant species, followed by A. minimus, A. maculatus and others. CONCLUSIONS: The malaria epidemic situation is stable in Tengchong County in 2013, and all the work in surveillance has been conducted successfully, but there still exist some difficulties in the process of malaria elimination. The local health departments should further strengthen the surveillance on imported cases and the management on migrant population as well as the capability building for health workers in malaria control in the future.

Antitumor Activities of Ethyl Acetate Extracts from Selaginella doederleinii Hieron In Vitro and In Vivo and Its Possible Mechanism.

The antitumor activities of ethyl acetate extracts from Selaginella doederleinii Hieron (SD extracts) in vitro and in vivo and its possible mechanism were investigated. HPLC method was developed for chemical analysis. SD extracts were submitted to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay on different cells, flow cytometry, and RT-PCR analysis using HepG2 cell and antitumor activity in vivo using H-22 xenograft tumor mice. Six biflavonoids from SD extracts were submitted to molecular docking assay. The results showed that SD extracts had considerable antitumor activity in vitro and in vivo without obvious toxicity on normal cells and could induce cell apoptosis. The mechanisms of tumorigenesis and cell apoptosis induced by SD extracts may be associated with decreasing the ratio of bcl-2 and bax mRNA level, activating caspase-3, suppressing survivin, and decreasing the gene expression of COX-2, 5-LOX, FLAP, and 12-LOX mRNA. The main active component in SD extracts is biflavonoids and some exhibited strong interactions with COX-2, 5-LOX, 12-LOX, and 15-LOX. These results offering evidence of possible mechanisms of SD extracts suppress cell proliferation and promote apoptosis and provide the molecular theoretical basis of clinical application of S. doederleinii for cancer therapy.

Risk factors for border malaria in a malaria elimination setting: a retrospective case-control study in Yunnan, China.

A retrospective case-control study was conducted to identify risk factors for border malaria in a malaria elimination setting of Yunnan Province, China. The study comprised 214 cases and 428 controls. The controls were individually matched to the cases on the basis of residence, age, and gender. In addition, statistical associations are based on matched analyses. The frequencies of imported, male, adult, and vivax malaria cases were respectively 201 (93.9%), 194 (90.7%), 210 (98.1%), and 176 (82.2%). Overnight stay in Myanmar within the prior month was independently associated with malaria infection (odds ratio [OR] 159.5, 95% confidence interval [CI] 75.1-338.9). In particular, stays in lowland and foothill (OR 5.5, 95% CI 2.5-11.8) or mid-hill (OR 42.8, 95% CI 5.1-319.8) areas, or near streamlets (OR 15.3, 95% CI 4.3-55.2) or paddy field or pools (OR10.1, 95% CI 4.4-55.8) were found to be independently associated with malaria. Neither forest exposure nor use of vector control measures was associated with malaria. In conclusion, travel to lowland and foothill or mid-hill hyperendemic areas, especially along the waterside in Myanmar, was found to be the highest risk factor for malaria. In considering the limitations of the study, further investigations are needed to identify the major determinants of malaria risk and develop new strategies for malaria elimination on China-Myanmar border.

Twist1 is a potential prognostic marker for colorectal cancer and associated with chemoresistance.

Twist1 is a highly conserved basic helix-loophelix transcription factor, and has been shown to play an important role in carcinogenesis of many tumors including colorectal cancer (CRC). Here we aimed to investigate the role of Twist1 in the clinical significance and chemoresistance in CRC. In this study, we examined the correlation between Twist1 expression and clinicopathological characteristics using immunohistochemistry in patients with CRC. The molecular mechanisms of Twist1 expression and its effects on chemosensitivity to 5-Fluorouracil and oxaliplatin were also explored by MTT assay, colony forming assay, flow cytometry assay. The results indicate that Twist1 is overexpressed in cancer tissue, and its positive expression are related to histological grade (P=0.004), T-stage (P=0.033), N-stage (P=0.000), M-stage (P=0.040), TNM stage (P=0.002) and recurrence (P=0.023). Moreover, positive Twist1 expression is correlated with poor overall survival in CRC patients (P<0.0001), and is a significant independent prognostic indicator. In addition, we show that knockdown of Twist1 inhibits proliferation, and increased the percentage of apoptotic cells of CRC cell lines. Our findings suggest that Twist1 promotes proliferation and chemoresistance of CRC cells. Twist1 may be a potential prognostic marker and a molecular target for therapies.

Emergence of human babesiosis along the border of China with Myanmar: detection by PCR and confirmation by sequencing.

Babesiosis is a tick-borne, zoonotic disease caused by Babesia spp. Two cases of babesiosis were detected by nested polymerase chain reaction (PCR) in Yunnan province, China, and further confirmed by molecular assay. The blood smears showed intraerythrocytic ring form and tetrads typical of small B. microti. In both cases, the rapid diagnostic test (RDT) ruled out the possibility of co-infections with malaria. Neither case was initially diagnosed because of the low Babesia parasitemia. These two cases of babesiosis in areas along the Myanmar-China border pose the question of the emergence of this under recognized infection in countries or areas where malaria is endemic.