Systematic investigation of the Borrelia miyamotoi spirochetes in ticks, wildlife and domestic animal hosts in Yunnan province, Southwest China

Background

Borrelia miyamotoi is a spirochete species transmitted via hard ticks. Following its discovery in Japan, this pathogen has been detected around the world, and is increasingly confirmed as a human pathogen causing febrile disease, namely relapsing fever. Its presence has been confirmed in the Northeast China. However, there is little information regarding the presence of B. miyamotoi and other hard-tick-borne relapsing fever spirochetes in southern China including Yunnan province, where tick and animal species are abundant and many people both inhabit and visit for recreation.

Methods

For the present study, we collected samples of ticks, wildlife, and domestic animal hosts from different counties in Yunnan province. Nucleic acids from samples were extracted, and the presence of B. miyamotoi and other relapsing fever spirochetes was confirmed using polymerase chain reaction (PCR) for the 16S rRNA specific target gene fragment. The positive samples were then amplified for partial genome of the flaB and glpQ genes. Statistical differences in its distribution were analyzed by SPSS 20 software. Sequence of partial 16S rRNA, flaB and glpQ genome were analyzed and phylogenetic trees were constructed.

Results

A total of 8260 samples including 2304 ticks, 4120 small mammals and 1836 blood of domestic animal hosts were collected for screening for infection of B. miyamotoi and other relapsing fever spirochetes. Cattle and sheep act as the main hosts and Rhipicephalus microplus, Haemaphysalis nepalensis, H. kolonini and Ixodes ovatus were identified as the important vector host with high prevalence or wide distribution. Only one Mus caroli (mouse) and one Sorex alpinus (shrew) were confirmed positive for relapsing fever spirochetes. Evidence of vertical transmission in ticks was also confirmed. Two known strains of B. miyamotoi and one novel relapsing fever spirochetes, B. theileri-like agent, were confirmed and described with their host adaptation, mutation, and potential risk of spreading and spillover for human beings.

Conclusions

Our results provide new evidence of relapsing fever spirochetes in vector and animal hosts in Yunnan province based on large sample sizes, and offer guidance on further investigation, surveillance and monitoring of this pathogen.

Study on the geographic distribution and influencing factors of Dai settlements in Yunnan based on geodetector

The Dai people are primarily found in Yunnan Province, China, and have a long heritage there. The latest national census reports that Yunnan is home to 1,259,000 individuals of the Dai ethnic group. This study focuses on 3504 Dai settlements in Yunnan, identified through county records. Using the ArcGIS spatial analysis platform, we first evaluated their settlements' spatial distribution patterns using metrics like the nearest neighbor index and geographic concentration index. Then, we applied geodetector to investigate the underlying mechanisms of their distribution. The results reveal that: (1) Dai settlements in Yunnan Province generally have a cohesive spatial distribution; at the provincial level, however, there is an uneven distribution pattern, with many densely populated areas and a pattern of "two cores, one belt, one area, and two points"; (2) The Dai settlements predominantly occupy the third gradient of the vertical zonation, with Dai gathering settlements primarily found in the Lancang, Ayeyarwaddy, and Red River basins. Conversely, Dai mixed settlements are mainly situated in the Lancang, Red, and Nu River basins; (3) Analysis via geodetector indicates that ethnocultural factors are the most significant in determining the spatial distribution of the Dai settlements, followed by socio-economic and natural factors; (4) The distribution of settlements is significantly influenced by the proportion of the Dai population within these settlements. Dai gathering settlements are typically located on flat slopes with elevations ranging from 500 to 1000 m and slopes of 0°-5°. Meanwhile, Dai mixed settlements are found on gentle slopes with elevations of 1000-2000 m and slopes of 5°-15°. The study reveals that the location of Dai settlements is strongly influenced by environmental considerations and has a significant explanation from similar origins.

Epidemiological survey of cystic echinococcosis in southwest China: From the Qinghai-Tibet plateau to the area of Yunnan

BACKGROUND

Echinococcosis is prevalent in 9 provinces in Western and Northern China. An epidemiological survey of echinococcosis in 2012 and 2016 showed cases of echinococcosis in Yunnan Province.

AIM

To understand the spatial distribution and epidemiological characteristics of echinococcosis in Yunnan for the prevention and control of echinococcosis and to reduce the risk of infection in Yunnan Province.

METHODS

Based on the China Information System for Disease Control and Prevention (CISDCP), echinococcosis cases reported from 36 hospitals and 34 Centers for Disease Control were investigated and epidemiologically analyzed from 2021 to 2022. The exclusion criteria included suspected cases, same case only counted once and cases not from Yunnan. A total of 705 cases were investigated, of which 397 cases were suitable for statistical analysis. In these 397 cases, epidemiological investigation was tracked in 187 cases. All data were inputted using double entry in the Excel database, with error correction by double-entry comparison. The data on echinococcosis cases in Yunnan Province were analyzed by ArcGIS 10.1 software to generate a density map of echinococcosis distribution. All statistical analyses were conducted using SPSS 17.0, including the chi-square test, linear regression test and logistic univariate and multivariate regression analyses.

RESULTS

A total of 397 cases were found in 89 counties in Yunnan Province. The number of cases in the top three prefectures were Dali (38.1%), Diqing (10.1%), and Kunming (8.3%), and the top five counties were Jianchuan (9.1%), Shangri La (8.3%), Eryuan (7. 6%), Heqing (6.9%), and Dali Districts (5.0%). There were significant differences between the different areas. The case reporting rate by CISDCP (33.8%) was low; the first case was reported by CISDCP in 2002, and the highest number of cases was 50 (2017). Confirmed and clinical cases accounted for 62.5% and 37.5%, respectively. However, 90.9% of the cases of hydatid disease were reported by the hospital system, and only 9.1% of the cases of hydatid disease were found in the community through active screening. The difference between the two methods of case detection was statistically significant. Most of the cases of echinococcosis were found in farmers/herdsmen (75.1%) and students (9.1%). In addition, Han (43.6%) and Bai (26.2%) had a higher incidence of infection than other nationalities, and the liver (87.7%) and lung (6.8%) were the most common sites of cyst formation. Among the analyzed cases, 187 were epidemiologically analyzed and the clinical symptoms were not obvious in the early stage in 47.1% of cases. The results of logistic regression analysis showed that the age group, education level, presence of dogs in the family (either previously or currently), and handwashing (occasionally or not) were factors related to echinococcosis infection. 55.6% of cases were in endemic areas, and 44.4% of cases were in non-endemic areas. Among 83 cases in non-endemic areas, only 4 cases had been to endemic areas and had a history of living, working, travelling, or hunting in echinococcosis epidemic areas.

CONCLUSION

Cases of echinococcosis were reported throughout the entire Yunnan province, with the majority distributed in Western Yunnan, suggesting that echinococcosis control should be strengthened in this area. We suggest that an epidemiological investigation should be carried out in the future, based on the clues from newly discovered cases in hospitals or from the CISDCP. The newly discovered cases in the hospital provided clues to comprehensively determine the location of cases and where epidemic spot investigation should be conducted.

Phytoextraction of highly cadmium-polluted agricultural soil by Sedum plumbizincicola: An eight-hectare field study

Phytoextraction with Sedum plumbizincicola is an in-situ, environmentally friendly and highly efficient remediation technique for slightly Cd-polluted soils but it remains a challenge to remediate highly Cd-polluted soils under field conditions. Here, an 8-ha field experiment was conducted to evaluate the feasibility of repeated phytoextraction by S. plumbizincicola of a highly Cd-polluted acid agricultural soil (pH 5.61, [Cd] 2.58 mg kg-1) in Yunnan province, southwest China. Mean shoot dry biomass production, Cd concentration and Cd uptake were 1.95 t ha-1, 170 mg kg-1 and 339 g ha-1 at the first harvest, and 0.91 t ha-1, 172 mg kg-1 and 142 g ha-1 at the second harvest. After two seasons of phytoextraction, soil total and CaCl2-extractable Cd concentrations decreased from 2.58 ± 0.69 to 1.53 ± 0.43 mg kg-1 and 0.22 ± 0.12 to 0.14 ± 0.07 mg kg-1, respectively. Stepwise multiple linear regression analysis shows that the shoot Cd concentration and uptake of S. plumbizincicola were positively related to soil CaCl2-extractable Cd concentrations, especially in the first crop. A negative relationship indicates that soil organic matter content played an important role in soil Cd availability and shoot Cd concentration in the first crop. In addition, the rhizosphere effect on soil CaCl2-extractable Cd concentration was negatively correlated with soil pH in the first crop. The accuracy of the calculation of soil Cd phytoextraction efficiency at field scale depends on all of the following factors being considered: shoot Cd uptake, cropping pattern, standardized sampling points, and the leaching and surface runoff of Cd. Phytoextraction with S. plumbizincicola is a feasible technique for efficient Cd removal from highly polluted soils and wide variation in soil properties can influence phytoextraction efficiency at the field scale.

Evaluation of the deficiency status of 25-hydroxyvitamin D and associated factors in Southwest China: A hospital-based retrospective cross-sectional analysis of a low-latitude, high-altitude, multiracial region

Vitamin D deficiency is widespread in different populations and regions worldwide and has become a global health issue. The vitamin D status of the population in the Yunnan Province of Southwest China has not been evaluated to date. Therefore, in this study, we evaluated the vitamin D status according to the serum concentrations of 25-hydroxyvitamin D (25(OH)D) in individuals of Yunnan Province, a low-latitude, high-altitude and multiracial region in China. The data on 25(OH)D concentrations from October 2012 to December 2017 were retrospectively collected and assessed using the laboratory information system from 52 950 hospital-based participants (age, 1 day-96 years; females, 73.74%). The serum concentration of 25(OH)D was evaluated using a chemiluminescent immunoassay. The analysis was stratified by sex, age, sampling season, testing year, minority, residential district, latitude, altitude and meteorological factors. Vitamin D status was classified as follows: severe deficiency: <10 ng/mL; deficiency: <20 ng/mL; insufficiency: <30 ng/mL; and sufficiency: ≥30 ng/mL. The results showed that vitamin D deficiency is highly prevalent in Yunnan Province in a hospital-based cohort, with a deficiency and severe deficiency rate of 65.1% and a sufficiency rate of 5.30%. Significantly lower vitamin D levels and sufficiency rates were observed in females than in males (20.13 ± 7.22 ng/mL vs. 17.56 ± 6.66 ng/mL and 8.20% vs. 4.20%; p < 0.01, respectively); in spring and winter (16.93 ± 6.24 ng/mL; 2.97% and 16.38 ± 6.43 ng/mL; 3.06%, respectively) than in summer and autumn (20.23 ± 7.14 ng/mL; 8.02% and 19.10 ± 6.97 ng/mL; 6.61% [p < 0.01], respectively); and in older individuals (0-6 years: 28.29 ± 13.13 ng/mL vs. >60 years: 14.88 ± 8.39 ng/mL; p < 0.01). Relatively higher vitamin D levels were observed in individuals of Yi, Zhuang, Hani, Dai, Miao and Lisu minorities and lower levels in individuals of Hui and Zang minorities compared with those of the Han nationality (p < 0.01). The mean sunlight duration, mean air temperature, maximum ultraviolet value and latitude were significantly correlated with vitamin D levels (r = -0.53, 0.60, 0.31, -0.68, respectively; p < 0.05). These results suggest that vitamin D status is influenced by sex, age, minority, latitude and some meteorological factors in areas with high and low altitudes. Hence, new public health policies, such as advice on sunshine exposure, food fortification and nutrition education, as well as the implementation of vitamin D supplementation programmes must be considered to alleviate vitamin D deficiency in Yunnan province, Southwest China.

Prevalence and Characteristics of Novel Pathogenic Leptospira Species in Bats in Yunnan Province, China

Leptospirosis has been identified as a zoonotic disease caused by pathogenic spirochetes of the bacterial genus Leptospira. Rodents are considered the primary hosts of these bacteria, whereas many recent studies suggest that bats may serve as potential natural reservoirs. However, studies on pathogenic spirochetes hosted by bat populations still need to be completed in China. In this study, a total of 276 bats belonging to five genera collected in Yunnan Province (Southwest China) from 2017 to 2021 were included in the screening. Pathogenic spirochetes were detected by PCR amplification and sequencing targeting four genes (rrs, secY, flaB, and LipL32), resulting in 17 positive samples. Phylogenetic analysis based on multi-loci concatenated sequences, inferred by MLST approach, identified the strains as two novel Leptospira species within the pathogenic group. Of note, only Rousettus leschenaultii was found to harbor these spirochetes, suggesting it may be one of the potential natural reservoirs in circulating leptospires in this region. Nevertheless, the pathogenesis and transmission dynamics still need to be fully understood, requiring in-depth studies on other animals and the surrounding population.

Genetic polymorphisms and phylogenetic characteristics of Tibeto-Burman-speaking Lahu population from southwest China based on 41 Y-STR loci

BACKGROUND

Male sex-linked Y-chromosome short tandem repeats (Y-STRs) have been widely used in forensic cases and population genetics research. At present, the forensic-related Y-STR data in the Chinese Lahu population are still poorly understood.

AIM

To enrich the available Y-STR data of this Chinese minority population and investigate its phylogenetic relationships with other reported populations.

SUBJECTS AND METHODS

The genetic polymorphisms of 41 Y-STR loci were analysed in 299 unrelated healthy Lahu male individuals from Southwest China. Phylogenetic analyses were performed by multidimensional scaling analysis and neighbor-joining phylogenetic tree construction.

RESULTS

A total of 379 alleles were observed at the 41 Y-STR loci. The allele frequencies ranged from 0.0033 to 0.9666. The genetic diversity values ranged from 0.0653 to 0.9072. A total of 254 different haplotypes of the 41 Y-STR loci were observed in 299 individuals. The values of haplotype diversity, haplotype match probability, and discrimination capacity were 0.9987, 0.0047, and 0.8495, respectively. The phylogenetic analysis indicated that the Tibeto-Burman-speaking Lahu population showed a close genetic relationship with the Yunnan Yi population.

CONCLUSIONS

The haplotype data of the present study can enrich the forensic databases of this Chinese minority population and will be useful for population genetics and forensic DNA application.

Genetic diversity of 15 STR loci in Yunnan Va ethnic minority and the phylogenetic relationships with 26 other populations

BACKGROUND

The Va (also called "Wa") people are an ethnic minority living mainly in the southwest of Yunnan Province.

AIM

This study was conducted to obtain the genetic information and forensic statistical parameters of 15 autosomal short tandem repeat (STR) loci included in the AmpFlSTR^®Identifiler™ kit (Applied Biosystems, Foster City, CA) in the Yunnan Va population, with a view to enriching the genetic databases of the Chinese Va population.

SUBJECTS AND METHODS

A total of 508 unrelated Chinese Va individuals were genotyped with this 15 STR kit, the genetic polymorphisms and associated forensic parameters were calculated. The genetic relationships between Chinese Va and 26 other Chinese populations were also evaluated.

RESULTS

All of the STR loci reached the Hardy-Weinberg equilibrium after Bonferroni correction. A total of 159 alleles were observed with allele frequencies ranging from 0.000984 to 0.606299. The combined discrimination power (CDP) and the cumulative probability of excluding (CPE) of the 15 STR loci were 0.999 999 999 999 999 988 126 and 0.999 995 734, respectively. Our results indicated that the geographically adjacent or ethnically close populations showed a higher genetic affinity.

CONCLUSIONS

The results of this study will enrich the forensic databases of the Chinese Va population and could be applied in forensic analysis.

The Effect of the "Triple-Layer Medical Security" Policy on the Vulnerability as Expected Poverty of Rural Households: Evidence from Yunnan Province, China

China launched the "critical battle against poverty" nationwide in 2012. As its main battlefield, Yunnan province promulgated the "triple medical security" (TMS) policy in 2017. This study, based on the pooled cross-section database of 2015-2020 of registered poor households in Yunnan province, employed the logit model to examine the effect of TMS on the vulnerability as expected poverty (VEP) of these households. It found that increasing the reimbursement rates for overall medical expenses and inpatient expenses and decreasing the proportion of out-of-pocket medical payment to income reduced the VEP; increases in the number of sick people in the family increased its VEP, and although the increase in the reimbursement rate for overall medical expenses or for inpatient expenses partially offset the VEP caused by the increase in the number of chronically ill people in the family, the VEP caused by the increase in the number of critically ill people would increase in the short term with the increase in the reimbursement rate for overall medical expenses or for inpatient expenses. The findings help improve policies concerning the medical security and health of the rural poor population, providing theoretical reference and practical guidance for future research.

The rediscovery of Caryapoilanei (Juglandaceae) after 63 years reveals a new record from China

Despite having been first published in 1941, Caryapoilanei (A.Chev.) J.-F.Leroy is only known from three collections in Vietnam, Laos and Thailand. It has not been recollected since then and was long suspected to have become extinct through repeated deforestation events. Here, we report the rediscovery, and meanwhile the first new record in China, of this extremely rare gigantic hickory species at Yunnan province 63 years after its last collection in 1958. Three small patchy subpopulations were found with a total of about 50 adult trees having diameter at breast height (DBH) larger than 60 cm, together with some seedlings and saplings, but the fruit set was low. Based on new and fresh material, we present a revised morphological description of C.poilanei, and an updated distribution map for the species. In addition, we also provide a key for the hickories in China. Lastly, we suggest C.poilanei should be listed as a Critically Endangered (CR) species according to the latest IUCN Red List Categories and Criteria.

Cadmium and Lead Pollution Characteristics of Soils, Vegetables and Human Hair Around an Open-cast Lead-zinc Mine

Atmospheric deposition of cadmium (Cd) and lead (Pb) was investigated together with the accumulation, distribution and health risks from potentially toxic metals in soils, vegetables and human hair at a mining area in southwest China. Annual atmospheric deposition of Cd and Pb were 41.1 and 192 g ha^- 1, respectively, and consisted mainly of dry deposition. Agricultural soils experienced high levels of metal pollution around the mine, with 66.4% and 57.3 % of vegetable samples grown on these polluted fields exceeding maximum permissible Cd and Pb concentrations, particularly the leafy vegetables. Residents living near the mining area had high Cd (0.75 mg kg^- 1) and Pb (6.87 mg kg^- 1) concentrations in their hair, and the maximum values occurred in occupationally exposed individuals. Long-term mining activities have resulted in high health risks to the local population due to Cd and Pb deposition and accumulation from the atmosphere, soils and vegetables.

Prevalence and Novel Genotypes Identification of Enterocytozoon bieneusi in Dairy Cattle in Yunnan Province, China

Simple Summary

We first report the prevalence of Enterocytozoon bieneusi in Holstein Cows and dairy buffalo in Yunnan province of China, with a percentage of positivity of 0.59% (5/841). Two novel zoonotic potential genotypes of E. bieneusi were found. We analyzed the different influencing factors (region, season, variety, breeding mode, gender, age), but the differences were not statistically significant.

Abstract

Enterocytozoon bieneusi is a fungus-like protist parasite that can cause diarrhea and enteric diseases. The infection of E. bieneusi has been reported in many host species, including cattle and humans. However, information on prevalence and genotype distribution of E. bieneusi in dairy cattle in Yunnan province in China is still absent. In this study, 490 Holstein Cows and 351 dairy buffalo fecal samples were collected from three regions in Yunnan province, China. By using nest-PCR that targets the internal transcribed spacer (ITS), we found that the prevalence of E. bieneusi was 0.59% (5/841). DNA sequence analysis showed that five E. bieneusi genotypes were identified in this study, including two novel genotypes, YNDCEB-90 and YNDCEB-174, and three known genotypes (I, J, BEB4). Phylogenetic analysis revealed that two novel genotypes, YNDCEB-90 and YNDCEB-174, were clustered into Group 1, representing the zoonotic potential. The remaining genotypes I, J, and BEB4, which are the most frequent genotypes of E. bieneusi infection in cattle and lead to E. bieneusi infection in humans, belonged to Group 2. Although the lower prevalence of E. bieneusi was detected in dairy cattle in Yunnan province, it indicates that dairy cattle should be considered to be one of the potential hosts for transmitting E. bieneusi to humans. These findings are important for the development of effective prevention strategies for microsporidiosis.

Identification of Tick-Borne Pathogens and Genotyping of Coxiella burnetii in Rhipicephalus microplus in Yunnan Province, China

Rhipicephalus microplus, a vector that can transmit many pathogens to humans and domestic animals, is widely distributed in Yunnan province, China. However, few reports on the prevalence of tick-borne pathogens (TBPs) in Rh. microplus in Yunnan are available. The aim of this study was to detect TBPs in Rh. microplus in Yunnan and to analyze the phylogenetic characterization of TBPs detected in these ticks. The adult Rh. microplus (n = 516) feeding on cattle were collected. The pooled DNA samples of these ticks were evaluated using metagenomic next-generation sequencing (mNGS) and then TBPs in individual ticks were identified using genus- or group-specific nested polymerase chain reaction (PCR) combined with DNA sequencing assay. As a result, Candidatus Rickettsia jingxinensis (24.61%, 127/516), Anaplasma marginale (13.18%, 68/516), Coxiella burnetii (3.10%, 16/516), and Coxiella-like endosymbiont (CLE) (8.33%, 43/516) were detected. The dual coinfection with Ca. R. jingxinensis and A. marginale and the triple coinfection with Ca. R. jingxinensis, A. marginale, and CLE were most frequent and detected in 3.68% (19/516) and 3.10% (16/516) of these ticks, respectively. The results provide insight into the diversity of TBPs and their coinfections in Rh. microplus in Yunnan province of China, reporting for the first time that C. burnetii had been found in Rh. microplus in China. Multilocus variable number tandem repeat analysis with 6 loci (MLVA-6) discriminated the C. burnetii detected in Rh. microplus in Yunnan into MLVA genotype 1, which is closely related to previously described genotypes found primarily in tick and human samples from different regions of the globe, indicating a potential public health threat posed by C. burnetii in Rh. microplus in Yunnan.

Molecular Investigation of Zoonotic Intestinal Protozoa in Pet Dogs and Cats in Yunnan Province, Southwestern China

Giardia duodenalis, Enterocytozoon bieneusi and Cryptosporidium spp. are common enteric pathogens that reside in the intestines of humans and animals. These pathogens have a broad host range and worldwide distribution, but are mostly known for their ability to cause diarrhea. However, very limited information on prevalence and genotypes of G. duodenalis, E. bieneusi and Cryptosporidium spp. in pet dogs and cats are available in China. In the present study, a total of 433 fecal samples were collected from 262 pet dogs and 171 pet cats in Yunnan province, southwestern China, and the prevalence and the genotypes of G. duodenalis, E. bieneusi and Cryptosporidium spp. were investigated by nested PCR amplification and DNA sequencing. The prevalence of G. duodenalis, E. bieneusi and Cryptosporidium spp. was 13.7% (36/262), 8.0% (21/262), and 4.6% (12/262) in dogs, and 1.2% (2/171), 2.3% (4/171) and 0.6% (1/171) in cats, respectively. The different living conditions of dogs is a risk factor that is related with the prevalence of G. duodenalis and E. bieneusi (p < 0.05). However, there were no statistically significant difference in prevalence of three pathogens in cats. DNA sequencing and analyses showed that four E. bieneusi genotypes (PtEb IX, CD9, DgEb I and DgEb II), one Cryptosporidium spp. (C. canis) and two G. duodenalis assemblages (C and D) were identified in dogs; two E. bieneusi genotypes (Type IV and CtEb I), one Cryptosporidium spp. (C. felis) and one G. duodenalis assemblage (F) were identified in cats. Three novel E. bieneusi genotypes (DgEb I, DgEb II and CtEb I) were identified, and the human-pathogenic genotypes/species Type IV C. canis and C. felis were also observed in this study, indicating a potential zoonotic threat of pet dogs and cats. Our results revealed the prevalence and genetic diversity of G. duodenalis, E. bieneusi and Cryptosporidium spp. infection in pet dogs and cats in Yunnan province, southwestern China, and suggested the potential threat of pet dogs and cats to public health.

in Yunling cattle in Yunnan Province, southwestern China

Yunling cattle is an unique cattle breed distributed in Yunnan Province, southwestern China. It is yet to know whether Yunling cattle are infected with Giardia duodenalis and Cryptosporidium spp.. The objectives of the present study were to investigate the prevalence and characterize the assemblages of G. duodenalis and species of Cryptosporidium spp. in Yunling cattle in Yunnan province. The overall prevalence of G. duodenalis and Cryptosporidium spp. were 10.49% (41/391) and 0.77% (3/391), respectively. The age was considered as the risk factor for Yunling cattle infection with G. duodenalis (χ² = 8.082, OR = 2.56, P = 0.004). Two assemblages of G. duodenalis, assemblage A (n = 1) and assemblage E (n = 40), were identified by amplification of the β-giardin (bg) and glutamate dehydrogenase (gdh) gene loci using the nested PCR methods. Furthermore, Cryptosporidium andersoni (n = 1) and Cryptosporidium ryanae (n = 2) were detected by nested PCR targeting the small subunit (SSU) rRNA gene. This is the first report of G. duodenalis and Cryptosporidium spp. in Yunling cattle in China, which provided baseline date for further studies of the prevalence, genetic identity, and public health potential of these parasites in Yunling cattle.

A thematic analysis of experiences of HIV risks among female sex workers in the Yunnan-Vietnam Chinese border region

Background

The Yunnan province is located near the “Golden Triangle” border region between China, Myanmar and Thailand, which has the highest HIV/AIDS prevalence in China. Female sex workers (FSWs) in the Yunnan province are highly vulnerable to HIV infection. The objective of this study was to examine the experiences of FSWs in the Yunnan to better understand the risk of infection and the potential for transmission of HIV.

Methods

Semi-structured interviews were conducted between May 2018 and June 2018 with 20 FSWs recruited in Hekou County, Yunnan Province, China. Thematic analysis was conducted to identify themes that highlighted increased exposure of FSWs to the risk of HIV infection and transmission.

Results

The findings showed that FSWs’ primary source for HIV information was gynecologists, with few visiting the local HIV charity Red Ribbon. FSWs reported infrequent visits for check-ups with some seeing a gynecologist once a year. FSWs felt that the onus was on them to prevent STI/HIV infection by using a condom during sex, regardless of their ability to negotiate use. FSWs were also reluctant to see a gynecologists for treatment. Instead, they resorted to douching as a way of preventing HIV/STIs and treating vaginal health problems, such as leucorrhea. Most FSWs worked without the influence of alcohol and drugs. A small number of FSWs reported heroin addiction and injecting drug use.

Conclusion

The findings suggest a need for innovative HIV prevention strategies among FSWs and their clients in the Chinese border region. Governmental agencies should continue to implement practical strategies in terms of HIV prevention education and condom use through tailored interventions that are localized. Such strategies should include localized tailored interventions that dispel myths about douching as a method of HIV/STI prevention and incorporate a mobile outreach approach, similar to the ‘roadside restaurant’ outreach that has been successful in rural China.

Analysis of initial laboratory diagnosis of malaria and its accuracy compared with re-testing from 2013 to 2018 in Yunnan Province, China

BACKGROUND

According to China's Malaria Eradication Action Plan, malaria cases diagnosed and reported by health authorities at the county level must be further re-confirmed by provincial laboratories. The Yunnan Province Malaria Diagnostic Reference Laboratory (YPMDRL) began the synchronous implementation of microscopic examinations and nested polymerase chain reaction (nested-PCR) testing to re-test the malaria cases initially diagnosed by county-level laboratories and to evaluate the consistency of Plasmodium species identified between by YPMDRL and by the county-level laboratories from 2013 to 2018 in Yunnan Province.

METHODS

Data on malaria initial diagnosis completed by county-level laboratories in Yunnan Province were collected weekly from the "China Disease Prevention and Control Information System" from 2013 to 2018. The YPMDRL performed Plasmodium microscopic examination and 18S rRNA gene nested-PCR testing on every malaria case managed by the China Disease Prevention and Control Information System. The re-testing detection results were fed back to the initial diagnosis and reporting unit for revision of malaria case types.

RESULTS

A total of 2,869 malaria cases were diagnosed and reported by county-level laboratories in Yunnan Province from 2013 to 2018. The re-testing rate was 95.6% (2,742/2,869), and the re-testing rate increased from 2013 to 2018. Among the re-tested 2,742 cases, 96.7% (2651/2742), 2.2% (59/2742), and 1.1% (32/2742) were doubly examined by microscopy and by nested-PCR, only by microscopy, and only by nested-PCR, respectively. The total Plasmodium species accuracy rate at county-level laboratories was 92.6% (2,543/2,742) reference to the diagnosis by YPMDRL. Among the inconsistent 199 cases, they were identified as including 103 negative cases, 45 falciparum malaria cases, 30 vivax malaria cases, 11 ovale malaria cases, and 10 malariae malaria cases by YPMDRL. From 2013 to 2018, the revised and registered malaria cases by the China Disease Prevention and Control Information System in Yunnan Province was 2,747 cases, including 2,305 vivax malaria cases, 421 falciparum malaria cases, 11 ovale malaria cases, and 10 malariae malaria cases.

CONCLUSIONS

The double re-testing strategy by microscopy and by gene testing increases the accuracy of diagnoses malaria in Yunnan Province, and gene testing can reliably differentiate Plasmodium species. The re-testing results provided by YPMDRL are the authoritative basis for revising malaria kind in Yunnan Province.

[Analysis of EGFR mutation and clinical features of lung cancer in Yunnan]

Objective: To analyze the EGFR mutation profile of lung cancer patients in Yunnan, and to provide evidence for clinical personalized treatment. Methods: Demographic and clinical data of 2 967 lung cancer patients undergoing EGFR identification were collected and analyzed from January 2014 to August 2019 in Yunnan Cancer Hospital. Results: The proportion of EGFR mutation in 2 967 patients with lung cancer was 46.2%. Univariate analysis showed that the proportion of EGFR mutation in women was higher than that in men (P<0.001) and displayed a downward trend with age (P=0.03). The mutation rate of ethnic minorities was higher than Han (P=0.012). Mutation rate in patients without smoking history was higher than those with smoking history (P<0.001), and patients without drinking history was higher than patients with drinking history (P<0.001). Mutation rate in patients without family history of lung cancer was higher than those with family history (P=0.008). The mutation rate of adenocarcinoma was higher than other pathological types (P<0.001). The mutation rate was different among stages, and it was higher in early patients than that in advanced patients (P<0.001). The mutation rate of tissue specimens was higher than those of cytology and peripheral blood samples (P<0.001). The mutation rate of Xuanwei area was lower than that in non-Xuanwei area (P<0.001). Multivariate analysis showed that gender (P<0.001), age (P=0.036), smoking history (P<0.001), pathological type (P<0.001), specimen type (P<0.001), and whether or not Xuanwei area (P<0.001) were the independent factors of EGFR mutation.The EGFR mutation was more common in female, non-smokers, adenocarcinoma, non-Xuanwei area, tissue specimen and young lung cancer patients.The mutation types of EGFR in 1 370 cases mainly included 19-Del and L858R. The predominant mutation of EGFR in Xuanwei area was L858R, while in non-Xuanwei area was 19-Del.The mutation rates of G719X, G719X+ L861Q, G719X+ S768I, and S768I in Xuanwei were higher while the mutation rates of 19-Del, L858R, and 20-ins were lower than non-Xuanwei area (P<0.05). The 19-Del mutation rate of ethnic minorities is higher than that of Han (P<0.001). The combined mutation rate of G719X, L861Q in Han was higher than that of ethnic minorities (P=0.005). Conclusions: The EGFR mutation rate in lung cancer patients in Yunnan is similar to Asian and Chinese, and higher in female, non-smokers, adenocarcinomas, young and non-Xuanwei area patients. The most common types of EGFR mutation in Yunnan are 19-Del and L858R. The predominant mutation of EGFR in Xuanwei area is L858R, while in non-Xuanwei area is 19-Del. The mutation rates of G719X, G719X+ L861Q, G719X+ S768I and S768I are higher in Xuanwei patients than those in non-Xuanwei patients. The combined mutation rate of G719X and L861Q in Han nationality is higher than that of ethnic minorities.

Polymorphism analysis of propeller domain of k13 gene in Plasmodium ovale curtisi and Plasmodium ovale wallikeri isolates original infection from Myanmar and Africa in Yunnan Province, China

Background

Eighteen imported ovale malaria cases imported from Myanmar and various African countries have been reported in Yunnan Province, China from 2013 to 2018. All of them have been confirmed by morphological examination and 18S small subunit ribosomal RNA gene (18S rRNA) based PCR in YNRL. Nevertheless, the subtypes of Plasmodium ovale could not be identified based on 18S rRNA gene test, thus posing challenges on its accurate diagnosis. To help establish a more sensitive and specific method for the detection of P. ovale genes, this study performs sequence analysis on k13-propeller polymorphisms in P. ovale.

Methods

Dried blood spots (DBS) from ovale malaria cases were collected from January 2013 to December 2018, and the infection sources were confirmed according to epidemiological investigation. DNA was extracted, and the coding region (from 206th aa to 725th aa) in k13 gene propeller domain was amplified using nested PCR. Subsequently, the amplified products were sequenced and compared with reference sequence to obtain CDS. The haplotypes and mutation loci of the CDS were analysed, and the spatial structure of the amino acid peptide chain of k13 gene propeller domain was predicted by SWISS-MODEL.

Results

The coding region from 224th aa to 725th aa of k13 gene from P. ovale in 83.3% of collected samples (15/18) were amplified. Three haplotypes were observed in 15 samples, and the values of Ka/Ks, nucleic acid diversity index (π) and expected heterozygosity (He) were 3.784, 0.0095, and 0.4250. Curtisi haplotype, Wallikeri haplotype, and mutant type accounted for 73.3% (11/15), 20.0% (3/15), and 6.7% (1/15). The predominant haplotypes of P. ovale curtisi were determined in all five Myanmar isolates. Of the ten African isolates, six were identified as P. o. curtisi, three were P. o. wallikeri and one was mutant type. Base substitutions between the sequences of P. o. curtisi and P. o. wallikeri were determined at 38 loci, such as c.711. Moreover, the A > T base substitution at c.1428 was a nonsynonymous mutation, resulting in amino acid variation of T476S in the 476th position. Compared with sequence of P. o. wallikeri, the double nonsynonymous mutations of G > A and A > T at the sites of c.1186 and c.1428 leads to the variations of D396N and T476S for the 396th and 476th amino acids positions. For P. o. curtisi and P. o. wallikeri, the peptide chains in the coding region from 224th aa to 725th aa of k13 gene merely formed a monomeric spatial model, whereas the double-variant peptide chains of D396N and T476S formed homodimeric spatial model.

Conclusion

The propeller domain of k13 gene in the P. ovale isolates imported into Yunnan Province from Myanmar and Africa showed high differentiation. The sequences of Myanmar-imported isolates belong to P. o. curtisi, while the sequences of African isolates showed the sympatric distribution from P. o. curtisi, P. o. wallikeri and mutant isolates. The CDS with a double base substitution formed a dimeric spatial model to encode the peptide chain, which is completely different from the monomeric spatial structure to encode the peptide chain from P. o. curtisi and P. o. wallikeri.

Vertical Transmission of Zika Virus by Jiegao and Mengding Aedes aegypti (Diptera: Culicidae) Strains in Yunnan Province in China

Zika virus (ZIKV) is a mosquito-borne pathogen classified in the genus Flavivirus of the family Flaviviridae. Vertical transmission is considered to be the primary way to maintain some arboviruses under adverse natural conditions, which play a critical epidemiological role in arbovirus spread and maintenance. Aedes aegypti is the primary vector for ZIKV. In this study, we demonstrated vertical transmission in two Ae. aegypti strains from Jiegao (JG) and Mengding (MD) in the border area of Yunnan province. The minimum infection rate of F1 adult progeny from JG Ae. aegypti strain was significantly higher than that of MD Ae. aegypti strain in the second gonotrophic cycle (1:14.29 and 1:200, respectively, p < 0.05). The cytopathic effect was observed in C6/36 cells after infection of ZIKV isolated from the progeny. The results suggest that Ae. aegypti mosquitoes from JG and MD play potential roles in ZIKV spread and maintenance. Therefore, more adult and eggs control methods should be implemented to control mosquitoes if a Zika epidemic occurs.

Economic burden and cost-utility analysis of three renal replacement therapies in ESRD patients from Yunnan Province, China

PURPOSE

To compare the economic burden and cost-utility analysis of the renal replacement therapies, including hemodialysis (HD), peritoneal dialysis (PD), and allograft kidney transplantation (KT) among end-stage renal disease (ESRD) patients from Yunnan Province, China.

METHODS

Multistage stratified random sampling method was used to select presentative sample of 298 patients from four hospitals in Yunnan Province. The two-step model was applied to calculate a direct economic burden; the human capital approach was used to analyze the indirect economic burden. SF-36 scale was applied to assess the quality of life, while the improving score of quality of life was used to evaluate the cost-utility score.

RESULTS

A total of 298 patients were analyzed, including 108 HD patients, 91 PD patients and 99 KT patients. The mean unit economic expenses of HD, PD, and KT were $11,783.6 ± 402.63, $11,059.8 ± 709.51, and $21,151.1 ± 11,419.57, respectively. Based on the cost-utility analysis, the cost of improving one unit of quality of life in KT, PD, and HD was $599.86, $1373.89 and $2021.20, respectively; a significant difference was observed between the KT group and the HD or PD group (P < 0.05).

CONCLUSIONS

The economic burden of ESRD in Yunnan was substantial. The cost-utility was the best in the renal transplantation group. Kidney transplantation is still recommended as the first approach for patients with ESRD, followed by PD.

Two new species of Alseodaphnopsis (Lauraceae) from southwestern China and northern Myanmar: evidence from morphological and molecular analyses

Alseodaphnopsis maguanensis and A. putaoensis, two new species of Alseodaphnopsis (Lauraceae) from southwestern China (Yunnan Province) and northern Myanmar (Kachin State), are here described and illustrated based on both morphological and molecular evidence. They are morphologically similar to Alseodaphnopsis rugosa and phylogenetically closely related to A. rugosa and A. hainanensis respectively. Their preliminary conservation status is also estimated according to the IUCN Red List Categories and Criteria.

Gene Mutation Spectrum of Thalassemia Among Children in Yunnan Province

Background: Thalassemia is an autosomal genetic disorder, found throughout the world. It is still not treatable and create socio economic problems. In this study, we investigated the prevalence and spectrum features of thalassemia in Yunnan Province, the southwestern area of China. During 2014-2018, a total of 3,539 suspected thalassemia children were detected with α- and β-thalassemia mutations by gap-Polymerase Chain Reaction (PCR) and reverse dot blot (RDB) analysis in Kunming Children's Hospital. Results: Of these patients, 1,130 were diagnosed thalassemia gene carriers with a carrying rate of 31.92%. Among them, α-thalassemia was 43.63%, β-thalassemia was 53.98%, cases with both α- and β- thalassemia was 2.39%. In α-thalassemia patients, the most common mutations was -^SEA/αα (52.13%), followed by -α^3.7/αα (27.79%), hemoglobin H disease (18.46%), and -α^4.2/αα (1.62%). Fifteen gene mutations and 30 genotypes were identified in β-thalassemia patients, with the five most common mutations CD17 (A>T) (29.51%), CD41-42 (-TTCT) (27.87%), IVS-II-654 (C>T) (14.92%), CD26 (G>A) (6.89%), and CD26/CD27 (2.62%) accounting for 81.81% of the β-globin gene mutations. Furthermore, we founded two rare mutations CD34 (TGG → TAG) and Int in Chinese populations. Conclusions: Our results suggested that the prevalence and gene mutation spectrum of thalassemia display obviously heterogeneity among children in Yunnan Province. The findings provide the valuable information for premarital and pre-pregnancy screening, prenatal diagnostic services, and designing appropriate prevention programs to control thalassemia for future in this area.

Evaluation of the short-term and long-term performance of biological invasion management in the China-Myanmar border region

Invasive alien species pose great threats to ecological and economic health and cause enormous losses to global ecosystems. The Mikania micrantha management program is a source of great theoretical and practical insights for regional agricultural and forestry development. In this paper, the invasion history and distribution patterns of M. micrantha in the China-Myanmar Border Region are summarized, and the short-term and long-term performance of the current post-border management program are evaluated. A literature survey found that M. micrantha was mainly distributed in 85 townships of five municipalities along the border in China with Myanmar, suggesting an explicit border-crossing scenario of M. micrantha. The M. micrantha management program has produced positive but short-term results due to the conduction of general investigations, establishment of an extensive monitoring network, development of integrated measures, and improvements of public awareness and participation. However, the long-term management performance was hampered by overlapping departmental functions, lagging and unreliable public feedback, inadequate funding, and biased and passive strategies. We suggest that invasive species committees, social media tools, public-private partnership, and forest restoration and conservation and biological control could greatly improve the situation. This regional-scale research provides referential insights for the development of biological invasion management systems in developing economies under transboundary contexts.

Prevalence and multi-locus genotypes of Enterocytozoon bieneusi in black-boned sheep and goats in Yunnan Province, southwestern China

Enterocytozoon bieneusi is a common pathogen in sheep and goats worldwide, threatening husbandry development and public health. However, there were few reports on native breeds of sheep and goats in China. In the present study, we investigated the prevalence and multi-locus genotypes (MLGs) of E. bieneusi in two important local breeds, black-boned sheep and goats, in Yunnan province, southwestern China. Of 661 faecal specimens collected from five counties of Yunnan province, 70 (10.59%) were positive for E. bieneusi infection. Infections were found in both black-boned sheep and goats, but no significant difference in prevalence was detected between two species. E. bieneusi was found in all age groups of black-boned sheep, while no infections were observed in 0-2-month black-boned goats. 12 genotypes were identified based on sequence variations of the internal transcribed spacer, including 10 known genotypes (BEB6, COS I, SX1, CM21, CHG3, CHG1, CHS5, EbpC, COS II, PigEb4) and two novel genotypes (named as YNS1 and YSM1), with BEB6 as the prevalent genotype both in black-boned sheep and goats. Phylogenetic analysis indicated that three genotypes of them, namely EbpC, CHS5 and PigEb4, were clustered into the zoonotic group 1, while the remaining nine genotypes were belonged to the host-adapted group 2. Multi-locus sequence typing (MLST) revealed 12 distinct multilocus genotypes (MLGs), with 11 MLGs detected in black-boned sheep and only one found in one black-boned goat. These findings expanded the reservoirs of E. bieneusi and provided fundamental data for controlling E. bieneusi infection in native small ruminants as well as other hosts in this province.

Food poisoning associated with ingestion of wild wasp broods in the upstream region of the Lancang river valley, Yunnan province, China

INTRODUCTION

Food poisoning due to wild wasp broods ingestion has long been noted in the upstream region of the Lancang river valley, Yunnan province, China. This study describes the epidemiological and clinical features of the poisoning and possible causes.

METHODS

Surveillance data collected between 2008 and 2016 were analyzed to produce demographic data on patients, information on clinical presentations, wasp species identification, and estimations of possible risk factors for symptomatic cases.

RESULTS

Eleven poisoning events were associated with the ingestion of wild wasp broods, including 46 exposed persons with 31 symptomatic living cases and 8 deceased cases that were reported in the Yunnan province between 2008 and 2016. Poisoning cases were only detected in the upstream region of the Lancang river valley in the autumn. The severity of the symptoms was correlated with an evident dose-effect relationship regarding the quantity ingested. The mean latent period from wild wasp broods ingestion to the onset of the symptoms was 10 h for symptomatic living cases and 7 h for deceased cases, respectively. Both gastrointestinal and neurological symptoms were commonly observed in the poisoning cases.

CONCLUSION

The toxin source may be indirectly caused by the wasp broods due to the prevalence of local poisonous plants, such as Tripterygium wilfordii Hook F, Tripterygium hypoglaucum Hutch and Vaccinium bracteatum Thunb. Educational programs at the start of wasp harvest season in September in the high-risk area should be carried out to reduce the incidence of poisonings.

Genetic analysis of 20 autosomal STR loci in the Miao ethnic group from Yunnan Province, Southwest China

The genetic polymorphisms of 20 autosomal short tandem repeat (STR) loci included in the PowerPlex^® 21 kit were evaluated from 748 unrelated healthy individuals of the Miao ethnic minority living in the Yunnan province in southwestern China. All of the loci reached Hardy-Weinberg equilibrium. These loci were examined to determine allele frequencies and forensic statistical parameters. The genetic relationship between the Miao population and other Chinese populations were also estimated. The combined discrimination power and probability of excluding paternity of the 20 STR loci were 0.999 999 999 999 999 999 999 991 26 and 0.999 999 975, respectively. The results suggested that the 20 STR loci were highly polymorphic, which makes them suitable for forensic personal identification and paternity testing.

The complete genomic analysis of an imported Vibrio cholerae from Myanmar in southwest China

We sequenced and analyzed an imported Vibrio cholerae from Mynamar in 2011 by using whole genome sequencing method in Yunnan Province, southwest China. Other 3 isolates of V. cholerae in Yunnan were also sequenced for comparing purpose. Illumina Hiseq2500 was used and the sequencing results were assembled and annotated. The comparative genomic analysis was also performed with 101 reference strains from China and abroad. The results showed the imported V. cholerae (YN2011004) had two chromosomes and one plasmid; chr1 contained 2727 predicted genes, and 958 genes for chr2. Phylogenomic tree results showed YN2011004 belonged to the seventh pandemic strain, clustered into wave 3 and clade 3B. The strain had the highly homology with SN083 and 4remapscaff isolated in 2010 from other parts of China, and clustered with SN117, VC50 remapscaff, VC57 remapscaff and SN034. These references V. cholerae mostly isolated from coastal areas of China in 2008. For the other 3 strains' comparison, it suggested that V. cholerae in 1990s in Yunnan had the close relationship with the prevalence of cholera in Southeast Asia. Therefore, we thought that the cholera in Yunnan was consistent with the epidemic trend of China, being the "sink" for external source and also acted as a "source" for spread. Moreover, we considered that the imported V. cholerae from Myanmar in 2011 actually was the exported strain from China, and it provided us a new sight for the bacterial change and evolution.