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Background: Lyme disease, caused by Borrelia burgdorferi sensu lato (BBSL), is commonly found in wild and domestic mammals worldwide. In China, human cases of B. burgdorferi infections have been identified across a wide distribution, but little direct surveillance of potential small mammal reservoirs has been performed in Yunnan Province, a tropical region in southwestern China. Here we report a thorough investigation of BBSL in small mammals collected from 2011 to 2016 from this region.Methods: Small mammals were captured using snap traps in 23 counties located in Yunnan Province. DNA was extracted from spleen tissue using DNA blood and tissue kits. A nested PCR targeting the 5S-23S rRNA intergenic spacer gene of BBSL was used for pathogen detection. Amplicons of 252bp expected sizes were sequenced directly and analyzed using BLAST algorithm. A phylogenetic tree was constructed using MEGA software and statistical analysis were conducted using SPSS version 17.0.Results: Overall, 3659 mammals belonging to 57 species were captured at 159 sample sites located in 23 counties in Yunnan Province. Borrelia burgdorferi s.l. was found in 146 mammals (3.99%), from 30 different species, 20 of which represent the first reported detection in that species. Sequence analysis revealed five genotypes of B. burgdorferi s.l., including B. afzelii, B. burgdorferi sensu stricto, B. japonica, B. garinii and B. valaisiana.Conclusions: Significant differences in prevalence rates of BBSL were observed at varying landscape types and altitudes. Small mammals in forested areas had higher prevalence rates than other landscape types, as did small mammals found at altitudes greater than 2500 meters. The five genotypes of BBSL detected, suggests high genetic diversity within this province.

Background: Lyme disease is caused by Borrelia burgdorferi sensu lato which is usually found in wild and domestic mammals worldwide. In China, Human cases of B. burgdorferi infections have been identified in a wide distribution, but little direct surveillance of potential rodent reservoirs has been performed in Yunnan Province, the tropical region, Sino-Burmese border area, southwestern China. Here we report a thoroughly investigation of B. burgdorferi sensu lato in small mammals collected in 2011 to 2016 in the region.Methods: A nested PCR was done for the 5S-23S rRNA intergenic spacer gene of Borrelia burgdorferi sensu lato. The PCR-positive amplicons were directly sequenced. Sequence analysis was carried out using a FASTA search on the Genbank database, with phylogenetic trees constructed using MEGA software, version 6.06. Statistical Analysis were conducted using SPSS.version 17.0.Results: Totally 57 species, 3659 mammals were captured at 159 sample sites located in 23 counties in Yunnan Province. Thirty species, 146 (3.99%) mammals were tested positive for B. bourgdorferi s.l . by nested PCR based on 5S-23S rRNA intergenic spacer gene. 20 species mammals were first reported infected with B. burgdorferi s.l. Sequence analysis revealed that five genotypes of B. burgdorferi s.l. were detected, including B. afzelii , B. burgdorferi sensu stricto, B. japonica , B. garinii and B. valaisiana.Conclusions: Significant differences in prevalence rates of B. bourgdorferi s.l were observed at varying landscape types and altitudes. Small mammals in forested areas had higher prevalence rates than other landscape types as did small mammals found at altitudes greater than 2500 meters. The 5S-23S rRNA intergenic spacer gene revealed that there were five genotypes of B. burgdorferi s.l. detected, indicating high genetic diversity within this province.

BackgroundLyme disease is caused byBorrelia burgdorferisensulato (BBSL) which is usually found in wild and domestic mammals worldwide. Human cases ofB. burgdorferiinfections have been identified in China, but little direct surveillance of potential rodent reservoirs has been performed in Yunnan Province, Southwestern China. Yunnan Province is a tropical area with a diverse topographic range and sustains a high biodiversity of small mammals that could potentially play an important role in the transmission of a variety ofB. burgdorferigenospecies.Methods3659 small mammals were captured in 159 sample siteslocated 23 countries inYunnan Province and screened for BBSL infection by nested PCR based on 5S-23S rRNA intergenic spacer gene of BBSL.Univariate and multivariate forward stepwise logistic regression analysis was used to access the association between infections and related risk factors.ResultsInfection with BBSL was confirmed in 3.99%(146/3659) of small mammals. Significant differences in prevalence rates of BBSL were observed at varying landscape types and altitudes.Small mammals in forested areas had higher prevalence rates than other landscape types as did small mammals found at altitudes greater than 2500 meters. The 5S-23S rRNA intergenic spacergene revealed that there were 5 genotype of BBSL, includingB. afzelii, B. burgdorferisensustricto, B.japonica, B.gariniiand B.valaisiana, which demonstrate the genetic diversity and regional distribution.ConclusionsThere exists a wide distribution and genetic diversity of endemic BBSL in Southwestern China, warranting further investigations and monitoring of clinical disease in individuals presenting with symptoms of Lyme disease in these areas.Author summaryLyme disease is caused byBorrelia burgdorferisensu lato (BBSL) which is usually found in wild and domestic mammals worldwide. Human cases ofBorrelia burgdorferisensu lato infections have been identified in China, but little direct surveillance of potential rodent reservoirs has been performed in Southwestern China. This study documents potential small mammal reservoir hosts collected from a large of sample sites from different landscape types and altitudes, with PCR and sequencing identifying the wide distribution and genetic diversity of endemicBorrelia burgdorferisensu lato in Southwestern China. This was the first report thatB. japonicawas detected inApodemus dracoandNiviventer excelsiorin China. This study adds to body of literature onBorrelia burgdorferisensu lato in China. This work will provide insight regarding small mammals to target for surveillance and we access the association between gender, developmental stage of rodents, environmental landscape and altitude to better prevent human exposure.

To understand the characteristics of community structure and spatial distribution of small mammals in agricultural area of Yunnan Province, a systematic investigation was carried out in 104 quadrats of 25 regions in Yunnan Province from August 2010 to April 2018 by rat trap night method. The spatial variation of community characteristics along environmental gradients was analyzed by community ecological indicators. The results showed that a total of 3240 small mammals were captured and cold be classified into 42 species in 21 genera, 9 families, and 4 orders. The largest number of small mammal was rodents, dominated by Apodemus chevrieri and Rattus tanezumi. The 25 regions were clustered into three classes. The altitudinal distribution of small mammals was similar to the latitudinal distribution in agricultural areas. The number of species was relatively less in the low latitude and altitude range, with Rattus spp. and Mus spp. as the dominant species. In the high latitude and altitude region, the dominant species changed into Apodemus, Niviventer and Eothenomys. With the increases of altitude, the diversity index showed unimodal distribution, with the highe-st species diversity occurred in the mid-altitude area. The diversity index of small mammal showed the "V" type pattern in longitude, being the highest in the 98°-99° E gra-dient zone. At the latitude level, it showed an overall upward trend from south to north. Results from the GAM analysis showed that the degree of influence on the small animals in the agricultural area was in order of longitude, altitude and latitude. The similarity analysis in the composition of small mammals showed that the moderate similarity occurred in the adjacent gradient zone, and the highest similarity occurred in middle altitude zone, middle latitude zone, and low longitude zone. The farther the distance between different gradient zones, the lower the similarity of community structure. There was high spatial heterogeneity in different dimensions of small mammals' community structure in Yunnan Province. The geographical distribution trend of species diversity showed different distribution patterns across environmental gradients.为了解云南省农耕区小型兽类群落结构及空间分布特征,根据云南不同经纬度、海拔等自然环境条件,于2010年8月—2018年4月,选取云南省25个调查样区中104块农耕地,采用铗夜法开展小型兽类调查,运用群落生态学指标对农耕区小型兽类的群落特征和沿环境梯度的空间分布进行研究.结果表明: 共捕获小型兽类3240头,隶属4目9科21属42种,其中啮齿目最多,以齐氏姬鼠和黄胸鼠为代表.25个样区聚类为三大类.小兽在纬度和垂直分布上类似,低纬度和低海拔范围的种类相对较少,以家鼠属和小鼠属为主,而高纬度和高海拔地区以姬鼠属、白腹鼠属和绒鼠属为主.小兽物种多样性指数随着海拔的增加呈现先增后降的单峰分布格局,峰值出现在中海拔地区;经度水平分布上,小兽多样性指数呈V型分布格局,在98°—99° E最高;而纬度水平上,小兽多样性指数由南到北总体呈上升趋势.广义可加模型(GAM)分析表明,各因子对农耕区小型兽类多样性指数分布格局的影响程度为经度海拔纬度.相似性分析表明,相邻梯度带之间小兽群落结构为中等相似,相似性最高出现在中海拔带、中纬度带、低经度带之间,不同梯度带距离越远,小兽相似性越低.云南省农耕区小兽群落结构在不同维度上存在较高的空间异质性,物种多样性的地理分布随环境梯度变化呈现出不同的分布格局.

Rare investigation on tick-borne pathogens was carried out in Yunnan, China. In this study, we did a survey on Ehrlichia infection in small mammals and ticks. A total of 40 small mammals and 49 ticks were collected from Tengchong, Yunnan province. PCR targeting 16S ribosomal RNA (rRNA), citrate synthase, GroEL heat-shock protein operon, and major outer membrane protein genes was performed and positive amplicons were sequenced.The 40 small mammals were identified as 10 species, 2 (5.0%) of which were infected with Ehrlichia, 4 (10.0%) were infected with Anaplasma phagocytophilum and another 2 (5.0%) were infected with Candidatus Neoehrlichia mikurensis. Six (12.2%) ticks were positive for Ehrlichia and another two (4.1%) were infected with A. phagocytophilum. Neither small mammals nor ticks had coinfection. The detected Ehrlichia was named as Ehrlichia sp. YN04, which was in the same clade of Ehrlichia sp. 360 by phylogenetic analysis. The sequences of the pathogen recovered from small mammals and ticks were identical with each other.The study reports one Ehrlichia species first detected from small mammals and ticks in mainland China. As Yunnan is a famous "Global Biodiversity Hotspot" in the world, we may expect much more tick-borne infectious pathogens existing and declare more public health attention in this region.

To understand the condition of the construction and management of sanitary latrines, and assess the effect of disposal of the excrement in rural schistosomiasis endemic areas in Yunnan Province.Three villages with schistosomiasis endemic were selected from Eryuan County and 30 households per village were sampled randomly for the field survey. The stool samples were sampled and tested according to the national standard.Totally 90 latrines were surveyed. The popularity rates of sanitary latrines in Yongle, Qiandian and Xinzhuang villages were 83.19%, 83.12% and 81.63% respectively. In the 90 household latrines, only 32.22% located inside the courtyard, and 91.67% of sanitary latrines and 70.00% of non-sanitary latrines had integrated buildings. Maggots or pupae or adult flies were found in 33.33% of sanitary latrines and all of non-sanitary latrines with the average amounts of 1.05 and 3.40 per latrine respectively. The removal rate of fecal coliform, the sedimentation rate of parasitic eggs and the mortality rate of Ascaris eggs were 90.00%, 80.61% and 95.20% on average respectively. The qualified rate of the fecal coliform of the outlet of the sanitary latrines was 41.67%, and the qualified rate of the mortality rate of Ascaris eggs was 78.13%. No living schistosome eggs were found at the outlets of latrines. For the effect of non-hazardous treatment, there was a statistically significant difference between the sanitary latrines and non-sanitary latrines.The latrine improvement has a good effect on non-hazardous treatment of the excrement in Yunnan Province, but the construction, application and management of sanitary latrines still need to be strengthened.

Background Babesia, usually found in wild and domestic mammals worldwide, have recently been responsible for emerging malaria-like zoonosis in infected patients. Human B. microti infection has been identified in China, primarily in the Southwest along the Myanmar border but little direct surveillance of B. microti infection in rodents has been carried out here (Yunnan province). In this region, a diverse topographic range combined with tropical moisture sustains a high biodiversity of small mammals, which might play important role on Babesia transmission. Methods Small mammals were captured in 141 sample locations from 18 counties located Yunnan Province, and screened for B. microti-like parasites infection by a nested PCR to target 18S rRNA gene of Babesia, plus directly sequencing for positive samples. Univariate and multivariate forward stepwise logistic regression analysis was used to access the association between infections and some related risk factors. Results Infection with Babesia microti was confirmed in 2.4% (53/ 2204) of small mammals. Significant differences in prevalence rates of B. microti were observed based on variations in forest, agricultural, and residential landscapes. Furthermore, adult small mammals had higher prevalence rates than younger, pubertal mammals. The near full-length 18S rRNA gene revealed that there were two types of B. microti, Kobe and Otsu, which demonstrate the genetic diversity and regional distribution. Conclusions There exists a wide distribution and genetic diversity of endemic B. microti in Southwestern China, warranting further investigations and monitoring of clinical disease in individuals presenting with Babesia like symptoms in these areas., Author summary Babesia spp are garnering more attention as causative agents of human disease, with B. microti responsible for most cases globally. Our study documents potential small mammal reservoir hosts, collected from a large of sample sites, with PCR and sequencing identifying the wide distribution and genetic diversity of endemic B. microti in Southwestern China. Our study adds to body of literature on Babesia in China, while focusing on potential rodent reservoirs of disease. This report will be important for public health, and for researchers in the field of parasitology.

To evaluate the effect of schistosomiasis control in Yunnan Province since achieving the transmission control standards, so as to provide the evidence for formulating the next prevention and control strategy.The schistosomiasis epidemic monitoring reports, annual reports, relevant information about Oncomrnelania hupensis snails, and schistosomiasis patient conditions were collected and analyzed for epidemic condition and characteristics of schistosomiasis in Yunnan Province from 2009 to 2012.The various epidemic monitoring indicators all decreased. In 2012, compared with 2009, the prevalence reduced by 33.33% after correction; the number of villages with schistosomiasis patients reduced by 55.56%; the adjusted positive rate of livestock stool tests reduced by 45.45%; the number of villages with infected cow reduced by 42.25%; the actual area with snails reduced by 13.58%; the density of living snails reduced by 25.66%, and no schistosome infected snails were found in 2012.There still exist schistosome infections in human and animals in some local areas of Yunnan Province, and it is difficult to achieve the standard of schistosomiasis transmission interrupted in a short period.

To understand the types of schisotsome infection sources and their roles in schistosomiasis transmission in mountainous endemic regions in Yunnan Province, so as to provide the evidence for implementing the comprehensive control measures based on infection source control.Two villages of typical mountainous regions in Nanjian County were chosen for field investigation. The Oncomelania hupensis snail status was surveyed by the methods of systematic and environmental sampling. The infections of schistosomiasis were surveyed in residents with the indirect haemagglutination and the hatching method, in livestock with the hatching method and in wild animals with the anatomical method and the hatching method. The distribution and pollution status of wild faeces were investigated in the snail environments nearby villages or with livestock frequent activities. The positives of schistosomiasis in wild faeces were tested with the hatching method. The pollution index of wild feces was calculated.A total of 533.56 hm2 were investigated in two villages, and the area with snails was 16.52 hm2. The rate of frame with snails was 1.03%, the average density of snails was 0.07 snails/0.1 m2, and no positive snails were found. The positive rate of blood examinations of population was 1.61%, but no persons were positive with the hatching method. The infection rates were 0.90%, and 0.62% in cattle and equus, respectively, and there were no positives in other livestock. Totally 472 piles of wild feces of 6 species (human, cattle, equus, goat, pig and dog) distributed in the investigation areas, and among them, the densities of wild feces of cattle, equus, and dog were 7.2, 4.3 piles/hm2, and 2.1 piles/hm2 respectively, being relatively higher than others. The hatching positive rates of wild faeces of cattle, equus, and dog were 2.27% (3/132), 2.63% (2/76), and 3.70% (1/27), respectively. The relative pollution indexes of wild faeces of cattle, equus, and dog were 80.68%, 15.89%, and 3.43%, respectively.After schistosomiasis transmission is controlled, the potential epidemic factors still remain in the mountainous endemic regions of schistosomiasis in Yunnan Province. The cattle are still the most infection source of schistosomiasis, but equus and dog as infection sources should be not neglected. We should extend the investigation and monitor scope of the infection sources, and carry out scientific and feasible control technique and management measures.

The molluscicidal effects of 10% salt of quinoid- 2' ,5-dichloro-4'-nitrosalicylanilide (LDS) with dusting method, 26% amine molluscicide (MNSC) and 50% niclosamide (WPN) with insufflation method were tested in the fields of mountainous areas of Yunnan Province. After 7, 15 and 30 days of the tests, the death rates of snails, decline rates of living snail densities, and occurrence rates of frames with living snails of the 10% LDS group were 72.69%-87.16%, 74.10%-88.84%, and 20.00%-30.00%, respectively; those of the 26% MNSC group were 66.21%-91.06%, 69.55%-91.36%, and 19.44%-27.78% respectively; those of the 50% WPN group were 78.10%-90.18%, 82.44%-91.60%, 17.50%-20.00%, respectively. The results showed that the molluscicidal effects of 10% LDS, 26% MNSC and 50% WPN were basically equal.

To evaluate the molluscicidal effect of 26% suspension concentrate of metaldehyde and niclosamide (MNSC) in the fields of mountainous areas in Yunnan Province.Some representative Oncomelania snail environments of schistosomiasis endemic regions were selected as study areas in Heqing County, Yunnan Province and 26% MNSC and 50% wettable powder of niclosamide ethanolamine salt (WPN) were used to kill the snails with the mechanical spraying and sprinkler spraying methods respectively.Seven, 15, 30 days after the spraying with the mechanical spraying method, in corn fields, the snail mortality rates were from 88.68% to 92.88% in the MNSC group, and from 89.86% to 90.32% in the WPN group respectively, and in the ditch, the snail mortality rates were from 89.97% to 94.46% in the MNSC group and from 90.08% to 96.74% in the WPN group respectively, and there was no significant difference between the 2 groups (P0.05); 7, 15, 30 days after the spraying with the sprinkler spraying method, in corn fields, the snail mortality rates were from 66.14% to 89.11% in the MNSC group, and from 78.40% to 91.22% in the WPN group, respectively, in the ditch, the snail mortality rates were from 84.13% to 94.27% in the MNSC group, and from 85.81% to 95.26% in the WPN group respectively, and there was no significant difference between the 2 groups (P0.05).26% MNSC has good molluscicidal effect in the fields of mountainous areas in Yunnan Province

To study the temporal trend and spatial distribution of premature mortality burden due to chronic obstructive pulmonary disease (COPD) in terms of years of life lost (YLL) in an urban region of Kunming for the years 1998-2003.Pan Long district was selected as the study region. YLL was used to measure premature mortality burden due to COPD. The tate of YLL per 1000 residents was calculated without age-weighting but with 3% discounting rate and broken down by year. Geographic information system (GIS) technique was used to display the spatial distribution of premature mortality burden due to COPD during the six years of study.During the years from 1998 to 2003, the premature mortality burden due to COPD decreased by years while males seemed to have a higher YLL rate of COPD than females. Central areas remained to have higher YLL/1000 population values of COPD for the six years, whereas remote areas tended to have a decreasing trend of YLL/1000 population values of COPD in the same period.Central areas of the city should be emphasized in further control of COPD in the urban region of Kunming.