Geographic information system (CIS) was applied to analyse the endemic situation of schistosomiasis and the distribution of snails in Dali City. Hie data of endemic situation of schistosomiasis in Dali City from 2002 to 2008 were collected and a CIS database was set up. The endemic situation and the distribution of snails and acute schistosomiasis cases were analyzed by ArcGIS 9. 2 software. The results showed that the schistosomiasis transmission areas included 11 towns, 91 villages, and 401 nature villages. The trend surface analysis suggested that snail distribution in 2008 had a trend to accumulate in the northwest, while the population infection had a trend of gathering to the southeast. All acute schistosomiasis cases distributed in 6 towns, 23 villages, which showed significant aggregation by space-time clustering analysis, and three endemic villages in Xizhou Town in 2002 were identified as the first stratum endemic areas. It is concluded that CIS as database and graphics management tools can describe the epidemic situation intuitively, imaginably and macrosopically.

Objective To understand the epidemiologic trend and characteristics of the distribution of schistosomiasis in Yunnan Province, China. Methods The data of two sampling surveys on schistosomiasis in Yunnan in 1995 and 2003 were collected, and the database of GIS was set up. The spatial status of rates of human infection and cattle infection were analyzed by using the GIS software, ArcView 3.2, contours method. The relationships between rates of human infection and cattle infection in 1995 and 2003 were analyzed with SPSS statistical software. Results The high-risk areas of schistosomiasis in Yunnan were Dali City, Yongsheng, Heqing, Eryuan, Weishan and Nanjian counties, and those areas contained different infection grades which were intertwine. The rate of human infection was descendent and the distribution of high-risk areas of schistosomiasis was decreasing. The infection rate of cattle was higher than before in the south of epidemic areas in Yunnan. Those epidemic areas of schistosomiasis could be identified as three spatial distributions. Conclusions The control and prevention of schistosomiasis in Yunnan should be focus on Dali City, Eryuan, Weishan, Yongsheng, Heqing and Nanjian counties, and the key is synchronistical chemotherapy in human and cattle.

Objective To develop a spatio-temporal model of mountainous Oncomelania hupensis snails based on the Bayes-ian model,and to analyze and identify the spatio-temporal pattern at a village scale. Methods The data including the intensity and spatial distribution of live and infected snails from 2000 to 2006 and the village boundary were collected. The independent and interactive spatio-temporal models were established,and then the best fitness model was selected to analyze the spatio-temporal pattern of live and infected snails. Results The interactive model of live snails and the independent model of infected snails were relative fitness models,and the models showed 95%CI(confidence interval)of the spatial and temporal coefficient included ze-ro,and indicated that the spatial and temporal correlation of live and infected snails was not significant at a village scale. Conclu-sion There is no significant spatial and temporal correlation of live and infected mountainous snails at a village scale,and the fur-thermore study should be carried out at a small scale.

Objective: To learn the genotypic drug resistance of men who have sex with men ( MSM ) with HIV who failed in antiviral therapy in Yunnan Province, in order to provide basis for improving the effect of antiviral therapy. Methods: The patients who were infected with HIV-1, homosexual transmitted and failed in antiviral therapy in Yunnan Province from 2014 to 2019 were recruited. Their plasma samples were tested by reverse transcription nested polymerase chain reaction ( RT-nPCR ) , the fragments were spliced using ContigExpress, and the resistance to 8 protease inhibitors ( PIs ) , 7 nucleoside reverse transcriptase inhibitors ( NRTIs ) and 5 non-nucleoside reverse transcriptase inhibitors ( NNRTIs ) were obtained from the HIV drug resistance data website of Stanford University. Results: A total of 205 HIV/AIDS cases were included, 169 positive plasma samples were amplified, 112 cases were drug resistant, and the rate of drug resistance was 66.27%. The patients who were aged 30-49 years ( 76.09% ) , had genotype of CRF01_AE ( 76.34% ) or treated by AZT+3TC+NVP ( 77.08% ) had higher resistance rate. The resistance rates of NNRTIs, NRTIs and PIs were 62.72%, 49.70% and 2.96%, respectively; the resistance rates of NVP and EFV in NNRTIs were 62.72% and 61.54%. The main mutation site associated with NNRTIs was K103, accounting for 21.89% ( 37 cases ) ; the main mutation site associated with NRTIs was M184, accounting for 39.64% ( 67 cases ) ; the main mutation sites associated with PIs were M46L/K, accounting for 2.96% ( 5 cases ) , resulting in high resistance to NFV. Conclusions The drug resistance rate of HIV-infected MSM with failure of antiviral therapy in Yunnan Province is relatively high, with CRF01_AE as the main gene subtype of drug resistance. The drug resistance rate of NNRTIs is relatively high, especially NVP and EFV.

Objective To investigate the influence factors of mortality among human immunodeficiency virus (HIV)-infected children under highly active antiretroviral therapy (HAART).Methods Retrospective cohort study of 652 children initiated HAART from 2005 to 2014 was conducted,and enrolled patients were followed-up until December,2015.Survival data was analyzed using Kaplan-Meier method and Cox regression model was used to identify independent predictors of mortality among these children on HARRT.Chi-square test and Fisher's exact test were used for comparison between groups.Results Overall,26 of the children died over a follow-up period of 3 116.24 child-years,with a mortality rate of 0.83 per 100 child-years.Twelve (46％)of deaths occurred during the first six months after starting HAART.Cox regression analysis of variables showed that the World Health Organization (WHO) clinical stages Ⅲ/Ⅳ (hazard rate [HR] =10.717,95％confidence interal [95％ CI]:4.189-4.749,P =0.000),baseline hemoglobin ＜ 80 g/L (HR =14.768,95 ％ CI:5.721-38.125,P =0.000),tuberculosis co-infection (HR =4.794,95％ CI:2.105-10.918,P =0.000),baseline CD4+T lymphocyte ＜ 50 cells/μL (HR =4.219,95％ CI:1.524-11.680,P =0.006),weight-for-age z-score ＜-2 (HR =2.983,95 ％ CI:1.094-8.135,P =0.033) were independently associated with death,whereas the age ＜ 7 year-old at HAART initiation was protectire (HR =0.293,95％ CI:0.126-0.684,P =0.005).Conclusions The mortality of children receiving HAART is strongly associated with WHO stages Ⅲ/Ⅳ,hemoglobin ＜ 80 g/L,weight-for-age z-score ＜-2,tuberculosis co-infection and older age at treatment.

Objective To investigate the subtypes distribution of human immunodeficiency virus (HIV)-1 epidemic strains and the characteristics of amino acid variation in different areas of Yunnan Province.Methods Totally 800 HIV/AIDS plasma specimens and epidemiological information were collected between 2012 and 2015 from 14 areas of Yunnan.Viral RNA was extracted and amplified using RT polymerase chain reaction (PCR).4.5 kb 5'halves fragments were obtained and directly sequenced.Subtypes of strains were identified by Genotyping,MEGA 6.06 and BLAST.Grouping was analyzed by location and subtype.Entropy software was used to analyze the difference of amino acid sequences between different groups according to the sampling location and subtypes to analyze the regional distribution and genetic variation of HIV-1 subtypes in Yunnan Province.Results Of the 800 plasma specimens,a total of 446 genomic sequences from 12 areas were successfully amplified and sequenced.After genotypes were identified,the subtypes of HIV-1 strains prevalent in Yunnan were CRF08_BC (58.3％),CRF01_AE (19.3％),CRF07_BC (11.6％),unknown recombinant forms (7.1％),B(B') (1.7％) and C (1.3％).The geographical distribution in Yunnan was analyzed.The CRF01_AE predominated in Dehong,Xishuangbarma and Wenshan.The CRF08_BC predominated in Lincang,Honghe and Puer (more than 70.0％) and CRF08_BC was prevalent in the other areas.But CRF07_BC in Kunming,Yuxi and Dali accounted for more than 20 ％.The constitutions of amino acid of three majors CRF08_BC,CRF01 _AE and CRF07_BC were different on 17,14 and 18 amino acid sites with statistical differences in the eastern and western regions of Yunnan Province (均P ＜ 0.05).Conclusions HIV-1 strains transmit and vary genetically in the province widely.The amino acid mutation sites of eastern and western strains are different.This difference represents that the same subtype strains in different geographical distribution vary on different genetic background and are selected by immune responses.The epidemic trends need to be closely monitored.

According to the requirement of the national assessment for achieving the infection control criteria, 42 villages (among them,25 villages belonged to the first stratum, and 17 villages belonged to the second stratum) in 14 counties from 5 provinces, including Hunnan, Hubei, Jiangxi, Anhui and Yunnan, were selected as sampling villages for the assessment.The results from the field assessment showed that 154 out of 9 067 people were found infected with Sckistosoma japonicum, with an average infection rate of 1.7% ranged from 0.31 % to 4.10% , and only Yongping Village from Weishan County and Tenglong Village from Eryuan County were not found any case. A total of 46 out of 3 323 head of cattle were infected with S. japonicum, with an average infection rate of 1.38% ranged from 0.26% to 3.79% , and no any infected individual detected in Nanling County. No outbreak occurred in those sampling villages. Therefore, it is indicated that the five sampling provinces have reached the national criteria on infection control of schistosomiasis.

Objective:To analyze the variation characteristics of gag gene sequence of human immunodeficiency virus type 1 (HIV-1) epidemic strains in four major acquired immunodeficiency syndrome (AIDS) endemic areas in Yunnan Province. Methods:A total of 480 human immunodeficiency virus (HIV)/AIDS patients from designated antiviral treatment institutions in Kunming City, Dehong Dai and Jingpo Autonomous Prefecture, Hani-Yi Autonomous Prefecture of Honghe and Lincang City in Yunnan Province from January 2019 to December 2020 were randomly selected. The epidemiological information of the patients was collected. The plasma samples were collected and sent to the Yunnan Provincial Infectious Diseases Hospital for analysis. HIV-1 gag gene was amplified by nested polymerase chain reaction for genotyping.The phylogenetic tree was constructed by MEGA 6.06, and the characteristic amino acids were analyzed by VESPA online analysis tool. The gene distances of gag and matrix protein p17, capsid protein p24, nucleocapsid protein p7 and p6 protein of gag protein were calculated by Distance program. The ratio of synonymous mutation frequnency and non-synonymous mutation frequnency (Ks/Ka) was analyzed by SNAP program. Statistical comparison among multiple groups was performed using analysis of variance. Results:The gag gene sequences were successfully obtained from 404 patients.Most of these patients were men (250 cases, 61.9%), 59.7%(241/404) of patients were aged 40 to 59 years, and the main transmission route was heterosexual transmission (61.4%, 248/404). The main epidemic subtypes of HIV-1 were circulating recombinant form(CRF)08_BC (38.4%, 155/404), CRF01_AE (18.3%, 74/404), unique recombinant form (URF) (12.9%, 52/404), CRF07_BC(9.7%, 39/404), C subtype (8.4%, 34/404), other subtypes (6.9%, 28/404) and B subtype (5.4%, 22/404). Two main spreading clusters were formed by CRF08_BC in the phylogenetic tree, and there were significant differences in the distribution of characteristic amino acids of eight loci between the two spreading clusters, including No.79, 93, 121, 122, 151, 363, 395 and 396. The gag gene distances of CRF01_ AE, CRF07_ BC and CRF08_ BC were 0.090±0.004, 0.088±0.004 and 0.078±0.002, respectively, and the difference was statistically significant ( F=118.33, P<0.001). The Ks/Ka values of gag of the three subtypes were 4.003±1.309, 4.141±0.860 and 4.514±1.215, respectively, and the difference was statistically significant ( F=1.35, P<0.001). The Ks/Ka values of p17 were 2.590±0.186, 2.831±0.496 and 2.936±0.475, respectively, and the difference was statistically significant ( F=1.59, P<0.001). The Ks/Ka values of p24 were 12.579±1.116, 10.185±0.494 and 8.522±0.595, respectively, and the difference was statistically significant ( F=1.61, P<0.001). The Ks/Ka values of p7 were 10.850±0.711, 9.717±0.932 and 8.522±0.026, respectively, and the difference was statistically significant ( F=4.24, P<0.001). The Ks/Ka values of p6 were 3.122±0.134, 3.040±1.498 and 4.841±0.353, respectively, and the difference was statistically significant ( F=10.68, P<0.001). Conclusions:CRF08_ BC is the main subtype in these four areas in Yunnan Province.The different clusters of CRF08_BC result in a different pattern of amino acid composition.The variation degree of different subtype gag gene is different in each section. Surveillance of HIV variant strains should be strengthened to control the epidemics of HIV.

Objective:To explore the relationship between drug resistance occurrence and the distribution pattern of polymorphic loci in individuals with human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS) treated with highly active anti-retroviral therapy (HAART).Methods:HAART-failed HIV/AIDS patients who successfully amplified the gene sequences of the pol region between June 2015 and December 2021 from 16 prefecture-level administrative regions in Yunnan Province were included.The resistant sequences were classified using the human immunodeficiency virus (HIV) basic local alignment search tool (BLAST) and validated through MEGA 6.0, and the obtained sequences were submitted to the Stanford University HIV Drug Resistance Database to identify drug resistance loci. The distribution of polymorphic loci was analyzed across patients exhibiting varying degrees of drug resistance, different treatment regimens and distinct HIV-1 subtypes.Changes of the frequencies of polymorphic loci in patients with different degrees of drug resistance were analyzed using trend chi-square test. Statistical comparisons and further paired comparisons were performed using chi-square test.Results:Gene sequences were amplified from 1 453 patients, and the resistance testing results showed 954 sensitive, 224 potentially or low resistant, 189 moderately resistant, and 86 highly resistant patients. The frequencies of mutations I15V, L19I, D60E in the HIV-1 protease region (PR region) and E36A, T39D, S48T mutations in the HIV-1 reverse transcriptase region (RT region) showed a decreasing trend as the degree of HIV-1 resistance escalated ( χ2trend=19.86, 9.16, 13.66, 37.64, 18.44 and 40.86, respectively, all P<0.01). Conversely, the mutations V77I in the PR region and K122E in the RT region showed an ascending trend ( χ2trend=12.19 and 10.03, respectively, both P<0.01). Distinct treatment groups, namely zidovudine (AZT)+ lamivudine (3TC)+ lopinavir/ritonavir (LPV/r), AZT+ 3TC+ efavirenz (EFV), AZT+ 3TC+ nevirapine (NVP), and tenofovir (TDF)+ 3TC+ EFV, were examined. Statistically significant differences in the frequencies of mutations E35D, M36I, and D60E in the PR region, as well as S48T, K122E, and R211K in the RT region, were observed among these treatment groups ( χ2=22.46, 9.32, 14.46, 26.85, 18.92 and 24.26, respectively, all P<0.05). In paired comparisons, AZT+ 3TC+ LPV/r group displayed higher frequencies of E35D, M36I, and D60E mutations, the AZT+ 3TC+ EFV group showed a higher frequency of S48T mutation, the AZT+ 3TC+ NVP group showed a higher frequency of K122E mutation, and the TDF+ 3TC+ EFV group exhibited a higher frequency of R211K mutation, all with statistically significant differences (all P<0.008). The differences in the frequencies of T12S, I15V, L19I, M36I, V77I, L89M in the PR region and E53D, I135V, S162C, R211K, K277R in the RT region among circulating recombinant form (CRF)08_BC, CRF07_BC and CRF01_AE subtype group were statistically significant ( χ2=693.60, 712.51, 798.11, 434.85, 386.91, 657.78, 932.58, 409.21, 344.39, 469.44 and 260.48, respectively, all P<0.001). In paired comparisons, the frequencies of T12S, I15V, L19I, E53D, I135V, S162C and R211K in CRF08_BC subtype, the frequencies of V77I and K277R in CRF07_BC subtype, and the frequencies of M36I and L89M in CRF01_AE subtype were higher than those in the other two groups, and the differences were all statistically significant (all P<0.017). Conclusions:The polymorphic loci resulting from HIV-1 HAART failure show different distribution patterns across various degrees of drug resistance, treatment regimens and HIV-1 subtypes.These loci demonstrate both specific and shared characteristics. It is necessary to enhance the surveillance of select polymorphic loci.

Objective To investigate the distribution patterns of mosquitoes and mosquito-borne viruses in Dehong prefecture,Yunnan province,China. Methods Mosquito samples were collected using the mosquito traps from five counties of Dehong prefecture on July,2007 and 2010. Mosquitoes were cell cultured for viral isolation,and positive isolates were identified using RT-PCR and sequence analysis. Results A total of 43 634 mosquitoes comprised of 29 species representing six genera were collected. Culex tritaeriorhynchus and Anopheles sinensis comprised 78.69% and 14.77% of the total. Six strains of viruses were isolated from the mosquito pools. RT-PCR and phylogenetic analysis revealed three strains from Cx. tritaeriorhynchus,identified as genotypeⅠJapanese encephalitis virus(JEV). One strain was identified from Cx. tritaeriorhynchus,as Getah virus (GETV). Two strains isolated from Cx. tritaeriorhynchus and Anopheles vagus were identified as Culex pipiens pallens Densovirus(CppDNV). Conclusion Cx. tritaeriorhynchus had been the major species of mosquitoes and mainly transmitting vector of mosquito-borne viruses in Dehong prefecture. GenotypeⅠJEV,GETV and CppDNV were the vectors causing transmission of mosquitoe-borne diseases in this area. Data from phylogenetic analysis showed that these newly discovered isolates seemed to have had close relationship with those viruses previously circulating in Yunnan and other provinces of China.