Chronic pain is a common clinical disease,which brings great burden to the patients.However,the pathogenesis underlying of chronic pain is complicated,which is affected by many factors,such as physiology,psychology and society.Therefore,the treatment of chronic pain has been a problem in clinical practice.Considering its complexity,a single way of treatment usually could not reach satisfactory results,so combination therapy is often used to treat chronic pain at present.The combination therapy includes pharmacological treatment,psychological approaches,interventional treatment,self management and so on.The treatment plans are distinct for different types of chronic pain,even the individual patients with the same kind of pain.The emergence of interdisciplinary rehabilitation programs shed light upon the treatment of chronic pain recent years.This paper reviewed the research on chronic pain treatment,in order to provide theoretical basis for clinical practice.

Objective To investigate the enterovirus ( EV)-carrying status and the circulating se-rotypes in healthy children from inner and border areas of Yunnan Province in 2014 and 2015 and to analyze the genetic characteristics of echovirus 6 (ECHO6), ECHO25 and ECHO11 strains. Methods Stool sam-ples were collected from children less than 15 years old living in 6 to 7 counties of 3 inner prefectures/cities and 8 to 9 counties of border prefectures/cities. Altogether 921 samples were collected including 453 sam-ples in 2014 (213 samples in inner counties and 240 samples in border counties) and 468 samples in 2015 (195 samples in inner counties and 273 samples in border counties). Viruses were isolated from the stool samples and their serotypes were identified by gene sequencing. Results The numbers of EV strains isola-ted from the samples collected in inner counties and border counties in 2014 were 20 ( isolating rate:9.39%, 20/213) and 16 (isolating rate: 6. 67%, 16/240), respectively. The overall isolating rate for 2014 was 7. 95% (36/453). The predominant species was enterovirus B, accounting for 88. 89% of all iso-lated strains (32/36), followed by enterovirus A species (11. 11%, 4/36). No strains of enterovirus spe-cies C (including poliovirus) and D was detected in 2014. In total, 46 EV strains were isolated in 2015 with an overall isolating rate of 9. 83% (46/468), including 13 strains in inner counties (isolating rate:6. 67%, 13/195) and 33 strains in border counties (isolating rate:12. 09%, 33/273). Most of the strains were enterovirus B species, accounting for 78. 26% (36/46), followed by enterovirus C species (19. 57%, 9/46) and enterovirus A species (2. 17%, 1/46). Altogether 82 EV strains were isolated in 2014 and 2015 with an isolating rate of 8. 90% (82/921), of which 33 strains were isolated in inner counties (8. 09%, 33/408) and 49 strains were isolated in border counties (9. 55%, 49/513). Among the 82 EV strains, 9 strains were polioviruses (0. 98%, 9/921) and all of them were Sabin-like polioviruses. The rest of the strains were non-polio enterovirus (7. 93%, 73/921). Conclusion In 2014, the EV isolating rate in inner counties (9. 39%) was higher than that in border counties (6. 67%). However, the EV isolating rate in border counties (12. 09%) was higher than that in inner counties (6. 67%) in 2015. Enterovirus B was the predominant species in both 2014 and 2015. No wild type polioviruses and enterovirus D species were detec-ted. Polio-free status was maintained well in Yunnan Province.

Objective To investigate the virus-carrying rate of non-polio enteroviruses ( NPEV) in patients with acute flaccid paralysis ( AFP) in Yunnan province of China in 2015 and to analyze the genetic characteristics of enterovirus 71 (EV71) strains. Methods A total of 213 cases under 15 years old with AFP were reported by Center for Disease Control and Prevention ( CDC) of Yunnan Province of China. Virus isolation was conducted for all samples and the serotypes of isolated NPEV strains were identified by VP1 se-quencing. The isolation rates of NPEV in the past consecutive 5 years were analyzed by SPSS22. 0 software. Phylogenetic trees of NPEV and EV71 strains were constructed by MEGA6. 06 software based on neighbor-joining algorithm and Kimura 2-parameter substitution model and the reliability of the phylogenetic trees was determined by bootstrap analysis with 100 pseudo replicate datasets. Results Altogether, 23 NPEV strains were isolated from 213 AFP cases. Among the 23 strains, 7 strains belonged to EV-A group (2 serotypes, 6 strains of which were EV71 ) , 14 strains belonged to EV-B group ( 8 serotypes ) and the other 2 strains belonged to EV-C group. No NPEV strains of EV-D group were identified. Statistical analysis showed that no significant differences in the isolation rates were observed in the past 5 years ( P=0. 101 ) . Conclusion The isolation rate of NPEV in patients with AFP in Yunnan province in 2015 was similar to that of the previ-ous years. The EV71 strains of C4 subgenotype were the predominant strains circulating in Yunnan province.

ObjectiveTo study echovirus 11 ( ECHO11 ) sequences genetic variability of the VP1 gene of 82 isolates from 15 countries and 2 provinces in China.MethodsThe VP1 sequences of 82 strains of echovirus 11 were downloaded from the GenBank,and their nucleotide and amino acid diversity were calculated and phylogenetic tree was constructed using Mega software.Results82 echovirus 11 strains were divided into 4 genotypes( A-D),Genotype A is further divided into 7 subgenotyps and genotype D into 7 subgenotyps.The prototype strain Gregory is the sole member of genotype B.Genotype C is divided into 3 genotypes.The sequence diversity between echovirus 11 strains is 21.7%-24.1% (AA diversity:6.0%-12.1% ).ConclusionOur results show that most genotypes contain isolates that have circulated over a wide geographical(several countries from different continents) and temporal range.Several genotypes were also shown to co-circulate in a region during the same period of time,showing that the epidemic of echovirus 11 has typical time and geographical characters.

Objective: In this study we analyzed the genetic characteristics of echovirus 30 (E-30) VP1 gene sequences from Yunnan province isolated from viral meningitis (VM) cases in 2010-2013. Methods: RT-PCR and VP1 gene sequencing were done for 9 E-30 strains isolated from VM cases in 2010-2013. VP1 gene sequences of E-30 reference strains were downloaded from the GenBank and their nucleotide (nt) and amino acid (aa) diversities were calculated by MEGA 5.1 software, the phylogenetic tree was constructed and the genetic characteristics and molecular epidemiology were analyzed. Results: In 2010-2013, 9 strains of E-30 viruses were detected from 79 VM cases caused by echoviruses, accounting for 11.39%(9/79), the overall positive rate was 1.63%(9/553). Phylogenetic analysis revealed that E-30 strains can be divided into four genotypes (genotype A, B, C and D), and genotype D can be further divided into seven sub-genotypes. Nine Yunnan VM isolates were distributed in D7 sub-genotype, and can be further clustered into 3 branches: 5 strains isolated in 2010 were clustered in branch 1, it is evident that these viruses were responsible for an aseptic meningitis outbreak in Kunming in that year; one 2011 isolate, together with 2013 isolate and one isolate from healthy children in 2010 were clustered in branch 2, these two branches were Yunnan special branches, and two 2011 isolates had the highest homology with 2003 VM outbreaks′ strains isolated from Shandong, Jiangsu, and Zhejiang, showing that these strains may have the same evolutionary sources. Conclusions Nine Yunnan VM isolates were distributed in D7 sub-genotype, and these strains have different evolutionary sources, showing that at different times E-30 viruses in the same sub-genotypes branch might prevail in different areas.

Objective: To detect the enterovirus VP4 and VP1 genes in 510 stool samples collected from hand, foot and mouth disease (HFMD) cases and analyze the phylogenetic characteristics of the entire VP1 genes of coxsackievirus A6 (CV-A6) strains in six prefectures/cities of Yunnan Province in 2018. Methods: Viral RNA was abstracted from the stool samples. VP4 gene sequences were amplified by RT-PCR and sequenced using the MD91/OL68-1 primer pair to identify viral genotypes. Whole VP1 gene sequences were amplified and sequenced using appropriate primer pairs. The whole VP1 gene sequences of CV-A6 reference strains were downloaded from GenBank. MEGA5.2 software was used to analyze the similarity in nucleotide and amino acid sequences between different strains and phylogenetic tree was constructed for analysis of genetic characteristics and molecular epidemiology. Results: VP4 and VP1 gene sequences were obtained from 57 out of 510 stool samples with a positive rate of 11.17% (57/510). There were 43 CV-A6 (8.43%, 43/510), six CV-A10 (1.17%, 6/510), two enterovirus A71 (EV-A71, 0.39%, 2/510) and two CV-A9 (0.39%, 2/510) strains. The other four strains were CV-A4 (0.19%, 1/510), CV-A5 (0.19%, 1/510), CV-B1 (0.19%, 1/510) and E11 (0.19%, 1/510). The phylogenetic analysis showed that all 43 CV-A6 strains belonged to sub-genotype D3. Conclusions In the 510 HFMD samples, CV-A6 strains were mostly detected with a detection rate of 8.43% and accounted for 75.44% (43/57) of all isolates, followed by CV-A10 (1.17%, 6/510) and EV-A71 (0.39%, 2/510). There was a large HFMD outbreak mainly caused by CV-A6 in Yunnan Province in 2018. The outbreak was caused by CV-A6 of sub-genotype D3, as was the case with pervious outbreaks in China.

Objective:To do genetic analysis on the VP1 gene of 2 Coxsackievirus A12 (CV-A12) isolated from hand, foot and mouth disease (HFMD) surveillance in Yunnan province.Methods:Coxsackievirus isolation was carried out in RD cells from the clinical samples. CV-A12 strains were identified by realtime RT-PCR and sequencing technology from the positive cultures. The VP1 region of the CV-A12 strain was further sequenced. The VP1 gene sequences were initially aligned and then used to construct the phylogenetic tree with GenBank reference strains.Results:The two CV-A12 strains had the highest homology with the Yunnan reference strains in 2018 and the amino acids in VP1 region had specific mutations with other cluster reference strains at multiple sites.Conclusions:The CV-A12 in the HFMD cases in Yunnan province has occured regional specific mutation in VP1 gene.

Objective:To analyze the etiology of hand, foot and mouth disease (HFMD) cases collected from Wenshan prefecture from 2014 to 2018 and the molecular epidemiology of coxsackievirus A6(CV-A6).Methods:Viruses were isolated by RD cells and Hep-2 cells from stool samples collected from HFMD patients in Wenshan prefecture from 2014 to 2018. Virus RNA was extracted and virus VP4/VP2 junction region sequence was firstly amplified and sequenced by MD91 and OL68-1 primer pairs, then the virus serotype was determined. Virus entire VP1 gene sequences were determined by relative primer pairs according to the references. The reference sequences of CV-A6 virus entire VP1 gene were downloaded from the GenBank and the phylogenetic tree was constructed and the genetic characteristics and molecular epidemiology were analyzed.Results:During five years of study period, a total of 581 strains of enteroviruses (EVs) was isolated with an isolation rate of 20.40% (581/2 848). Among 581 strains, 74 strains were CV-A6, accounting for 12.74% (74/581); 124 were CV-A16, accounting for 21.34% (124/581); 374 were EV-A71, accounting for 64.37% (374/581); nine were other EVs, accounting for 1.55% (9/581). The entire VP1 sequences of 74 CV-A6 strains were filtered by constructing a phylogenetic tree and the completely same strains were excluded from analysis. We finally analyzed the phylogenetic characteristics of 22 strains isolated in this study with 52 reference strains. The results showed that all 22 Wenshan strains belonged to D3a sub-genotype, of which 21 strains belonged to cluster 1, and only one strain belonged to cluster 2.Conclusions:From 2014 to 2018, the outbreaks of HFMD in Wenshan prefecture were mainly caused by EV-A71, CV-A16 and CV-A6, accounting for 64.37%, 21.34% and 12.74% respectively. Phylogenetic analysis showed, similar to the situation in China, the sub-genotype D3a of CV-A6 was the predominant virus and the cluster 1 was the main sub-genotype in this outbreak.

Objective To analyze the genetic characteristics of VP1 3'region of human coxsack-ievirus B2 (CV-B2) strains isolated from Yunnan province. Methods RT-PCR and gene sequencing were performed to analyze the VP1 3'region of 15 CV-B2 strains isolated from acute flaccid paralysis ( AFP) cases during 2005 to 2006, healthy children in 2013 and hand, foot and mouth disease (HFMD) cases in 2014 in Yunnan province. CV-B2 VP1 gene reference sequences were downloaded from the Genbank. Nucleotide (nt) and amino acid (aa) diversities were calculated by MEGA5. 2 software and a phylogenetic tree was constructed. Genetic and molecular epidemiological characteristics of CV-B2 strains circulating in Yunnan province were analyzed. Results A total of 15 CV-B2 strains were isolated, which were one from 232 AFP cases in 2005, one from 240 AFP cases in 2006, 12 from 400 healthy children in 2013 and one from 500 HFMD cases in 2014. Phylogenetic analysis of the 15 CV-B2 strains in Yunnan province and those down-loaded from the GenBank showed that CV-B2 could be genetically divided into five genotypes. The prototype strain Ohio-1 and one strain (01-1) isolated in Taiwan in 1988 belonged to genotype 1. Strains isolated in France in 2006, 2007 and 2010 belonged to genotype 2. Strains isolated in Yunnan, Shandong, Henan, Fu-jian and Taiwan belonged to genotype 3. Strains isolated in Russia, Yunnan AFP cases in 2005 and 2006 and India belonged to genotype 4. Strains isolated in Taiwan, Shandong and New South Wales, Australia be-longed to genotype 5. Different genotypes distributed in different countries/areas with some confined within specific countries/areas. Conclusions The 12 strains isolated from healthy children and one from HFMD cases in Yunnan province belonged to genotype 3, while the two strains isolated from AFP cases belonged to genotype 4. Diversities in nt and aa sequences between the strains isolated from the healthy children and HFMD case were only 0. 76％ and 0. 03％, respectively, indicating that they might come from the same transmission source. However, the nt and aa diversities between the isolates of genotype 3 ( from healthy children and HFMD case) and genotype 4 (from AFP cases in 2005 and 2006) were 15. 11％-15. 22％ and 2. 76％-2. 72％, respectively. Correlation of CV-B2 with AFP and HFMD was worthy of further study.

Objective:To analyze the etiological characteristics of hand, foot and mouth disease (HFMD) cases and to investigate the genetic characteristics of VP1 region of coxsackievirus A6 (CVA6) and CVA16 strains in Wenshan prefecture of Yunnan Province in 2020.Methods:Virus RNA was extracted directly from stool samples of children with HFMD in Wenshan prefecture of Yunnan Province in 2020. Enterovirus (EV) VP4/VP2 junction region was amplified using MD91/OL68-1 primers and sequenced, and then the serotypes of EV isolates were preliminarily identified. Amplification and sequencing of the complete VP1 gene were performed. A phylogenetic tree was constructed by MEGA 5.2 software with the reference strains from GenBank. Genetic and molecular epidemiological characteristics of CVA6 and CVA16 were analyzed.Results:Thirty-two strains of EV and one strain of astrovirus MLB1 were detected in 317 specimens with an overall virus detection rate of 10.41% (33/317). Among the 32 EV strains, 31 (96.88%) were enterovirus species A (EVA) and one (3.12%) was EVB. EVC and EVD were not detected. CVA6 was the predominant EV, accounting for 62.50% (20/32), followed by CVA16 (18.75%, 6/32), CVA4 (9.37%, 3/32) and CVA10 (3.12%, 1/32). EVA71 was not detected. The phylogenetic analysis showed 20 CVA6 strains belonged to D3a sub-genotype and could be further divided into three clusters. Six CVA16 strains belonged to B1a sub-genotype, which was one of the predominant genotypes circulating in China, and could be divided into two clusters.Conclusions:The detection rate of pathogens causing HFMD in Wenshan prefecture in 2020 was 10.41% and the most common etiologic agents were CVA6 and CVA16. Based on the genetic analysis of the VP1 gene, the predominant genotype circulating in Wenshan prefecture in 2020 was CVA6 D3a sub-genotype, followed by CVA16 B1a sub-genotype. EVA71 was not detected.