Binghui Wang

Phylogenetic analysis of dengue virus reveals the high relatedness between imported and local strains during the 2013 dengue outbreak in Yunnan, China: a retrospective analysis

BackgroundAn outbreak of dengue virus (DENV) occurred in Yunnan province. More than 2,000 individuals were infected from August to November 2013. In this study, we aimed to characterize the origin and prevalence of DENV in Dehong prefecture of Yunnan province using phylogenetic and evolutionary analyses of DENV strains collected from local patients and foreign travelers.MethodsA total of 41 DENV-positive serum samples were randomly collected from travelers who entered China at Ruili port or local patients with dengue fever in Dehong prefecture of Yunnan province, China. The envelope (E) gene of DENV was amplified and sequenced. The distributions and evolutionary characteristics of different genotypes were elucidated by phylogenetic and Bayesian analyses.ResultsPhylogenetically, all of the 41 DENV-positive samples could be classified into genotype I (43.9%) of serotype DENV-1 and the Asian I genotype (56.1%) of serotype DENV-2. DENV strains derived from local patients and foreign travelers were scattered equally within these two clusters. Furthermore, the DENV strains from the two populations exhibited high relatedness based on evolutionary characteristics.ConclusionsThese results suggested that imported and local DENV strains occurring during the dengue outbreak in 2013 were highly related. Additionally, these data may suggest that this dengue outbreak was caused by a newly imported infection from the neighboring country of Myanmar.

HIV‐1 prevalence and subtype/recombinant distribution among travelers entering China from Vietnam at the HeKou port in the Yunnan province, China, between 2003 and 2012

The aim of this study was to assess HIV‐1 prevalence and the distribution of HIV‐1 subtypes among travelers crossing the border at the HeKou land port. Between 2003 and 2012, 22,799 persons were randomly recruited from people entering China from Vietnam. In this crossing border population, a total of 161 (0.71%) travelers were determined as HIV‐1‐positive. From them, 140 HIV‐1‐positive serum samples were collected for RNA extraction and subsequent RT‐nested PCR amplification of the group‐specific antigen (gag)‐RT with a length of 2.6 kb. The DNA sequences were analyzed to determine the HIV‐1 subtypes/recombinants. We found that the circulating recombinant form 01_AE (CRF01_AE) was the most common HIV‐1 subtype, accounting for 49.4% (41/83) of the subtyped 83 samples, followed by CRF08_BC (26.5%, 22/83) and CRF07_BC (7.2%, 6/83). Only 1 sample was classified as subtype C. Thirteen cases could not be clustered into any known subtypes or CRFs and presented as unique recombinant forms (URFs). Of them, 6 recombination patterns were identified. They had distinct structures consisting of fragments of subtypes B, C, CRF01_AE, CRF07_BC and CRF08_BC. Between 2003 and 2012, CRF01_AE and CRE08_BC were shown to be the most prevalent recombinant forms identified each year. But yearly change of each subtype is uncertain regular among in these travelers during the past decade. Understanding the distribution of HIV‐1 subtypes/recombinants and how it changes across time among individuals entering China from Vietnam through this land port is crucial to establish strategies for the prevention of HIV cross‐border transmission. J. Med. Virol. 87:1500–1509, 2015.

The distinct distribution and phylogenetic characteristics of dengue virus serotypes/genotypes during the 2013 outbreak in Yunnan, China: Phylogenetic characteristics of 2013 dengue outbreak in Yunnan, China.

Since 2000, sporadic imported cases of dengue fever were documented almost every year in Yunnan Province, China. Unexpectedly, a large-scale outbreak of dengue virus (DENV) infection occurred from August to December 2013, with 1538 documented cases. In the current study, 81 dengue-positive patient samples were collected from Xishuangbanna, the southernmost prefecture of the Yunnan province, and 23 from Dehong, the westernmost prefecture of the Yunnan province. The full-length envelope genes were amplified and sequenced. Phylogenetic analysis revealed that nine strains (39.1%) and 14 strains (60.9%) from the Dehong prefecture were classified as genotype I of DENV-1 and Asian I genotype of DENV-2, respectively. All strains from Xishuangbanna were identified as genotype II of DENV-3. Bayesian coalescent analysis indicates that the outbreak originated from bordering southeastern Asian countries. These three epidemic genotypes were predicted to originate in Thailand and then migrate into Yunnan through different routes.

Ethnic and geographic variations in HPV prevalence and genotype distribution in north-western Yunnan, China.

The prevalence and genotype distribution of human papillomavirus (HPV) vary throughout the world. To assess the prevalence and genotype distribution of HPV among three ethnic groups in two geographic locations in north‐western Yunnan, we recruited 522 women in Shangri‐le (n = 255) and Lijiang (n = 267). PCR amplification of HPV DNA was performed on cervical cells from these women using two consensus primer systems (MY09/11 and GP5/6). Amplified‐HPV DNA was genotyped using the HPV GenoArray test. Geographically, the HPV prevalence was significantly higher (P = 0.002) among Shangri‐le women than among Lijiang women. Infections with high‐risk (HR)‐HPV and with multiple HPV genotypes were also significantly more common (P = 0.001) among women in Shangri‐le than women in Lijiang. Additionally, the prevalence of overall, HR‐HPV, and single genotype HPV infections was significantly higher (P = 0.001) among Tibetan women than among Naxi and Han women. HPV‐16 and HPV‐33 were significantly more frequent in Shangri‐le women compared with Lijiang (P = 0.006) women. In addition, HPV‐16 (9.81%) and HPV‐33 (5.88%) were significantly more prevalent in Tibetan women than in Naxi and Han women. Here, for the first time, we highlight the significant variation in the prevalence and genotype distribution of HPV in various populations in the north‐western region of Yunnan Province. J. Med. Virol. 88:532–540, 2016.

Prevalence of human immunodeficiency virus 1 infection in the last decade among entry travelers in Yunnan Province, China.

BackgroundYunnan is not only considered the region with the most concerning human immunodeficiency virus (HIV)-1 prevalence, but is also the central hub for the spread of HIV-1 from Southeast Asia to the other provinces of China. Yunnan has the highest proportion of entry travelers who have transmitted HIV from neighbored Southeast Asian countries to mainland of China.MethodsBetween 2003 and 2012, we recruited 280,961 entry travelers at land ports located in 7 bordering prefectures respectively in the Yunnan Province for HIV-1 screening. Based on the detection of HIV-1 antibody, the HIV-1 infection rate was determined.ResultsAmong the recruited entry travelers, 2380 were determined HIV-1 positive with infection rate of 0.85%. Travelers entering the Dehong port had the highest HIV-1 infection rate (5.12%), followed by those entering Baoshan (0.88%), Lincang (0.83%), and Honghe (0.71%). For all HIV-1 positive cases, travelers aged 21–30 and 31–40 were the most commonly infected individuals, accounting for 38.45% and 37.77% of all cases, respectively. The most common occupation of the infected population was driver (42.38%), and the proportion of industrials had increased yearly. Based on the reported risk factors, sexual transmission was the main HIV-1 infection route (77.11%) of this population.ConclusionsWe have clarified the rate of HIV-1 infection among this bridge population. The characteristics of HIV-1 positive population and high geographical heterogeneity have provided the necessary epidemiological data for monitoring the HIV-1 epidemic among cross-border travelers in Yunnan and to further understand the cross-border spreading of the HIV-1 infection.

Genetic polymorphisms of the IFNλ genes are associated with biochemical features in Han Chinese with HCV infection from Yunnan Province, China

Hepatitis C virus (HCV) is the pathogenic factor for hepatitis C disease, which could lead to chronic or serious hepatic diseases. Previous studies have identified that the IL28B gene polymorphisms were associated with therapeutic effect and viral clearness of HCV patients. We aimed to test whether genetic polymorphisms of three IFNλ genes (IL28A, IL28B and IL29) are associated with HCV infection in Han Chinese. We collected whole blood of 261 HCV infectious patients without any therapy and 265 matched normal controls from Yunnan Province. Among these subjects, 28.4% (74/261) of HCV patients and 26.8% (71/265) of controls were male. Ten SNPs (rs8099917, rs10853728, rs11883177, rs12980602, rs4803224, rs11671087, rs11665818, rs8108008, rs7248931, and rs30461), which covered the whole region of the IL28A, IL28B, and IL29 genes, were genotyped. Our results showed that there was no association between genotypes and alleles of the IFNλ gene polymorphisms and HCV infection. One haplotype (TGCTGTGGAT), which was consisted of ten SNPs, showed a significantly higher frequency in HCV patients (11/522 = 2.1%) than in controls (1/530 = 0.2%) (P = 0.003). We performed association analyses for biochemical features and genotype of each SNP, and found that HCV patients with certain genotypes of some SNPs had a higher level of the ALT/AST ratio and total blood bilirubin (TBIL) compared to healthy controls. Our results suggested the IFNλ gene polymorphisms might be associated with clinical features of HCV patients from Yunnan Province, China.

Status of Human Papillomavirus Infection in the Ethnic Population in Yunnan Province, China

HPV genotypes have distinct distributions among various ethnic populations worldwide. In December 2013, 237 and 159 cervical samples were collected from Hani and Han ethnic women, respectively, in Mojiang, a rural county in southern Yunnan. The overall HPV infection rate (21.1%) among the Hani women was significantly higher than that among the Han women (12.6%). The high-risk (HR) and low-risk (LR) HPV and single- and multiple-genotype infection rates among the Hani women were 11.0%, 4.6%, 15.6%, and 5.5%, respectively. HPV-16 (3.8%) was the most prevalent genotype among the Hani women, followed by HPV-52 (1.7%), HPV-31 (0.8%), and HPV-33 (0.8%). Comparatively, the Han women had lower infection rates of high-risk (8.2%), low-risk (1.2%), single-genotype (9.4%), and multiple-genotype HPV infections (3.1%). HPV-16 (3.1%) was also the predominant genotype among the Han women, followed by HPV-52 (1.3%), HPV-33 (0.6%), HPV-44 (0.6%), and HPV-54 (0.6%). The area background, number of children, and past history of STIs were recognized as potential risk factors for HPV infection. Rural background, age, education level, number of children, and illness history were significantly associated with HPV infection among the Hani women. These findings highlight the urgent need for HPV prevention and control strategies in Yunnan, particularly for the Hani ethnic women.

Distribution and diversity of hepatitis B virus genotypes in Yunnan, China

Hepatitis B virus (HBV) is one of the most prevalent pathogens in the world, and infection with this virus is a serious threat for public health. Yunnan is considered as an important endemic center for blood‐borne viruses such as human immunodeficiency virus and hepatitis C virus, in China. However, the distribution and diversity of HBV subgenotypes remain unclear in Yunnan province. In the current study, HBV positive samples were collected from different prefectures of Yunnan province and their molecular epidemiological characters were determined. Phylogenetic analysis on the pre‐S/S gene (865 bps) showed the prevalence of four HBV genotypes, including genotype B (24 cases, 33.3%), genotype C (45 cases, 62.5%), genotype I (two cases, 2.78%) and C/D recombinants (one case, 1.39%). The most prevalent genotypes B and C could be sub classified into subgenotype B2 and C1, C2, C5, and C7, respectively. Clusters of subgenotype B2 and C2 consisted of strains from China and other East Asian countries, while subgenotype C1, C5, and C7 and genotype I formed a cluster together with strains from Southeast Asia. Using Bayesian inference from phylogenetic, HBV genotypes B and C were estimated to have originated in 1860s and 1910s with an evolutionary rate of 3.26 and 8.01 × 10−4 substitutions/site/year, respectively. These findings indicate that the distribution of HBV genotypes in Yunnan was influenced by strains from the rest of China and the neighboring countries. J. Med. Virol. 86: 1675–1682, 2014.

HIV prevalence and phylogenetic characteristics among entry travelers in Xishuangbanna prefecture, Yunnan province, between 2003 and 2012.

Xishuangbanna is a popular tourist destination in southern Yunnan Province, bordering with Vietnam and Laos, and Myanmar. There are more than 2 million cross‐border travelers annually entering China at two land ports, Daluo and Mohan. To clarify the characteristics of HIV‐1 prevalence among entry travelers, a retrospective epidemic investigation was conducted. Between 2003 and 2012, 196 among 91 432 entry travelers were detected to be HIV‐1‐positive, accounting for infection rate of 0.21%. Eighty‐one gag‐pol gene sequences were obtained for phylogenetic analyses and subsequent recombination analysis. It was shown that the most prevalent HIV‐1 subtype in this population was circulating recombinant form (CRF) 01_AE (42, 51.86%), followed by CRF08_BC (17, 20.99%), CRF07_BC (4, 4.94%), B’ (2, 2.47%), C (2, 2.47%), other recombinants (9, 11.11%), and undefined subtype (5, 6.17%). HIV‐1 genotype distribution among travelers entering at two land ports is different, CRF01_AE and CRF08_BC accounted for a larger percentage among individuals from Daluo, whereas the proportions of subtype C and undefined URFs were larger among individuals from Mohan. The undefined subtype indicates the occurrence of novel HIV‐1 subtype or CRF. This finding is useful for developing of AIDS prevention strategies.

Prevalence of genital human papillomavirus among rural and urban populations in southern Yunnan province, China

This study was designed to investigate and compare the HPV prevalence, genotypes distribution and associated risk factors in rural and urban women living in Xishuang Banna district, in the province of Yunnan. A total of 177 and 190 women from rural and urban areas were engaged, respectively. HPV DNA was amplified using the L1 consensus primers system (MY09/11 and GP5/6) and HPV GenoArray test was conducted for genotyping. Proportions were compared by chi-square test, and logistic regression was used to evaluate risk factors. A total of 54 women were positive for HPV DNA. Among rural women, 23 women were positive for HPV infection, of which 21 showed a single infection and 2 had a multiple infection. HPV-16 (10/23) was the most prevalent genotype followed by HPV-52 (5/23), and HPV-58 (5/23). Urban women had a higher infection rate for overall HPV (31/54) and for multiple genotype infection (8/31). HPV-52 (9/31) was the most prevalent genotype followed by HPV-39 (7/31) and HPV-68 (5/31). The age-specific HPV prevalence was also different between rural and urban women. In urban area, women with age <35 years had the highest HPV prevalence, which declined thereafter as age advanced. However, in rural women the highest HPV prevalence was observed in an older age group (>56 years). Ethnicity, smoking and parity were significantly associated with HPV infection among urban women. Our study demonstrates that HPV prevalence and genotype distribution varies among women from rural and urban areas in the south of Yunnan.