Ling Chen

Yunnan Center for Disease Control and Prevention, Yün-nan, Yunnan, China

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Publications (5)6.47 Total impact

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    ABSTRACT: Yunnan has been severely affected by HIV/AIDS in China. Recently, the reported prevalence of HIV-1 among men who have sex with men (MSM) in Yunnan was high in China. To monitor dynamic HIV-1 epidemic among Yunnan MSM, HIV-1 genetic characteristics and transmitted drug resistance (TDR) were investigated. Blood samples from 131 newly HIV-1 diagnosed MSM were continuously collected at fixed sites from January 2010 to December 2012 in Kunming City, Yunnan Province. Partial gag, pol and env genes were sequenced. Phylogenetic, evolutionary and genotypic drug resistance analyses were performed. Multiple genotypes were identified among MSM in Kunming, including CRF01_AE (64.9%), CRF07_BC (25.2%), unique recombinant forms (URFs, 5.3%), subtype B (3.1%) and CRF08_BC (1.5%). CRF01_AE and CRF07_BC were the predominant strains. The mean of genetic distance within CRF01_AE were larger than that within CRF07_BC. The estimated introducing time of CRF01_AE in Yunnan MSM (1996.9) is earlier than that of CRF07_BC (2002.8). In this study, subtype B was first identified in Yunnan MSM. CRF08_BC seems to be the distinctive strain in Yunnan MSM, which was seldom found among MSM outside Yunnan. The proportion of URFs increased, which further contributed to genetic diversity among MSM. Strikingly, genetic relatedness was found among these strains with MSM isolates from multiple provinces, which suggested that a nationwide transmission network may exist. TDR-associated mutations were identified in 4.6% individuals. The multivariate analysis revealed that non-native MSM and divorced/widowed MSM were independently associated with a higher TDR rate. This work revealed diverse HIV-1 genetics, national transmission networks and a baseline level of TDR in MSM. These findings enhance our understanding of the distribution and evolution of HIV-1 in MSM, and are valuable for developing HIV prevention strategies for MSM.
    Preview · Article · Jan 2014 · PLoS ONE
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    ABSTRACT: To timely identify the HIV-1 infection in window-period and to estimate the HIV-1 incidence among people who came for voluntary counseling and testing (VCT)service as well as men who have sex with men(MSM), respectively. HIV antibody negative samples that were determined by screening tests between January and October 2012, were collected and tested with pooling HIV-1 RNA testing technique(2-staged pooling by 50 : 1, 10 : 1). Positive cases were followed-up for HIV antibody testing while HIV incidence was calculated under Ron Brookmeyer's method, among VCT and MSM populations. Among 1400 HIV antibody negative samples of VCT, two showed HIV-1 RNA positive during the antibody window period with the HIV-1 incidence as 1.87% per year(95% CI:1.23%-2.65%). Among 500 HIV antibody negative samples from MSM population, two showed HIV-1 RNA positive in the antibody window period, with HIV-1 incidence as 5.31% per year(95% CI:3.52%-7.45%). Pooling HIV-1 RNA testing seemed a powerful tool for HIV antibody testing in the window-period. Measures should be taken to strengthen the HIV diagnostic programs among MSM and other high risk groups, during the HIV antibody window-period. More frequent detection approach as pooling HIV-1 RNA testing might be a good choice.
    No preview · Article · Aug 2013 · Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi
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    ABSTRACT: Background Yunnan has the longest endured Human Immunodeficiency Virus-1 (HIV-1) epidemic in China, and the genetic diversity of HIV-1 constitutes an essential characteristic of molecular epidemiology in this region. To obtain a more comprehensive picture of the dynamic changes in Yunnan’s HIV-1 epidemic, a cross-sectional molecular epidemiological investigation was carried out among recently infected individuals. Methodology/Principal Findings We sequenced partial gag (HXB2∶781–1861) and env (HXB2∶7002–7541) genes from 308 plasma samples of recently infected patients. With phylogenetic analysis, 130 specimens generated interpretable genotyping data. We found that the circulating genotypes included: CRF08_BC (40.8%), unique recombinant forms (URFs, 27.7%), CRF01_AE (18.5%), CRF07_BC (9.2%), subtype B (2.3%) and C (1.5%). CRF08_BC was the most common genotype, and was predominant in both intravenous drug users (IDUs) and heterosexually transmitted populations. CRF08_BC and CRF07_BC still predominated in eastern Yunnan, but CRF08_BC showed increasing prevalence in western Yunnan. Strikingly, the URFs raised dramatically in most regions of Yunnan. Seven different types of URFs were detected from 12 prefectures, suggesting that complicated and frequent recombination is a salient feature of Yunnan’s HIV-1 epidemic. Among URFs, two BC clusters with distinctive recombination patterns might be potential new CRF_BCs. CRF01_AE was no longer confined to the prefectures bordering Myanmar, and had spread to the eastern part of Yunnan, especially the capital city of Kunming, with a large number of infections in the transient population. The ratios of the main genotypes showed no statistical differences between infected IDUs and heterosexually transmitted infections. Conclusions/Significance The changing patterns of the dominant HIV-1 genotypes in Yunnan indicate the complex evolving dynamic nature of the epidemic. Understanding new trends in molecular epidemiology of HIV-1 infection is critical for adjusting current prevention strategies and vaccine development in Yunnan.
    Full-text · Article · Mar 2013 · PLoS ONE
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    ABSTRACT: To explore the application of Dried Blood Spot (DBS) testing for early detection of HIV infection among infants. All of the infants aged between 6 weeks and 18 months and born by HIV positive mothers from 14 Maternity and Child Health Care Hospitals in Kunming, Dali, Dehong, Lincang of Yunnan province were investigated from 2010 to 2011. By using DBS and Roche HIV-1 DNA test techniques, 286 infants were tested for HIV early diagnosis and compared with HIV antibody results of 18 months infants. DBS from uninfected infants were taken periodically and screened of HIV antibody to find their time of antibody-disappearing. The information of treatment for pregnant women and feeding methods for infants was also investigated. A total of 286 infants were tested with HIV-1 DNA among which 148 infants were male and 138 infants female, and 8 infants were HIV-1 DNA positive and the infection rate was 2.8% (8/286) that was in accord with their antibodies results in 18 months old; the other 278 infants whose HIV-1 DNA was negative was also negative with their antibodies. By following up the antibody test of 143 HIV negative infants the cumulate rates of antibody-disappearing at the age of 6, 9, 12 and 18 months were 14.0% (20/143), 61.5% (88/143), 88.1% (126/143) and 100.0% (143/143), respectively. Among 286 HIV positive pregnant women, the group with anti-viral treatment had a lower rate of HIV infection with their infants that was 2.14% (6/280) while the group without anti-viral treatment had a high rate of HIV infection with their infants that was 33.33% (2/6). There was significantly different in the rates of two groups (P < 0.01). The HIV infection rate of infants fed with milk powder was 2.55% (7/274) and the rate was 8.33% (1/12) with breast milk. The HIV-1 DNA detection techniques with DBS sample was effective for the early diagnosis of HIV in infants from 6 weeks to 18 months.
    No preview · Article · May 2012 · Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine]
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    ABSTRACT: To analyze the geographical distribution and risk factors of HIV-1 subtypes in Yunnan province. Blood samples from 1319 HIV positives were collected in Yunnan Province from 2001 to 2006. The nested polymerase chain reaction was used to amplify the gag (p24)-protease fragments from RNA extracted from plasma or sera. The sequences were used for subtype determination by phylogenetic tree analysis. Among 1319 samples studied, the subtypes has been successfully obtained from 644 samples that were constituted of seven subtypes: CRF08_BC, CRF07_BC, CRF07/08_BC, CRF01_AE, C, B' and URFB/C. C/CRF07_BC/CRF08_BC were distributed in the whole province, but CRF01_AE were mainly distributed in the boarding areas with Myanmar such as Dehong, Baoshan, Xishuangbanna and Puer. Moreover, injecting drugs users accounted for 61.6% (270/438) among C/CRF07_BC/CRF08_BC infections, while only 8.5% (15/177) among CRF01_AE infections. Our data indicated that at least seven subtypes were identified in Yunnan province, the relationship between subtypes and transmission routes were analyzed, and the geographic difference of subtypes was also observed.
    No preview · Article · Jan 2009 · Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine]

Publication Stats

31 Citations
6.47 Total Impact Points

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  • 2013-2014
    • Yunnan Center for Disease Control and Prevention
      Yün-nan, Yunnan, China