[Evaluation of PIMA analyzer detecting CD4 cell count of venous and capillary blood in HIV-infected individuals].

OBJECTIVE: This study is aimed at evaluating the utility of the portable CD4 analyzers (PIMA). METHODS: The paired finger prick blood (25 µl) and 5 ml venous blood samples were collected from 196 HIV infected patients, who came to Yunnan CDC voluntary counseling and testing (VCT) clinic for CD4 test services, from May to August, 2012. The absolute CD4 cell counts were measured by PIMA (using venous and finger-prick blood) and by Calibur (using venous blood) as the reference. The PIMA and Calibur CD4 results were compared using the Wilcoxon matched-pairs test, and the Spearman's rank correlation coefficients were estimated. The Bland-Altman plots were used to assess the consistency of the two methods. RESULTS: The median absolute CD4 counts of 196 venous blood samples obtained by PIMA and by Calibur were 268 (range:169-403) cells/µl and 302 (range:181-474) cells/µl respectively, which showed significant difference (Z = -7.31, P < 0.01). The median absolute CD4 counts measured by PIMA and by Calibur (using 188 finger-prick and venous blood samples respectively) were 271 (range: 165-450) cells/µl and 304 (range:188-476) cells/µl, which also showed significant difference (Z = -7.60, P < 0.01). The CD4 counts obtained by PIMA CD4 analyzer (using venous and finger-prick blood) showed strong positive correlation with the CD4 counts obtained by the reference method (using venous blood), and the r values were 0.94 and 0.92 respectively (P < 0.01) . The mean biases (limit of agreement) were -38.7 (-210.9-133.5)cells/µl and -45.4 (-221.8-131.0) cells/µl, respectively.Using 350 CD4 counts as the threshold for ART treatment initiation, the sensitivity and specificity of PIMA were 99.1% and 79.3% for venous blood samples, and 97.2%and 78.5% for finger-prick blood samples, respectively. CONCLUSION: The CD4 counts obtained by PIMA are lower than that obtained by Calibur, while the sensitivity is high.

[Early detection of HIV infection with Dried Blood Spot testing among infants in Yunnan province].

OBJECTIVE: To explore the application of Dried Blood Spot (DBS) testing for early detection of HIV infection among infants. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[The analysis of human immunodeficiency virus-1 subtypes in Yunnan province].

OBJECTIVE: To analyze the geographical distribution and risk factors of HIV-1 subtypes in Yunnan province. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Dominance of HIV-1 subtype CRF01_AE in sexually acquired cases leads to a new epidemic in Yunnan province of China.

BACKGROUND: Dating back to the first epidemic among injection drug users in 1989, the Yunnan province has had the highest number of human immunodeficiency virus type 1 (HIV-1) infections in China. However, the molecular epidemiology of HIV-1 in Yunnan has not been fully characterized. METHODS AND FINDINGS: Using immunoassays, we identified 103,015 accumulated cases of HIV-1 infections in Yunnan between 1989 and 2004. We studied 321 patients representing Yunnan's 16 prefectures from four risk groups, 11 ethnic populations, and ten occupations. We identified three major circulating subtypes: C/CRF07_BC/CRF08_BC (53%), CRF01_AE (40.5%), and B (6.5%) by analyzing the sequence of p17, which is part of the gag gene. For patients with known risk factors, 90.9% of injection drug users had C/CRF07_BC/CRF08_BC viruses, whereas 85.4% of CRF01_AE infections were acquired through sexual transmission. No distinct segregation of CRF01_AE viruses was found among the Dai ethnic group. Geographically, C/CRF07_BC/CRF08_BC was found throughout the province, while CRF01_AE was largely confined to the prefectures bordering Myanmar. Furthermore, C/CRF07_BC/CRF08_BC viruses were found to consist of a group of viruses, including C, CRF08_BC, CRF07_BC, and new BC recombinants, based on the characterization of their reverse transcriptase genes. CONCLUSIONS: This is the first report of a province-wide HIV-1 molecular epidemiological study in Yunnan. While C/CRF07_BC/CRF08_BC and CRF01_AE are codominant, the discovery of many sexually transmitted CRF01_AE cases is new and suggests that this subtype may lead to a new epidemic in the general Chinese population. We discuss implications of our results for understanding the evolution of the HIV-1 pandemic and for vaccine development.

HIV-1 genetic characteristics and transmitted drug resistance among men who have sex with men in Kunming, China.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Emerging variability in HIV-1 genetics among recently infected individuals in Yunnan, China.

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.

[A dynamic analysis on incidence and trend of HIV-1 epidemics among intravenous drug users, attendants at the STD clinics and pregnant women in Yunnan province, China].

OBJECTIVE: BED-CEIA assay was used in HIV/AIDS surveillance sentinel sites to identify recent HIV-1 infection, to estimate HIV-1 incidence and to understand the epidemic trends in Yunnan province. METHODS: Serum specimens were collected from IDUs in sentinel sites, attendants in STD clinics and pregnant women under a cross sectional study from 2000 to 2007. Specimens confirmed as HIV-1 positive were tested with BED-CEIA to find recent HIV-1 infection, then the annual HIV-1 incidence for each group was calculated and the trends of HIV-1 incidence observed. RESULTS: 144 780 serum specimens were collected and 4932 of them were confirmed as HIV-1 positive. 4678 positive specimens were tested with BED-CEIA and 723 ont of them were identified as recent infections. Specimens from the two years were combined for testing. The average HIV-1 prevalence among IDUs was 18.2% - 26.9% from 2000 to 2007 and the annual incidence were 14.65%, 6.21%, 4.06%, 2.23% respectively. The average HIV-1 prevalence among attendants in STD clinics was 1.6% - 3.2% and the annual incidence rates were 1.46%, 0.76%, 0.52%, 0.33% respectively. The average HIV-1 prevalence among pregnant women was 0.2% - 0.5% and the annual incidence rates were 0.16%, 0.11%, 0.10%, 0.09% respectively. CONCLUSION: HIV-1 incidence rates among IDUs, STDs and pregnant women showed a steady decrease.