Low prevalence of transmitted drug resistance among newly diagnosed HIV-1 patients in Latvia

Transmitted drug resistance (TDR) is a concern because it may reduce the efficacy of antiretroviral treatment. Plasma samples of 119 HIV-1-infected patients who were newly diagnosed at the Infectology Center of Latvia in 2005 and 2006 were analyzed by an in-house genotypic resistance assay to determine the prevalence of TDR in Latvia. TDR was identified using the WHO 2009 list of mutations for surveillance of TDR as implemented in the Stanford Calibrated Population Resistance tool. Neighbor-joining phylogenetic analyses were used to determine genetic subtype and investigate the relatedness of the sequences. Resistance testing was successful in 117 of 119 patients. The study population represented ～20% of all patients that were diagnosed in Latvia in 2005 and 2006 and was well distributed between gender, transmission routes, and areas of residence. Four patients showed evidence of TDR, which represents a prevalence of TDR of 3.4% (95% CI: 0.9-8.5%). All four patients displayed single, but different resistance mutations (M46I, F53L, M41L, and G190A). All patients, except one, were predicted to respond well to standard first-line therapy in Latvia. The prevalence of TDR in Latvia was low, which partly may be due to the low proportion of HIV-1 patients who receive antiretroviral therapy. The results indicate that routine resistance testing in Latvia currently should be focused on patients who display treatment failure, rather than treatment naive patients.     

Technologies for measuring HIV-1 drug resistance

Abstract

Drug resistance testing significantly improves response to antiretroviral treatment in HIV-1-infected patients, therefore it has recently been implemented into current guidelines for the management of antiretroviral therapy. Knowledge about technologies for measuring drug resistance is important for several reasons: (a) differences exist between different technologies and also between assays based on the same technology; (b) the results of resistance testing are strongly dependent on the reliability and precision of the technology used; and (c) technical aspects have to be considered for a clinically relevant interpretation of drug resistance. The spectrum of genotypic and phenotypic technologies as well as the technical quality is increasing, which shifts the emphasis to the interpretation of resistance profiles. The interpretation is based on the knowledge of drug resistance-associated mutations as well as correlations between genotype and phenotype and clinical response, which are incorporated into rules-based systems. Bioinformatic techiques are used to generate mathematical models for the prediction of drug resistance from genotype. Both approaches are converging toward the prediction of clinical response. Because therapy response is dependent on many additional variables, further efforts are required for the generation of a large clinical database. This will be the basis of a prediction system that will optimize the antiretroviral therapy for each individual patient.     

Evolution of transmitted HIV-1 drug resistance in HIV-1-infected patients in Italy from 2000 to 2010

Prevalence and predictors of transmitted drug resistance (TDR), defined as the presence of at least one WHO surveillance drug resistance mutation (SDRM), were investigated in antiretroviralna?ve HIV-1-infected patients, with a genotypic resistance test (GRT) performed ≤6 months before starting cART between 2000 and 2010. 3163 HIV-1 sequences were selected (69% subtype B). Overall, the prevalence of TDR was 12% (13.2% subtype B, 9% non-B). TDR significantly declined overall and for the single drug classes. Older age independently predicted increased odds of TDR, whereas a more recent GRT, a higher HIV-RNA and C vs. B subtype predicted lower odds of TDR.     

北京市2016年新确证未治疗HIV感染者传播性耐药突变研究

目的 分析北京市2016年新确证HIV感染者HIV病毒pol基因传播性耐药突变特征.方法 利用一步法逆转录PCR和巢式PCR扩增感染者体内HIV病毒的pol基因,并对扩增产物进行测序.对得到的序列信息进行分析,分别获得病毒的亚型分布、耐药突变类型和构成.结果 2016年北京市新确证HIV感染者传播性耐药突变比例为4.2％.712名感染者中,CRF01_AE亚型为主要流行亚型,占49.3％,CRF07_BC亚型占28.8％,B亚型占10.3％.结论 与往年的研究相比,北京市未治疗的HIV感染者耐药率有所下降,总体上属于低水平的HIV耐药流行.     

Molecular epidemiology of HIV-1 subtypes and drug resistant strains in Taiwan

The Taiwanese government has provided free highly active antiretroviral therapy since April 1997. Previously, we have reported on the molecular epidemiology of HIV‐1 in Taiwan from 1988 to 1998. In addition, an outbreak of circulating recombinant form (CRF) 07_BC among intravenous drug users was noted in 2004. Therefore, the purposes of this study were to elucidate the distribution of HIV‐1 subtypes among different high‐risk groups in Taiwan from 1999 to 2000 and to conduct surveillance on drug resistance among treatment naïve patients from 1997 to 2000. Blood samples from 239 HIV‐1/AIDS patients and their subtypes were examined using DNA sequencing and phylogenetic analysis. The results showed that among 226 male patients, 213 (94.2%) had subtype B, 11 (4.9%) had CRF01_AE, 1 had unique recombinant strain related to both CRF07_BC and CRF08_BC (strain T12‐99TW) and 1 had CRF08_BC (strain L9312‐00TW). The patients infected with T12‐99TW and L9312‐00TW were intravenous drug users and had needle‐sharing experiences in Yunnan Province, China. Of the 13 HIV‐1‐infected females, 7 (53.8%) had subtype B, 5 (38.5%) had CRF01_AE, and 1 (7.7%) had subtype C. Phylogenetic analysis demonstrated that the neither strain T12‐99TW nor L9312‐00TW clustered with CRF07_BC strains isolated from Taiwanese intravenous drug users in 2004. In addition, 126 treatment naïve patients were selected for genotypic DR analysis and the results showed that 4.3% (2/47) homosexual males had M184V mutations. This is the first report on the identification of CRF08_BC and a unique recombinant strain related to both CRF07_BC and CRF08_BC in Taiwan. J. Med. Virol. 80:183–191, 2008. © 2007 Wiley‐Liss, Inc.     

人类基因组中与HIV-1感染相关的基因多态性及其意义

为探讨ＣＣＲ５、ＣＣＲ２和ＳＤＦ１等位基因的突变和多态性特点,评估不同人群对ＨＩＶ－１感染的遗传易感性,作者收集近年来国际上报道的人类免疫缺陷病毒（ｈｕｍａｎ ｉｍｍｕｎｏｄｅｆｉｃｉｅｎｃｙ ｖｉｒｕｓ－１,ＨＩＶ－１）感染基因相关文献资料,其中包括作者检测的中国人基因组的ＣＣＲ５、ＣＣＲ２和ＳＤＦ１基因多态性的检测结果。通过对比分析,结果显示世界上不同人群的ＨＩＶ－１相关基因的突变和我态性有一     

A study of the genetic variability of human respiratory syncytial virus in Croatia, 2006–2008

Human respiratory syncytial virus (HRSV) is a common etiological agent of acute lower respiratory tract disease in infants. The molecular epidemiology of HRSV in Croatia over four consecutive seasons (from 2006 to 2008) was investigated. A total of 72 HRSV samples were chosen from 696 screened cases in a pediatric clinic in Zagreb. Molecular characterization of HRSV revealed the predominance of HRSV group B viruses in the first two epidemic seasons and HRSV group A viruses in the next two seasons. According to the phylogenetic analysis, NA1 and BA9 were the predominant circulating HRSV genotypes detected during the study. Overall, 82.9% of all HRSV A strains belonged to the NA1 genotype. The HRSV B genotype BA9, detected in two consecutive seasons (2006 and 2007), was the predominant circulating HRSV B genotype, accounting for 80.6% of all HRSV B strains. This study provides data on the circulation pattern of HRSV genotypes in Croatia and their molecular characterization. J. Med. Virol. 84:1985–1992, 2012. © 2012 Wiley Periodicals, Inc.