Prevalence and evolution of drug resistance HIV-1 variants in Henan, China

To understand the prevalence and evolution of drug resistant HIV strains in Henan China after the implementation of free antiretroviral therapy for AIDS patients. 45 drug na?ve AIDS patients, 118 AIDS patients who received three months antiretroviral therapy and 124 AIDS patients who received six months antiretroviral treatment were recruited in the southern part of Henan province. Information on general condition, antiretroviral medicines, adherence and clinical syndromes were collected by face to face interview. Meanwhile, 14 ml EDTA anticoagulant blood was drawn. CD4/CD8 T cell count, viral load and genotypic drug resistance were tested. The rates of clinical improvement were 55.1% and 50.8% respectively three months and six months after antiretroviral therapy. The mean CD4 cell count after antiretroviral therapy was significantly higher than in drug na?ve patients. The prevalence rate of drug resistant HIV strains were 13.9%, 45.4% and 62.7% in drug na?ve patients, three month treatment patients and six month treatment patients, respectively. The number of resistance mutation codons and the frequency of mutations increased significantly with continued antiretroviral therapy. The mutation sites were primarily at the 103, 106 and 215 codons in the three-month treatment group and they increased to 15 codon mutations in the six-month treatment group. From this result, the evolution of drug resistant strains was inferred to begin with the high level NNRTI resistant strain, and then develop low level resistant strains to NRTIs. The HIV strains with high level resistance to NVP and low level resistance to AZT and DDI were highly prevalent because of the AZT+DDI+NVP combination therapy. These HIV strains were also cross resistant to DLV, EFV, DDC and D4T. Poor adherence to therapy was believed to be the main reason for the emergence and prevalence of drug resistant HIV strains. The prevalence of drug resistant HIV strains was increased with the continuation of antiretroviral therapy in the southern part of Henan province. Measures, that could promote high level adherence, provide new drugs and change ART regimens in failing patients, should be implemented as soon as possible.     

河南省部分地区人类免疫缺陷病毒1型耐药性发生和演变的队列研究

目的 了解河南省某地人类免疫缺陷病毒(HIV)耐药性毒株的进化演变规律.方法 将河南省南部某地74例接受齐多夫定(AZT)+去羟肌苷(ddI)+奈韦拉平(NVP)联合抗病毒治疗的艾滋病患者纳入研究队列,分别在抗病毒治疗后3、6、12、18个月进行随访调查,通过逐一访谈了解一般情况、服药方案、服药依从性及保障措施、抗病毒治疗前后的临床表现等,同时采集14 ml EDTA抗凝静脉血,检测CD4/CD8细胞数、病毒载量及基因型耐药性.结果 核苷类反转录酶抑制剂中,发生频率最高的耐药突变位点是:67、118、151和215.治疗3、6、12、18个月时AZT耐药发生率分别为6.76%、13.51%、14.86%和9.46%,ddI的耐药发生率分别为2.70%、6.76%、8.11%和5.45%,AZT的耐药发生率高于ddI,核苷类反转录酶抑制剂的耐药性呈现出先上升后下降的趋势.非核苷类反转录酶抑制剂的耐药发生率高于核苷类反转录酶抑制剂,发生频率最高的耐药突变位点是:103和181.治疗3、6、12、18个月时,NVP耐药发生率分别为9.46%、18.92%、22.97%和32.43%.非核苷类反转录酶抑制剂呈现出持续上升的耐药发生趋势.耐药和不耐药患者的病毒载量和CD4+T淋巴细胞计数无显著性差异.服药依从性差可能是耐药发生的主要影响因素.结论 本组患者中已出现对非核苷类反转录酶抑制剂的高度耐药,服药依从性是耐药发生的主要影响因素.应加强服药的监督管理,改善患者的服药依从性.     

Study of HIV-1 Drug Resistance in Patients Receiving Free Antiretroviral Therapy in China

To investigate the prevalence of drug-resistance mutations,resistance to antiretroviral drugs,and the subsequent virological response to therapy in treatment-naive and antiretroviral-treated patients infected with HIV/AIDS in Henan,China,a total of 431 plasma samples were collected in Queshan county between 2003 and 2004,from patients undergoing the antiretroviral regimen Zidovudine Didanosine Nevirapine(Azt Ddi Nvp).Personal information was collected by face to face interview.Viral load and genotypic drug resistance were tested.Drug resistance mutation data were obtained by analyzing patient-derived sequences through the HIVdb Program(http://hivdb.stanford.edu).Overall,38.5% of treatment-naive patients had undetectable plasma viral load(VL),the rate significantly increased to 61.9% in 0 to 6 months treatment patients(mean 3 months)(P<0.005)but again significantly decrease to 38.6% in 6 to 12 months treatment patients(mean 9 months)(P<0.001)and 40.0% in patients receiving more than 12 months treatment(mean 16 months)(P<0.005).The prevalence of drug resistance in patients who had a detectable VL and available sequences were 7.0%,48.6%,70.8%,72.3% in treatment-na?ve,0 to 6 months treatment,6 to 12 months treatment,and treatment for greater than 12 months patients,respectively.No mutation associated with resistance to Protease inhibitor(PI)was detected in this study.Nucleoside RT inhibitor(NRTI)mutations always emerged after non-nucleoside RT inhibitor(NNRTI)mutations,and were only found in patients treated for more than 6 months,with a frequency less than 5%,with the exception of mutation T215Y(12.8%,6/47)which occurred in patients treated for more than 12 months.NNRTI mutations emerged quickly after therapy begun,and increased significantly in patients treated for more than 6 months(P<0.005),and the most frequent mutations were K103N,V106A,Y181C,G190A.There had been optimal viral suppression in patients undergoing treatment for less than 6 months in Queshan,Henan.The drug resistance strains were highly prevalent in antiretroviral-treated patients,and increased with the continuation of therapy,with many patients encountering virological failure after 6 months therapy.     

Treatment Effect and Drug-Resistant Mutations in Chinese AIDS Patients Switching to Second-Line Antiretroviral Therapy

This study aimed to investigate treatment effect, drug resistance changes, and their influencing factors in Chinese AIDS patients after switching to second-line antiretroviral therapy, and thus provide important information for the scale-up of second-line antiretroviral treatment in China. In Weishi county of Henan province, where second-line antiretroviral therapy was introduced early in China, 195 AIDS patients were enrolled, of which 127 patients met the switching criterion and 68 patients volunteered to switch drugs without meeting the switching criterion. CD4 cell count, viral load and in-house PCR genotyping for drug resistance were measured for all 195 subjects before drug switch, as well as 6 and 12 months after drug switch. Extensive secondary mutations to the protease inhibitor were observed, which suggested that long-term drug resistance surveillance is necessary for patients switching to second-line antiretroviral therapy. Multidrug resistance and cross-resistance were extensive in Chinese patients that experienced first-line treatment failure. Patients need timely CD4 count, viral load, and drug resistance monitoring in order to switch to second-line therapy under conditions of relatively good immunity and low viral duplication levels.     

Study of HIV-1 drug resistance in patients receiving free antiretroviral therapy in China

To investigate the prevalence of drug-resistance mutations, resistance to antiretroviral drugs, and the subsequent virological response to therapy in treatment-naive and antiretroviral-treated patients infected with HIV/AIDS in Henan, China, a total of 431 plasma samples were collected in Queshan county between 2003 and 2004, from patients undergoing the antiretroviral regimen Zidovudine + Didanosine + Nevirapine (Azt+Ddi+Nvp). Personal information was collected by face to face interview. Viral load and genotypic drug resistance were tested. Drug resistance mutation data were obtained by analyzing patient-derived sequences through the HIVdb Program (http://hivdb.stanford.edu). Overall, 38.5% of treatment-naive patients had undetectable plasma viral load (VL), the rate significantly increased to 61.9% in 0 to 6 months treatment patients (mean 3 months) (P<0.005) but again significantly decrease to 38.6% in 6 to 12 months treatment patients (mean 9 months) (P<0.001) and 40.0% in patients receiving more than 12 months treatment (mean 16 months) (P<0.005). The prevalence of drug resistance in patients who had a detectable VL and available sequences were 7.0%, 48.6%, 70.8%, 72.3% in treatment-naïve, 0 to 6 months treatment, 6 to 12 months treatment, and treatment for greater than 12 months patients, respectively. No mutation associated with resistance to Protease inhibitor (PI) was detected in this study. Nucleoside RT inhibitor (NRTI) mutations always emerged after non-nucleoside RT inhibitor (NNRTI) mutations, and were only found in patients treated for more than 6 months, with a frequency less than 5%, with the exception of mutation T215Y (12.8%, 6/47) which occurred in patients treated for more than 12 months. NNRTI mutations emerged quickly after therapy begun, and increased significantly in patients treated for more than 6 months (P<0.005), and the most frequent mutations were K103N, V106A, Y181C, G190A. There had been optimal viral suppression in patients undergoing treatment for less than 6 months in Queshan, Henan. The drug resistance strains were highly prevalent in antiretroviral-treated patients, and increased with the continuation of therapy, with many patients encountering virological failure after 6 months therapy.     

Screening for and Verification of Novel Mutations Associated with Drug Resistance in the HIV Type 1subtype B′ in China

Objective

Mutations associated with HIV drug resistance have been extensively characterized at the HIV-1 polymerase domain, but more studies have verified that mutations outside of the polymerase domain also results in resistance to antiviral drugs. In this study, mutations were identified in 354 patients experiencing antiretroviral therapy (ART) failure and in 97 naïve-therapy patients. Mutations whose impact on antiviral drugs was unknown were verified by phenotypic testing.

Methods

Pol sequences of HIV subtype B^′ obtained from patients experiencing ART failure and from naïve-therapy patients were analyzed for mutations distinct between two groups. Mutations that occurred at a significantly higher frequency in the ART failure than the naïve-therapy group were submitted to the Stanford HIV Drug Resistance Database (SHDB) to analyze the correlation between HIV mutations and drug resistance. For mutations whose impact on the antiviral drug response is unknown, the site-directed mutagenesis approach was applied to construct plasmids containing the screened mutations. 50% inhibitory concentration (IC₅₀) to AZT, EFV and NVP was measured to determine the response of the genetically constructed viruses to antiviral drugs.

Results

7 mutations at 6 positions of the RT region, D123E, V292I, K366R, T369A, T369V, A371V and I375V, occurred more frequently in the ART failure group than the naïve-therapy group. Phenotypic characterization of these HIV mutants revealed that constructed viruses with mutations A371V and T369V exhibited dual resistance to AZT and EFV respectively, whereas the other 5 mutations showed weak resistance. Although the impact of the other six mutations on response to NVP was minimal, mutation T369V could enhance resistance to NVP.

Conclusions

This study demonstrated that mutations at the RT C-terminal in subtype B′ could result in resistance to RT inhibitors if the mutations occurred alone, but that some mutations could promote susceptibility to antiviral drugs.     

Knowledge and adherence to antiretroviral therapy among adult people living with HIV/AIDS treated in the health care centers of the association "Espoir Vie Togo" in Togo,West Africa

Background  

The efficiency of antiretroviral therapy (ART) depends on a near perfect level of patients' adherence. The level of adherence of adults HIV-infected patients treated in the HIV/AIDS health care centres of the association "Espoir Vie Togo" in Togo, West Africa is not properly documented. The aim of the present study was to examine by means of self-reports the knowledge, the adherence level and associated factors to antiretroviral therapy (ART) among these patients.     

HIV behind Bars: Human Immunodeficiency Virus Cluster Analysis and Drug Resistance in a Reference Correctional Unit from Southern Brazil

People deprived of liberty in prisons are at higher risk of infection by the human immunodeficiency virus (HIV) due to their increased exposure through intravenous drug use, unprotected sexual activity, tattooing in prison and blood exposure in fights and rebellions. Yet, the contribution of intramural HIV transmission to the epidemic is scarcely known, especially in low- and middle-income settings. In this study, we surveyed 1,667 inmates incarcerated at Presídio Central de Porto Alegre, located in southern Brazil, for HIV infection and molecular characterization. The HIV seroprevalence was 6.6% (110/1,667). Further analyses were carried out on 40 HIV-seropositive inmates to assess HIV transmission clusters and drug resistance within the facility with the use of molecular and phylogenetic techniques. The molecular epidemiology of HIV-1 subtypes observed was similar to the one reported for the general population in southern Brazil, with the predominance of HIV-1 subtypes C, B, CRF31_BC and unique BC recombinants. In particular, the high rate (24%) of URF_BC found here may reflect multiple exposures of the population investigated to HIV infection. We failed to find HIV-infected inmates sharing transmission clusters with each other. Importantly, the analysis of HIV-1 pol genomic fragments evidenced high rates of HIV primary and secondary (acquired) drug resistance and an alarming proportion of virologic failure among patients under treatment, unveiling suboptimal access to antiretroviral therapy (ARV), low ARV adherence and dissemination of drug resistant HIV strains in primary infections. Our results call for immediate actions of public authority to implement preventive measures, serological screening and, for HIV-seropositive subjects, clinical and treatment follow-up in order to control HIV infection and limit the spread of drug resistance strains in Brazilian prisons.     

Analysis of HIV-1 drug-resistant variants in plasma and peripheral blood mononuclear cells from untreated individuals: implications for clinical management

Genotypic resistance analysis on viral DNA and plasma was performed in 56 therapy naive patients with recent and chronic infection to assess the prevalence of mutations associated with drug resistance and compare cell-free and cell-associated strains. Direct sequencing of DNA provirus disclosed key mutations to RT inhibitors more frequently than in plasma RNA. In addition, major mutations associated with drug resistance in the PR region were only found in PBMCs. Although our data are limited to a small cohort, they show a different resistance profile between plasma and PBMC compartments and may yield additional information for first-line antiretroviral regimens.     

Errors in medication history at hospital admission: prevalence and predicting factors

Background

Data on adverse drug reactions (ADRs) related to antiretroviral (ARV) use in public health practice are few indicating the need for ART safety surveillance in clinical care.

Objectives

To evaluate the incidence, type and risk factors associated with adverse drug reactions (ADRs) among patients on antiretroviral drugs (ARV).

Methods

Patients initiated on ARVs between May 2006 and May 2009 were evaluated in a retrospective cohort analysis in three health facilities in Nigeria. Regimens prescribed include nucleoside backbone of zidovudine (AZT)/lamivudine (3TC), stavudine (d4T)/3TC, or tenofovir (TDF)/3TC in combination with either nevirapine (NVP) or efavirenz (EFV). Generalized Estimating Equation (GEE) model was used to identify risk factors associated with occurrence of ADR.

Results

2650 patients were followed-up for 2456 person-years and reported 114 ADRs (incidence rate = 4.6/100 person-years).There were more females 1706(64%) and 73(64%) of the ADRs were reported by women. Overall, 61(54%) of ADRs were reported by patients on AZT with 54(47%) of these occurring in patients on AZT/NVP. The commonest ADRs reported were pain 25(30%) and skinrash 10(18%). Most ADRs were grade 1(39%) with only 1% being life threatening (grade 4). Adjusted GEE analysis showed that ADR was less likely to occur in patients on longer duration of ART compared to the first six months on treatment; 6-12 months AOR 0.38(95% CI:0.16-0.91) and 12-24 months AOR 0.34(95% CI:0.16-0.73) respectively. Compared to patients on TDF, ADR was less likely to occur in patients on d4T and AZT AOR 0.18(95% CI 0.05-0.64) and AOR 0.24(95% CI:0.7-0.9) respectively. Age, gender and CD4 count were not significantly associated with ADRs.

Conclusion

ADRs are more likely to occur within the first six months on treatment. Close monitoring within this period is required to prevent occurrence of severe ADR and improve ART adherence. Further research on the tolerability of tenofovir in this environment is recommended.