HIV Drug Resistance Threshold Survey Research Articles

HIV-1 drug resistance transmission threshold survey in Dehong prefecture of Yunnan province, 2015

Objective: To study the HIV-1 drug resistance transmission level in HIV infected persons receiving no antiviral therapy in Dehong prefecture of Yunnan province in 2015. Methods: A total of 72 plasma samples were collected from recently reported HIV-infected persons aged 16-25 years in Dehong from January to July 2015 for drug resistance gene detection. Results: Forty eight samples were successfully sequenced and analyzed. Among them, 31.2% (15/48) were from Chinese, and 68.8% (33/48) were from Burmese. Based on pol sequences, HIV genotypes included URF (52.08%, 25/48), CRF01_AE (16.67%, 8/48), RF07_BC (10.42%, 5/48), subtype B (6.25%, 3/48), subtype C (6.25%, 3/48), CRF57_BC (6.25%, 3/48) and CRF08_BC (2.08%, 1/48). One drug resistant mutation site to non-nucleoside analog reverse transcriptase inhibitor (NNRTI) and two drug resistant mutation site to nucleoside analog reverse transcriptase inhibitor (NRTI) were detected in four sequences. Based on the statistical method of HIV drug resistance threshold survey, the prevalence of HIV-1 drug resistant strain was 5%-15%. Conclusions: The proportion of Burmese among newly reported HIV-infected individuals aged 16-25 years in Dehong in 2015 was higher. HIV-1 genetic diversity was found in Dehong. The prevalence of HIV-1 drug resistant strain had reached a moderate level in Dehong.

Study on the threshold of HIV-1 drug resistance in Dehong prefecture of Yunnan province in 2014

To study the HIV-1 genotypes and transmitted drug resistance (TDR) in Dehong prefecture of Yunnan province in 2014. A total of 70 plasma samples of recently reported HIV-infected individuals between 16 and 25 years old were collected in Dehong prefecture from January to August 2014. Among them, 58 samples which met the criterion of HIV drug resistance threshold survey (HIVDR-TS) were subjected to genetic drug resistance detection. 50 plasma samples were successfully sequenced and analyzed. Among them, 34.0% were Chinese and 66.0% were Burmese. Based on pol sequences, all the identified HIV genotypes would include CRF01_AE (28.0%), subtype C(20.0%), URF(20.0% ), CRF62_BC(10.0% ), CRF08_BC(8.0% ), CRF07_BC (4.0%), CRF64_BC(4.0%), subtype B(4.0%) and CRF55_01B(2.0%). One drug, which resistant mutation to proteinase inhibitors had been detected in one sequence. Based on the statistical method of HIVDR-TS, the prevalence of transmitted HIV-1 drug resistance was adjusted as <5%. The proportion of Burmese was relatively higher among those newly reported HIV-infected individuals aged 16 to 25 in Dehong. We noticed that the novel circulating recombinant forms began to function. However, the level of transmission through HIV-1 drug resistant strains still kept low in Dehong.

Analysis on HIV-1 genetics and threshold of drug resistance in Dehong prefecture of Yunnan province in 2013

To study the HIV-1 genotypes and transmitted drug resistance (TDR) in Dehong prefecture of Yunnan province in 2013. Referring to the guidelines for HIV drug resistance threshold survey (HIVDR-TS), 54 plasma samples of recently reported HIV-infected individuals, aged between 16 and 25 years, were collected in Dehong prefecture from January to August 2013. Genotyping of partial pol gene was performed by using reverse transcriptional PCR. HIV-1 genotype. Prevalent levels of HIV-1 drug resistance transmission were analyzed. Forty-eight plasma samples were successfully sequenced and analyzed. Among them, 45.8% were Chinese and the rest 54.2% were all Burmese. Based on pol sequences, identified HIV genotypes included subtype C (41.7%), URF (31.3%), CRF01_AE (12.5%), CRF07_BC (10.4%), CRF08_BC (2.1%) and subtype B (2.1%), C subtype appeared dominated in Chinese while URF was dominated in Burmese. One drug resistant mutation to non-nucleoside reverse transcriptase inhibitors (NNRTIs) was detected in one sequence from Burmese. Based on the statistical method of HIVDR-TS, the prevalence of transmitted HIV-1 drug resistance was adjusted as < 5%. Diverse HIV-1 genotypes were found in this study, and the current HIV-1 drug resistant strains transmission was catalogued as at low prevalence level, in Dehong. To prevent the increase of the prevalence of transmitted HIV-1 drug resistance, standard treatment and scientific management for people living with HIV/AIDS should be strictly followed. Meanwhile, relevant surveillance, including drug resistance surveillance should also be performed among cross-border migrant population.

Prevalence of Transmitted HIV-1 Drug Resistance among Young Adults Attending HIV Counselling and Testing Clinics in Kigali, Rwanda

Scaling-up antiretroviral therapy (ART) in resource-limited settings has raised concerns of emerging HIV drug resistance (DR) and its transmission to newly infected individuals. To assess the prevalence of transmitted drug resistance (TDR) in recently HIV-infected individuals, a WHO TDR threshold survey was conducted among young adults in Kigali, Rwanda. Between May and July 2011, HIV subtype and genotyping were performed on dried blood spots (DBS) prepared from blood specimens collected from newly HIV-diagnosed and ART-naive individuals aged 15 to 21 years in eight HIV voluntary counselling and testing (VCT) sites in Kigali. In total, 57 of the 68 DBS collected from eligible participants were successfully amplified. The median age of participants was 20 years and 86% were female. Most participants (96%) were infected with subtype A1 virus. Two participants (4%) had the K103N non-nucleoside reverse transcriptase inhibitor (NNRTI) mutation and one (2%) had the M46L protease inhibitor (PI) mutation. The TDR prevalence was 3.5% (95% CI 0.4, 12.1) for NNRTI and 1.8% (95% CI 0.0, 9.4) for PI. The prevalence of HIV TDR in VCT attendees in Kigali was characterized as low (<5%) for all drug classes according to the WHO HIV DR threshold survey methodology. Despite a decade of widespread ART in Rwanda, TDR prevalence remains low, and so the current first-line ART regimens should continue to be effective. However, as scale-up of ART continues, frequent HIV DR surveillance is needed to monitor the effectiveness of available ART regimens at the population level.

Low prevalence of the transmitted HIV-1 drug resistance among newly diagnosed HIV-1 individuals in Jiangsu Province, China during 2009-2011.

BackgroundPrevalence of The transmitted HIV drug resistance (THDR) has been reported in many countries. In China, the low level THDR was found in only a few provinces. To know the transmitted HIV drug resistance in east of China, we investigated THDR during 2009–2011 in Jiangsu province of China.MethodsBetween January and August of 2009, 2010, and 2011, we consecutively collected 50, 54, 53 blood specimens respectively from qualified individuals at surveillance sentinel sites in Jiangsu province according to protocol of HIV Drug Resistance Threshold Survey (HIVDR-TS) recommended by WHO. The region of pol gene including protease and partial retro-transcriptase was amplified, sequenced and edited. Then the sequences were submitted to HIV drug resistance database to analysis transmitted HIV drug resistance mutations using Calibrated Population Resistance tool. The reference sequences of different HIV-1 subtypes were downloaded from HIV database and Genebank. The phylogenetic trees were inferred using the neighbor-joining method.ResultsOur results show that THDR has been at low level from 2009 to 2011, only K101E and V179D mutation was detected which did not belong to the major HIV-1 drug resistance mutations. Phylogenetic analysis showed that CRF01_AE is the predominant subtype, and followed by CRF07_BC and B subtype. Subtype B consists of the two distinct clusters.ConclusionsThe low level of THDR suggests that anti-retroviral treatment was implemented more effectively and THDR surveillance should be conducted two years later in Jiangsu province of China. CRF01_AE has become the predominant subtype and dual infection of HIV may be common in Jiangsu province.

Resistance to antiretroviral drugs in newly diagnosed, young treatment‐naïve HIV‐positive pregnant women in the province of KwaZulu‐Natal, South Africa

In 2004, KwaZulu-Natal initiated one of the world's largest HIV/AIDS treatment programs. Studies in South Africa have shown that patients on antiretroviral therapy (ART) develop rapidly and transmit drug resistant mutations. Since resistance testing is not widely available in Kwazulu-Natal, the Department of Health conducted the first HIV drug resistance (HIVDR) threshold survey in 2005, which did not identify any mutations associated with HIVDR. The objective of this study was to conduct a follow-up threshold survey to update the information on HIVDR. This study was conducted in 2009 in five antenatal care sites in Kwazulu-Natal using the HIVDR threshold survey method developed by WHO. Two hundred and thirteen newly-diagnosed HIV positive, drug-naïve primigravidae, less than 22 years of age were included in the survey. Of the 82 HIV positive specimens, 17 had insufficient volume for genotyping and, of the remaining 65, 47 were genotyped sequentially. Drug resistance was identified by sequencing the HIV-1 pol gene, using the ViroSeq® HIV-1 genotyping system v2.0. Of the 47 samples that were genotyped, only one presented with a K103N mutation, which equates to a prevalence of transmitted HIVDR of <5%. The low prevalence of transmitted HIVDR is in keeping with statistical models of the early stages of ART rollout. As ART coverage is increasing continuously, there is a need to ensure that vigilance of HIVDR continues so that the emergence and spread of HIVDR is minimized.

Prevalence of Transmitted HIV Drug Resistance in Botswana: Lessons Learned from the HIVDR-Threshold Survey Conducted Among Women Presenting for Routine Antenatal Care as Part of the 2007 National Sentinel Survey

The emergence and spread of transmitted drug resistance (TDR) poses a major threat to the success of the rapidly expanding antiretroviral treatment (ART) programs in resource-limited countries. The World Health Organization recommends the use of the HIV Drug Resistance Threshold Survey (HIVDR-TS) as an affordable means to monitor the presence of TDR in these settings. We report our experiences and results of the 2007 HIVDR-TS in Botswana, a country with one of the longest-existing national public ART programs in Africa. The HIVDR-TS and HIV-1 incidence testing were performed in the two largest national sites as part of the 2007 antenatal Botswana Sentinel Survey. The HIVDR-TS showed no significant drug resistance mutations (TDR less than 5%) in one site. TDR prevalence, however, could not be ascertained at the second site due to low sample size. The agreement between HIVDR-TS eligibility criteria and laboratory-based methodologies (i.e., BED-CEIA and LS-EIA) in identifying recently HIV-1 infected adults was poor. Five years following the establishment of Botswana's public ART program, the prevalence of TDR remains low. The HIVDR-TS methodology has limitations for low-density populations as in Botswana, where the majority of antenatal sites are too small to recruit sufficient numbers of patients. In addition, the eligibility criteria (age <25 years and parity (first pregnancy)) of the HIVDR-TS performed poorly in identifying recent HIV-1 infections in Botswana. An alternative sampling strategy should be considered for the surveillance of HIVDR in Botswana and similar geographic settings.

Surveillance of HIV drug resistance transmission in Iran: experience gained from a pilot study

We performed a pilot surveillance study on transmitted HIV drug resistance (TDR) in Iran, with specimens collected and stored as dried blood spots (DBS). The protease region and relevant positions in the reverse transcriptase region of the pol gene were sequenced to detect mutations known to be associated with resistance to drugs in standard first-line regimens. Seventy-three specimens were collected, with 39 (53%) specimens yielding sequence from both protease and at least part of RT. Specimens were almost exclusively HIV-1 subtype CRF 35_A1D based on pol sequencing. Mutations were restricted to RT, with D67DG and V75AV each seen in a single specimen. An atypical protease inhibitor mutation, I47M, appeared at a resistance-associated position in protease from a single specimen. These preliminary data showed that the rate of transmitted drug resistance in Iran, within the areas sampled, was 5.1% (2/39). However, the small sample size makes this figure only an approximation. Due to the sampling strategy and resulting small sample size, we were unable to accurately calculate TDR rates for individual areas using the WHO HIV drug resistance threshold survey method. Increasing the sample size and improving the yield from DBS would improve the accuracy of drug resistance surveillance and facilitate wider application of this methodology in Iran.

Low Prevalence of HIV Type 1 Drug Resistance Mutations in Untreated, Recently Infected Patients from Burkina Faso, Côte d'Ivoire, Senegal, Thailand, and Vietnam: The ANRS 12134 Study

The frequency of transmitted HIV drug resistance (HIVDR) was evaluated in the context of rapid scale-up of antiretroviral treatment in Thailand, Vietnam, Burkina Faso, Côte d'Ivoire, and Senegal by using an adaptation of the WHO generic protocol of the HIV Drug Resistance Threshold Survey (HIVDR-TS) for sample collection and classification. Resistance-associated mutations were interpreted using the 2009 WHO list for epidemiological surveys. We included 266 subjects from the five study sites. Of the 266 RT and PR sequences analyzed, two from Vietnam harbored virus with major drug resistance mutations (G190A in RT for one individual and M46I in PR for the second individual). Phylogenetic analysis revealed that CRF01_AE predominates (>90%) in Thailand and Vietnam. CRF02 (>65%) cocirculates with other HIV-1 variants in Senegal and Côte d'Ivoire. The prevalence of HIVDRM is scored as low (< or = 5%) in all the five sites for the three drug classes analyzed. A continuous population survey for HIVDRM will provide a rational basis for maintaining or changing the current first line regimen in these countries.

The prevalence of HIV-1 drug-resistant strains in Beijing, in 2008

Objective To study the prevalence of HIV-1 drug-resistant strains in antiretroviral therapy-naive HIV-1 infectors,and provide background information for HIV-1 drug resistance survey and clin-ical antiretroviral therapy in Beijing in 2008. Methods Referring to the guidelines for HIV drug resistance threshold survey(HIVDR-TS) of WHO, collecting 60-70 plasma samples of HIV-1 infectors who were detec-ted in 6 months and not more than 25 years,we detected HIV-1 pol genotype and genetic mutations associated with drug resistance,counted the prevalence of drug-resistant strains, and evaluated the prevalent level. Re-Sults Of 61 plasma samples answering for the standards, 50 were successfully sequenced and genotyped pol sequence. The major infection route was homosex, which accounted for 62%. B, CRF01_AE, and CRF07_ BC were major genetic subtype, which accounted for 42%, 28% and 26%, respectively. One Pl-resistant strain was found, the incidence of which was 2% (1/50). One NRTI-resistant strain was found, the inci-dence of which was 2% (1/50). No NRTI-resistant strain was found, the incidence of which was 0. The in-cidence of drug-resistant strains in the protease (PR) region was 2%, and the incidence of reverse tran-scriptase (RT) region was also 2%. Both of the prevalence were classified as low level ( <5% ). Conclu-sion PR, RT-resistant HIV-1 strains were found in drug-naive infectors, and the prevalence was low in Beijing. Current antiretrovirai therapy regiments were still feasible. Most of the AIDS patients did not need to test drug resistance before antiretroviral therapy. Key words: HIV; Drug resistance

Evaluation of transmitted HIV drug resistance among recently-infected antenatal clinic attendees in four Central African countries

The rapid expansion of antiretroviral treatment in resource-limited settings is raising concerns regarding the emergence and transmission of HIV drug resistance (HIVDR). We evaluated the extent of transmission of drug-resistant HIV strains in four Central African countries: the Republic of Congo, Central African Republic, Chad and Cameroon. The World Health Organization (WHO) HIVDR threshold survey was implemented in major treatment areas in each country. Pregnant women who were aged <25 years, who were at first pregnancy and who were HIV type-1-positive were enrolled at each site in 2006-2007 for genotyping. HIVDR prevalence was categorized using the WHO threshold survey binomial sequential sampling method. The prevalence of HIVDR in Brazzaville and Bangui sites could not be classified because the eligible sample number was not reached. HIVDR prevalence was low (<5%) in N'Djamena for all drug classes. In Yaoundé, we found one individual with the D67D/N mutation and two with K103N. HIVDR prevalence was categorized as low (<5%) for protease inhibitors (PIs) and nucleoside reverse transcriptase inhibitors (NRTIs), and moderate (> or =5-< or =15%) for non-NRTIs (NNRTIs). HIVDR prevalence in Douala was low for PIs and NNRTIs, and moderate for NRTIs as we identified one individual with M184V plus K101E plus G190A mutations and a second with D67D/N. The moderate HIVDR prevalence found in Yaoundé and Douala indicate that efforts should be made in Cameroon to prevent HIVDR; however, additional surveys are needed to confirm this trend. This study highlighted challenges presented by the WHO methodology, such as additional costs, workload, difficulties in acquiring even small sample numbers and the necessity for better quality assurance of HIV testing and record keeping at antenatal clinics.

Recommendations for surveillance of transmitted HIV drug resistance in countries scaling up antiretroviral treatment

BackgroundThe World Health Organization (WHO) HIV drug resistance (HIVDR) threshold survey method was developed for surveillance of transmitted HIVDR in resource-limited countries. The method is being implemented with minimal resources as a routine public health activity to produce comparable results in multiple countries and areas within countries. Transmitted drug resistant HIV strains will be seen first in cities or health districts where antiretroviral treatment (ART) has been widely available for years. WHO recommends countries begin surveillance in these areas.MethodsEach survey requires ≤47 specimens from individuals consecutively diagnosed with HIV to categorize resistance to each relevant drug class as &lt;5%, 5–15% or &gt;15%. Use of routinely collected information and remnant specimens is recommended to minimize costs. Site and individual eligibility criteria are designed to minimize inclusion of ARV-experienced individuals and individuals infected before ART was available.ResultsSurveys have been implemented in 21 countries. In this supplement, seven countries report results of &lt;5% transmitted HIVDR in areas where ART has been available for the longest time period. The main challenges in implementation are acquiring sufficient numbers of eligible specimens and optimizing specimen handling.ConclusionThe WHO HIVDR threshold survey method is feasible in resource-limited countries and produces information relevant to ART and drug resistance prevention planning.

HIV drug resistance transmission threshold survey in Bangkok, Thailand

BackgroundAntiretroviral therapy (ART) began in Thailand in the Bangkok Metropolitan Area (BMA) in 1988 and scale-up began in 2001. The national first-line regimen is stavudine, lamivudine and nevirapine in fixed-dose combination, which is a regimen with a low genetic barrier for resistance. Because viral load and resistance testing are not widely available, unidentified HIV drug resistance (HIVDR) may occur during treatment and could be transmitted.MethodsWe undertook a threshold survey to assess HIVDR transmission in two subsets of recently infected individuals in the BMA. The first group consisted of returning blood donors tested at the Thai Red Cross National Blood Centre who seroconverted within the past 12 months. The second group comprised recently infected (as defined by BED assay) clients of the Thai Red Cross voluntary counselling and testing centre (VCT).ResultsGenotyping of 50 consecutive specimens each from blood donors and VCT clients during 2005–2006 showed no mutations associated with HIVDR in the reverse transcriptase or protease regions of the HIV pol gene. These results are categorized by the WHO HIV drug resistance threshold survey method as representing a low prevalence (&lt;5%) of transmitted HIV drug resistance.ConclusionsEvery effort should be made to minimize the emergence of resistance in treated individuals and to prevent primary and secondary HIV transmission. To continue to monitor HIVDR transmission, Thailand has planned additional surveys – including longitudinal surveys – in these and additional groups of individuals.

HIV drug resistance threshold survey using specimens from voluntary counselling and testing sites in Hanoi, Vietnam

Background In countries where antiretroviral therapy has been available or is being rapidly expanded, the World Health Organization (WHO) recommends surveillance for transmitted HIV drug resistance (HIVDR) by threshold surveillance methods using specimens from antenatal clinics or voluntary counselling and testing (VCT) sites. The aim of this study was to implement the HIVDR threshold survey in VCT sites in Vietnam, where HIV prevalence is high. Estimating transmitted resistance in the infected population will enable the appropriateness of current antiretroviral drug regimens to be assessed and will inform plans for future HIVDR surveillance. Methods Consecutive blood specimens were collected from 70 newly diagnosed HIV-positive clients 18–24 years of age at two sites in Hanoi, Vietnam. Informed consent and serum specimens were obtained from each eligible client, with serum frozen at -70°C until shipping to Thailand for resistance testing using the TruGene system. Results From February until August 2006, 559 clients were eligible to participate in this survey. Of the 535 clients (95.7%) who agreed to participate, 70 (13%) were HIV-positive and were included in the survey. Of the 70 specimens sent for genotyping, 52 consecutive samples were amplified, 49 of which could be genotyped. Only 1 of 49 genotyped specimens had mutations associated with drug resistance (L74V and Y181C) in the reverse transcriptase gene, indicating that the prevalence of transmitted HIVDR to all drugs and drug classes evaluated was &lt;5%. Conclusion The prevalence of transmitted HIVDR was low in Hanoi as determined using threshold surveillance methods. The Ministry of Health plans to repeat this survey methodology in one more province and to confirm these findings by expanded HIVDR surveillance.

Surveillance of transmitted HIV drug resistance in the Manzini-Mbabane corridor, Swaziland, in 2006

BackgroundIn resource-limited settings where anti-retroviral treatment (ART) is being scaled-up, the World Health Organization (WHO) recommends the surveillance of transmitted HIV drug resistance (HIVDR). We used the WHO's HIVDR threshold survey method to assess transmitted HIVDR in three antenatal clinic (ANC) sites along the corridor between the two most populous cities in Swaziland, where ART was introduced in 2003.MethodsFrom July–August 2006, remnant sera were aliquoted from HIV serosurvey specimens collected from 70 primagravidas &lt;25 years old attending ANC during the national HIV serosurvey. Genotyping was performed at the National Institute for Communicable Diseases, South Africa. Transmitted resistance was defined by the WHO's surveillance list of mutations. HIVDR prevalence was categorized using the WHO's threshold survey binomial sequential sampling method.ResultsAmong the 70 eligible specimens, 61 were sequenced – 60 (98%) were identified as subtype C and one as subtype B. No major nucleoside or non-nucleoside reverse transcriptase inhibitor mutations occurred among the first 34 consecutive specimens, which supported a transmitted resistance categorization to these drug classes as &lt;5%. One protease inhibitor mutation, M46I, was seen among the first 44 specimens, supporting a categorization of PI resistance as &lt;5%.ConclusionOur survey indicates that prevalence of transmitted HIVDR among recently infected pregnant women along the Manzini-Mbabane corridor is low (&lt;5%). Surveys will be carried out in this area biannually and may be extended to other areas. Surveys for transmitted resistance make up one element among a spectrum of activities to assess and support minimization of HIVDR.

Surveillance of transmitted HIV drug resistance among women attending antenatal clinics in Dar es Salaam, Tanzania

BackgroundIn resource-limited settings where antiretroviral treatment (ART) access is being scaled-up, the World Health Organization (WHO) recommends surveillance of transmitted HIV drug resistance (HIVDR). We used the WHO HIVDR threshold survey method to assess transmitted HIVDR in Dar es Salaam where ART was introduced in 1995 and where ∼11,000 people are currently on ART.MethodsFrom November 2005 to February 2006, dried blood spot (DBS) specimens were made from remnant specimens collected during the national HIV serosurvey from 60 primagravidas &lt;25 years old attending six antenatal clinics for routine syphilis testing. Genotyping was performed at the Centers for Disease Control and Prevention, Atlanta, Georgia, USA. Protease and reverse transcriptase drug resistance mutations were identified using the Stanford University HIV drug resistance database. We used the National Institutes of Health genotyping tool for HIV-1 subtyping. HIVDR prevalence categorization was based on the WHO threshold survey binomial sequential sampling method.ResultsAmong the 60 eligible specimens collected, 50 DBS were successfully amplified using RT-PCR. Sequencing was performed on the first 39 specimens: 13 (33.3%) were subtype A1, 13 (33.3%) subtype C, and 4 (10.3%) subtype D, the remainder differed in the closest subtype based on protease versus reverse transcriptase. No resistance mutations were seen; HIVDR to all drug classes was categorized as &lt;5%.ConclusionsOur survey indicates that prevalence of transmitted HIVDR among recently infected pregnant women in Dar es Salaam is low (&lt;5%). The survey should be repeated during the next HIV sentinel survey in Dar es Salaam and extended to other regions where ART is being scaled up.