Prevalence Of Primary Drug Resistance Research Articles

Risk assessment of first-line treatment failure in untreated HIV patients in Northwestern Federal District of the Russian Federation

The HIV infection epidemic in Russia continues to evolve, and HIV infection cases have been registered in all territorial entities of the Russian Federation. 2021 Treatment coverage was 82.2% and 56.4% individuals under dispensary observation and living with diagnosed HIV infection. 79.9% receiving ART subjects were shown to achieve undetectable viral load. Highly active antiretroviral therapy (HAART) currently represents a combination of three (less frequently four) antiretroviral drugs targeting pathways involved in various stages of HIV replication in vivo. Treatment failure is a problem facing doctors and patients using HAART. The most common cause of therapeutic failure is the development of HIV drug resistance. The emergence of resistance is associated with processes involving mutation occurring in the viral genome influenced by evolutionary factors. Therefore, it is important clinically and programmatically to learn more about the rate of first-line treatment failure, the rate of switching to a second-line ART regimen, and to identify patients at risk to develop strategies for preventing development of further failure cases. The study was aimed at analyzing ineffectiveness of first-line ART therapy in patients in Northwestern Federal District of the Russian Federation. Materials and methods. Sequencing reactions were performed using the AmpliSens HIV Resist-Seq. Assembly of consensus sequences from fragments obtained during sequencing was carried out using Unipro UGENE software. Isolate genotyping was performed using the MEGA-X software with the Neighbor-joining algorithm. Results. The HIV pol genes in 239 patients with first-line ART failure and 100 nave patients were sequenced; all sequences genotyped as HIV-1 subsubtype A6. According to analysis, 82% of patients had at least one significant mutation associated with drug resistance for the corresponding viral subtype. In total, we encountered 87 different drug resistance mutations. Conclusion. We have shown increased proportion of patients with first-line ART failure among all patients with treatment failure. The main cause for such changes is probably related to the prevalence of primary drug resistance, estimated here at 8%. Specific differences were found between drug resistance mutation profiles in patients without suppressed viral load and patients with virological breakthrough. The overall results of the study indicate a need to diagnose and characterize HIV drug resistance prior to initiation of therapy in order to avoid ineffective first-line antiretroviral treatment.

Prevalence of Primary Drug Resistance Among Newly Diagnosed HIV-1-Infected Individuals in Hunan Province, China.

At present, research on the prevalence of primary drug resistance (PDR) in Hunan Province is limited. Therefore, we explored the current status of HIV-1 PDR in Hunan to provide a basis for antiretroviral therapy (ART) and a theoretical foundation for prevention and control of the HIV/AIDS epidemic. Three hundred seventy newly diagnosed HIV-1-infected individuals who had not received ART in Hunan province, China, were enrolled in the study. Plasma samples were collected, RNA was extracted, two rounds of gene amplification were carried out with the in-house method, and subtype analysis and drug resistance analysis were carried out with relevant software. We found that the most prevalent subtypes of HIV-1 in Hunan Province are CRF_01AE (126/359, 35.1%) and CRF07_BC (85/359, 23.7%). The PDR rate among newly diagnosed HIV/AIDS patients was 10.0% (36/359). Among them, the drug resistance rates of protease inhibitors, nucleotide reverse transcriptase inhibitors, non-nucleotide reverse transcriptase inhibitors, and integrase inhibitors were 0.3% (1/359), 3.3% (12/359), 8.36% (30/359), and 0.6% (2/359), respectively. The distribution of HIV-1 subtypes in Hunan Province is diverse and complex, and the PDR rate has exceeded the low-level warning line set by the World Health Organization (<5%). Therefore, we should conduct pretreatment drug resistance assays to determine the optimal primary ART so that patients can obtain better antiretroviral treatment outcomes and transmission of drug-resistant strains in the population can be blocked.

Primary resistance to integrase inhibitors in Shenzhen.

In recent years, integrase strand transfer inhibitor (INSTI)-containing regimens have been increasingly adopted in treatment for HIV/AIDS and promoted as non-occupational post-exposure prophylaxis in China. This study aims to describe the prevalence of resistance to integrase and drug resistance mutations (DRMs) among ART-naive patients in Shenzhen, China. Serum samples and demographic information were collected from newly reported ART-naive patients in Shenzhen in 2020. The study sequenced the coding sequence of the HIV-1 integrase gene and determined the DRMs.​. In this study, 1682 newly reported cases were included and 1071 of them were successfully sequenced finally. The prevalence of primary drug resistance was 1.77%, with 19 samples showing varying degrees of resistance to INSTIs. The study detected six major DRMs in 16 individuals and eight accessory DRMs in 24 individuals. The prevalence of transmitted drug resistance (TDR) mutations was 1.21%, with five transmitted mutations detected in 13 individuals. The prevalence of drug resistance to raltegravir and elvitegravir was statistically higher than to bictegravir, cabotegravir and dolutegravir. The prevalence of INSTI resistance in Shenzhen in 2020 was relatively high. ​Continued surveillance for resistance to INSTIs is recommended and treatment regimens should be adopted based on the pattern of resistance to INSTIs. ​Dolutegravir or bictegravir is first recommended when considering INSTIs as treatment regimens.

Primary HIV drug resistance among newly HIV type-1 diagnosed patients in St. Petersburg

There is concern that the widespread use of antiretroviral drugs (ARV) to treat human immunodeficiency virus 1 (HIV-1) infection may result in the emergence of transmission of drug-resistant virus among persons newly infected with HIV-1. Russia is one of a growing number of countries in the world where drug-resistant HIV is becoming a serious health problem because it has the potential to compromise the efficacy of antiretroviral therapy (ART) at the population level.Materials and methods.We performed a genetic analysis of the HIV-1 plasma derived pol gene among the newly diagnosed ART-naïve HIV-1 infected patients during the period from November 2018 to October 2019 in the St. Petersburg Clinical Infectious Diseases Hospital named after S.P. Botkin. We used reverse transcriptase polymerase chain reaction (RT-PCR) followed by direct sequencing of PCR products to determine the prevalence of primary drug resistance (PDR) conferring mutations. HIV-1 genotypes were determined by phylogenetic analysis.Results.The predominant HIV-1 subtype was A1 (87.2%), followed by B (11.8%) and CRF06_cpx (1%). The overall prevalence of PDR was 11%. Virus with known resistance-conferring mutations to any nucleoside reverse transcriptase inhibitors (NRTIs) was found in 8 individuals, to any non NRTIs in 5 subjects, and to any protease inhibitors in 1 case. Multidrug-resistant virus was identified in 2 individuals (2%).Conclusion.The distribution of HIV-1 genotypes in St. Petersburg, Russia is diverse. The emerging prevalence of PDR in ART-naïve patients demonstrates the significance of constant monitoring due to the challenges it presents towards treatment.

Primary drug resistance among Mycobacterium tuberculosis isolates from treatment naïve and new pulmonary tuberculosis patients in relation to their socio-economic status

BACKGROUND: Multidrug-resistant Tuberculosis (TB) has become an area of growing concern throughout the World, despite the global efforts in eliminating TB. Detection of primary drug resistance in treatment naïve patients, either due to spontaneous mutation or due to transmission of drug-resistant strains is an important indicator of the presence of drug-resistant strains in the community.OBJECTIVES: The objective is to estimate the prevalence of primary drug resistance in treatment naïve pulmonary TB patients and to identify the socio-economic class of the resistant population.MATERIALS AND METHODS: A total of 272 treatment naïve presumptive TB patients were enrolled in the study from September 2018 to December 2020. The samples were subjected to GeneXpert, for detecting the presence of Mycobacterium TB (MTB) along with Rifampicin (RIF) resistance detection. Phenotypic drug susceptibility testing (DST) was performed on all positive mycobacterial cultures using the 1% proportion method against first-line anti-tuberculous drugs. Socioeconomic status of the patients was also assessed based on updated Kuppuswamy Socioeconomic scale (2018).RESULTS: Of the 272 samples subjected to GeneXpert MTB/RIF assay, MTB was detected in 193 (71%) samples and RIF resistance (rpoB gene) was detected in 25 (9%) samples. Phenotypic DST detected multidrug-resistant (MDR) in 22 (8%) samples. Majority of the MDR patients (55%) were belonging to the upper lower (IV) class of Kuppuswamy socio-economic scale.CONCLUSION: High prevalence of MDR-TB among treatment naïve pulmonary TB patients was noted in patients belonging to Class IV of Kuppuswamy socio-economic scale.

Baseline Investigation of HIV-1 Primary Drug Resistance Among Newly Diagnosed Treatment-Naïve HIV-1 Individuals in Hebei, China.

Human immunodeficiency virus (HIV) primary drug resistance (PDR) has influenced the long-term therapeutic effects of antiretroviral drugs. However, for the overall PDR prevalence in China, no report was found in published articles. In our study, an extensive cross-sectional investigation based on all newly diagnosed treatment-naive HIV-infected individuals was conducted. The overall prevalence of HIV-1 PDR among newly diagnosed treatment-naive HIV-1 individuals was 8.3% (60/720), obviously beyond the warning line (5.0%) set by WHO. The prevalence of PDR to PIs, nucleoside reverse transcriptase inhibitors, and non-nucleoside reverse transcriptase inhibitors was 4.9% (35/720), 0.4% (3/720), and 2.5% (18/720), respectively. Moreover, the occurrence of HIV-1 PDR strains was random among different prefectures. HIV-1 PDR strains were extensively circulating among the sexual contact population inside and outside the Hebei province, especially between neighboring provinces and Hebei. Hebei province has become the moderate level PDR epidemic area. Enhanced surveillance for PDR is necessary among treatment-naïve individuals in Hebei, and we must take effective measures to cut off the spread of HIV PDR strains.

Prevalence and patterns of drug resistance among pulmonary tuberculosis patients in Hangzhou, China

BackgroundTo evaluate prevalence and patterns of drug resistance among pulmonary tuberculosis (TB) patients in Hangzhou City, China.MethodsSputum samples of smear positive TB patients enrolled in 2011 and 2015 were collected and tested for drug susceptibility, and demographic and medical record data were extracted from the electronic database of China Information System for Disease Control and Prevention. Chi-square test was used to compare drug resistance prevalence between new and treated patients and between male and female patients, and Chi-square test for trend was used to compare the prevalence over calendar years 2011 and 2015.ResultsOf 1326 patients enrolled in 2015, 22.3% had resistance to any first-line anti-TB drugs and 8.0% had multi-drug resistance (MDR); drug resistance rates among previously treated cases were significantly higher than among new cases. Significant declines of resistance to isoniazid, rifampin, ethambutol and streptomycin, and MDR from 2011 to 2015 were observed among previously treated patients, while a significant decline of resistance to rifampin was observed among new cases.ConclusionsWhile the prevalence of acquired drug resistance decreased due to due to implementation of DOTS-Plus program, the prevalence of primary drug resistance due to transmission remained high. Greater efforts should be made to screen drug resistance for case finding and to reduce transmission through improving the treatment and management of drug-resistant patients.

HIV resistance in men who have sex with men: a Meta-analysis

To assess the prevalence of HIV primary drug resistance and drug resistance gene mutations among men who have sex with men (MSM). Methods: We searched eight electronic databases (CNKI, VIP, CBM, Wanfang Database, PubMed, Web of Knowledge, Springer, Medline) for the studies of HIV drug resistance relevant to MSM. Drug resistance and drug resistance mutations data were pooled and analyzed according to statistical test of homogeneity. Subgroups were further divided according to sample size, location, race, quality rating score, sampling time. Results: Forty-three studies were included in this Meta-analysis. The pooled rate of total to protease inhibitor (PI), nucleoside reverse transcriptase inhibitor(NRTI) or non-nucleoside reverse transcriptase inhibitor (NNRTI) were 10.21% (95% CI 8.65% to12.03%), 2.98% (95% CI 2.25% to 3.93%), 4.05% (95% CI 3.14% to 5.21%), 4.42% (95% CI 3.31% to 5.88%), respectively. The pooled rates of PI major mutation, PI secondary mutations, NRTI mutations and NNRTI mutations were 0.55% (95% CI 0.38% to 0.80%), 1.31% (95% CI 0.98% to 1.75%), 0.85% (95% CI 0.51% to 1.40%), 1.19% (95% CI 0.70% to 2.01%), 0.79% (95% CI 0.55% to 1.13%), 1.73% (95% CI 1.21% to 2.46%), 0.86% (95% CI 0.61% to 1.21%), 2.24% (95% CI 1.77% to 2.83%), respectively. Sample size, region, and race were heterogeneous sources; the rate of resistance mutations and gene mutation rate were different in different subgroups. Conclusion: The prevalence of primary drug resistance among MSM was high in Americas and Europe, and it was gradually increased in Asia. We should pay attention to the high incidence of PI secondary mutations.

HIV genetic subtypes and HIV drug resistance in China: a Meta-analysis

Objective: To assess the relationship between HIV genetic subtypes and HIV resistance in China. Methods: The literature retrieval was conducted by using Chinese Science-Technology Journal Database (VIP), Wanfang Data, Chinese Journal Full-text Database (CNKI), PubMed and Web of Science to select the papers on the relationship between HIV subtypes and HIV drug resistance in China during 2005-2015. Eligible papers were included according to the inclusion. Meta-analysis was performed by using software Stata 12.0. Results: A total of 43 papers were selected and the pooled rate of drug resistance was 15.1% and the rate of primary drug resistance was 9.5%, the subtypes associated drug resistance were CRF01_AE, CRF07_BC, CRF08_ BC, B/B'and C. The pooled rates of drug resistance of each subtype were 12.8%, 7.4%, 14.3%, 25.7% and 34.9% and the rates of primary drug resistance of each subtype were 7.3%, 5.7%, 11.5%,15.5% and 23.9%, respectively. Subgroup analysis showed that both treated and area subgroup showed a significant difference among groups (P<0.05). The rates of primary resistance of each subtype in northern China and southwestern China were higher than that in southern China. Conclusion: The distribution of HIV genotypes in China was complex and the prevalence of primary drug resistance of each subtype was high, together with a significant difference among subtypes. It is necessary to strengthen the monitoring of different subtypes of drug resistant strains in China to prevent the recombination and spreading of resistant strains.

High prevalence of primary drug resistance in children with intrathoracic tuberculosis in India

Background:Drug susceptibility testing (DST) of Mycobacterium tuberculosis (Mtb) isolates is crucial for the effective treatment of tuberculosis. Data on DST patterns in Mtb isolates in childhood tuberculosis are scanty.Aims:To determine drug resistance patterns in Mtb isolates from a paediatric TB cohort in North India.Methods:403 children aged 6 months to14 year with probable intrathoracic tuberculosis were enrolled prospectively. All were treatment-naïve. 802 ambulatory-induced sputa (IS) and 787 gastric aspirate (GA) samples were cultured in BACTEC-MGIT960 system, and DST of the Mtb isolates was undertaken using the automated BACTEC-MGIT960 SIRE kit.Results:Of the 403 children, 147 (36.4%) were culture-confirmed: 132 (89.8%) isolates were Mtb and 15 (10.2%) non-tuberculous mycobacteria (NTM). Five Mtb isolates were contaminated and the remaining 127 were subjected to in-vitro drug susceptibility testing against streptomycin, isoniazid, rifampicin and ethambutol. Twenty-six (20.47%) isolates were resistant to one or more drugs, seven (5.5%) were resistant to rifampicin singly or in combination, and 11 (8.7%) were resistant to isoniazid singly or in combination. Mono-resistance to isoniazid, rifampicin, streptomycin and ethambutol was detected in four (3.1%), one (0.8%), four (3.1%) and two (1.6%), respectively. Five children (3.9%) had MDR-TB; 101 (79.9%) children had Mtb isolates which were sensitive to all four drugs.Conclusions:The rifampicin and isoniazid resistance rates were much higher than those in the adult TB population in India.

Molecular Epidemiology and Transmission Dynamics of Recent and Long-Term HIV-1 Infections in Rural Western Kenya.

ObjectiveTo identify unique characteristics of recent versus established HIV infections and describe sexual transmission networks, we characterized circulating HIV-1 strains from two randomly selected populations of ART-naïve participants in rural western Kenya.MethodsRecent HIV infections were identified by the HIV-1 subtype B, E and D, immunoglobulin G capture immunoassay (IgG BED-CEIA) and BioRad avidity assays. Genotypic and phylogenetic analyses were performed on the pol gene to identify transmitted drug resistance (TDR) mutations, characterize HIV subtypes and potential transmission clusters. Factors associated with recent infection and clustering were assessed by logistic regression.ResultsOf the 320 specimens, 40 (12.5%) were concordantly identified by the two assays as recent infections. Factors independently associated with being recently infected were age ≤19 years (P = 0.001) and history of sexually transmitted infections (STIs) in the past six months (P = 0.004). HIV subtype distribution differed in recently versus chronically infected participants, with subtype A observed among 53% recent vs. 68% chronic infections (p = 0.04) and subtype D among 26% recent vs. 12% chronic infections (p = 0.012). Overall, the prevalence of primary drug resistance was 1.16%. Of the 258 sequences, 11.2% were in monophyletic clusters of between 2–4 individuals. In multivariate analysis factors associated with clustering included having recent HIV infection P = 0.043 and being from Gem region P = 0.002.ConclusionsRecent HIV-1 infection was more frequent among 13–19 year olds compared with older age groups, underscoring the ongoing risk and susceptibility of younger persons for acquiring HIV infection. Our findings also provide evidence of sexual networks. The association of recent infections with clustering suggests that early infections may be contributing significant proportions of onward transmission highlighting the need for early diagnosis and treatment as prevention for ongoing prevention. Larger studies are needed to better understand the structure of these networks and subsequently implement and evaluate targeted interventions.

HIV-1 Subtype Diversity and Prevalence of Primary Drug Resistance in a Single-Center Pediatric Cohort in Germany

Objectives: Data on drug-resistant mutations (DRMs) in HIV-1-infected therapy-naïve children are scarce. The aim of this study was to determine the HIV-1 subtype distribution and the prevalence of DRMs in therapy-naïve HIV-1-infected children who received routine care at the University Hospital Düsseldorf, Düsseldorf, Germany. Methods: Records of all HIV-1-infected children who received routine care between January 2005 and December 2015 were analyzed retrospectively. The collected data included demographics, clinical characteristics, CD4 cell count, viral load, HIV-1 subtype, and resistance genotype at baseline. Results: 83 HIV-1-infected children received routine care during the observation period. HIV-1 subtypes were available in 61/83 patients (73.5%) and baseline HIV-1 resistance in 24 (29%). The prevalence of major DRMs was 29% (21% nucleoside reverse-transcriptase inhibitors [NRTIs], 12.5% non-NRTIs, and 4% protease inhibitors). Minor mutations in the protease gene were common (58%). Non-B subtypes were predominant (77%). Conclusions: We report a predominance of non-subtype-B infections and a higher prevalence of DRMs compared to other pediatric cohorts from resource-rich settings. The difference in HIV-1 subtype distribution is due to the fact that a relevant proportion of pediatric patients in Germany are immigrants from high-prevalence settings in sub-Saharan Africa where non-B subtypes predominate.

Genetic diversity of HIV-1 and transmitted drug resistance among newly diagnosed individuals with HIV infection in Hangzhou, China.

HIV transmitted drug resistance (TDR) can compromise antiretroviral therapy (ART) in resource-limited countries like China where ART has been scaled up and thus leads to an important public health concern. The aim of the study was to elucidate the HIV-1 genetic characteristics and TDR in Hangzhou, China. Two-hundred eleven ART-naive, newly diagnosed individuals were enrolled during January and August 2013. Specimens were classified as recent or chronic infections using the BED capture enzyme immunoassay (BED-CEIA). The pol fragment covering the entire protease and the first 300 codons of the reverse transcriptase gene was amplified by RT-PCR and nested PCR. Genotypic drug resistance (DR) and phylogenetic analysis were performed on the 200 obtained sequences. Multiple genotypes were identified, including CRF01_AE (62.0%), CRF07_BC (31.0%), subtype B (2.0%), CRF08_BC (1.5%), CRF55_01B (1.0%), CRF18_cpx (0.5%), and unique recombinant forms (URFs, 2.0%). All the four URFs were found in men who have sex with men, consisting of a recombination of CRF01_AE with subtype B or CRF07_BC. The prevalence of primary DR in newly diagnosed individuals in Hangzhou was low (4.0%). The proportion of DR mutation to protease inhibitors (PIs), nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) was 1.5%, 1.5%, and 1.0%, respectively. BED-CEIA revealed that 21.8% (45/211) of the specimens were associated with recent infections. The prevalence of TDR in recent infections was moderate (6.5%). High HIV diversity and relatively high prevalence of TDR in new infections has been found in Hangzhou, indicating an increasing challenge for future HIV prevention and treatment.

Rilpivirine Resistance-Associated Mutations Among Antiretroviral-Naive Patients Infected With HIV-1 in Asia

Rilpivirine Resistance-Associated Mutations Among Antiretroviral-Naive Patients Infected With HIV-1 in Asia

Prevalência de resistência primária em pacientes com tuberculose pulmonar sem fatores de risco conhecidos para resistência primária

To estimate the prevalence of primary resistance to the drugs in the basic treatment regimen for tuberculosis in treatment-naïve patients with pulmonary tuberculosis and no known risk factors for such resistance, as well as to identify factors potentially associated with drug resistance. This was an exploratory cross-sectional study. We analyzed the medical records of the subjects enrolled in two clinical trials of treatments for drug-susceptible tuberculosis between November 1, 2004 and March 31, 2011 at the Prof. Newton Bethlem Outpatient Clinic of the Federal University of Rio de Janeiro Thoracic Diseases Institute, located in the city of Rio de Janeiro, Brazil. The inclusion criteria were being > 18 years of age, testing positive for AFB in the first sputum sample, having a positive culture for Mycobacterium tuberculosis, having undergone drug susceptibility testing, and being treatment-naïve. Patients with a history of imprisonment or hospitalization were excluded, as were those who had been in contact with drug-resistant tuberculosis patients. We included 209 patients. The overall prevalence of primary drug resistance was 16.3%. The overall prevalence of resistance to isoniazid and streptomycin was, respectively, 9.6% and 9.1%, compared with 5.8% and 6.8% for single-drug resistance to isoniazid and streptomycin, respectively. The prevalence of resistance to two or more drugs was 3.8%, and the prevalence of multidrug resistance was 0.5%. No statistically significant associations were found between the variables studied and drug susceptibility testing results. In this sample, the prevalence of primary drug resistance was high despite the absence of known risk factors.

The primary HIV drug resistance in partial region of Henan province

To study the prevalence of primary HIV drug resistance in antiretroviral therapy (ART) areas of Henan province. A total of 121 drug-naive long-term infected individuals and 154 patients with newly diagnosed from January 2011 to March 2012 were recruited, the questionnaires were surveyed and whole blood were collected to analyze the CD4(+)T cell counts and viral load. In-house method for genotypic resistance test was determined in those with viral load > 1000 copies/ml samples, the differences of demographic characteristics, immunological parameters and primary drug resistance were compared between the two groups. A total of 121 cases of long-term individuals who had infected (12.50 ± 3.21) years were mainly previous paid blood donors, and the age was (46.61 ± 9.32) years old. The infection route of the newly diagnosed were diversity, including blood, sexual transmission and others, the cases were 73, 73, 8, respectively, the confirmatory year was (0.91 ± 0.28) years, and average age was (22.21 ± 3.11) years old. The difference were statistically significant in the route of transmission, age and infection time from demographic analysis of the two groups (P < 0.05). The absolute M(P(25)-P(75)) counts of CD4(+)T lymphocytes of long-term group was 322 (217 - 422) cell/µl, which was lower than the newly diagnosed was 434(308 - 578) cell/µl (P < 0.05), and viral load was 4.0 (2.96 - 4.64) copies/ml, 3.77 (2.94 - 4.53) copies/ml, the difference was not significant (P > 0.05). The prevalence of primary drug resistance in long-term group and newly diagnosed was 5.79% (7/121), 9.09% (14/154), respectively, and the difference was statistically different (P < 0.05), and one PI-resistant strain was found in the newly diagnosed group. The primary drug resistant strains in untreated patients were found in Henan province of ART areas, and there was difference in degree of resistance between long-term infected individuals and newly diagnosed.

Prevalence of and Viral Outcomes Associated with Primary HIV-1 Drug Resistance

Primary, or transmitted, HIV antiretroviral resistance is an ongoing concern despite continuing development of new antiretroviral therapies. We examined HIV surveillance data, including both patient demographic characteristics and laboratory data, combined with HIV genotypic test results to evaluate the comprehensiveness of drug resistance surveillance, prevalence of primary drug resistance, and impact, if any, of primary resistance on population-based virological outcomes. The King County, WA Variant, Atypical, and Resistant HIV Surveillance (VARHS) system increased coverage of eligible genotypic testing – within three months of an HIV diagnosis among antiretroviral naïve individuals -- from – 15% in 2003 to 69% in 2010. VARHS under-represented females, Blacks, Native Americans, and injection drug users. Primary drug resistance was more common among males, individuals aged 20 – 29 years, men who had sex with men, and individuals with an initial CD4+ lymphocyte count of 200 cells/µL and higher. High level resistance to two or three antiretroviral classes declined over time. Over 90% of sequences were HIV-1 subtype B. The proportion of individuals with a most recent viral load (closest to April 2011) that was undetectable (<50 copies/mL) was not statistically significantly associated with primary drug resistance. This was true for both number and type of antiretroviral drug class; although small numbers of specimens with drug resistance may have limited our statistical power. In summary, although we found disparities in testing coverage and prevalence of drug resistance, we were unable to detect a significantly deleterious impact of primary drug resistance based on a most recent viral load.

Primary drug resistance to anti‐tuberculosis drugs in major towns of Amhara region, Ethiopia

Drug resistance is a major obstacle to effective TB control program performance. In this study, we assessed the prevalence of primary drug resistance in Mycobacterium tuberculosis (Mtb) isolates in Amhara Region, Ethiopia. A total of 112 Mtb isolates from cases with newly diagnosed pulmonary TB were subjected to drug susceptibility testing (DST) in a cross-sectional study. Isolates were tested for sensitivity to isoniazid, rifampicin, ethambutol, and streptomycin using the MGIT 960 protocol. A total of 93 Mtb isolates yielded valid DST results and 28 (30.1%) were resistant to one or more of first line anti-TB drugs. One isolate (1.0%) was multi-drug resistant (MDR), five (5.4%) were classified as poly-resistant and 22 showed single drug resistance to either streptomycin (n = 19) or isoniazid (n = 3). Isolates from HIV-positive patients were more likely to be resistant to at least one of the four anti-TB drugs compared with HIV-negative individuals (odds ratio 2.76, 95% confidence interval 1.06-7.22; p = 0.03). The study showed a high prevalence of primary drug resistance. Even though the prevalence of MDR was low, conditions that can contribute to the development of MDR are increasing. Therefore, regular monitoring of drug resistance and enhanced implementation of TB/HIV collaborative activities in the study region are imperative.

HIV-1 drug resistance in antiretroviral-naive individuals in sub-Saharan Africa after rollout of antiretroviral therapy: a multicentre observational study

There are few data on the epidemiology of primary HIV-1 drug resistance after the roll-out of antiretroviral treatment (ART) in sub-Saharan Africa. We aimed to assess the prevalence of primary resistance in six African countries after ART roll-out and if wider use of ART in sub-Saharan Africa is associated with rising prevalence of drug resistance. We did a cross-sectional study in antiretroviral-naive adults infected with HIV-1 who had not started first-line ART, recruited between 2007 and 2009 from 11 regions in Kenya, Nigeria, South Africa, Uganda, Zambia, and Zimbabwe. We did population-based sequencing of the pol gene on plasma specimens with greater than 1000 copies per mL of HIV RNA. We identified drug-resistance mutations with the WHO list for transmitted resistance. The prevalence of sequences containing at least one drug-resistance mutation was calculated accounting for the sampling weights of the sites. We assessed the risk factors of resistance with multilevel logistic regression with random coefficients. 2436 (94.1%) of 2590 participants had a pretreatment genotypic resistance result. 1486 participants (57.4%) were women, 1575 (60.8%) had WHO clinical stage 3 or 4 disease, and the median CD4 count was 133 cells per μL (IQR 62-204). Overall sample-weighted drug-resistance prevalence was 5.6% (139 of 2436; 95% CI 4.6-6.7), ranging from 1.1% (two of 176; 0.0-2.7) in Pretoria, South Africa, to 12.3% (22 of 179; 7.5-17.1) in Kampala, Uganda. The pooled prevalence for all three Ugandan sites was 11.6% (66 of 570; 8.9-14.2), compared with 3.5% (73 of 1866; 2.5-4.5) for all other sites. Drug class-specific resistance prevalence was 2.5% (54 of 2436; 1.8-3.2) for nucleoside reverse-transcriptase inhibitors (NRTIs), 3.3% (83 of 2436; 2.5-4.2) for non-NRTIs (NNRTIs), 1.3% (31 of 2436; 0.8-1.8) for protease inhibitors, and 1.2% (25 of 2436; 0.7-1.7) for dual-class resistance to NRTIs and NNRTIs. The most common drug-resistance mutations were K103N (43 [1.8%] of 2436), thymidine analogue mutations (33 [1.6%] of 2436), M184V (25 [1.2%] of 2436), and Y181C/I (19 [0.7%] of 2436). The odds ratio for drug resistance associated with each additional year since the start of the ART roll-out in a region was 1.38 (95% CI 1.13-1.68; p=0.001). The higher prevalence of primary drug resistance in Uganda than in other African countries is probably related to the earlier start of ART roll-out in Uganda. Resistance surveillance and prevention should be prioritised in settings where ART programmes are scaled up. Ministry of Foreign Affairs of the Netherlands.

Surveillance of Transmitted Antiretroviral Drug Resistance among HIV-1 Infected Women Attending Antenatal Clinics in Chitungwiza, Zimbabwe

The rapid scale-up of highly active antiretroviral therapy (HAART) and use of single dose Nevirapine (SD NVP) for prevention of mother-to-child transmission (pMTCT) have raised fears about the emergence of resistance to the first line antiretroviral drug regimens. A cross-sectional study was conducted to determine the prevalence of primary drug resistance (PDR) in a cohort of young (<25 yrs) HAART-naïve HIV pregnant women attending antenatal clinics in Chitungwiza, Zimbabwe. Whole blood was collected in EDTA for CD4 counts, viral load, serological estimation of duration of infection using the BED Calypte assay and genotyping for drug resistance. Four hundred and seventy-one women, mean age 21 years; SD: 2.1 were enrolled into the study between 2006 and 2007. Their median CD4 count was 371cells/µL; IQR: 255–511 cells/µL. Two hundred and thirty-six samples were genotyped for drug resistance. Based on the BED assay, 27% were recently infected (RI) whilst 73% had long-term infection (LTI). Median CD4 count was higher (p<0.05) in RI than in women with LTI. Only 2 women had drug resistance mutations; protease I85V and reverse transcriptase Y181C. Prevalence of PDR in Chitungwiza, 4 years after commencement of the national ART program remained below WHO threshold limit (5%). Frequency of recent infection BED testing is consistent with high HIV acquisition during pregnancy. With the scale-up of long-term ART programs, maintenance of proper prescribing practices, continuous monitoring of patients and reinforcement of adherence may prevent the acquisition and transmission of PDR.