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1.
Brief Bioinform ; 23(1)2022 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-34962257

RESUMEN

The study of genetic minority variants is fundamental to the understanding of complex processes such as evolution, fitness, transmission, virulence, heteroresistance and drug tolerance in Mycobacterium tuberculosis (Mtb). We evaluated the performance of the variant calling tool LoFreq to detect de novo as well as drug resistance conferring minor variants in both in silico and clinical Mtb next generation sequencing (NGS) data. The in silico simulations demonstrated that LoFreq is a conservative variant caller with very high precision (≥96.7%) over the entire range of depth of coverage tested (30x to1000x), independent of the type and frequency of the minor variant. Sensitivity increased with increasing depth of coverage and increasing frequency of the variant, and was higher for calling insertion and deletion (indel) variants than for single nucleotide polymorphisms (SNP). The variant frequency limit of detection was 0.5% and 3% for indel and SNP minor variants, respectively. For serial isolates from a patient with DR-TB; LoFreq successfully identified all minor Mtb variants in the Rv0678 gene (allele frequency as low as 3.22% according to targeted deep sequencing) in whole genome sequencing data (median coverage of 62X). In conclusion, LoFreq can successfully detect minor variant populations in Mtb NGS data, thus limiting the need for filtering of possible false positive variants due to sequencing error. The observed performance statistics can be used to determine the limit of detection in existing whole genome sequencing Mtb data and guide the required depth of future studies that aim to investigate the presence of minor variants.


Asunto(s)
Mycobacterium tuberculosis/genética , Secuenciación Completa del Genoma , Proteínas Bacterianas , Frecuencia de los Genes , Genotipo , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Mutación INDEL , Mutación , Polimorfismo de Nucleótido Simple , Tuberculosis Resistente a Múltiples Medicamentos/microbiología
2.
PLoS Comput Biol ; 19(11): e1011648, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38019772

RESUMEN

BACKGROUND: Whole genome sequencing (WGS) holds great potential for the management and control of tuberculosis. Accurate analysis of samples with low mycobacterial burden, which are characterized by low (<20x) coverage and high (>40%) levels of contamination, is challenging. We created the MAGMA (Maximum Accessible Genome for Mtb Analysis) bioinformatics pipeline for analysis of clinical Mtb samples. METHODS AND RESULTS: High accuracy variant calling is achieved by using a long seedlength during read mapping to filter out contaminants, variant quality score recalibration with machine learning to identify genuine genomic variants, and joint variant calling for low Mtb coverage genomes. MAGMA automatically generates a standardized and comprehensive output of drug resistance information and resistance classification based on the WHO catalogue of Mtb mutations. MAGMA automatically generates phylogenetic trees with drug resistance annotations and trees that visualize the presence of clusters. Drug resistance and phylogeny outputs from sequencing data of 79 primary liquid cultures were compared between the MAGMA and MTBseq pipelines. The MTBseq pipeline reported only a proportion of the variants in candidate drug resistance genes that were reported by MAGMA. Notable differences were in structural variants, variants in highly conserved rrs and rrl genes, and variants in candidate resistance genes for bedaquiline, clofazmine, and delamanid. Phylogeny results were similar between pipelines but only MAGMA visualized clusters. CONCLUSION: The MAGMA pipeline could facilitate the integration of WGS into clinical care as it generates clinically relevant data on drug resistance and phylogeny in an automated, standardized, and reproducible manner.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Humanos , Mycobacterium tuberculosis/genética , Filogenia , Genómica , Genoma , Tuberculosis/tratamiento farmacológico , Tuberculosis/genética
3.
Brief Bioinform ; 22(4)2021 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-33009560

RESUMEN

BACKGROUND: Whole genome sequencing (WGS) is increasingly used for Mycobacterium tuberculosis (Mtb) research. Countries with the highest tuberculosis (TB) burden face important challenges to integrate WGS into surveillance and research. METHODS: We assessed the global status of Mtb WGS and developed a 3-week training course coupled with long-term mentoring and WGS infrastructure building. Training focused on genome sequencing, bioinformatics and development of a locally relevant WGS research project. The aim of the long-term mentoring was to support trainees in project implementation and funding acquisition. The focus of WGS infrastructure building was on the DNA extraction process and bioinformatics. FINDINGS: Compared to their TB burden, Asia and Africa are grossly underrepresented in Mtb WGS research. Challenges faced resulted in adaptations to the training, mentoring and infrastructure building. Out-of-date laptop hardware and operating systems were overcome by using online tools and a Galaxy WGS analysis pipeline. A case studies approach created a safe atmosphere for students to formulate and defend opinions. Because quality DNA extraction is paramount for WGS, a biosafety level 3 and general laboratory skill training session were added, use of commercial DNA extraction kits was introduced and a 2-week training in a highly equipped laboratory was combined with a 1-week training in the local setting. INTERPRETATION: By developing and sharing the components of and experiences with a sequencing and bioinformatics training program, we hope to stimulate capacity building programs for Mtb WGS and empower high-burden countries to play an important role in WGS-based TB surveillance and research.


Asunto(s)
Biología Computacional , Genoma Bacteriano , Mycobacterium tuberculosis/genética , Tuberculosis/genética , Secuenciación Completa del Genoma , África/epidemiología , Asia/epidemiología , Costo de Enfermedad , Humanos , Mycobacterium tuberculosis/aislamiento & purificación , Tuberculosis/epidemiología
4.
Clin Infect Dis ; 75(1): 141-151, 2022 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-34665866

RESUMEN

BACKGROUND: In 2010, the World Health Organization (WHO) revised dosing guidelines for treatment of childhood tuberculosis. Our aim was to investigate first-line antituberculosis drug exposures under these guidelines, explore dose optimization using the current dispersible fixed-dose combination (FDC) tablet of rifampicin/isoniazid/pyrazinamide; 75/50/150 mg, and suggest a new FDC with revised weight bands. METHODS: Children with drug-susceptible tuberculosis in Malawi and South Africa underwent pharmacokinetic sampling while receiving first-line tuberculosis drugs as single formulations according the 2010 WHO recommended doses. Nonlinear mixed-effects modeling and simulation was used to design the optimal FDC and weight-band dosing strategy for achieving the pharmacokinetic targets based on literature-derived adult AUC0-24h for rifampicin (38.7-72.9), isoniazid (11.6-26.3), and pyrazinamide (233-429 mg ∙ h/L). RESULTS: In total, 180 children (42% female; 13.9% living with human immunodeficiency virus [HIV]; median [range] age 1.9 [0.22-12] years; weight 10.7 [3.20-28.8] kg) were administered 1, 2, 3, or 4 FDC tablets (rifampicin/isoniazid/pyrazinamide 75/50/150 mg) daily for 4-8, 8-12, 12-16, and 16-25 kg weight bands, respectively. Rifampicin exposure (for weight and age) was up to 50% lower than in adults. Increasing the tablet number resulted in adequate rifampicin but relatively high isoniazid and pyrazinamide exposures. Administering 1, 2, 3, or 4 optimized FDC tablets (rifampicin/isoniazid/pyrazinamide 120/35/130 mg) to children < 6, 6-13, 13-20. and 20-25 kg, and 0.5 tablet in < 3-month-olds with immature metabolism, improved exposures to all 3 drugs. CONCLUSIONS: Current pediatric FDC doses resulted in low rifampicin exposures. Optimal dosing of all drugs cannot be achieved with the current FDCs. We propose a new FDC formulation and revised weight bands.


Asunto(s)
Pirazinamida , Tuberculosis , Adulto , Antituberculosos/uso terapéutico , Niño , Combinación de Medicamentos , Etambutol/uso terapéutico , Femenino , Humanos , Lactante , Isoniazida , Masculino , Estudios Prospectivos , Pirazinamida/farmacocinética , Rifampin/uso terapéutico , Comprimidos/uso terapéutico , Tuberculosis/tratamiento farmacológico
5.
Antimicrob Agents Chemother ; 66(7): e0032222, 2022 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-35758754

RESUMEN

Studies have shown that variants in bedaquiline-resistance genes can occur in isolates from bedaquiline-naive patients. We assessed the prevalence of variants in all bedaquiline-candidate-resistance genes in bedaquiline-naive patients, investigated the association between these variants and lineage, and the effect on phenotype. We used whole-genome sequencing to identify variants in bedaquiline-resistance genes in isolates from 509 bedaquiline treatment naive South African tuberculosis patients. A phylogenetic tree was constructed to investigate the association with the isolate lineage background. Bedaquiline MIC was determined using the UKMYC6 microtiter assay. Variants were identified in 502 of 509 isolates (98.6%), with the highest (85%) prevalence of variants in the Rv0676c (mmpL5) gene. We identified 36 unique variants, including 19 variants not reported previously. Only four isolates had a bedaquiline MIC equal to or above the epidemiological cut-off value of 0.25 µg/mL. Phylogenetic analysis showed that 14 of the 15 variants observed more than once occurred monophyletically in one Mycobacterium tuberculosis (sub)lineage. The bedaquiline MIC differed between isolates belonging to lineage 2 and 4 (Fisher's exact test, P = 0.0004). The prevalence of variants in bedaquiline-resistance genes in isolates from bedaquiline-naive patients is high, but very few (<2%) isolates were phenotypically resistant. We found an association between variants in bedaquiline resistance genes and Mycobacterium tuberculosis (sub)lineage, resulting in a lineage-dependent difference in bedaquiline phenotype. Future studies should investigate the impact of the presence of variants on bedaquiline-resistance acquisition and treatment outcome.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Resistente a Múltiples Medicamentos , Antituberculosos/farmacología , Antituberculosos/uso terapéutico , Diarilquinolinas/farmacología , Humanos , Pruebas de Sensibilidad Microbiana , Mycobacterium tuberculosis/genética , Filogenia , Prevalencia , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología , Tuberculosis Resistente a Múltiples Medicamentos/microbiología
6.
J Clin Microbiol ; 60(1): e0064621, 2022 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-34133895

RESUMEN

The next-generation, short-read sequencing technologies that generate comprehensive, whole-genome data with single nucleotide resolution have already advanced tuberculosis diagnosis, treatment, surveillance, and source investigation. Their high costs, tedious and lengthy processes, and large equipment remain major hurdles for research use in high tuberculosis burden countries and implementation into routine care. The portable next-generation sequencing devices developed by Oxford Nanopore Technologies (ONT) are attractive alternatives due to their long-read sequence capability, compact low-cost hardware, and continued improvements in accuracy and throughput. A systematic review of the published literature demonstrated limited uptake of ONT sequencing in tuberculosis research and clinical care. Of the 12 eligible articles presenting ONT sequencing data on at least one Mycobacterium tuberculosis sample, four addressed software development for long-read ONT sequencing data with potential applications for M. tuberculosis. Only eight studies presented results of ONT sequencing of M. tuberculosis, of which five performed whole-genome and three did targeted sequencing. Based on these findings, we summarize the standard processes, reflect on the current limitations of ONT sequencing technology, and the research needed to overcome the main hurdles. The low capital cost, portable nature and continued improvement in the performance of ONT sequencing make it an attractive option for sequencing for research and clinical care, but limited data are available on its application in the tuberculosis field. Important research investment is needed to unleash the full potential of ONT sequencing for tuberculosis research and care.


Asunto(s)
Mycobacterium tuberculosis , Secuenciación de Nanoporos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Mycobacterium tuberculosis/genética , Análisis de Secuencia de ADN , Programas Informáticos
7.
J Clin Microbiol ; 60(1): e0190721, 2022 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-34757831

RESUMEN

Pyrazinamide is an important component of both drug-susceptible and drug-resistant tuberculosis treatment regimens. Although approximately 50% of rifampin-resistant isolates are also resistant to pyrazinamide, pyrazinamide susceptibility testing is not routinely performed due to the challenging nature of the assay. We investigated the diagnostic accuracy of genotypic and phenotypic methods and explored the occurrence of pyrazinamide heteroresistance. We assessed pyrazinamide susceptibility among 358 individuals enrolled in the South African EXIT-RIF cohort using Sanger and targeted deep sequencing (TDS) of the pncA gene, whole-genome sequencing (WGS), and phenotypic drug susceptibility testing. We calculated the diagnostic accuracy of the different methods and investigated the prevalence and clinical impact of pncA heteroresistance. True pyrazinamide susceptibility status was assigned to each isolate using the Köser classification and expert rules. We observed 100% agreement across genotypic methods for detection of pncA fixed mutations; only TDS confidently identified three isolates (0.8%) with minor variants. For the 355 (99.2%) isolates that could be assigned true pyrazinamide status with confidence, phenotypic DST had a sensitivity of 96.5% (95% confidence interval [CI], 93.8 to 99.3%) and specificity of 100% (95% CI, 100 to 100%), both Sanger sequencing and WGS had a sensitivity of 97.1% (95% CI, 94.6 to 99.6%) and specificity of 97.8% (95% CI, 95.7 to 99.9%), and TDS had sensitivity of 98.8% (95% CI, 97.2 to 100%) and specificity of 97.8% (95% CI, 95.7 to 99.9%). We demonstrate high sensitivity and specificity for pyrazinamide susceptibility testing among all assessed genotypic methods. The prevalence of pyrazinamide heteroresistance in Mycobacterium tuberculosis isolates was lower than that identified for other first-line drugs.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Resistente a Múltiples Medicamentos , Amidohidrolasas/genética , Antituberculosos/farmacología , Antituberculosos/uso terapéutico , Genómica , Humanos , Pruebas de Sensibilidad Microbiana , Mutación , Mycobacterium tuberculosis/genética , Pirazinamida/farmacología , Pirazinamida/uso terapéutico , Tuberculosis Resistente a Múltiples Medicamentos/microbiología
8.
BMC Infect Dis ; 22(1): 876, 2022 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-36418994

RESUMEN

BACKGROUND: Bedaquiline (BDQ) is a core drug for rifampicin-resistant tuberculosis (RR-TB) treatment. Accurate prediction of a BDQ-resistant phenotype from genomic data is not yet possible. A Bayesian method to predict BDQ resistance probability from next-generation sequencing data has been proposed as an alternative. METHODS: We performed a qualitative study to investigate the decision-making of physicians when facing different levels of BDQ resistance probability. Fourteen semi-structured interviews were conducted with physicians experienced in treating RR-TB, sampled purposefully from eight countries with varying income levels and burden of RR-TB. Five simulated patient scenarios were used as a trigger for discussion. Factors influencing the decision of physicians to prescribe BDQ at macro-, meso- and micro levels were explored using thematic analysis. RESULTS: The perception and interpretation of BDQ resistance probability values varied widely between physicians. The limited availability of other RR-TB drugs and the high cost of BDQ hindered physicians from altering the BDQ-containing regimen and incorporating BDQ resistance probability in their decision-making. The little experience with BDQ susceptibility testing and whole-genome sequencing results, and the discordance between phenotypic susceptibility and resistance probability were other barriers for physicians to interpret the resistance probability estimates. Especially for BDQ resistance probabilities between 25% and 70%, physicians interpreted the resistance probability value dynamically, and other factors such as clinical and bacteriological treatment response, history of exposure to BDQ, and resistance profile were often considered more important than the BDQ probability value for the decision to continue or stop BDQ. In this grey zone, some physicians opted to continue BDQ but added other drugs to strengthen the regimen. CONCLUSIONS: This study highlights the complexity of physicians' decision-making regarding the use of BDQ in RR-TB regimens for different levels of BDQ resistance probability.. Ensuring sufficient access to BDQ and companion drugs, improving knowledge of the genotype-phenotype association for BDQ resistance, availability of a rapid molecular test, building next-generation sequencing capacity, and developing a clinical decision support system incorporating BDQ resistance probability will all be essential to facilitate the implementation of BDQ resistance probability in personalizing treatment for patients with RR-TB.


Asunto(s)
Rifampin , Tuberculosis Resistente a Múltiples Medicamentos , Humanos , Rifampin/farmacología , Rifampin/uso terapéutico , Teorema de Bayes , Antituberculosos/efectos adversos , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Toma de Decisiones
9.
BMC Med Inform Decis Mak ; 22(1): 56, 2022 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-35236355

RESUMEN

BACKGROUND: Personalized medicine tailors care based on the patient's or pathogen's genotypic and phenotypic characteristics. An automated Clinical Decision Support System (CDSS) could help translate the genotypic and phenotypic characteristics into optimal treatment and thus facilitate implementation of individualized treatment by less experienced physicians. METHODS: We developed a hybrid knowledge- and data-driven treatment recommender CDSS. Stakeholders and experts first define the knowledge base by identifying and quantifying drug and regimen features for the prototype model input. In an iterative manner, feedback from experts is harvested to generate model training datasets, machine learning methods are applied to identify complex relations and patterns in the data, and model performance is assessed by estimating the precision at one, mean reciprocal rank and mean average precision. Once the model performance no longer iteratively increases, a validation dataset is used to assess model overfitting. RESULTS: We applied the novel methodology to develop a treatment recommender CDSS for individualized treatment of drug resistant tuberculosis as a proof of concept. Using input from stakeholders and three rounds of expert feedback on a dataset of 355 patients with 129 unique drug resistance profiles, the model had a 95% precision at 1 indicating that the highest ranked treatment regimen was considered appropriate by the experts in 95% of cases. Use of a validation data set however suggested substantial model overfitting, with a reduction in precision at 1 to 78%. CONCLUSION: Our novel and flexible hybrid knowledge- and data-driven treatment recommender CDSS is a first step towards the automation of individualized treatment for personalized medicine. Further research should assess its value in fields other than drug resistant tuberculosis, develop solid statistical approaches to assess model performance, and evaluate their accuracy in real-life clinical settings.


Asunto(s)
Sistemas de Apoyo a Decisiones Clínicas , Tuberculosis Resistente a Múltiples Medicamentos , Humanos , Bases del Conocimiento , Aprendizaje Automático , Medicina de Precisión , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico
10.
Clin Microbiol Rev ; 34(1)2020 12 16.
Artículo en Inglés | MEDLINE | ID: mdl-33055230

RESUMEN

Successful treatment of tuberculosis (TB) can be hampered by Mycobacterium tuberculosis populations that are temporarily able to survive antibiotic pressure in the absence of drug resistance-conferring mutations, a phenomenon termed drug tolerance. We summarize findings on M. tuberculosis tolerance published in the past 20 years. Key M. tuberculosis responses to drug pressure are reduced growth rates, metabolic shifting, and the promotion of efflux pump activity. Metabolic shifts upon drug pressure mainly occur in M. tuberculosis's lipid metabolism and redox homeostasis, with reduced tricarboxylic acid cycle activity in favor of lipid anabolism. Increased lipid anabolism plays a role in cell wall thickening, which reduces sensitivity to most TB drugs. In addition to these general mechanisms, drug-specific mechanisms have been described. Upon isoniazid exposure, M. tuberculosis reprograms several pathways associated with mycolic acid biosynthesis. Upon rifampicin exposure, M. tuberculosis upregulates the expression of its drug target rpoB Upon bedaquiline exposure, ATP synthesis is stimulated, and the transcription factors Rv0324 and Rv0880 are activated. A better understanding of M. tuberculosis's responses to drug pressure will be important for the development of novel agents that prevent the development of drug tolerance following treatment initiation. Such agents could then contribute to novel TB treatment-shortening strategies.


Asunto(s)
Antituberculosos/farmacología , Farmacorresistencia Bacteriana Múltiple , Mycobacterium tuberculosis/metabolismo , Tuberculosis/microbiología , Antituberculosos/uso terapéutico , Proteínas Bacterianas/metabolismo , Ciclo del Ácido Cítrico/efectos de los fármacos , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Humanos , Metabolismo de los Lípidos/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Mutación , Mycobacterium tuberculosis/efectos de los fármacos , Tuberculosis/tratamiento farmacológico
11.
AIDS Care ; 33(7): 879-887, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-32835504

RESUMEN

There is limited information about the best strategy for adolescent girls and young women (AGYW) to negotiate HIV testing with their male partners. HIV self-testing as a strategy has the potential to overcome barriers to traditional HIV testing among men. We conducted formative feasibility research on secondary distribution of HIV self-tests by HIV negative AGYW to their male partners in northern Johannesburg, South Africa. A total of 8 focus group discussions with AGYW and men and 20 key informant interviews with community stakeholders were conducted to determine the best approach to partner-initiated testing. This study suggested that AGYW-initiated secondary distribution of HIV self-testing to their male sexual partners is considered an acceptable strategy by AGYW, men, and the community at large. The benefits included empowerment of women, reduction in HIV-testing associated stigma, and increased privacy and confidentiality for the men who test. Major concerns were safety of the AGYW, safety of men testing positive at home, and the lack of pre- and post-test counseling. The outcomes of the formative research were used to refine strategies for a secondary distribution of HIV self-testing intervention.


Asunto(s)
Infecciones por VIH , Parejas Sexuales , Adolescente , Consejo , Femenino , Infecciones por VIH/diagnóstico , Humanos , Masculino , Conducta Sexual , Estigma Social , Sudáfrica
12.
Qual Health Res ; 31(4): 722-735, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33570470

RESUMEN

Provision of high-quality HIV care is challenging, especially in rural primary care clinics in high HIV burden settings. We aimed to better understand the main challenges to quality HIV care provision and retention in antiretroviral treatment (ART) programs in rural South Africa from the health care providers' perspective. We conducted semi-structured qualitative interviews with 23 providers from nine rural clinics. Using thematic and framework analysis, we found that providers and patients face a set of complex and intertwined barriers at the structural, programmatic, and individual levels. More specifically, analyses revealed that their challenges are primarily structural (i.e., health system- and microeconomic context-specific) and programmatic (i.e., clinic- and provider-specific) in nature. We highlight the linkages that providers draw between the challenges they face, the motivation to do their job, the quality of the care they provide, and patients' dissatisfaction with the care they receive, all potentially resulting in poor retention in care.


Asunto(s)
Infecciones por VIH , Antirretrovirales/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Personal de Salud , Humanos , Investigación Cualitativa , Calidad de la Atención de Salud , Sudáfrica
13.
J Antimicrob Chemother ; 75(5): 1123-1129, 2020 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-32016320

RESUMEN

BACKGROUND: Molecular assays are endorsed for detection and confirmation of rifampicin-resistant TB. The frequency, causal mechanisms and impact of discordant results between molecular tests are not well understood. METHODS: The prevalence of discordant results was determined by pairwise comparison of molecular test results in a cohort of 749 rifampicin-resistant TB patients in three South African provinces. Culture isolates were sent to a research laboratory for WGS and rifampicin MIC determination. Clinical information was collected through medical file review. RESULTS: The prevalence of discordances between Xpert MTB/RIF and MTBDRplus was 14.5% (95% CI 10.9%-18.9%), 5.6% (95% CI 2.2%-13.4%) between two consecutive Xpert assays and 4.2% (95% CI 2.2%-7.8%) between two consecutive MTBDRplus assays. Likely mechanisms of discordances were false rifampicin susceptibility on MTBDRplus (due to variants not included in mutant probes or heteroresistance with loss of minor variants in culture), false resistance on molecular assay in rifampicin-susceptible isolates, and human error. The healthcare worker changed the treatment regimen in 33% of patients with discordant results and requested 232 additional molecular tests after a first confirmatory test was performed in 460 patients. A follow-up Xpert assay would give the healthcare worker the 'true' rifampicin-resistant TB diagnosis in at least 73% of discordant cases. CONCLUSIONS: The high rate of discordant results between Xpert and MTBDRplus has important implications for the laboratory, clinician and patient. While root causes for discordant result are multiple, a follow-up Xpert assay could guide healthcare workers to the correct treatment in most patients.


Asunto(s)
Antibióticos Antituberculosos , Mycobacterium tuberculosis , Tuberculosis Resistente a Múltiples Medicamentos , Antibióticos Antituberculosos/farmacología , Farmacorresistencia Bacteriana , Humanos , Mycobacterium tuberculosis/genética , Rifampin/farmacología , Sensibilidad y Especificidad , Tuberculosis Resistente a Múltiples Medicamentos/diagnóstico , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología
14.
AIDS Behav ; 24(4): 1197-1206, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31560093

RESUMEN

Adherence clubs for patients stable on antiretroviral treatment (ART) offer decongestion of clinics and task-shifting, improved adherence and retention in care. Findings on patient acceptability by club location (in the clinic vs. the community) are limited. This was a mixed-methods study set within a randomized controlled trial of community versus clinic-based adherence clubs for retention in care at Witkoppen Health and Welfare Centre in Johannesburg, South Africa. Participants were surveyed on preferences for adherence club-based care (e.g. location, convenience). We conducted in-depth interviews (IDIs) with 36 participants, and surveyed 568 participants: 49% in community-based clubs and 51% in clinic-based clubs. Participants in both arms favorably rated adherence clubs. Almost all (95%) in clinic-based clubs would recommend them to a friend, while fewer (88% in community-based club participants would do so (p = 0.004). Participants found clubs promoted social support, and were convenient and time-saving, though concerns around stigma and access to other health care were noted within community-based clubs. Adherence clubs are a highly acceptable form of differentiated care for stable ART patients. These data indicate that clinic-based clubs may be preferred above community-based clubs, potentially for reasons of stigma and access to additional health care services.


Asunto(s)
Fármacos Anti-VIH , Infecciones por VIH , Cumplimiento de la Medicación , Fármacos Anti-VIH/uso terapéutico , Antirretrovirales/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Humanos , Grupo Paritario , Ensayos Clínicos Controlados Aleatorios como Asunto , Sudáfrica
15.
PLoS Med ; 16(5): e1002808, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-31112543

RESUMEN

BACKGROUND: Adherence clubs, where groups of 25-30 patients who are virally suppressed on antiretroviral therapy (ART) meet for counseling and medication pickup, represent an innovative model to retain patients in care and facilitate task-shifting. This intervention replaces traditional clinical care encounters with a 1-hour group session every 2-3 months, and can be organized at a clinic or a community venue. We performed a pragmatic randomized controlled trial to compare loss from club-based care between community- and clinic-based adherence clubs. METHODS AND FINDINGS: Patients on ART with undetectable viral load at Witkoppen Health and Welfare Centre in Johannesburg, South Africa, were randomized 1:1 to a clinic- or community-based adherence club. Clubs were held every other month. All participants received annual viral load monitoring and medical exam at the clinic. Participants were referred back to clinic-based standard care if they missed a club visit and did not pick up ART medications within 5 days, had 2 consecutive late ART medication pickups, developed a disqualifying (excluding) comorbidity, or had viral rebound. From February 12, 2014, to May 31, 2015, we randomized 775 eligible adults into 12 pairs of clubs-376 (49%) into clinic-based clubs and 399 (51%) into community-based clubs. Characteristics were similar by arm: 65% female, median age 38 years, and median CD4 count 506 cells/mm3. Overall, 47% (95% CI 44%-51%) experienced the primary outcome of loss from club-based care. Among community-based club participants, the cumulative proportion lost from club-based care was 52% (95% CI 47%-57%), compared to 43% (95% CI 38%-48%, p = 0.002) among clinic-based club participants. The risk of loss to club-based care was higher among participants assigned to community-based clubs than among those assigned to clinic-based clubs (adjusted hazard ratio 1.38, 95% CI 1.02-1.87, p = 0.032), after accounting for sex, age, nationality, time on ART, baseline CD4 count, and employment status. Among those who were lost from club-based care (n = 367), the most common reason was missing a club visit and the associated ART medication pickup entirely (54%, 95% CI 49%-59%), and was similar by arm (p = 0.086). Development of an excluding comorbidity occurred in 3% overall of those lost from club-based care, and was not different by arm (p = 0.816); no deaths occurred in either arm during club-based care. Viral rebound occurred in 13% of those lost from community club-based care and 21% of those lost from clinic-based care (p = 0.051). In post hoc secondary analysis, among those referred to standard care, 72% (95% CI 68%-77%) reengaged in clinic-based care within 90 days of their club-based care discontinuation date. The main limitations of the trial are the lack of a comparison group receiving routine clinic-based standard care and the potential limited generalizability due to the single-clinic setting. CONCLUSIONS: These findings demonstrate that overall loss from an adherence club intervention was high in this setting and that, importantly, it was worse in community-based adherence clubs compared to those based at the clinic. We urge caution in assuming that the effectiveness of clinic-based interventions will carry over to community settings, without a better understanding of patient-level factors associated with successful retention in care. TRIAL REGISTRATION: Pan African Clinical Trials Registry (PACTR201602001460157).


Asunto(s)
Atención Ambulatoria/organización & administración , Fármacos Anti-VIH/uso terapéutico , Servicios de Salud Comunitaria/organización & administración , Procesos de Grupo , Infecciones por VIH/tratamiento farmacológico , Cumplimiento de la Medicación , Adolescente , Adulto , Consejo , Femenino , Infecciones por VIH/diagnóstico , Infecciones por VIH/virología , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Persona de Mediana Edad , Educación del Paciente como Asunto , Sudáfrica , Factores de Tiempo , Resultado del Tratamiento , Carga Viral , Adulto Joven
16.
J Antimicrob Chemother ; 74(8): 2347-2351, 2019 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-31081020

RESUMEN

OBJECTIVES: To evaluate the proportion of children with lopinavir Cmin ≥1 mg/L when receiving a novel 8-hourly lopinavir/ritonavir dosing strategy during rifampicin co-treatment. METHODS: HIV-infected children on lopinavir/ritonavir and rifampicin were enrolled in a prospective pharmacokinetic study. Children were switched from standard-of-care lopinavir/ritonavir-4:1 with additional ritonavir (1:1 ratio) twice daily to 8-hourly lopinavir/ritonavir-4:1 using weight-banded dosing. Rifampicin was dosed at 10-20 mg/kg/day. After 2 weeks, plasma samples were collected ∼2, 4, 6, 8 and 10 h after the morning lopinavir/ritonavir-4:1 dose, ALT was obtained to assess safety and treatment was switched back to standard of care. ClinicalTrials.gov registration number: NCT01637558. RESULTS: We recruited 11 children in two weight bands: 5 (45%) were 10-13.9 kg and received 20-24 mg/kg/dose of lopinavir and 6 (55%) children weighed 6-9.9 kg and received 20-23 mg/kg/dose of lopinavir. The median age was 15 months (IQR = 12.6-28.8 months). The median (IQR) lopinavir Cmin was 3.0 (0.1-5.5) mg/L. Seven (63.6%) of the 11 children had Cmin values ≥1 mg/L. Children with a lopinavir mg/kg dose below the median 21.5 were more likely to have Cmin <1 mg/L (P = 0.02). There was a strong positive correlation between lopinavir and ritonavir concentrations. No associations were found between lopinavir AUC2-10 and age, sex, weight, nutritional status or mg/kg/dose of lopinavir. CONCLUSIONS: These data do not support the use of 8-hourly lopinavir/ritonavir at studied doses. Evaluation of higher doses is needed to optimize treatment outcomes of TB and HIV in young children.


Asunto(s)
Fármacos Anti-VIH/farmacocinética , Antibióticos Antituberculosos/administración & dosificación , Infecciones por VIH/tratamiento farmacológico , Lopinavir/farmacocinética , Rifampin/administración & dosificación , Ritonavir/farmacocinética , Tuberculosis/tratamiento farmacológico , Alanina Transaminasa/sangre , Fármacos Anti-VIH/administración & dosificación , Fármacos Anti-VIH/efectos adversos , Antibióticos Antituberculosos/efectos adversos , Niño , Preescolar , Combinación de Medicamentos , Femenino , Infecciones por VIH/complicaciones , Humanos , Lactante , Recién Nacido , Lopinavir/administración & dosificación , Lopinavir/efectos adversos , Masculino , Plasma/química , Estudios Prospectivos , Rifampin/efectos adversos , Ritonavir/administración & dosificación , Ritonavir/efectos adversos , Resultado del Tratamiento , Tuberculosis/complicaciones
17.
Am J Obstet Gynecol ; 221(1): 48.e1-48.e18, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30807762

RESUMEN

BACKGROUND: Subfertility among couples affected by HIV has an impact on the well-being of couples who desire to have children and may prolong HIV exposure. Subfertility in the antiretroviral therapy era and its determinants have not yet been well characterized. OBJECTIVE: The objective of the study was to investigate the burden and determinants of subfertility among HIV-affected couples seeking safer conception services in South Africa. STUDY DESIGN: Nonpregnant women and male partners in HIV seroconcordant or HIV discordant relationships desiring a child were enrolled in the Sakh'umndeni safer conception cohort at Witkoppen Clinic in Johannesburg between July 2013 and April 2017. Clients were followed up prospectively through pregnancy (if they conceived) or until 6 months of attempted conception, after which they were referred for infertility services. Subfertility was defined as not having conceived within 6 months of attempted conception. Robust Poisson regression was used to assess the association between baseline characteristics and subfertility outcomes; inverse probability weighting was used to account for missing data from women lost to safer conception care before 6 months of attempted conception. RESULTS: Among 334 couples enrolled, 65% experienced subfertility (inverse probability weighting weighted, 95% confidence interval, 0.59-0.73), of which 33% were primary subfertility and 67% secondary subfertility. Compared with HIV-negative women, HIV-positive women not on antiretroviral therapy had a 2-fold increased risk of subfertility (weighted and adjusted risk ratio, 2.00; 95% confidence interval, 1.19-3.34). Infertility risk was attenuated in women on antiretroviral therapy but remained elevated, even after ≥2 years on antiretroviral therapy (weighted and adjusted risk ratio, 1.63; 95% confidence interval, 0.98-2.69). Other factors associated with subfertility were female age (weighted and adjusted risk ratio, 1.03, 95% confidence interval, 1.01-1.05 per year), male HIV-positive status (weighted and adjusted risk ratio, 1.31; 95% confidence interval, 1.02-1.68), male smoking (weighted and adjusted risk ratio, 1.29; 95% confidence interval, 1.05-1.60), and trying to conceive for ≥1 year (weighted and adjusted risk ratio, 1.38; 95% confidence interval, 1.13-1.68). CONCLUSION: Two in 3 HIV-affected couples experienced subfertility. HIV-positive women were at increased risk of subfertility, even when on antiretroviral therapy. Both male and female HIV status were associated with subfertility. Subfertility is an underrecognized reproductive health problem in resource-limited settings and may contribute to prolonged HIV exposure and transmission within couples. Low-cost approaches for screening and treating subfertility in this population are needed.


Asunto(s)
Infecciones por VIH/epidemiología , Infertilidad/epidemiología , Adulto , Factores de Edad , Terapia Antirretroviral Altamente Activa , Circuncisión Masculina , Femenino , Fertilización , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/transmisión , Humanos , Inseminación Artificial , Masculino , Profilaxis Pre-Exposición , Atención Preconceptiva , Factores de Riesgo , Fumar/epidemiología , Sudáfrica , Carga Viral
18.
AIDS Care ; 31(1): 117-124, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30304947

RESUMEN

We examined the prevalence of mental health conditions, social support, and associated factors among adolescents living with HIV. We conducted a cross-sectional analysis with adolescents (ages 9-19) attending a primary care clinic in Johannesburg, South Africa. We analyzed the results of four self-report tools: Children's Depression Inventory-Short, Revised Manifest Anxiety Scale, Child Post-Traumatic Stress Disorder (PTSD) Checklist, and a modified version of the Medical Outcomes Study Social Support Scale. We used robust Poisson regression to quantify the association between social support and mental health. Among 278 adolescents, the majority were perinatally infected with HIV (92%), and had at least one deceased parent (59%). Depression symptom threshold scores were found among 8% of adolescents, and 7% screened positive for symptoms of anxiety. Few (1%) met the criteria for PTSD. Overall, 12% of adolescents screened positive for symptoms of depression, anxiety or PTSD. Older adolescents reported less social support than younger adolescents. Adolescents were less likely to have mental health symptoms if they had higher measures of social support (adjusted Prevalence Ratio 0.38, 95% CI 0.20-0.73). Attention should be paid to social support for adolescents living with HIV as this may play an important role in their mental health.


Asunto(s)
Ansiedad/psicología , Depresión/psicología , Infecciones por VIH/epidemiología , Infecciones por VIH/psicología , Salud Mental , Apoyo Social , Trastornos por Estrés Postraumático/psicología , Adolescente , Ansiedad/epidemiología , Niño , Estudios Transversales , Depresión/epidemiología , Femenino , Infecciones por VIH/tratamiento farmacológico , Humanos , Masculino , Salud Mental/etnología , Salud Mental/estadística & datos numéricos , Prevalencia , Sudáfrica/epidemiología , Trastornos por Estrés Postraumático/epidemiología , Adulto Joven
19.
BMC Public Health ; 19(1): 532, 2019 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-31072352

RESUMEN

BACKGROUND: In 2012, South Africa adopted the Contraception and Fertility Planning guidelines to incorporate safer conception services into care for HIV-affected couples trying to conceive. These guidelines lacked clear implementation and training recommendations. The objective of this study was to investigate factors influencing integration of safer conception services in a clinical setting. METHODS: Twenty in-depth interviews were conducted between October-November 2017 with providers and staff at Witkoppen Clinic in Johannesburg, where the Sakh'umndeni safer conception demonstration project had enrolled patients from July 2013-July 2017. Semi-structured interview guides engaged providers on their perspectives following the Sakh'umndeni project and possible integration plans to inform the translation of the stand-alone Sakh'umndeni services into a routine service. A grounded theory approach was used to code interviews and an adaptation of the Atun et al. (2010) 'Integration of Targeted Interventions into Health Systems' conceptual framework was applied as an analysis tool. RESULTS: Five themes emerged: (1) The need for safer conception training; (2) The importance of messaging and demand generation; (3) A spectrum of views around the extent of integration of safer conception services; (4) Limitations of family planning services as an integration focal point; and (5) Benefits and challenges of a "couples-based" intervention. In-depth interviews suggested that counselors, as the first point of contact, should inform patients about safer conceptions services, followed by targeted reinforcement of safer conception messaging by all clinicians, and referral to more intensively trained safer conception providers. CONCLUSION: A safer conception counseling guide would facilitate consultations. While many providers felt that the services belonged in family planning, lack of HIV management skills, men and women trying to conceive within family planning may pose barriers.


Asunto(s)
Anticoncepción/estadística & datos numéricos , Consejo/organización & administración , Servicios de Planificación Familiar/organización & administración , Infecciones por VIH/prevención & control , Actitud del Personal de Salud , Fertilización , Teoría Fundamentada , Humanos , Seguridad del Paciente , Atención Primaria de Salud/organización & administración , Derivación y Consulta/organización & administración , Sudáfrica
20.
BMC Public Health ; 19(1): 87, 2019 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-30658611

RESUMEN

BACKGROUND: HIV immunosuppression increases susceptibility to other STIs and STIs can enhance HIV transmission, reduce CD4 cell count and increase viral load. Co-infections of HIV and STIs may thus reduce the preventive benefits of ART. Little is known about the incidence rate of STIs among long-term patients on ART. METHOD: We conducted a secondary data analysis of all patients enrolled in a rural and an urban longitudinal cohort studies who initiated ART between April 2003 and July 2007 followed up to 2016. Patients were screened for STI every three months using "a syndromic and case management approaches". STI incidence rate, was defined as the number of new cases per population at risk over the follow-up review period. We performed a time-to-event and Kaplan Meier analysis. We used a multivariable Cox proportional hazards regression model to assess for factors associated with STI incidence. RESULT: Of 1012 participants, 402 (39.8%) were urban and 610 (60.2%) rural residents. Mean age was 42.8 years (SD 8.5). The total number of follow up time was 44,304 person years. We observed STI incidence rate of 2.1 per 1000 person-years after follow-up. Rural residence (adjusted hazard ratio [aHR] 3.53, 95% CI: 1.95-6.39), younger age (aHR 2.05, 95% CI: 1.02-4.12 for 18-34 years and aHR 1.65, 95% CI: 1.00-2.72 for 35-44 years) were factors associated with higher incidence of STIs. Being male (aHR 0.51, 95% CI: 0.27-0.93) was associated with a lower incidence of STIs. CONCLUSION: We found STIs incidence rate of approximately 3 per 1000 person-years among patients on long-term (≥ 4 years) ART followed up-to 3.5 years. Rural and younger persons on ART should be routinely screened for STIs because high incidence of STIs may undo the preventative effects of ART for all.


Asunto(s)
Antirretrovirales/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Servicios de Salud Rural/estadística & datos numéricos , Enfermedades de Transmisión Sexual/epidemiología , Servicios Urbanos de Salud/estadística & datos numéricos , Adolescente , Adulto , Femenino , Infecciones por VIH/epidemiología , Humanos , Incidencia , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Uganda/epidemiología , Adulto Joven
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