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1.
Nature ; 603(7902): 679-686, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35042229

RESUMO

The SARS-CoV-2 epidemic in southern Africa has been characterized by three distinct waves. The first was associated with a mix of SARS-CoV-2 lineages, while the second and third waves were driven by the Beta (B.1.351) and Delta (B.1.617.2) variants, respectively1-3. In November 2021, genomic surveillance teams in South Africa and Botswana detected a new SARS-CoV-2 variant associated with a rapid resurgence of infections in Gauteng province, South Africa. Within three days of the first genome being uploaded, it was designated a variant of concern (Omicron, B.1.1.529) by the World Health Organization and, within three weeks, had been identified in 87 countries. The Omicron variant is exceptional for carrying over 30 mutations in the spike glycoprotein, which are predicted to influence antibody neutralization and spike function4. Here we describe the genomic profile and early transmission dynamics of Omicron, highlighting the rapid spread in regions with high levels of population immunity.


Assuntos
COVID-19/epidemiologia , COVID-19/virologia , Evasão da Resposta Imune , SARS-CoV-2/isolamento & purificação , Anticorpos Neutralizantes/imunologia , Botsuana/epidemiologia , COVID-19/imunologia , COVID-19/transmissão , Humanos , Modelos Moleculares , Mutação , Filogenia , Recombinação Genética , SARS-CoV-2/classificação , SARS-CoV-2/imunologia , África do Sul/epidemiologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia
2.
Nature ; 592(7854): 438-443, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33690265

RESUMO

Continued uncontrolled transmission of SARS-CoV-2 in many parts of the world is creating conditions for substantial evolutionary changes to the virus1,2. Here we describe a newly arisen lineage of SARS-CoV-2 (designated 501Y.V2; also known as B.1.351 or 20H) that is defined by eight mutations in the spike protein, including three substitutions (K417N, E484K and N501Y) at residues in its receptor-binding domain that may have functional importance3-5. This lineage was identified in South Africa after the first wave of the epidemic in a severely affected metropolitan area (Nelson Mandela Bay) that is located on the coast of the Eastern Cape province. This lineage spread rapidly, and became dominant in Eastern Cape, Western Cape and KwaZulu-Natal provinces within weeks. Although the full import of the mutations is yet to be determined, the genomic data-which show rapid expansion and displacement of other lineages in several regions-suggest that this lineage is associated with a selection advantage that most plausibly results from increased transmissibility or immune escape6-8.


Assuntos
COVID-19/virologia , Mutação , Filogenia , Filogeografia , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , COVID-19/epidemiologia , COVID-19/imunologia , COVID-19/transmissão , Análise Mutacional de DNA , Evolução Molecular , Aptidão Genética , Humanos , Evasão da Resposta Imune , Modelos Moleculares , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidade , Seleção Genética , África do Sul/epidemiologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo , Fatores de Tempo
3.
J Infect Dis ; 227(7): 917-925, 2023 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-36735316

RESUMO

BACKGROUND: Neisseria gonorrhoeae is a major public health problem due to increasing incidence and antimicrobial resistance. Genetic markers of reduced susceptibility have been identified; the extent to which those are representative of global antimicrobial resistance is unknown. We evaluated the performance of whole-genome sequencing (WGS) used to predict susceptibility to ciprofloxacin and other antimicrobials using a global collection of N. gonorrhoeae isolates. METHODS: Susceptibility testing of common antimicrobials and the recently developed zolifodacin was performed using agar dilution to determine minimum inhibitory concentrations (MICs). We identified resistance alleles at loci known to contribute to antimicrobial resistance in N. gonorrhoeae from WGS data. We tested the ability of each locus to predict antimicrobial susceptibility. RESULTS: A total of 481 N. gonorrhoeae isolates, collected between 2004 and 2019 and making up 457 unique genomes, were sourced from 5 countries. All isolates with demonstrated susceptibility to ciprofloxacin (MIC ≤0.06 µg/mL) had a wild-type gyrA codon 91. Multilocus approaches were needed to predict susceptibility to other antimicrobials. All isolates were susceptible to zoliflodacin, defined by an MIC ≤0.25 µg/mL. CONCLUSIONS: Single marker prediction can be used to inform ciprofloxacin treatment of N. gonorrhoeae infection. A combination of molecular markers may be needed to determine susceptibility for other antimicrobials.


Assuntos
Anti-Infecciosos , Gonorreia , Humanos , Neisseria gonorrhoeae , Antibacterianos/farmacologia , Gonorreia/tratamento farmacológico , Gonorreia/epidemiologia , Ciprofloxacina/farmacologia , Anti-Infecciosos/farmacologia , Testes de Sensibilidade Microbiana , Farmacorresistência Bacteriana/genética , Azitromicina/farmacologia
4.
Lancet ; 399(10323): 437-446, 2022 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-35065011

RESUMO

BACKGROUND: The SARS-CoV-2 omicron variant of concern was identified in South Africa in November, 2021, and was associated with an increase in COVID-19 cases. We aimed to assess the clinical severity of infections with the omicron variant using S gene target failure (SGTF) on the Thermo Fisher Scientific TaqPath COVID-19 PCR test as a proxy. METHODS: We did data linkages for national, South African COVID-19 case data, SARS-CoV-2 laboratory test data, SARS-CoV-2 genome data, and COVID-19 hospital admissions data. For individuals diagnosed with COVID-19 via TaqPath PCR tests, infections were designated as either SGTF or non-SGTF. The delta variant was identified by genome sequencing. Using multivariable logistic regression models, we assessed disease severity and hospitalisations by comparing individuals with SGTF versus non-SGTF infections diagnosed between Oct 1 and Nov 30, 2021, and we further assessed disease severity by comparing SGTF-infected individuals diagnosed between Oct 1 and Nov 30, 2021, with delta variant-infected individuals diagnosed between April 1 and Nov 9, 2021. FINDINGS: From Oct 1 (week 39), 2021, to Dec 6 (week 49), 2021, 161 328 cases of COVID-19 were reported in South Africa. 38 282 people were diagnosed via TaqPath PCR tests and 29 721 SGTF infections and 1412 non-SGTF infections were identified. The proportion of SGTF infections increased from two (3·2%) of 63 in week 39 to 21 978 (97·9%) of 22 455 in week 48. After controlling for factors associated with hospitalisation, individuals with SGTF infections had significantly lower odds of admission than did those with non-SGTF infections (256 [2·4%] of 10 547 vs 121 [12·8%] of 948; adjusted odds ratio [aOR] 0·2, 95% CI 0·1-0·3). After controlling for factors associated with disease severity, the odds of severe disease were similar between hospitalised individuals with SGTF versus non-SGTF infections (42 [21%] of 204 vs 45 [40%] of 113; aOR 0·7, 95% CI 0·3-1·4). Compared with individuals with earlier delta variant infections, SGTF-infected individuals had a significantly lower odds of severe disease (496 [62·5%] of 793 vs 57 [23·4%] of 244; aOR 0·3, 95% CI 0·2-0·5), after controlling for factors associated with disease severity. INTERPRETATION: Our early analyses suggest a significantly reduced odds of hospitalisation among individuals with SGTF versus non-SGTF infections diagnosed during the same time period. SGTF-infected individuals had a significantly reduced odds of severe disease compared with individuals infected earlier with the delta variant. Some of this reduced severity is probably a result of previous immunity. FUNDING: The South African Medical Research Council, the South African National Department of Health, US Centers for Disease Control and Prevention, the African Society of Laboratory Medicine, Africa Centers for Disease Control and Prevention, the Bill & Melinda Gates Foundation, the Wellcome Trust, and the Fleming Fund.


Assuntos
COVID-19/fisiopatologia , Hospitalização/estatística & dados numéricos , SARS-CoV-2/genética , Índice de Gravidade de Doença , Adolescente , Adulto , COVID-19/epidemiologia , COVID-19/virologia , Teste de Ácido Nucleico para COVID-19 , Criança , Pré-Escolar , Feminino , Genoma Viral , Humanos , Armazenamento e Recuperação da Informação , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , África do Sul/epidemiologia , Adulto Jovem
5.
BMC Health Serv Res ; 23(1): 1452, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38129852

RESUMO

BACKGROUND: Research out of South Africa estimates the total unmet need for care for those with type 2 diabetes mellitus (diabetes) at 80%. We evaluated the care cascade using South Africa's National Health Laboratory Service (NHLS) database and assessed if HIV infection impacts progression through its stages. METHODS: The cohort includes patients from government facilities with their first glycated hemoglobin A1c (HbA1c) or plasma glucose (fasting (FPG); random (RPG)) measured between January 2012 to March 2015 in the NHLS. Lab-diagnosed diabetes was defined as HbA1c ≥ 6.5%, FPG ≥ 7.0mmol/l, or RPG ≥ 11.1mmol/l. Cascade stages post diagnosis were retention-in-care and glycaemic control (defined as an HbA1c < 7.0% or FPG < 8.0mmol/l or RPG < 10.0mmol/l) over 24-months. We estimated gaps at each stage nationally and by people living with HIV (PLWH) and without (PLWOH). RESULTS: Of the 373,889 patients tested for diabetes, 43.2% had an HbA1c or blood glucose measure indicating a diabetes diagnosis. Amongst those with lab-diagnosed diabetes, 30.9% were retained-in-care (based on diabetes labs) and 8.7% reached glycaemic control by 24-months. Prevalence of lab-diagnosed diabetes in PLWH was 28.6% versus 47.3% in PLWOH. Among those with lab-diagnosed diabetes, 34.3% of PLWH were retained-in-care versus 30.3% PLWOH. Among people retained-in-care, 33.8% of PLWH reached glycaemic control over 24-months versus 28.6% of PLWOH. CONCLUSIONS: In our analysis of South Africa's NHLS database, we observed that 70% of patients diagnosed with diabetes did not maintain in consistent diabetes care, with fewer than 10% reaching glycemic control within 24 months. We noted a disparity in diabetes prevalence between PLWH and PLWOH, potentially linked to different screening methods. These differences underscore the intricacies in care but also emphasize how HIV care practices could guide better management of chronic diseases like diabetes. Our results underscore the imperative for specialized strategies to bolster diabetes care in South Africa.


Assuntos
Diabetes Mellitus Tipo 2 , Infecções por HIV , Humanos , Glicemia , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/terapia , Hemoglobinas Glicadas , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/terapia , África do Sul/epidemiologia
7.
Proc Natl Acad Sci U S A ; 116(46): 23284-23291, 2019 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-31659018

RESUMO

Antimicrobial-resistant (AMR) infections pose a major threat to global public health. Similar to other AMR pathogens, both historical and ongoing drug-resistant tuberculosis (TB) epidemics are characterized by transmission of a limited number of predominant Mycobacterium tuberculosis (Mtb) strains. Understanding how these predominant strains achieve sustained transmission, particularly during the critical period before they are detected via clinical or public health surveillance, can inform strategies for prevention and containment. In this study, we employ whole-genome sequence (WGS) data from TB clinical isolates collected in KwaZulu-Natal, South Africa to examine the pre-detection history of a successful strain of extensively drug-resistant (XDR) TB known as LAM4/KZN, first identified in a widely reported cluster of cases in 2005. We identify marked expansion of this strain concurrent with the onset of the generalized HIV epidemic 12 y prior to 2005, localize its geographic origin to a location in northeastern KwaZulu-Natal ∼400 km away from the site of the 2005 outbreak, and use protein structural modeling to propose a mechanism for how strain-specific rpoB mutations offset fitness costs associated with rifampin resistance in LAM4/KZN. Our findings highlight the importance of HIV coinfection, high preexisting rates of drug-resistant TB, human migration, and pathoadaptive evolution in the emergence and dispersal of this critical public health threat. We propose that integrating whole-genome sequencing into routine public health surveillance can enable the early detection and local containment of AMR pathogens before they achieve widespread dispersal.


Assuntos
Evolução Molecular , Tuberculose Extensivamente Resistente a Medicamentos/genética , Mycobacterium tuberculosis/genética , Tuberculose Extensivamente Resistente a Medicamentos/epidemiologia , Genoma Bacteriano , Infecções por HIV/complicações , Humanos , Filogenia , Filogeografia , Estudos Prospectivos , África do Sul/epidemiologia , Sequenciamento Completo do Genoma
8.
Clin Infect Dis ; 73(11): 2083-2092, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-33882121

RESUMO

BACKGROUND: Bedaquiline improves treatment outcomes in patients with rifampin-resistant (RR) tuberculosis but prolongs the QT interval and carries a black-box warning from the US Food and Drug Administration. The World Health Organization recommends that all patients with RR tuberculosis receive a regimen containing bedaquiline, yet a phase 3 clinical trial demonstrating its cardiac safety has not been published. METHODS: We conducted an observational cohort study of patients with RR tuberculosis from 3 provinces in South Africa who received regimens containing bedaquiline. We performed rigorous cardiac monitoring, which included obtaining electrocardiograms in triplicate at 4 time points during bedaquiline therapy. Participants were followed up until the end of therapy or 24 months. Outcomes included final tuberculosis treatment outcome and QT interval prolongation (QT prolongation), defined as any QT interval corrected by the Fridericia method (QTcF) >500 ms or an absolute change from baseline (ΔQTcF) >60 ms. RESULTS: We enrolled 195 eligible participants, of whom 40% had extensively drug-resistant tuberculosis. Most participants (97%) received concurrent clofazimine. Of the participants, 74% were cured or successfully completed treatment, and outcomes did not differ by human immunodeficiency virus status. QTcF continued to increase throughout bedaquiline therapy, with a mean increase (standard deviation) of 23.7 (22.7) ms from baseline to month 6. Four participants experienced a QTcF >500 ms and 19 experienced a ΔQTcF >60 ms. Older age was independently associated with QT prolongation. QT prolongation was neither more common nor more severe in participants receiving concurrent lopinavir-ritonavir. CONCLUSIONS: Severe QT prolongation was uncommon and did not require permanent discontinuation of either bedaquiline or clofazimine. Close monitoring of the QT interval may be advisable in older patients.


Assuntos
Tuberculose Extensivamente Resistente a Medicamentos , Tuberculose Resistente a Múltiplos Medicamentos , Idoso , Antituberculosos/efeitos adversos , Estudos de Coortes , Diarilquinolinas/efeitos adversos , Tuberculose Extensivamente Resistente a Medicamentos/tratamento farmacológico , Humanos , Estudos Prospectivos , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico
9.
PLoS Med ; 18(3): e1003479, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33789340

RESUMO

BACKGROUND: Despite widespread availability of HIV treatment, patient outcomes differ across facilities. We propose and evaluate an approach to measure quality of HIV care at health facilities in South Africa's national HIV program using routine laboratory data. METHODS AND FINDINGS: Data were extracted from South Africa's National Health Laboratory Service (NHLS) Corporate Data Warehouse. All CD4 counts, viral loads (VLs), and other laboratory tests used in HIV monitoring were linked, creating a validated patient identifier. We constructed longitudinal HIV care cascades for all patients in the national HIV program, excluding data from the Western Cape and very small facilities. We then estimated for each facility in each year (2011 to 2015) the following cascade measures identified a priori as reflecting quality of HIV care: median CD4 count among new patients; retention 12 months after presentation; 12-month retention among patients established in care; viral suppression; CD4 recovery; monitoring after an elevated VL. We used factor analysis to identify an underlying measure of quality of care, and we assessed the persistence of this quality measure over time. We then assessed spatiotemporal variation and facility and population predictors in a multivariable regression context. We analyzed data on 3,265 facilities with a median (IQR) annual size of 441 (189 to 988) lab-monitored HIV patients. Retention 12 months after presentation increased from 42% to 47% during the study period, and viral suppression increased from 66% to 79%, although there was substantial variability across facilities. We identified an underlying measure of quality of HIV care that correlated with all cascade measures except median CD4 count at presentation. Averaging across the 5 years of data, this quality score attained a reliability of 0.84. Quality was higher for clinics (versus hospitals), in rural (versus urban) areas, and for larger facilities. Quality was lower in high-poverty areas but was not independently associated with percent Black. Quality increased by 0.49 (95% CI 0.46 to 0.53) standard deviations from 2011 to 2015, and there was evidence of geospatial autocorrelation (p < 0.001). The study's limitations include an inability to fully adjust for underlying patient risk, reliance on laboratory data which do not capture all relevant domains of quality, potential for errors in record linkage, and the omission of Western Cape. CONCLUSIONS: We observed persistent differences in HIV care and treatment outcomes across South African facilities. Targeting low-performing facilities for additional support could reduce overall burden of disease.


Assuntos
Infecções por HIV/tratamento farmacológico , Instalações de Saúde/estatística & dados numéricos , Adulto , Idoso , Contagem de Linfócito CD4/estatística & dados numéricos , Estudos de Coortes , Atenção à Saúde/organização & administração , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , África do Sul , Resultado do Tratamento , Carga Viral/estatística & dados numéricos , Adulto Jovem
10.
Antimicrob Agents Chemother ; 65(10): e0075921, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-34280016

RESUMO

Antimicrobial resistance (AMR) is a major challenge to managing infectious diseases. Africa has the highest incidence of gonorrhoea, but there is a lack of comprehensive data from sparse surveillance programs. This study investigated the molecular epidemiology and AMR profiles of Neisseria gonorrhoeae isolates in KwaZulu-Natal province (KZN), South Africa. Repository isolates from patients attending public health care clinics for sexually transmitted infection (STI) care were used for phenotypic and genotypic analysis. An Etest was performed to determine antimicrobial susceptibility. Whole-genome sequencing (WGS) was used to determine epidemiology and to predict susceptibility by detecting resistance-associated genes and mutations. Among the 61 isolates, multiple sequence types were identified. Six isolates were novel, as determined by multilocus sequence typing. N. gonorrhoeae sequence typing for antimicrobial resistance (NG-STAR) determined 48 sequence types, of which 35 isolates had novel antimicrobial profiles. Two novel penA alleles and eight novel mtrR alleles were identified. Point mutations were detected in gyrA, parC, mtrR, penA, ponA, and porB1. This study revealed a high prevalence of AMR (penicillin 67%, tetracycline 89%, and ciprofloxacin 52%). However, spectinomycin, cefixime, ceftriaxone, and azithromycin remained 100% effective. This study is one of the first to comprehensively describe the epidemiology and AMR of N. gonorrhoeae in KZN, South Africa and Africa, using WGS. KZN has a wide strain diversity and most of these sequence types have been detected in multiple countries; however, more than half of our isolates have novel antimicrobial profiles. Continued surveillance is crucial to monitor the emergence of resistance to cefixime, ceftriaxone, and azithromycin.


Assuntos
Gonorreia , Neisseria gonorrhoeae , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Ceftriaxona , Farmacorresistência Bacteriana/genética , Gonorreia/tratamento farmacológico , Gonorreia/epidemiologia , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Neisseria gonorrhoeae/genética , África do Sul/epidemiologia
11.
Sex Transm Infect ; 97(8): 555-565, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33608480

RESUMO

OBJECTIVES: STIs cause inflammation that is detrimental for both HIV risk and reproductive health. We assessed the impact of point-of-care (POC) STI testing, immediate treatment and expedited partner therapy (EPT) on genital tract cytokines among a cohort of young South African women. METHODS: HIV-negative women underwent POC testing for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) by Xpert CT/NG and OSOM TV, and for bacterial vaginosis (BV) by microscopy. Women with STIs and/or BV received immediate treatment, EPT for STIs and retested after 6 and 12 weeks. Concentrations of 48 cytokines were measured in cervicovaginal fluid at each visit using multiplex ELISA technology. The impact of STI treatment on cytokine concentrations was assessed by multivariable linear mixed models and principal component analysis. RESULTS: The study enrolled 251 women with median age of 23 years (IQR 21-27). The prevalence of CT, NG and TV were 14.3%, 4.4% and 4.0%, and 34.3% had BV. Women with STIs or BV at baseline (n=94) had significantly higher concentrations of pro-inflammatory cytokines (interleukin (IL)-1α, IL-1ß, IL-6, tumour necrosis factor (TNF)-α, TNF-ß, IL-18 and macrophage inflammatory factor (MIF)) and chemokines (IL-8, IL-16, macrophage inflammatory protein (MIP)-1α, IFN-α2, monokine induced by gamma interferon (MIG), monocyte chemoattractant protein (MCP)-3, regulated on activation normal T cell expressed and secreted and eotaxin) compared with women without (n=157). STI treatment was strongly associated with reduced concentrations of pro-inflammatory cytokines IL-6 (p=0.004), IL-1ß (p=0.013), TNF-α (p=0.018) and chemokines MIG (p=0.008) and growth-related oncogene (GRO)-α (p=0.025). A lower Nugent score was associated with a reduction in pro-inflammatory cytokines IL-1α (p=0.003), TNF-related apoptosis-inducing ligand (p=0.004), MIF (p=0.010) and IL-18 (p<0.001), but an increase in chemokines MIG (p=0.020), GRO-α (p<0.001), IP-10 (p<0.001), MIP-1ß (p=0.008) and MCP-1 (p=0.005). Principal component analysis showed differences in STI and BV-related inflammatory profiles, but that resolution restored a profile consistent with vaginal health. CONCLUSIONS: A comprehensive STI intervention effectively reduced genital inflammation among young women, thereby improving vaginal health and potentially reducing HIV risk.


Assuntos
Citocinas/imunologia , Inflamação/imunologia , Testes Imediatos/normas , Infecções do Sistema Genital/imunologia , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/tratamento farmacológico , Vaginose Bacteriana/diagnóstico , Vaginose Bacteriana/tratamento farmacológico , Adolescente , Adulto , Antibacterianos/uso terapêutico , Estudos de Coortes , Citocinas/análise , Feminino , Humanos , Inflamação/tratamento farmacológico , Estudos Prospectivos , Infecções do Sistema Genital/tratamento farmacológico , Infecções do Sistema Genital/microbiologia , Infecções Sexualmente Transmissíveis/microbiologia , Vagina/efeitos dos fármacos , Vagina/microbiologia , Adulto Jovem
12.
Clin Infect Dis ; 70(11): 2396-2402, 2020 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-31342067

RESUMO

BACKGROUND: Tuberculosis (TB) is the leading infectious cause of death globally, and drug-resistant TB strains pose a serious threat to controlling the global TB epidemic. The clinical features, locations, and social factors driving transmission in settings with high incidences of drug-resistant TB are poorly understood. METHODS: We measured a network of genomic links using Mycobacterium tuberculosis whole-genome sequences. RESULTS: Patients with 2-3 months of cough or who spent time in urban locations were more likely to be linked in the network, while patients with sputum smear-positive disease were less likely to be linked than those with smear-negative disease. Associations persisted using different thresholds to define genomic links and irrespective of assumptions about the direction of transmission. CONCLUSIONS: Identifying factors that lead to many transmissions, including contact with urban areas, can suggest settings instrumental in transmission and indicate optimal locations and groups to target with interventions.


Assuntos
Tuberculose Extensivamente Resistente a Medicamentos , Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Antituberculosos/uso terapêutico , Tuberculose Extensivamente Resistente a Medicamentos/tratamento farmacológico , Humanos , Mycobacterium tuberculosis/genética , África do Sul/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico
13.
Am J Epidemiol ; 189(12): 1492-1501, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32648905

RESUMO

South African guidelines recommend repeat viral load testing within 6 months when human immunodeficiency virus (HIV) viral loads exceed 1,000 copies/mL. We assessed whether South African facilities follow viral load monitoring guidelines and whether guidelines improve HIV-related outcomes, using a regression discontinuity design in a national HIV cohort of 174,574 patients (2013-2015). We assessed whether patients with viral loads just above versus just below 1,000 copies/mL were more likely to receive repeat testing in 6 months, and we compared differences in clinic transfers, retention, and viral suppression. The majority (67%) of patients with viral loads of >1,000 copies/mL did not receive repeat testing within 6 months, and these patients were 8.0% (95% confidence interval (CI): 6.2, 9.7) more likely to receive repeat testing compared with ≤1,000 copies/mL. Eligibility for repeat testing (>1,000 copies/mL) was associated with greater 12-month retention (risk difference = 2.9%, 95% CI: 0.6, 5.2) and combined suppression and retention (risk difference = 5.8%, 95% CI: 3.0, 8.6). Patients with viral loads of >1,000 copies/mL who actually received repeat testing were 85.2% more likely to be both retained and virally suppressed at 12 months (95% CI: 35.9, 100.0). Viral load monitoring might improve patient outcomes, but most patients with elevated viral loads do not receive monitoring within recommended timelines.


Assuntos
Fidelidade a Diretrizes/estatística & dados numéricos , Infecções por HIV/virologia , Carga Viral , Adulto , Feminino , Humanos , Masculino , Retenção nos Cuidados , África do Sul
14.
Am J Epidemiol ; 189(7): 735-745, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32242216

RESUMO

Patterns of transmission of drug-resistant tuberculosis (TB) remain poorly understood, despite over half a million incident cases worldwide in 2017. Modeling TB transmission networks can provide insight into drivers of transmission, but incomplete sampling of TB cases can pose challenges for inference from individual epidemiologic and molecular data. We assessed the effect of missing cases on a transmission network inferred from Mycobacterium tuberculosis sequencing data on extensively drug-resistant TB cases in KwaZulu-Natal, South Africa, diagnosed in 2011-2014. We tested scenarios in which cases were missing at random, missing differentially by clinical characteristics, or missing differentially by transmission (i.e., cases with many links were under- or oversampled). Under the assumption that cases were missing randomly, the mean number of transmissions per case in the complete network needed to be larger than 20, far higher than expected, to reproduce the observed network. Instead, the most likely scenario involved undersampling of high-transmitting cases, and models provided evidence for super-spreading. To our knowledge, this is the first analysis to have assessed support for different mechanisms of missingness in a TB transmission study, but our results are subject to the distributional assumptions of the network models we used. Transmission studies should consider the potential biases introduced by incomplete sampling and identify host, pathogen, or environmental factors driving super-spreading.


Assuntos
Transmissão de Doença Infecciosa/estatística & dados numéricos , Tuberculose Extensivamente Resistente a Medicamentos/epidemiologia , Tuberculose Extensivamente Resistente a Medicamentos/transmissão , Modelos Estatísticos , Vigilância da População/métodos , Feminino , Humanos , Incidência , Masculino , Mycobacterium tuberculosis , África do Sul/epidemiologia
15.
N Engl J Med ; 376(3): 243-253, 2017 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-28099825

RESUMO

BACKGROUND: Drug-resistant tuberculosis threatens recent gains in the treatment of tuberculosis and human immunodeficiency virus (HIV) infection worldwide. A widespread epidemic of extensively drug-resistant (XDR) tuberculosis is occurring in South Africa, where cases have increased substantially since 2002. The factors driving this rapid increase have not been fully elucidated, but such knowledge is needed to guide public health interventions. METHODS: We conducted a prospective study involving 404 participants in KwaZulu-Natal Province, South Africa, with a diagnosis of XDR tuberculosis between 2011 and 2014. Interviews and medical-record reviews were used to elicit information on the participants' history of tuberculosis and HIV infection, hospitalizations, and social networks. Mycobacterium tuberculosis isolates underwent insertion sequence (IS)6110 restriction-fragment-length polymorphism analysis, targeted gene sequencing, and whole-genome sequencing. We used clinical and genotypic case definitions to calculate the proportion of cases of XDR tuberculosis that were due to inadequate treatment of multidrug-resistant (MDR) tuberculosis (i.e., acquired resistance) versus those that were due to transmission (i.e., transmitted resistance). We used social-network analysis to identify community and hospital locations of transmission. RESULTS: Of the 404 participants, 311 (77%) had HIV infection; the median CD4+ count was 340 cells per cubic millimeter (interquartile range, 117 to 431). A total of 280 participants (69%) had never received treatment for MDR tuberculosis. Genotypic analysis in 386 participants revealed that 323 (84%) belonged to 1 of 31 clusters. Clusters ranged from 2 to 14 participants, except for 1 large cluster of 212 participants (55%) with a LAM4/KZN strain. Person-to-person or hospital-based epidemiologic links were identified in 123 of 404 participants (30%). CONCLUSIONS: The majority of cases of XDR tuberculosis in KwaZulu-Natal, South Africa, an area with a high tuberculosis burden, were probably due to transmission rather than to inadequate treatment of MDR tuberculosis. These data suggest that control of the epidemic of drug-resistant tuberculosis requires an increased focus on interrupting transmission. (Funded by the National Institute of Allergy and Infectious Diseases and others.).


Assuntos
Antituberculosos/uso terapêutico , Tuberculose Extensivamente Resistente a Medicamentos/transmissão , Mycobacterium tuberculosis/genética , Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Infecções Oportunistas Relacionadas com a AIDS/transmissão , Adolescente , Adulto , Contagem de Linfócito CD4 , Criança , Tuberculose Extensivamente Resistente a Medicamentos/complicações , Tuberculose Extensivamente Resistente a Medicamentos/epidemiologia , Tuberculose Extensivamente Resistente a Medicamentos/microbiologia , Feminino , Infecções por HIV/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Apoio Social , África do Sul/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Adulto Jovem
16.
Eur J Clin Microbiol Infect Dis ; 39(8): 1481-1485, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32193689

RESUMO

Diagnosis of bacterial vaginosis (BV) in resource-poor settings relies on semiquantitative microscopy algorithm such as the Nugent score (NS). We evaluated a quantitative real-time PCR (qPCR) assay to detect and quantify individual BV-associated bacterial communities. Vaginal swabs from 247 South African women attending an STI clinic were evaluated for BV using NS. We used qPCR to analyze DNA from vaginal swabs for eight BV-associated bacteria, Gardnerella vaginalis (GV), Prevotella bivia (PB), BV-associated bacteria 2 (BVAB2), Megasphaera-1 (M-1), Atopobium vaginae (AV), Lactobacillus crispatus (LC), Lactobacillus jensenii (LJ), and Lactobacillus iners (LI). Sensitivities and specificities were generated for each qPCR assay. Using a ROC analysis, cutoffs were calculated for each bacterial species. A logistic regression model was used to determine the strongest predictors of BV status. Nugent scores indicated 35.6% of patients harbor BV-associated flora (NS 7-10). AV, GV, GAMB (GV + AV + M-1 + BVAB2), and LC + LJ showed the highest AUC, sensitivities, and specificities (listed respectively): AV (0.96; 96%; 93%), GV (0.88; 78%; 79%), GAMB (0.9; 87%; 82%), and LC + LJ (0.84; 82%; 72%) (all p < 0.05). Increased GAMB copies (effect = 0.15, p = 0.01) and decreased LC + LJ copies (effect = - 0.26, p < 0.0001) demonstrated the strongest association with higher BV scoring. Scoring of BV did not differ across our qPCR assay when compared to the commercial BD MAX® and the gold standard Nugent scores. We developed an accurate assay, which has the potential to be used as a BV diagnosis tool that is cost-effective and has the potential to be utilized in a resource limited setting.


Assuntos
Vaginose Bacteriana/diagnóstico , Actinobacteria/isolamento & purificação , Adulto , Área Sob a Curva , DNA Bacteriano/análise , Feminino , Gardnerella vaginalis/isolamento & purificação , Humanos , Lactobacillus/isolamento & purificação , Valor Preditivo dos Testes , Prevotella/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Manejo de Espécimes , Vaginose Bacteriana/microbiologia , Adulto Jovem
17.
BMC Infect Dis ; 20(1): 491, 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32650729

RESUMO

BACKGROUND: Bacterial vaginosis (BV) increases HIV risk and adverse reproductive outcomes. Standard-of-care (SOC) for BV are antibiotics; however, cure rates are low. Probiotics for vaginal health may be useful in improving cure and recurrence although the regulatory framework governing probiotics and the conduct of randomized clinical trials to evaluate these has not been established in South Africa. We performed an exploratory single-blind trial evaluating a commercial oral-vaginal-combination probiotic as adjunct to SOC for BV treatment. METHODS: Women with symptomatic vaginal discharge were screened for BV and common sexually transmitted infections (STIs). BV+ (Nugent 7-10) but STI- women were randomized to vaginal metronidazole alone (n = 12) or to metronidazole followed by a commercial oral/vaginal probiotic (n = 18). The primary qualitative outcome was to test the regulatory landscape for conducting randomized probiotic trials in South Africa; and acceptability of vaginal application by women. BV cure at 1 month (Nugent≤3) was the primary quantitative endpoint. Secondary quantitative endpoints were BV recurrence, symptoms, vaginal microbiota and genital cytokine changes over 5 months post-treatment. RESULTS: The  South African Health Products Regulatory Authority (SAHPRA) reviewed and approved this trial. As probiotics continue to be regulated as health supplements in South Africa, SAHPRA required a notification application for this trial. Acceptability and adherence to the oral and vaginal application of the probiotic were high, although women reported a preference for oral capsules. 44.8% of women cleared BV one-month post-treatment, and no significant differences in BV cure (RR = 0.52, 95% CI = 0.24-1.16), recurrence, vaginal pH, symptoms, microbiota or vaginal IL-1α concentrations were found between SOC and intervention groups in this pilot study with an over-the-counter product. CONCLUSION: Navigation of the SAHPRA registration process for evaluating a commercial probiotic in a randomised trial laid the foundation for planned larger trials of improved probiotic products for vaginal health in South Africa. Although adherence to the vaginally delivered probiotic was high, women preferred oral application and we recommend that improvements in the content and method of application for future probiotics for vaginal health should be considered. TRIAL REGISTRATION: This trial was registered on 17 October 2017 with the South African National Clinical Trial Register ( http://www.sanctr.gov.za/ ; BV-trial1; DOH-27-1117-5579 ).


Assuntos
Probióticos/uso terapêutico , Vaginose Bacteriana/microbiologia , Vaginose Bacteriana/terapia , Administração Intravaginal , Adulto , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Suplementos Nutricionais , Aprovação de Drogas , Feminino , Humanos , Interleucina-1alfa/metabolismo , Adesão à Medicação , Metronidazol/administração & dosagem , Metronidazol/uso terapêutico , Microbiota , Projetos Piloto , Recidiva , Método Simples-Cego , África do Sul , Resultado do Tratamento , Adulto Jovem
18.
BMC Infect Dis ; 20(1): 847, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33198649

RESUMO

BACKGROUND: Hepatitis B virus (HBV), Human Immunodeficiency virus (HIV) and Tuberculosis (TB) are common infections in South Africa. We utilized the opportunity of care provision for HIV-TB co-infected patients to better understand the relationship between these coinfections, determine the magnitude of the problem, and identify risk factors for HBV infection in HIV infected patients with and without TB in KwaZulu-Natal, South Africa. METHODS: This retrospective cohort analysis was undertaken in 2018. In-care HIV infected patients were included in the analysis. Results from clinical records were analysed to determine the prevalence, incidence, persistence and factors associated with HBsAg positivity in HIV-infected patients with or without TB co-infection. RESULTS: A total of 4292 HIV-infected patients with a mean age of 34.7 years (SD: 8.8) were included. Based on HBsAg positivity, the prevalence of HBV was 8.5% (363/4292) [95% confidence interval (CI): 7.7-9.3] at baseline and 9.4% (95%CI: 8.6-10.3%) at end of follow-up. The HBV incidence rate was 2.1/100 person-years (p-y). Risk of incident HBV infection was two-fold higher among male patients (HR 2.11; 95% CI: 1.14-3.92), while severe immunosuppression was associated with a greater than two-fold higher risk of persistent infection (adjusted risk ratio (RR) 2.54; 95% CI 1.06-6.14; p = 0.004. Additionally, active TB at enrolment was associated with a two-fold higher risk of incident HBV infection (aHR 2.38; 95% CI: 0.77-7.35). CONCLUSION: The provision of HIV care and treatment in high HBV burden settings provide a missed opportunity for HBV screening, immunization and care provision.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Coinfecção/epidemiologia , HIV , Vírus da Hepatite B/imunologia , Hepatite B/diagnóstico , Hepatite B/epidemiologia , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/epidemiologia , Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Infecções Oportunistas Relacionadas com a AIDS/virologia , Adulto , Fármacos Anti-HIV/uso terapêutico , Coinfecção/virologia , Feminino , Seguimentos , Hepatite B/virologia , Antígenos de Superfície da Hepatite B/imunologia , Humanos , Incidência , Masculino , Prevalência , Estudos Retrospectivos , Fatores de Risco , África do Sul/epidemiologia , Tuberculose/diagnóstico , Tuberculose/microbiologia , Adulto Jovem
19.
Chem Biodivers ; 17(5): e1900550, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32149467

RESUMO

Two series of carbazole analogs of 8-methoxy-N-substituted-9H-carbazole-3-carboxamides (series 1) and carbazolyl substituted rhodanines (series 2) were synthesized through facile synthetic routes. All the final compounds from these two series were evaluated for their preliminary in vitro antifungal and antibacterial activity against four fungal (Candida albicans, Cryptococcus neoformans, Cryptococcus tropicalis and Aspergillus niger) and four bacterial (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa) strains, respectively. Among the tested compounds, three compounds of series 1 displayed promising antifungal and antibacterial activity, especially against C. neoformans and S. aureus. In addition, one compound of series 1 displayed notable antimicrobial activity (MIC: 6.25 µg/mL) against clinical isolates of C. albicans and C. neoformans (MIC: 12.5 µg/mL). From the second series, four compounds exhibited significant antifungal and antibacterial activity, especially against C. neoformans and S. aureus. The most active compound of series 2 displayed a prominent antimicrobial activity against C. neoformans (MIC: 3.125 µg/mL) and S. aureus (MIC: 1.56 µg/mL), respectively.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Carbazóis/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Aspergillus niger/efeitos dos fármacos , Bacillus subtilis/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Carbazóis/síntese química , Carbazóis/química , Cryptococcus/efeitos dos fármacos , Relação Dose-Resposta a Droga , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-Atividade
20.
J Med Virol ; 91(10): 1797-1803, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31180137

RESUMO

Occult hepatitis B virus (HBV) infection (OBI) is defined as the presence of HBV DNA in the liver with or without detectable HBV DNA in the serum of individuals testing HBV surface antigen (HBsAg) negative using currently available assays. The prevalence of OBI among patients receiving hemodialysis (HD) treatment remains poorly characterized in South Africa despite the high prevalence of HBV. We sought to determine the prevalence of OBI in HD units in tertiary hospitals of KwaZulu-Natal and to characterize the HBV S gene mutations potentially responsible for OBI. A cross-sectional descriptive study of residual diagnostic plasma samples from 85 HBsAg-negative patients receiving HD treatment was included. The PreS/S gene was amplified with a nested HBV polymerase chain reaction for downstream next-generation sequencing, to determine the viral genotype and identify S gene mutations associated with OBI. Nine of the 85 samples had OBI, based on detectable HBV DNA. The point prevalence of OBI was 10.6% (95% control interval: 5.5%-19.1%). Phylogenetic analysis of the samples with OBI showed that all belonged to genotype A. Three (~33%) samples had mutations in the major hydrophilic region (MHR) within the S gene, three (~33%) had mutations within the S gene but outside the MHR, whilst the remaining three had no mutations observed. The prevalence of OBI in HBsAg-negative patients undergoing HD was 10.6%, suggesting that OBI is a clinically significant problem in patients with HD in this region. The screening methods for HBV infection need to be revised to include nucleic acid testing.


Assuntos
Vírus da Hepatite B/isolamento & purificação , Hepatite B/diagnóstico , Hepatite B/epidemiologia , Adulto , Sequência de Aminoácidos , Estudos Transversais , Feminino , Genótipo , Unidades Hospitalares de Hemodiálise , Vírus da Hepatite B/genética , Humanos , Masculino , Filogenia , Diálise Renal , África do Sul/epidemiologia , Carga Viral , Proteínas Virais
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