Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
Open Forum Infect Dis ; 11(3): ofae118, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38505295

RESUMO

Background: In South Africa, the annual incidence of enteric fever averaged 0.1 per 100 000 persons between 2003 and 2018. During 2021 an increase in the number of enteric fever cases was observed. An outbreak investigation was conducted to determine the magnitude and source of the outbreak. Methods: We performed a cross-sectional descriptive study. Data were collected through telephonic or face-to-face interviews with cases or proxies via a standardized case investigation form. Whole genome sequencing was performed on all Salmonella Typhi isolates. Drinking water samples were collected, tested, and analyzed. Descriptive analysis was performed with Microsoft Excel. Results: Between January 2020 and September 2022, a cluster of 53 genetically highly related Salmonella Typhi isolates was identified from 5 provinces in South Africa. Isolates associated with the cluster showed ≤5 allelic differences, as determined following core genome multilocus sequence typing analysis. Most cases (60%, 32/53) were in the North West province. Males represented 68% (36/53). Of these, 72% (26/36) were aged 15 to 49 years, with a median age of 31 years. Where occupation was known within this age group, 78% (14/18) were illegal gold miners. Illegal miners reported illness onset while working underground. Five municipal tap water samples were tested and showed no evidence of fecal contamination. Conclusions: This outbreak predominantly affected illegal gold miners, likely due to the consumption of contaminated groundwater while working in a gold mine shaft. In addition, this investigation highlights the value of whole genome sequencing to detect clusters and support epidemiologic investigation of enteric fever outbreaks.

2.
BMC Public Health ; 23(1): 2329, 2023 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-38001453

RESUMO

BACKGROUND: Drug-resistant tuberculosis (DR-TB) epidemic is driven mainly by the effect of ongoing transmission. In high-burden settings such as South Africa (SA), considerable demographic and geographic heterogeneity in DR-TB transmission exists. Thus, a better understanding of risk-factors for clustering can help to prioritise resources to specifically targeted high-risk groups as well as areas that contribute disproportionately to transmission. METHODS: The study analyzed potential risk-factors for recent transmission in SA, using data collected from a sentinel molecular surveillance of DR-TB, by comparing demographic, clinical and epidemiologic characteristics with clustering and cluster sizes. A genotypic cluster was defined as two or more patients having identical patterns by the two genotyping methods used. Clustering was used as a proxy for recent transmission. Descriptive statistics and multinomial logistic regression were used. RESULT: The study identified 277 clusters, with cluster size ranging between 2 and 259 cases. The majority (81.6%) of the clusters were small (2-5 cases) with few large (11-25 cases) and very large (≥ 26 cases) clusters identified mainly in Western Cape (WC), Eastern Cape (EC) and Mpumalanga (MP). In a multivariable model, patients in clusters including 11-25 and ≥ 26 individuals were more likely to be infected by Beijing family, have XDR-TB, living in Nelson Mandela Metro in EC or Umgungunglovo in Kwa-Zulu Natal (KZN) provinces, and having history of imprisonment. Individuals belonging in a small genotypic cluster were more likely to infected with Rifampicin resistant TB (RR-TB) and more likely to reside in Frances Baard in Northern Cape (NC). CONCLUSION: Sociodemographic, clinical and bacterial risk-factors influenced rate of Mycobacterium tuberculosis (M. tuberculosis) genotypic clustering. Hence, high-risk groups and hotspot areas for clustering in EC, WC, KZN and MP should be prioritized for targeted intervention to prevent ongoing DR-TB transmission.


Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Humanos , África do Sul/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Mycobacterium tuberculosis/genética , Fatores de Risco , Análise por Conglomerados , Antituberculosos/uso terapêutico
3.
PLOS Glob Public Health ; 3(9): e0001718, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37682831

RESUMO

Diarrhoea is a recognised complication of HIV-infection, yet there are limited local aetiological data in this high-risk group. These data are important for informing public health interventions and updating diagnostic and treatment guidelines. This study aimed to determine the pathogenic causes of diarrhoeal admissions in people living with HIV (PLHIV) compared to hospital controls between July 2018 and November 2021. Admitted diarrhoeal cases (n = 243) and non-diarrhoeal hospital controls (n = 101) ≥5 years of age were enrolled at Kalafong, Mapulaneng and Matikwana hospitals. Stool specimens/rectal swabs were collected and pathogen screening was performed on multiple platforms. Differences in pathogen detections between cases and controls, stratified by HIV status, were investigated. The majority (n = 164, 67.5%) of enrolled diarrhoeal cases with known HIV status were HIV-infected. Pathogens could be detected in 66.3% (n = 228) of specimens, with significantly higher detection in cases compared to controls (72.8% versus 50.5%, p<0.001). Amongst PLHIV, prevalence of Cystoisospora spp. was significantly higher in cases than controls (17.7% versus 0.0%, p = 0.028), while Schistosoma was detected more often in controls than cases (17.4% versus 2.4%, p = 0.009). Amongst the HIV-uninfected participants, prevalence of Shigella spp., Salmonella spp. and Helicobacter pylori was significantly higher in cases compared to controls (36.7% versus 12.0%, p = 0.002; 11.4% versus 0.0%, p = 0.012; 10.1% versus 0.0%, p = 0.023). Diarrhoeal aetiology differed by HIV status, with Shigella spp. (36.7%) and Salmonella spp. (11.4%) having the highest prevalence amongst HIV-uninfected cases and Shigella spp. (18.3%), Cystoisospora (17.7%), and Cryptosporidium spp. (15.9%) having the highest prevalence in cases amongst PLHIV. These differences should be considered for the development of diagnostic and treatment guidelines.

4.
Emerg Infect Dis ; 29(8): 1687-1690, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37352549

RESUMO

Since February 2022, Malawi has experienced a cholera outbreak of >54,000 cases. We investigated 6 cases in South Africa and found that isolates linked to the outbreak were Vibrio cholerae O1 serotype Ogawa from seventh pandemic El Tor sublineage AFR15, indicating a new introduction of cholera into Africa from south Asia.


Assuntos
Cólera , Vibrio cholerae O1 , Humanos , Cólera/epidemiologia , África do Sul/epidemiologia , Vibrio cholerae O1/genética , Ásia Meridional , Malaui , Surtos de Doenças
5.
Microb Genom ; 9(6)2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37339282

RESUMO

The National Institute for Communicable Diseases in South Africa participates in national laboratory-based surveillance for human isolates of Salmonella species. Laboratory analysis includes whole-genome sequencing (WGS) of isolates. We report on WGS-based surveillance of Salmonella enterica serovar Typhi (Salmonella Typhi) in South Africa from 2020 through 2021. We describe how WGS analysis identified clusters of enteric fever in the Western Cape Province of South Africa and describe the epidemiological investigations associated with these clusters. A total of 206 Salmonella Typhi isolates were received for analysis. Genomic DNA was isolated from bacteria and WGS was performed using Illumina NextSeq technology. WGS data were investigated using multiple bioinformatics tools, including those available at the Centre for Genomic Epidemiology, EnteroBase and Pathogenwatch. Core-genome multilocus sequence typing was used to investigate the phylogeny of isolates and identify clusters. Three major clusters of enteric fever were identified in the Western Cape Province; cluster one (n=11 isolates), cluster two (n=13 isolates), and cluster three (n=14 isolates). To date, no likely source has been identified for any of the clusters. All isolates associated with the clusters, showed the same genotype (4.3.1.1.EA1) and resistome (antimicrobial resistance genes: bla TEM-1B, catA1, sul1, sul2, dfrA7). The implementation of genomic surveillance of Salmonella Typhi in South Africa has enabled rapid detection of clusters indicative of possible outbreaks. Cluster identification allows for targeted epidemiological investigations and a timely, coordinated public health response.


Assuntos
Salmonella typhi , Febre Tifoide , Humanos , Salmonella typhi/genética , Febre Tifoide/epidemiologia , Febre Tifoide/microbiologia , África do Sul/epidemiologia , Genoma Bacteriano , Genômica
6.
EClinicalMedicine ; 39: 101072, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34405139

RESUMO

BACKGROUND: We describe the epidemiology of COVID-19 in South Africa following importation and during implementation of stringent lockdown measures. METHODS: Using national surveillance data including demographics, laboratory test data, clinical presentation, risk exposures (travel history, contacts and occupation) and outcomes of persons undergoing COVID-19 testing or hospitalised with COVID-19 at sentinel surveillance sites, we generated and interpreted descriptive statistics, epidemic curves, and initial reproductive numbers (Rt). FINDINGS: From 4 March to 30 April 2020, 271,670 SARS-CoV-2 PCR tests were performed (462 tests/100,000 persons). Of these, 7,892 (2.9%) persons tested positive (median age 37 years (interquartile range 28-49 years), 4,568 (58%) male, cumulative incidence of 13.4 cases/100,000 persons). Hospitalization records were found for 1,271 patients (692 females (54%)) of whom 186 (14.6%) died. Amongst 2,819 cases with data, 489/2819 (17.3%) travelled internationally within 14 days prior to diagnosis, mostly during March 2020 (466 (95%)). Cases diagnosed in April compared with March were younger (median age, 37 vs. 40 years), less likely female (38% vs. 53%) and resident in a more populous province (98% vs. 91%). The national initial Rt was 2.08 (95% confidence interval (CI): 1.71-2.51). INTERPRETATION: The first eight weeks following COVID-19 importation were characterised by early predominance of imported cases and relatively low mortality and transmission rates. Despite stringent lockdown measures, the second month following importation was characterised by community transmission and increasing disease burden in more populous provinces.

7.
BMC Microbiol ; 21(1): 157, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-34044775

RESUMO

BACKGROUND: Studies have shown that drug-resistant tuberculosis (DR-TB) in South Africa (SA) is clonal and is caused mostly by transmission. Identifying transmission chains is important in controlling DR-TB. This study reports on the sentinel molecular surveillance data of Rifampicin-Resistant (RR) TB in SA, aiming to describe the RR-TB strain population and the estimated transmission of RR-TB cases. METHOD: RR-TB isolates collected between 2014 and 2018 from eight provinces were genotyped using combination of spoligotyping and 24-loci mycobacterial interspersed repetitive-units-variable-number tandem repeats (MIRU-VNTR) typing. RESULTS: Of the 3007 isolates genotyped, 301 clusters were identified. Cluster size ranged between 2 and 270 cases. Most of the clusters (247/301; 82.0%) were small in size (< 5 cases), 12.0% (37/301) were medium sized (5-10 cases), 3.3% (10/301) were large (11-25 cases) and 2.3% (7/301) were very large with 26-270 cases. The Beijing genotype was responsible for majority of RR-TB cases in Western and Eastern Cape, while the East-African-Indian-Somalian (EAI1_SOM) genotype accounted for a third of RR-TB cases in Mpumalanga. The overall proportion of RR-TB cases estimated to be due to transmission was 42%, with the highest transmission-rate in Western Cape (64%) and the lowest in Northern Cape (9%). CONCLUSION: Large clusters contribute to the burden of RR-TB in specific geographic areas such as Western Cape, Eastern Cape and Mpumalanga, highlighting the need for community-wide interventions. Most of the clusters identified in the study were small, suggesting close contact transmission events, emphasizing the importance of contact investigations and infection control as the primary interventions in SA.


Assuntos
Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Antituberculosos/farmacologia , Farmacorresistência Bacteriana , Genótipo , Humanos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase , Rifampina/farmacologia , África do Sul , Tuberculose Resistente a Múltiplos Medicamentos/transmissão
8.
PLoS One ; 15(4): e0230504, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32255811

RESUMO

Multidrug-resistant (MDR) TB is more difficult to diagnose and treat compared with drug-susceptible TB. Young children are at greater risk of severe TB disease and death when treatment is delayed compared to adults. We sought to describe characteristics of children (<13 years) diagnosed with MDR TB between 2008-2010 in three South African provinces and assess factors associated with pre-treatment loss to follow-up. We matched laboratory and medical records at treatment facilities to identify pre-treatment loss and examined demographic and clinical characteristics for association with loss. Categorical variables were examined for association using Pearson's x2 or Fisher's exact test, employing Bonferroni correction for multiple pairwise comparisons. Between 2008-2010, 156 children were diagnosed with laboratory-confirmed MDR TB. Only 44% (n = 69) were documented as having received treatment. Young children (<2 years) (47/59, 80%), children with extrapulmonary (EP) TB (27/34, 79%), and children diagnosed at general hospitals (60/97, 62%) were most likely to be lost before treatment. Children most vulnerable to death from TB are most likely to be lost before treatment, possibly leading to underestimates of disease burden, case notifications, and poor outcomes among this population. Point-of-care diagnosis and robust follow-up may reduce pre-treatment loss in this population.


Assuntos
Falha de Tratamento , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Antituberculosos/uso terapêutico , Criança , Pré-Escolar , Bases de Dados Factuais , Hospitais Gerais , Humanos , Lactente , África do Sul , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico
9.
N Engl J Med ; 382(7): 632-643, 2020 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-32053299

RESUMO

BACKGROUND: An outbreak of listeriosis was identified in South Africa in 2017. The source was unknown. METHODS: We conducted epidemiologic, trace-back, and environmental investigations and used whole-genome sequencing to type Listeria monocytogenes isolates. A case was defined as laboratory-confirmed L. monocytogenes infection during the period from June 11, 2017, to April 7, 2018. RESULTS: A total of 937 cases were identified, of which 465 (50%) were associated with pregnancy; 406 of the pregnancy-associated cases (87%) occurred in neonates. Of the 937 cases, 229 (24%) occurred in patients 15 to 49 years of age (excluding those who were pregnant). Among the patients in whom human immunodeficiency virus (HIV) status was known, 38% of those with pregnancy-associated cases (77 of 204) and 46% of the remaining patients (97 of 211) were infected with HIV. Among 728 patients with a known outcome, 193 (27%) died. Clinical isolates from 609 patients were sequenced, and 567 (93%) were identified as sequence type 6 (ST6). In a case-control analysis, patients with ST6 infections were more likely to have eaten polony (a ready-to-eat processed meat) than those with non-ST6 infections (odds ratio, 8.55; 95% confidence interval, 1.66 to 43.35). Polony and environmental samples also yielded ST6 isolates, which, together with the isolates from the patients, belonged to the same core-genome multilocus sequence typing cluster with no more than 4 allelic differences; these findings showed that polony produced at a single facility was the outbreak source. A recall of ready-to-eat processed meat products from this facility was associated with a rapid decline in the incidence of L. monocytogenes ST6 infections. CONCLUSIONS: This investigation showed that in a middle-income country with a high prevalence of HIV infection, L. monocytogenes caused disproportionate illness among pregnant girls and women and HIV-infected persons. Whole-genome sequencing facilitated the detection of the outbreak and guided the trace-back investigations that led to the identification of the source.


Assuntos
Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Listeria monocytogenes/isolamento & purificação , Listeriose/epidemiologia , Produtos da Carne/microbiologia , Adolescente , Adulto , Idoso , Técnicas de Tipagem Bacteriana , Estudos de Casos e Controles , Feminino , Doenças Transmitidas por Alimentos/etiologia , Doenças Transmitidas por Alimentos/mortalidade , Infecções por HIV/complicações , HIV-1 , Humanos , Recém-Nascido , Listeria monocytogenes/genética , Listeriose/etiologia , Listeriose/mortalidade , Masculino , Produtos da Carne/efeitos adversos , Pessoa de Meia-Idade , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Recall e Retirada de Produto , Distribuição por Sexo , África do Sul/epidemiologia , Sequenciamento Completo do Genoma , Adulto Jovem
10.
Pediatr Infect Dis J ; 36(12): e322-e327, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28746263

RESUMO

OBJECTIVE: To describe outcomes of HIV-infected pediatric patients with drug-resistant tuberculosis (DR TB). METHODS: Demographic, clinical and laboratory data from charts of pediatric patients treated for DR TB during 2005-2008 were collected retrospectively from 5 multi-DR TB hospitals in South Africa. Data were summarized, and Pearson χ test or Fisher exact test was used to assess differences in variables of interest by HIV status. A time-to-event analysis was conducted using days from start of treatment to death. Variables of interest were first assessed using the Kaplan-Meier method. Cox proportional hazard models were fit to estimate crude and adjusted hazard ratios. RESULTS: Of 423 eligible participants, 398 (95%) had culture-confirmed DR TB and 238 (56%) were HIV infected. A total of 54% were underweight, 42% were male and median age was 10.7 years (interquartile range: 5.5-15.3). Of the 423 participants, 245 (58%) were successfully treated, 69 (16%) died, treatment failed in 3 (1%), 36 (9%) were lost to follow-up and 70 (17%) were still on treatment, transferred or had unknown outcomes. Time to death differed by HIV status (P = 0.008), sex (P < 0.001), year of tuberculosis diagnosis (P = 0.05) and weight status (P = 0.002). Over the 2-year risk period, the adjusted rate of death was 2-fold higher among participants with HIV compared with HIV-negative participants (adjusted hazard ratio = 2.28; 95% confidence interval: 1.11-4.68). CONCLUSIONS: Male, underweight and HIV-infected children with DR TB were more likely to experience death when compared with other children with DR TB within this study population.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Antituberculosos/uso terapêutico , Infecções por HIV , Tuberculose Resistente a Múltiplos Medicamentos , Adolescente , Criança , Pré-Escolar , Coinfecção , Feminino , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Infecções por HIV/mortalidade , Humanos , Lactente , Recém-Nascido , Estimativa de Kaplan-Meier , Masculino , Estudos Retrospectivos , África do Sul/epidemiologia , Resultado do Tratamento , Tuberculose Resistente a Múltiplos Medicamentos/complicações , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/mortalidade
11.
PLoS One ; 11(1): e0146106, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26752297

RESUMO

BACKGROUND: In South Africa and other high prevalence countries, transmission is a significant contributor to rising rates of multidrug resistant tuberculosis (MDR-TB). Thus, there is a need to develop an early detection system for transmission clusters suitable for high burden settings. We have evaluated the discriminatory power and clustering concordance of a novel and simple genotyping approach, combining spoligotyping with pncA sequencing (SpoNC), against two well-established methods: IS6110-RFLP and 24-loci MIRU-VNTR. METHODS: A total of 216 MDR-TB isolates collected from January to June 2010 from the NHLS Central TB referral laboratory in Braamfontein, Johannesburg, representing a diversity of strains from South Africa, were included. The isolates were submitted for genotyping, pncA sequencing and analysis to the Centre for Tuberculosis in South Africa and the Public Health Research Institute Tuberculosis Center at Rutgers University in the United States. Clustering rates, Hunter-Gaston Discriminatory Indexes (HGI) and Wallace coefficients were compared between the methods. RESULTS: Overall clustering rates were high by both IS6110-RFLP (52.8%) and MIRU-VNTR (45.8%), indicative of on-going transmission. Both 24-loci MIRU-VNTR and IS6110-RFLP had similar HGI (0.972 and 0.973, respectively), with close numbers of unique profiles (87 vs. 70), clustered isolates (129 vs. 146), and cluster sizes (2 to 26 vs. 2 to 25 isolates). Spoligotyping alone was the least discriminatory (80.1% clustering, HGI 0.903), with 28 unique types. However, the discriminatory power of spoligotyping was improved when combined with pncA sequencing using the SpoNC approach (61.8% clustering, HGI 0.958). A high proportion of MDR-TB isolates had mutations in pncA (68%, n = 145), and pncA mutations were significantly associated with clustering (p = 0.007 and p = 0.0013 by 24-loci MIRU-VNTR and IS6110-RFLP, respectively), suggesting high rates of resistance to pyrazinamide among all MDR-TB cases and particularly among clustered cases. CONCLUSION: We conclude that SpoNC provides good discrimination for MDR-TB surveillance and early identification of outbreaks in South Africa, with 24-loci MIRU-VNTR applied for pncA wild-type strains as needed.


Assuntos
Efeitos Psicossociais da Doença , Mycobacterium tuberculosis/fisiologia , Vigilância da População , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/genética , Análise por Conglomerados , Técnicas de Genotipagem , Humanos , Mutação/genética , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação
12.
Lancet Glob Health ; 3(8): e450-e457, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26187490

RESUMO

BACKGROUND: In South Africa, sputum smear microscopy has been replaced with Xpert MTB/RIF as the initial diagnostic test for tuberculosis. In a pragmatic parallel cluster-randomised trial, we evaluated the effect on patient and programme outcomes. METHODS: We randomly allocated 20 laboratories (clusters) in medium-burden districts of South Africa to either an Xpert (immediate Xpert) or microscopy (Xpert deferred) group (1:1), stratified by province. At two primary care clinics per laboratory, a systematic sample of adults giving sputum for tuberculosis investigation was assessed for eligibility. The primary outcome was mortality at 6 months from enrolment. Masking of participants' group allocation was not possible because of the pragmatic trial design. The trial is registered with the ISRCTN registry (ISRCTN68905568) and the South African Clinical Trial Register (DOH-27-1011-3849). FINDINGS: Between June and November, 2012, 4972 people were screened, and 4656 (93·6%) enrolled (median age 36 years; 2891 [62%] female; 2212 [62%] reported being HIV-positive). There was no difference between the Xpert and microscopy groups with respect to mortality at 6 months (91/2324 [3·9%] vs 116/2332 [5·0%], respectively; adjusted risk ratio [aRR] 1·10, 95% CI 0·75-1·62]). INTERPRETATION: Xpert did not reduce mortality at 6 months compared with sputum microscopy. Improving outcomes in drug-sensitive tuberculosis programmes might require not only better diagnostic tests but also better linkage to care. FUNDING: Bill & Melinda Gates Foundation.


Assuntos
Infecções por HIV/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Escarro/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Pulmonar/diagnóstico , Adulto , Análise de Variância , Antituberculosos/uso terapêutico , Comorbidade , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Determinação de Ponto Final , Feminino , Infecções por HIV/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Avaliação de Processos e Resultados em Cuidados de Saúde/métodos , Avaliação de Processos e Resultados em Cuidados de Saúde/estatística & dados numéricos , Rifampina/uso terapêutico , África do Sul , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/mortalidade , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/mortalidade
13.
PLoS One ; 7(11): e49898, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23226229

RESUMO

INTRODUCTION: Globally, multidrug resistant tuberculosis (MDR-TB) remains underdiagnosed. The Genotype MTBDRplus®, a rapid drug susceptibility testing (DST) assay used to detect resistance to isoniazid and rifampicin in the diagnosis of MDR-TB, has good diagnostic accuracy, but its impact on patient outcomes in routine practice is unproven. We assessed the clinical impact of routine DST using MTBDRplus in a single health district in South Africa. METHODS: Data were collected on all adult pulmonary TB patients registered at 25 public health clinics in the periods before and after introduction of an expanded DST algorithm using MTBDRplus version 1.0. RESULTS: We collected data on 1176 TB patients before implementation and 1177 patients afterwards. In the before period, measured MDR-TB prevalence among new cases was 0.7% (95% CI1.4-3.1%), and among retreatment cases 6.2% (95% CI:3.5-8.8%), versus 3.7% (95% CI:2.4-5.0, p<0.01) and 6.6% (95% CI:3.8-9.4%, p = 0.83) respectively after MTBDRplus introduction. The median times from sputum collection to MDR treatment in the before and after periods were 78 days (IQR:52-93) and 62 days (IQR:32-86, p = 0.05), respectively. Among MDR-TB cases, 27% (95%CI:10-44) in the before period converted sputum cultures to negative by 8 months following treatment initiation, while 52% (95%CI:38-66) converted in the intervention period (p = 0.04). CONCLUSIONS: The expanded use of MTBDRplus DST resulted in a substantial increase in the proportion of new cases identified as MDR-TB; though time to MDR treatment was reduced, it was still over two months. Culture conversion for MDR-TB patients improved after introduction of MTBDRplus. This work illustrates the mixture of successes and challenges resulting from increased access to rapid DST in a setting with a high TB burden.


Assuntos
Antituberculosos/uso terapêutico , Técnicas de Tipagem Bacteriana , Isoniazida/uso terapêutico , Testes de Sensibilidade Microbiana/métodos , Mycobacterium tuberculosis/genética , Rifampina/uso terapêutico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Pulmonar/tratamento farmacológico , Adulto , Antituberculosos/farmacologia , Estudos de Coortes , Farmacorresistência Bacteriana Múltipla , Feminino , Humanos , Isoniazida/farmacologia , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , Rifampina/farmacologia , África do Sul , Análise de Sobrevida , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/mortalidade , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/mortalidade
14.
PLoS One ; 6(9): e24789, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21961045

RESUMO

BACKGROUND: The LightCycler® Mycobacterium Detection Kit based on real-time PCR technology for the detection of Mycobacterium tuberculosis, Mycobacterium avium and Mycobacterium kansasii was recently developed. This study evaluated its analytical sensitivity, specificity and reproducibility. METHODOLOGY/PRINCIPAL FINDINGS: Plasmid standards were prepared and used to determine the limit of detection. The assay was also performed against organisms other than mycobacteria, other mycobacterial strains and interfering substances to exclude cross-reactivity and interference. Reference standards were prepared and tested to assess the assay's reproducibility. All PCR assays were performed using the LightCycler® 2.0 Instrument. The detection limit for M. tuberculosis was 28 copies per microlitre. Neither cross-reactivity nor interference occurred with non-mycobacterial organisms and substances tested. Overall reproducibility for consecutive measurements, run-to-run, lot-to-lot, day-to-day and laboratory-to-laboratory achieved a coefficient of variance of less than two percent. SIGNIFICANCE: The LightCycler® Mycobacterium Detection kit has shown to be a robust and accurate assay with the potential to be used as a rapid TB diagnostic test.


Assuntos
Infecções por Mycobacterium/microbiologia , Mycobacterium avium/genética , Mycobacterium kansasii/genética , Mycobacterium tuberculosis/genética , Kit de Reagentes para Diagnóstico/normas , Técnicas Bacteriológicas/normas , Técnicas de Laboratório Clínico/normas , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Bacteriano/normas , Diagnóstico Diferencial , Humanos , Infecções por Mycobacterium/diagnóstico , Mycobacterium avium/isolamento & purificação , Mycobacterium kansasii/isolamento & purificação , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Especificidade da Espécie , Temperatura de Transição
15.
Pediatr Infect Dis J ; 28(12): 1123-5, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19935274

RESUMO

HIV-1 drug resistance patterns in 41 children failing antiretroviral therapy in South Africa were examined. Resistance mutation profiles were similar to adults published from the region, with the exception of high rates of lopinavir/r resistance (44%). Ninety-eight percent presented with known drug resistance mutations with M184V (82%) and K103N (44%), the dominant mutations.


Assuntos
Antirretrovirais/administração & dosagem , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , HIV-1/genética , Criança , Pré-Escolar , Estudos de Coortes , Farmacorresistência Viral , Feminino , Programas Governamentais , Humanos , Lactente , Masculino , Mutação , RNA Viral/sangue , África do Sul , Falha de Tratamento , Produtos do Gene pol do Vírus da Imunodeficiência Humana/genética
16.
J Clin Microbiol ; 47(7): 2209-17, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19420172

RESUMO

The implementation of antiretroviral therapy demands the need for increased access to viral load (VL) monitoring. Newer real-time VL testing technologies are faster and have larger dynamic ranges and fully automated extraction to benefit higher throughputs in resource-poor environments. The Abbott RealTime human immunodeficiency virus type 1 (HIV-1) assay was evaluated as a new option for testing for HIV-1 subtype C in South Africa, and its performance was compared to the performance of existing assays (the Cobas AmpliPrep-Cobas TaqMan HIV-1, version 1, assay; the AmpliPrep-Cobas Monitor standard HIV-1 assay; and the NucliSENS EasyQ-EasyMag HIV-1 assay) in a high-throughput laboratory. The total precision of the RealTime HIV-1 assay was acceptable over all viral load ranges. This assay compared most favorably with the Cobas AmpliPrep-Cobas TaqMan HIV-1 assay (R(2) = 0.904), with a low standard deviation of difference being detected (0.323 copies/ml). The bias against comparator assays ranged from -0.001 copies/ml to -0.228 copies/ml. Variability in the reporting of VLs for a 20-member subtype panel compared to the variability of other assays was noted with subtypes G and CRF02-AG. The RealTime HIV-1 assay can test 93 samples per day with minimal manual preparation, less staff, and the minimization of contamination through automation. This assay is suitable for HIV-1 subtype C VL quantification in South Africa.


Assuntos
Infecções por HIV/virologia , HIV-1/isolamento & purificação , Técnicas de Diagnóstico Molecular/métodos , Kit de Reagentes para Diagnóstico , Carga Viral/métodos , Humanos , África do Sul
17.
J Clin Microbiol ; 46(12): 3941-5, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18923017

RESUMO

The new Cobas AmpliPrep/Cobas TaqMan HIV-1 Qual test offers advanced automation for the detection of human immunodeficiency virus type 1 (HIV-1) RNA and DNA in dried blood spots (DBS) and whole blood. An analytical evaluation using an HIV-1 secondary standard yielded limits of detection of 514, 710, and 1,090 HIV RNA copies/ml for EDTA plasma, whole blood, and DBS, respectively. The precision and reproducibility of HIV-1 detection was equivalent for DBS and whole blood. Inclusivity was demonstrated for a reference panel of HIV-1 subtypes A to N. A clinical evaluation of the Cobas AmpliPrep/Cobas TaqMan HIV-1 Qual test was performed at a center for routine diagnostics in Johannesburg, South Africa, using 1,013 clinical specimens from HIV-1 exposed children. The Amplicor HIV-1 DNA test v1.5 with the MagNApure DNA isolation procedure was used as the reference method. A total of 995 valid results for whole blood with both methods yielded 691 and 303 concordant negative and positive results for the Cobas AmpliPrep/Cobas TaqMan HIV-1 Qual test, respectively. For the 800 valid DBS specimen results, 495 and 300 concordant negative and positive results were obtained, respectively. The resulting clinical specificities and sensitivities of the new test were 100% and 99.7% for whole blood and DBS, respectively. The new test was characterized by its robustness, enhanced automation, and improved sample throughput. The Cobas AmpliPrep/Cobas TaqMan HIV-1 Qual test will support early, reliable diagnosis of HIV in children in routine laboratory settings.


Assuntos
Sangue/virologia , Dessecação , Infecções por HIV/diagnóstico , HIV-1/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Criança , Pré-Escolar , DNA Viral/isolamento & purificação , HIV-1/genética , Humanos , Lactente , RNA Viral/isolamento & purificação , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade , África do Sul , Manejo de Espécimes/métodos
18.
J Pediatr Hematol Oncol ; 25(2): 167-8, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12571472

RESUMO

The progress of a female child with African type Fanconi anemia that evolves in time into paroxysmal nocturnal hemoglobinuria is described. Modern diagnostic methods are used to confirm this process. A discussion of possible mechanisms ensues.


Assuntos
Anemia de Fanconi/complicações , Hemoglobinúria Paroxística/etiologia , Criança , Eritrócitos/metabolismo , Eritrócitos/patologia , Anemia de Fanconi/sangue , Feminino , Citometria de Fluxo , Hemoglobinúria Paroxística/sangue , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA