Last data update: Nov 04, 2024. (Total: 48056 publications since 2009)
Records 1-17 (of 17 Records) |
Query Trace: Auld SC[original query] |
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Modeling missing cases and transmission links in networks of extensively drug-resistant tuberculosis in KwaZulu-Natal, South Africa (preprint)
Nelson KN , Gandhi NR , Mathema B , Lopman BA , Brust JCM , Auld SC , Ismail N , Omar SV , Brown TS , Allana S , Campbell A , Moodley P , Mlisana K , Shah NS , Jenness SM . bioRxiv 2019 655969 The transmission patterns of drug-resistant tuberculosis (TB) remain poorly understood, despite over half a million incident cases in 2017. Modeling TB transmission networks can provide insight into the nature and drivers of transmission, but incomplete and non-random sampling of TB cases can pose challenges to making inferences from epidemiologic and molecular data. We conducted a quantitative bias analysis to assess the effect of missing cases on a transmission network inferred from Mtb sequencing data on extensively drug-resistant (XDR) TB cases in South Africa. We tested scenarios in which cases were missing at random, differentially by clinical characteristics, or differentially by transmission (i.e., cases with many links were under or over-sampled). Under the assumption cases were missing at random, cases in the complete, modeled network would have had a mean of 20 or more transmission links, which is far higher than expected, in order to reproduce the observed, partial network. Instead, we found that the most likely scenario involved undersampling of high-transmitting cases, and further models provided evidence for superspreading behavior. This is, to our knowledge, the first study to define and assess the support for different mechanisms of missingness in a study of TB transmission. Our findings should caution interpretation of results of future studies of TB transmission in high-incidence settings, given the potential for biased sampling, and should motivate further research aimed at identifying the specific host, pathogen, or environmental factors contributing to superspreading. |
Modeling Missing Cases and Transmission Links in Networks of Extensively Drug-Resistant Tuberculosis in KwaZulu-Natal, South Africa.
Nelson KN , Gandhi NR , Mathema B , Lopman BA , Brust JCM , Auld SC , Ismail N , Omar SV , Brown TS , Allana S , Campbell A , Moodley P , Mlisana K , Shah NS , Jenness SM . Am J Epidemiol 2020 189 (7) 735-745 Transmission patterns of drug-resistant tuberculosis (TB) remain poorly understood, despite over half a million incident cases 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, differentially by clinical characteristics or by transmission (i.e., cases with many links were under or over-sampled). Under the assumption 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 superspreading. This is the first study to assess 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 superspreading. |
Pre-detection history of extensively drug-resistant tuberculosis in KwaZulu-Natal, South Africa.
Brown TS , Challagundla L , Baugh EH , Omar SV , Mustaev A , Auld SC , Shah NS , Kreiswirth BN , Brust JCM , Nelson KN , Narechania A , Kurepina N , Mlisana K , Bonneau R , Eldholm V , Ismail N , Kolokotronis SO , Robinson DA , Gandhi NR , Mathema B . Proc Natl Acad Sci U S A 2019 116 (46) 23284-23291 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 approximately 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. |
Social mixing and clinical features linked with transmission in a network of extensively drug-resistant (XDR) tuberculosis cases in KwaZulu-Natal, South Africa.
Nelson KN , Jenness SM , Mathema B , Lopman BA , Auld SC , Shah NS , Brust JCM , Ismail N , Omar SV , Brown TS , Allana S , Campbell A , Moodley P , Mlisana K , Gandhi NR . Clin Infect Dis 2019 70 (11) 2396-2402 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 a high incidence of drug-resistant TB are poorly understood. METHODS: We measured a network of genomic links using Mycobacterium tuberculosis (Mtb) whole genome sequences. RESULTS: Cases with 2-3 months of cough or who spent time in urban locations, were more likely to be linked in the network, while cases 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. |
Extensively drug-resistant tuberculosis 'hotspots' and sociodemographic associations in Durban, South Africa
Peterson ML , Gandhi NR , Clennon J , Nelson KN , Morris N , Ismail N , Allana S , Campbell A , Brust JCM , Auld SC , Mathema B , Mlisana K , Moodley P , Shah NS . Int J Tuberc Lung Dis 2019 23 (6) 720-727 BACKGROUND In KwaZulu-Natal, South Africa, the incidence of extensively drug-resistant tuberculosis (XDR-TB) is driven by the transmission of resistant strains. As data suggest that cases may be spatially clustered, we sought to identify 'hotspots' and describe these communities. METHODS We enrolled XDR-TB patients diagnosed from 2011 to 2014 in eThekwini. Global positioning system (GPS) coordinates for participant homes were collected and hotspots were identified based on population-adjusted XDR-TB incidence. The sociodemographic features of hotspots were characterised using census data. For a subset of participants, we mapped non-home XDR-TB congregate locations and compared these with results including only homes. RESULTS Among 132 participants, 75 (57%) were female and 87 (66%) lived in urban or suburban locations. Fifteen of 197 census tracts were identified as XDR-TB hotspots with >/=95% confidence. Four spatial mapping methods identified one large hotspot in northeastern eThekwini. Hotspot communities had higher proportions of low educational attainment (12% vs. 9%) and unemployment (29.3% vs. 20.4%), and lower proportion of homes with flush toilets (36.4% vs. 68.9%). The case density shifted towards downtown Durban when congregate locations (e.g., workplaces) for 43 (33%) participants were mapped. CONCLUSIONS In eThekwini, XDR-TB case homes were clustered into hotspots with more poverty indicators than non-hotspots. Prevention efforts targeting hotspot communities and congregate settings may be effective in reducing community transmission.. |
Closing the book on Category II: time for individualized regimens for patients with recurrent tuberculosis
Auld SC , Gandhi NR , Shah NS . Int J Tuberc Lung Dis 2018 22 (10) 1113-1114 FOLLOWING THE CLINICAL TRIALS by the Singapore Tuberculosis Service and the British Medical Research Council in the 1970s, the 6-month ‘short-course’ tuberculosis (TB) regimen, based on isoniazid, rifampicin, and pyrazinamide, was widely adopted in the 1980s.1,2 However, for patients undergoing retreatment for TB disease, there was no clear evidence-based treatment regimen. In an effort to fill this gap, in 1991 the World Health Organization (WHO) endorsed the ‘Category II’ regimen, an 8-month regimen with the addition of streptomycin, as a retreatment regimen for patients with TB disease relapse, treatment failure, or treatment after an interruption of at least 2 months.3 Despite this endorsement, it was already recognized that the addition of a single drug to a failing regimen set the stage for the amplification of drug resistance and poor clinical outcomes.4–6 Nearly two decades later, in the face of mounting data pointing to its ineffectiveness, in 2010 the WHO recommended against using the Category II regimen.7 This reversal remains highly relevant for the 19% of retreatment cases estimated to have drug resistance in the context of relapsed or recurrent disease in 2016.8 |
Extensively drug-resistant tuberculosis in South Africa: genomic evidence supporting transmission in communities.
Auld SC , Sarita Shah N , Mathema B , Brown TS , Ismail N , Omar SV , Brust JCM , Nelson KN , Allana S , Campbell A , Mlisana K , Moodley P , Gandhi NR . Eur Respir J 2018 52 (4) Background: Despite evidence that transmission is driving an extensively drug-resistant (XDR) tuberculosis epidemic, our understanding of where and between whom transmission occurs is limited. We sought to determine whether there was genomic evidence of transmission between individuals without an epidemiologic connection.Methods: We conducted a prospective study of XDR tuberculosis patients in KwaZulu-Natal, South Africa, during 2011-2014. We collected sociodemographic and clinical data, and identified epidemiologic links based on person-to-person or hospital-based connections. We performed whole-genome sequencing on the Mycobacterium tuberculosis isolates and determined pairwise single nucleotide polymorphism (SNP) differences.Findings: Among 404 participants, 123 (30%) had person-to-person or hospital-based links, leaving 281 (70%) epidemiologically unlinked. The median SNP difference between participants with person-to-person and hospital-based links was 10 (IQR 8-24) and 16 (IQR 10-23), respectively. The median SNP difference between unlinked participants and their closest genomic link was 5 (IQR 3-9); half of unlinked participants were within 7 SNPs of at least five participants.Conclusions: The majority of epidemiologically unlinked XDR tuberculosis patients had low pairwise SNP differences, consistent with transmission, with at least one other participant. These data suggest that much of transmission may result from casual contact in community settings between individuals not known to one another. |
Spatial Patterns of Extensively Drug-Resistant Tuberculosis Transmission in KwaZulu-Natal, South Africa.
Nelson KN , Shah NS , Mathema B , Ismail N , Brust JCM , Brown TS , Auld SC , Omar SV , Morris N , Campbell A , Allana S , Moodley P , Mlisana K , Gandhi NR . J Infect Dis 2018 218 (12) 1964-1973 Background: Transmission is driving the global drug-resistant tuberculosis epidemic; nearly three-quarters of drug-resistant tuberculosis cases are attributable to transmission. Geographic patterns of disease incidence, combined with information on probable transmission links, can define the spatial scale of transmission and generate hypotheses about factors driving transmission patterns. Methods: We combined whole-genome sequencing data with home GPS coordinates from 344 participants with extensively drug-resistant (XDR) tuberculosis in KwaZulu-Natal, South Africa diagnosed from 2011-2014. We aimed to determine if genomically linked (</=5 single nucleotide polymorphisms [SNP] differences) cases lived close to one another, which would suggest a role for local community settings in transmission. Results: 182 study participants were genomically linked, comprising 1084 case-pairs. The median distance between case-pairs' homes was 108 km (IQR: 64-162 km). Between-district, as compared to within-district, links accounted for the majority (912/1084, 84%) of genomic links. Half (526, 49%) of genomic links involved a case from Durban, the urban center of KwaZulu-Natal. Conclusions: The high proportions of between-district links with Durban provide insight into possible drivers of province-wide XDR-tuberculosis transmission, including urban-rural migration. Further research should focus on characterizing the contribution of these drivers to overall XDR-tuberculosis transmission in KwaZulu-Natal to inform design of targeted strategies to curb the drug-resistant tuberculosis epidemic. |
Where is tuberculosis transmission happening? Insights from the literature, new tools to study transmission and implications for the elimination of tuberculosis.
Auld SC , Shah NS , Cohen T , Martinson NA , Gandhi NR . Respirology 2018 More than 10 million new cases of tuberculosis (TB) are diagnosed worldwide each year. The majority of these cases occur in low- and middle-income countries where the TB epidemic is predominantly driven by transmission. Efforts to 'end TB' will depend upon our ability to halt ongoing transmission. However, recent studies of new approaches to interrupt transmission have demonstrated inconsistent effects on reducing population-level TB incidence. TB transmission occurs across a wide range of settings, that include households and hospitals, but also community-based settings. While home-based contact investigations and infection control programmes in hospitals and clinics have a successful track record as TB control activities, there is a gap in our knowledge of where, and between whom, community-based transmission of TB occurs. Novel tools, including molecular epidemiology, geospatial analyses and ventilation studies, provide hope for improving our understanding of transmission in countries where the burden of TB is greatest. By integrating these diverse and innovative tools, we can enhance our ability to identify transmission events by documenting the opportunity for transmission-through either an epidemiologic or geospatial connection-alongside genomic evidence for transmission, based upon genetically similar TB strains. A greater understanding of locations and patterns of transmission will translate into meaningful improvements in our current TB control activities by informing targeted, evidence-based public health interventions. |
Research roadmap for tuberculosis transmission science: Where do we go from here and how will we know when we're there?
Auld SC , Kasmar AG , Dowdy DW , Mathema B , Gandhi NR , Churchyard GJ , Rustomjee R , Shah NS . J Infect Dis 2017 216 S662-s668 High rates of tuberculosis transmission are driving the ongoing global tuberculosis epidemic, and there is a pressing need for research focused on understanding and, ultimately, halting transmission. The ongoing tuberculosis-human immunodeficiency virus (HIV) coepidemic and rising rates of drug-resistant tuberculosis in parts of the world add further urgency to this work. Success in this research will require a concerted, multidisciplinary effort on the part of tuberculosis scientists, clinicians, programs, and funders and must span the research spectrum from biomedical sciences to the social sciences, public health, epidemiology, cost-effectiveness analyses, and operations research. Heterogeneity of tuberculosis disease, both among individual patients and among communities, poses a substantial challenge to efforts to interrupt transmission. As such, it is likely that effective interventions to stop transmission will require a combination of approaches that will vary across different epidemiologic settings. This research roadmap summarizes key gaps in our current understanding of transmission, as laid out in the preceding articles in this series. We also hope that it will be a call to action for the global tuberculosis community to make a sustained commitment to tuberculosis transmission science. Halting transmission today is an essential step on the path to end tuberculosis tomorrow. |
Transmission of Extensively Drug-Resistant Tuberculosis in South Africa.
Shah NS , Auld SC , Brust JC , Mathema B , Ismail N , Moodley P , Mlisana K , Allana S , Campbell A , Mthiyane T , Morris N , Mpangase P , van der Meulen H , Omar SV , Brown TS , Narechania A , Shaskina E , Kapwata T , Kreiswirth B , Gandhi NR . N Engl J Med 2017 376 (3) 243-253 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.). |
IFN-γ Release Assay Result Is Associated with Disease Site and Death in Active Tuberculosis
Auld SC , Lee SH , Click ES , Miramontes R , Day CL , Gandhi NR , Heilig CM . Ann Am Thorac Soc 2016 13 (12) 2151-2158 RATIONALE: The interferon gamma release assays and tuberculin skin tests are used to support the diagnosis of both latent and active tuberculosis. However, we previously demonstrated that a negative tuberculin test in active tuberculosis is associated with disseminated disease and death. It is unknown whether the same associations exist for interferon gamma release assays. OBJECTIVES: To determine the association between these tests and site of tuberculosis and death among persons with active tuberculosis. METHODS: We analyzed interferon gamma release assay and tuberculin test results for all persons with culture-confirmed tuberculosis reported to the US National Tuberculosis Surveillance System from 2010-2014. We used logistic regression to calculate the association between these tests and site of disease and death. MEASUREMENTS AND MAIN RESULTS: 24,803 persons with culture-confirmed tuberculosis had either of these test results available for analysis. Persons with a positive tuberculin test had lower odds of disseminated disease (i.e., miliary or combined pulmonary and extrapulmonary disease), but there was no difference in the odds of disseminated disease with a positive interferon gamma release assay. However, persons who were positive to either of these tests had lower odds of death. An indeterminate interferon gamma release assay result was associated with greater odds of both disseminated disease and death. CONCLUSIONS: Despite perceived equivalence in clinical practice, interferon gamma release assay and tuberculin test results have different associations with tuberculosis site yet similar associations with the risk of death. Furthermore, an indeterminate interferon gamma release assay result in a person with active tuberculosis is not unimportant, and rather carries greater odds of disseminated disease and death. Prospective study may improve our understanding of the underlying mechanisms by which these tests are associated with disease localization and death. |
Mixed impact of Xpert((R)) MTB/RIF on tuberculosis diagnosis in Cambodia
Auld SC , Moore BK , Kyle RP , Eng B , Nong K , Pevzner ES , Eam KK , Eang MT , Killam WP . Public Health Action 2016 6 (2) 129-35 SETTING: National Tuberculosis (TB) Program sites in northwest Cambodia. OBJECTIVE: To evaluate the impact of Xpert((R)) MTB/RIF at point of care (POC) as compared to non-POC sites on the diagnostic evaluation of people living with the human immunodeficiency virus (PLHIV) with TB symptoms and patients with possible multidrug-resistant (MDR) TB. DESIGN: Observational cohort of patients undergoing routine diagnostic evaluation for TB following the rollout of Xpert. RESULTS: Between October 2011 and June 2013, 431 of 822 (52%) PLHIV with TB symptoms and 240/493 (49%) patients with possible MDR-TB underwent Xpert. Xpert was more likely to be performed when available as POC. A smaller proportion of PLHIV at POC sites were diagnosed with TB than at non-POC sites; however, at POC sites, a higher proportion of those diagnosed with TB were bacteriologically positive. There was poor agreement between Xpert and other tests such as smear microscopy and culture. Overall, the evaluation of patients with possible MDR-TB increased following Xpert rollout, yet for patients confirmed as having drug resistance on drug susceptibility testing, only 46% had rifampin resistance that would be identified with Xpert. CONCLUSION: Although utilization of Xpert was low, it may have contributed to an increase in evaluations for possible MDR-TB and a decline in empiric treatment for PLHIV when available as POC. |
Rollout of Xpert MTB/RIF in northwest Cambodia for the diagnosis of tuberculosis among PLHA
Auld SC , Moore BK , Killam WP , Eng B , Nong K , Pevzner EC , Eam KK , Eang MT , Warren D , Whitehead SJ . Public Health Action 2014 4 (4) 216-221 OBJECTIVE: To describe the implementation and utilization of the Xpert MTB/RIF (Xpert) assay to diagnose tuberculosis (TB) among people living with the human immunodeficiency virus/acquired immune-deficiency syndrome (HIV/AIDS, PLHA) in Cambodia. DESIGN: Following the rollout of Xpert, an evaluation was conducted in four provinces of Cambodia from March to December 2012 to determine the utilization, performance, and turnaround time (TAT) of Xpert among PLHA. Data were collected from paper-based patient registers. RESULTS: Of 497 PLHA with a positive TB symptom screen, 357 (72%) were tested with smear microscopy, and 250 (50%) with Xpert; 25 (10%) PLHA tested with Xpert were positive for TB and none were rifampicin-resistant. The utilization of Xpert increased from 23% to 75%, with a median TAT of 1 day. Across districts, utilization ranged from zero to 85%, while the TAT ranged from zero to 22 days. CONCLUSION: While early data show increasing utilization of Xpert for PLHA with a positive symptom screen, most patients underwent smear microscopy as an initial diagnostic test. Training delays and challenges associated with specimen referral may have contributed to variability in Xpert uptake and TAT, particularly for sites without onsite Xpert testing. Enhanced programmatic support, particularly for specimen referral and results reporting, may facilitate appropriate utilization. |
Association between tuberculin skin test result and clinical presentation of tuberculosis disease
Auld SC , Click ES , Heilig CM , Miramontes R , Cain KP , Bisson GP , Mac Kenzie WR . BMC Infect Dis 2013 13 (1) 460 BACKGROUND: The tuberculin skin test (TST) is used to test for latent tuberculosis (TB) infection and support the diagnosis of active TB. However, little is known about the relationship between the TST result and the clinical presentation of TB disease. METHODS: We analyzed US TB surveillance data, 1993--2010, and used multinomial logistic regression to calculate the association between TST result (0--4 mm [negative], 5--9 mm, 10--14 mm, and >= 15 mm) and clinical presentation of disease (miliary, combined pulmonary and extrapulmonary, extrapulmonary only, non-cavitary pulmonary, and cavitary pulmonary). For persons with pulmonary disease, multivariate logistic regression was used to calculate the odds of having acid-fast bacilli (AFB) positive sputum. RESULTS: There were 64,238 persons with culture-confirmed TB included in the analysis, which was stratified by HIV status and birthplace (US- vs. foreign-born). Persons with a TST >= 15 mm were less likely to have miliary or combined pulmonary and extrapulmonary disease, but more likely to have cavitary pulmonary disease than non-cavitary pulmonary disease. Persons with non-cavitary pulmonary disease with a negative TST were significantly more likely to have AFB positive sputum. CONCLUSIONS: Clinical presentation of TB disease differed according to TST result and persons with a negative TST were more likely to have disseminated disease (i.e., miliary or combined pulmonary and extrapulmonary). Further study of the TST result may improve our understanding of the host-pathogen relationship in TB disease. |
Reaching beyond our Xpert potential: reflections on the 43rd Union World Conference
Auld SC , Pevzner E . Int J Tuberc Lung Dis 2013 17 (3) 423-4 The 43rd Union World Conference on Lung Health | could also have been called the fi rst Union World | Conference on GeneXpert®. If you search the digital | abstract book you will fi nd the term ‘Xpert’ mentioned a remarkable 325 times compared to 84 times | in 2011 and 12 times in 2010.1–3 After nearly half a | century without notable advances in the diagnosis | and treatment of tuberculosis (TB), the TB community is understandably excited about the potential for | Xpert to contribute to substantial gains in the ongoing fi ght against this global killer. At the same time, | we must temper our excitement and prepare for the | continuing challenges of diagnosing, treating, and | preventing TB, with or without Xpert. | Unlike human immunodefi ciency virus prevention | and control programs, for whom diagnostics and | treatments have evolved rapidly over the last several | decades, TB control programs have witnessed few | changes since the 1970s.4,5 This long-term stability | has fostered the development of well-established national TB programs (NTPs) with straightforward diagnostic algorithms, decentralized treatment, and robust recording and reporting systems. Yet these very | strengths have the potential to become weaknesses as | we embark upon an era of innovation and discovery. | In addition to the many conference sessions on Xpert, | we also heard about the various ‘pipelines’ for new | diagnostics and biomarkers, novel drug regimens for | treating childhood and multidrug-resistant TB, and, | hopefully, a new TB vaccine. Unfortunately, our wellestablished model for NTPs may be ill-equipped to | integrate and benefi t from these anticipated advances. |
Completeness and concordance of TB and HIV surveillance systems for TB-HIV co-infected patients in South Africa
Auld SC , Kim L , Webb EK , Podewils LJ , Uys M . Int J Tuberc Lung Dis 2013 17 (2) 186-91 SETTING: South Africa currently maintains separate surveillance systems for tuberculosis (TB) and human immunodeficiency virus (HIV). There are future plans for integration of these systems; however, the consistency of information across the existing systems has not previously been assessed. OBJECTIVE: To determine the completeness and concordance of data in the TB and HIV surveillance systems for TB-HIV co-infected patients. DESIGN: In a retrospective cohort evaluation of the records of TB-HIV co-infected patients in the Eden District of the Western Cape, data were abstracted from paper-based and electronic TB and HIV surveillance sources. Concordance was measured using Fleiss' kappa coefficient. RESULTS: Demographic variables had high completeness and concordance across the TB and HIV systems. Completeness and concordance for clinical variables was somewhat lower, particularly for TB variables in the HIV systems and HIV variables in the TB systems. CONCLUSION: Varying levels of completeness and concordance of surveillance data for TB-HIV co-infected patients highlight challenges in the current TB and HIV surveillance systems. Future integration of TB and HIV programs in this region will need to support more accurate data collection at all levels. |
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