SUNScholar - Browsing by Author "Dunbar, Rory"

Browsing by Author "Dunbar, Rory"

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Accuracy and completeness of notification of tuberculosis in two high incident communities in Cape Town, South Africa
(Stellenbosch : Stellenbosch University, 2011-12) Dunbar, Rory; Barnes, J. M.; Beyers, Nulda; Stellenbosch University. Faculty of Health Sciences. Dept. of Interdisciplinary Health Sciences. Community Health.
ENGLISH ABSTRACT: Introduction: Tuberculosis (TB) treatment registers and laboratory records are essential recording and reporting tools in TB control programmes. Reliable data are essential for any TB control programme but under-registration of TB cases has been well documented internationally, due to under-reporting of patients on treatment or failure to initiate treatment. The accuracy and completeness of routinely collected data are seldom monitored. Aim: This study used record linking to assess the accuracy and completeness of TB treatment register data and the feasibility of estimating the completeness of bacteriological confirmed pulmonary TB registration in two high incident communities in South Africa with capturerecapture methods. Methods: All cases of bacteriologically confirmed TB defined as 2 smear-positive results and/or at least one culture-positive result were included. Record linking was performed between three data sources: (1) TB treatment registers; and (2) all smear and culture results from (a) the nearest central laboratory, and (b) the referral hospital laboratory. To estimate the completeness of TB treatment recording three-source log-linear capture-recapture models were used, with internal validity analysis. Results: The TB treatment registers had 435 TB cases recorded of which 204 (47%) were bacteriologically confirmed cases. An additional 39 cases that were recorded as nonbacteriological cases in the TB treatment register, were reclassified as bacteriologically confirmed. In addition, there were 63 bacteriologically confirmed cases identified from the laboratory databases which were not recorded in the TB treatment register. The final total number of bacteriologically confirmed TB cases across all 3 databases was 306, an increase of 50% over what had initially been recorded in the TB treatment register. The log-linear capture-recapture model estimated the number of bacteriologically confirmed TB cases not found in any of the data sources at 20, resulting in a total number of bacteriologically confirmed TB cases of 326 (95% CI 314-355). The completeness of registration of bacteriologically confirmed pulmonary TB cases was 79% after record linking and 75% after the capture-recapture estimate. Conclusions: The results presented in this thesis highlighted the concern regarding the accuracy and completeness of routinely collected TB recording and reporting data. A high percentage of bacteriologically confirmed cases from both laboratories were not recorded in the TB treatment registers. Capture-recapture can be useful, but not essential, for evaluation of TB control programmes, also in resource-limited settings, but methodology and results should be carefully assessed. The present study estimated the extent of the problem of underreporting of TB in South Africa and identified challenges in the process. Interventions to reduce underreporting of TB are urgently needed.
Comparing tuberculosis diagnostic yield in smear/culture and xpert MTB/RIF-based algorithms using a non-randomised stepped-wedge design
(Public Library of Science, 2016-03) Naidoo, Pren; Dunbar, Rory; Lombard, Carl; Du Toit, Elizabeth; Caldwell, Judy; Detjen, Anne; Squire, S. Bertel; Enarson, Donald A.; Beyers, Nulda
Setting Primary health services in Cape Town, South Africa. Study Aim To compare tuberculosis (TB) diagnostic yield in an existing smear/culture-based and a newly introduced Xpert MTB/RIF-based algorithm. Methods TB diagnostic yield (the proportion of presumptive TB cases with a laboratory diagnosis of TB) was assessed using a non-randomised stepped-wedge design as sites transitioned to the Xpert based algorithm. We identified the full sequence of sputum tests recorded in the electronic laboratory database for presumptive TB cases from 60 primary health sites during seven one-month time-points, six months apart. Differences in TB yield and temporal trends were estimated using a binomial regression model. Results TB yield was 20.9% (95% CI 19.9% to 22.0%) in the smear/culture-based algorithm compared to 17.9% (95%CI 16.4% to 19.5%) in the Xpert based algorithm. There was a decline in TB yield over time with a mean risk difference of -0.9% (95% CI -1.2% to -0.6%) (p<0.001) per time-point. When estimates were adjusted for the temporal trend, TB yield was 19.1% (95% CI 17.6% to 20.5%) in the smear/culture-based algorithm compared to 19.3% (95% CI 17.7% to 20.9%) in the Xpert based algorithm with a risk difference of 0.3% (95% CI -1.8% to 2.3%) (p = 0.796). Culture tests were undertaken for 35.5% of smear-negative compared to 17.9% of Xpert negative low MDR-TB risk cases and for 82.6% of smear-negative compared to 40.5% of Xpert negative high MDR-TB risk cases in respective algorithms. Conclusion Introduction of an Xpert based algorithm did not produce the expected increase in TB diagnostic yield. Studies are required to assess whether improving adherence to the Xpert negative algorithm for HIV-infected individuals will increase yield. In light of the high cost of Xpert, a review of its role as a screening test for all presumptive TB cases may be warranted.
Complementary surveillance strategies are needed to better characterise the epidemiology, care pathways and treatment outcomes of tuberculosis in children
(BioMed Central, 2018-03-23) Du Preez, Karen; Schaaf, H. Simon; Dunbar, Rory; Walters, Elisabetta; Swartz, Alvera; Solomons, Regan; Hesseling, Anneke C.
Background: Tuberculosis (TB) in young and HIV-infected children is frequently diagnosed at hospital level. In settings where general hospitals do not function as TB reporting units, the burden and severity of childhood TB may not be accurately reflected in routine TB surveillance data. Given the paucibacillary nature of childhood TB, microbiological surveillance alone will miss the majority of hospital-managed children. The study objective was to combine complementary hospital-based surveillance strategies to accurately report the burden, spectrum and outcomes of childhood TB managed at referral hospital-level in a high TB burden setting. Methods: We conducted a prospective cohort study including all children (< 13 years) managed for TB at a large referral hospital in Cape Town, South Africa during 2012. Children were identified through newly implemented clinical surveillance in addition to existing laboratory surveillance. Data were collected from clinical patient records, the National Health Laboratory Service database, and provincial electronic TB registers. Descriptive statistics were used to report overall TB disease burden, spectrum, care pathways and treatment outcomes. Univariate analysis compared characteristics between children identified through the two hospital-based surveillance strategies to characterise the group of children missed by existing laboratory surveillance. Results: During 2012, 395 children (180 [45.6%] < 2 years) were managed for TB. Clinical surveillance identified 237 (60%) children in addition to laboratory surveillance. Ninety (24.3%) children were HIV co-infected; 113 (29.5%) had weight-for-age z-scores <− 3. Extra-pulmonary TB (EPTB) was diagnosed in 188 (47.6%); 77 (19.5%) with disseminated TB. Favourable TB treatment outcomes were reported in 300/344 (87.2%) children with drugsusceptible and 50/51 (98.0%) children with drug-resistant TB. Older children (OR 1.7; 95% CI 1.0–2.8), children with EPTB (OR 2.3; 95% CI 1.5–3.6) and in-hospital deaths (OR 5.4; 95% CI 1.1–26.9) were more frequently detected by laboratory surveillance. TB/HIV co-infected children were less likely to be identified through laboratory surveillance (OR 0.3; 95% CI 0.2–0.5). Conclusions: The burden and spectrum of childhood TB disease managed at referral hospital level in high burden settings is substantial. Hospital-based surveillance in addition to routine TB surveillance is essential to provide a complete picture of the burden, spectrum and impact of childhood TB in settings where hospitals are not TB reporting units.
The complex relationship between human immunodeficiency virus infection and death in adults being treated for tuberculosis in Cape Town, South Africa
(BioMed Central, 2015) Osman, Muhammad; Seddon, James A.; Dunbar, Rory; Draper, Heather R.; Lombard, Carl; Beyers, Nulda
Background: Despite recognised treatment strategies, mortality associated with tuberculosis (TB) remains significant. Risk factors for death during TB treatment have been described but the complex relationship between TB and HIV has not been fully understood. Methods: A retrospective analysis of all deaths occurring during TB treatment in Cape Town, South Africa between 2009 and 2012 were done to investigate risk factors associated with this outcome. The main risk factor was HIV status at the start of treatment and its interaction with age, sex and other risk factors were evaluated using a binomial regression model and thus relative risks (RR) are reported. Results: Overall in the 93,133 cases included in the study 4619 deaths (5 %) were recorded. Across all age groups HIV-positive patients were more than twice as likely to die as HIV-negative patients, RR = 2.19 (95 % CI: 2.03–2.37). However in an age specific analysis HIV-positive patients 15–24 and 25–34 years old were at an even higher risk of dying than HIV-negative patients, RR = 4.82 and RR = 3.76 respectively. Gender also modified the effect of HIV- with positive women having a higher risk of death than positive men, RR = 2.74 and RR = 1.94 respectively. Conclusion: HIV carries an increased risk of death in this study but specific high-risk groups pertaining to the impact of HIV are identified. Innovative strategies to manage these high risk groups may contribute to reduction in HIV-associated death in TB patients.
Effect of Universal Testing and Treatment on HIV Incidence — HPTN 071 (PopART)
(Massachusetts Medical Society, 2019-07) Hayes, Richard J.; Donnell, Deborah; Floyd, Sian; Mandla, Nomtha; Bwalya, Justin; Sabapathy, Kalpana; Yang, Blia; Phiri, Mwelwa; Schaap, Ab; Eshleman, Susan H.; Piwowar-Manning, Estelle; Kosloff, Barry; James, Anelet; Skalland, Timothy; Wilson, Ethan; Emel, Lynda; Macleod, David; Dunbar, Rory; Simwinga, Musonda; Makola, Nozizwe; Bond, Virginia; Moore, Ayana; Griffith, Sam; Sista, Nirupama Deshmane; Vermund, Sten H.; El-Sadr, Wafaa; Burns, David N.; Hargreaves, James R.; Hauck, Katharina; Fraser, Christophe; Shanaube, Kwame; Bock, Peter; Beyers, Nulda; Ayles, Helen; Fidler, Sarah
BACKGROUND: A universal testing and treatment strategy is a potential approach to reduce the incidence of human immunodeficiency virus (HIV) infection, yet previous trial results are inconsistent. METHODS: In the HPTN 071 (PopART) community-randomized trial conducted from 2013 through 2018, we randomly assigned 21 communities in Zambia and South Africa (total population, approximately 1 million) to group A (combination prevention intervention with universal antiretroviral therapy [ART]), group B (the prevention intervention with ART provided according to local guidelines [universal since 2016]), or group C (standard care). The prevention intervention included home-based HIV testing delivered by community workers, who also supported linkage to HIV care and ART adherence. The primary outcome, HIV incidence between months 12 and 36, was measured in a population cohort of approximately 2000 randomly sampled adults (18 to 44 years of age) per community. Viral suppression (<400 copies of HIV RNA per milliliter) was assessed in all HIV-positive participants at 24 months. RESULTS: The population cohort included 48,301 participants. Baseline HIV prevalence was 21% or 22% in each group. Between months 12 and 36, a total of 553 new HIV infections were observed during 39,702 person-years (1.4 per 100 person-years; women, 1.7; men, 0.8). The adjusted rate ratio for group A as compared with group C was 0.93 (95% confidence interval [CI], 0.74 to 1.18; P=0.51) and for group B as compared with group C was 0.70 (95% CI, 0.55 to 0.88; P=0.006). The percentage of HIV-positive participants with viral suppression at 24 months was 71.9% in group A, 67.5% in group B, and 60.2% in group C. The estimated percentage of HIV-positive adults in the community who were receiving ART at 36 months was 81% in group A and 80% in group B. CONCLUSIONS: A combination prevention intervention with ART provided according to local guidelines resulted in a 30% lower incidence of HIV infection than standard care. The lack of effect with universal ART was unanticipated and not consistent with the data on viral suppression. In this trial setting, universal testing and treatment reduced the population-level incidence of HIV infection. (Funded by the National Institute of Allergy and Infectious Diseases and others; HPTN 071 [PopArt] ClinicalTrials.gov number, NCT01900977. opens in new tab.)
Has universal screening with Xpert® MTB/RIF increased the proportion of multidrugresistant tuberculosis cases diagnosed in a routine operational setting?
(Public Library of Science, 2017-02-15) Naidoo, Pren; Dunbar, Rory; Caldwell, Judy; Lombard, Carl; Beyers, Nulda
Setting: Primary health services in Cape Town, South Africa where the introduction of Xpert® MTB/RIF (Xpert) enabled simultaneous screening for tuberculosis (TB) and drug susceptibility in all presumptive cases. Study aim: To compare the proportion of TB cases with drug susceptibility tests undertaken and multidrug-resistant tuberculosis (MDR-TB) diagnosed pre-treatment and during the course of 1st line treatment in the previous smear/culture and the newly introduced Xpert-based algorithms. Methods: TB cases identified in a previous stepped-wedge study of TB yield in five sub-districts over seven one-month time-points prior to, during and after the introduction of the Xpert-based algorithm were analysed. We used a combination of patient identifiers to identify all drug susceptibility tests undertaken from electronic laboratory records. Differences in the proportions of DST undertaken and MDR-TB cases diagnosed between algorithms were estimated using a binomial regression model. Results: Pre-treatment, the probability of having a DST undertaken (RR = 1.82)(p<0.001) and being diagnosed with MDR-TB (RR = 1.42)(p<0.001) was higher in the Xpert-based algorithm than in the smear/culture-based algorithm. For cases evaluated during the course of 1st-line TB treatment, there was no significant difference in the proportion with DST undertaken (RR = 1.02)(p = 0.848) or MDR-TB diagnosed (RR = 1.12)(p = 0.678) between algorithms. Conclusion: Universal screening for drug susceptibility in all presumptive TB cases in the Xpert-based algorithm resulted in a higher overall proportion of MDR-TB cases being diagnosed and is an important strategy in reducing transmission. The previous strategy of only screening new TB cases when 1st line treatment failed did not compensate for cases missed pre-treatment.
High prevalence of Tuberculosis and insufficient case detection in two communities in the Western Cape, South Africa
(PLoS ONE, 2013-04) Claassens, Mareli; Van Schalkwyk, Cari; De Haan, Leonie; Floyd, Sian; Dunbar, Rory; Van Helden, Paul; Godfrey-Faussett, Peter; Ayles, Helen; Borgdorff, Martien; Enarson, Donald; Beyers, Nulda
Background: In South Africa the estimated incidence of all forms of tuberculosis (TB) for 2008 was 960/100000. It was reported that all South Africans lived in districts with Directly Observed Therapy, Short-course. However, the 2011 WHO report indicated South Africa as the only country in the world where the TB incidence is still rising. Aims: To report the results of a TB prevalence survey and to determine the speed of TB case detection in the study communities. Methods: In 2005 a TB prevalence survey was done to inform the sample size calculation for the ZAMSTAR (Zambia South Africa TB and AIDS Reduction) trial. It was a cluster survey with clustering by enumeration area; all households were visited within enumeration areas and informed consent obtained from eligible adults. A questionnaire was completed and a sputum sample collected from each adult. Samples were inoculated on both liquid mycobacterium growth indicator tube (MGIT) and Lo¨ wenstein-Jensen media. A follow-up HIV prevalence survey was done in 2007. Results: In Community A, the adjusted prevalence of culture positive TB was 32/1000 (95%CI 25–41/1000) and of smear positive TB 8/1000 (95%CI 5–13/1000). In Community B, the adjusted prevalence of culture positive TB was 24/1000 (95%CI17–32/1000) and of smear positive TB 9/1000 (95%CI 6–15/1000). In Community A the patient diagnostic rate was 0.38/person-year while in community B it was 0.30/person-year. In both communities the adjusted HIV prevalence was 25% (19–30%). Discussion: In both communities a higher TB prevalence than national estimates and a low patient diagnostic rate was calculated, suggesting that cases are not detected at a sufficient rate to interrupt transmission. These findings may contribute to the rising TB incidence in South Africa. The TB epidemic should therefore be addressed rapidly and effectively, especially in the presence of the concurrently high HIV prevalence.
How can virtual implementation modelling inform the scale-up of new molecular diagnostic tools for tuberculosis?
(Stellenbosch : Stellenbosch University, 2018-03) Dunbar, Rory; Beyers, Nulda; Langey, Ivor; Naidoo, Pren; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Paediatrics and Child Health.
ENGLISH ABSTRACT: The aim of this dissertation was to develop an operational model to explain why the expected increase in the number of tuberculosis (TB) cases detected was not found in our empirical study, Policy Relevant Outcomes from Validating Evidence on ImpacT (PROVE IT), done in 142 health clinics in Cape Town after the roll-out of a new TB diagnostic test, Xpert MTB/RIF (Xpert). I then used the model to model the effect of interventions to improve the detection of TB and rifampicin resistant (RMP-R) TB. Strategies were modelled to reduce laboratory cost for detecting TB as well as the effect of introducing a more sensitive molecular diagnostic test, Xpert MTB/RIF Ultra (Ultra), as a replacement for Xpert on the number of TB and RMP-R TB cases detected. I developed and validated an operational model using a discrete event simulation approach for the detection of TB and RMP-R TB in a smear/culture-based algorithm and an Xpert-based algorithm using data from published articles as well as from the step-wedge analysis of the Xpert-based TB diagnostic algorithm in Cape Town (PROVE IT). The model was adapted to incorporate a more sensitive molecular diagnostic test as a replacement test for Xpert in the Xpert-based algorithm. All comparisons between algorithms were conducted with identical population characteristics and adherence to diagnostic algorithms. The empirical study found no increase in the number of TB cases detected (20.9% smear/culture-based and 17.7% with the Xpert-based algorithm) while the operational model, using identical population characteristics and adherence to diagnostic algorithms (adherence to algorithms as observed from the analysis of routine data in the empirical study), showed that there were more TB cases detected in the Xpertbased algorithm than in the smear/culture-based algorithm (an increase of 13.3%) (Chapter 2). The model indicated that a decrease in background TB prevalence and the extensive use of culture testing for smear-negative HIV-positive TB cases during the smear/culture-based algorithm contributed to not finding an increase in the number of TB cases detected in the empirical study. When adherence to the diagnostic algorithms was modelled to be 100%, the model indicated a 95.4% increase in the number of RMP-R TB cases detected in the Xpertbased algorithm compared to the smear/culture-based algorithm, while the empirical study showed only a 54% increase (Chapter 3). This difference is attributable to the differences in drug susceptibility test (DST) screening strategy between algorithms as well as poor adherence to diagnostic algorithms. In the smear/culture-based algorithm, only high MDR-TB risk cases are screened for RMP-R pre-treatment compared to all presumptive TB cases screened for RMP-R with the Xpert-based algorithm. The empirical study found that the proportion of TB cases with DST undertaken pretreatment increased from 42.7% in the smear/culture-based algorithm to 78.9% in the Xpert-based algorithm. The model indicated that for the Xpert-based algorithm compared to the smearbased algorithm (with 100% adherence to algorithms), the cost per TB case detected would increase by 114% with only a 5.5% increase in the number of TB cases detected (Chapter 3). Even though the model indicated a small increase in the number of TB cases detected, the real benefit of the Xpert-based algorithm is the 95.4% increase in RMP-R TB cases detected with only a 15.8% increase in the cost per RMP-R TB case detected (Chapter 3). The model indicated that the best approach to improve the laboratory cost per TB case detected, would be a combined approach of increasing the TB prevalence among presumptive cases tested by using either a triage test or other pre-screening strategies, and a reduction in the price of Xpert cartridges (Chapter 4). With an increase in TB prevalence among presumptive cases tested to between 25.9% – 30.8% and the price of the Xpert cartridge reduced by 50%, the cost per TB case detected would range from US$50 to US$59, a level that is comparable with the cost per TB case detected in the smear/culture-based algorithm (US$48.77) found in the empirical laboratory costing study. Finally, when modelling the use of the not-yet released Xpert MTB/RIF Ultra as a replacement for Xpert MTB/RIF (Chapter 5), the number of TB cases detected would increase by 3.4% and RMP-R TB cases detected by 3.5%. The number of falsepositive TB cases detected with Ultra would however increase by 166.6%. We could not model the cost per TB case and cost per RMP-R TB case diagnosed with Ultra, as the price is not available yet. Ultra has small benefits over that of Xpert for both the number of TB and RMP-R TB cases detected and therefore the cost of introducing Ultra would be an important consideration in the decision to implement Ultra. The introduction of Ultra poses potential health system and patient related challenges due to the high number of false-positive TB cases detected. Alternative strategies, such as alternative diagnostic algorithms, will have to be considered to find a balance between increased detection of TB cases and unnecessarily starting patients on TB treatment due to false positive results. The strengths of the model used in this dissertation are that the model was developed and validated using detailed routine data and information collected with the empirical study on health and laboratory processes in a large number of clinics. The model made a direct comparison between the algorithms taking into account differences in population characteristics and adherence to algorithms. Generalisability of findings from the model and the use of the model for other settings may be limited as the model was validated against data from a well-resourced, urban setting, with good health and laboratory infrastructure and therefore may not reflect reality in other settings, such rural areas. The findings from the studies presented in this dissertation highlight the important role that an operation model can play in informing decision makers on the optimal use of a new diagnostic test in an operational setting, even after the rollout of the new test. Operational modelling can therefore be an effective tool to be used to assist the health department to optimise the way in which tests are currently used and could serve to inform decision makers about the implementation of new, more sensitive, diagnostic tests.
Missed opportunities for retention in pre-ART care in Cape Town, South Africa
(Public Library of Science -- PLoS, 2014-05) Du Toit, Elizabeth; Van Schalkwyk, Cari; Dunbar, Rory; Jennings, Karen; Yang, Blia; Coetzee, David; Beyers, Nulda; Fox, Matthew
Background: Few studies have evaluated access to and retention in pre-ART care. Objectives: To evaluate the proportion of People Living With HIV (PLWH) in pre-ART and ART care and factors associated with retention in pre-ART and ART care from a community cohort. Methods: A cross sectional survey was conducted from February – April 2011. Self reported HIV positive, negative or participants of unknown status completed a questionnaire on their HIV testing history, access to pre-ART and retention in pre-ART and ART care. Results: 872 randomly selected adults who reported being HIV positive in the ZAMSTAR 2010 prevalence survey were included and revisited. 579 (66%) reconfirmed their positive status and were included in this analysis. 380 (66%) had initiated ART with 357 of these (94%) retained in ART care. 199 (34%) had never initiated ART of whom 186 (93%) accessed pre-ART care, and 86 (43%) were retained in pre-ART care. In a univariable analysis none of the factors analysed were significantly associated with retention in care in the pre-ART group. Due to the high retention in ART care, factors associated with retention in ART care, were not analysed further. Conclusion: Retention in ART care was high; however it was low in pre-ART care. The opportunity exists, if care is better integrated, to engage with clients in primary health care facilities to bring them back to, and retain them in, pre-ART care.
Morbidity and mortality up to 5 years post tuberculosis treatment in South Africa : a pilot study
(Elsevier, 2019) Osman, Muhammad; Welte, Alex; Dunbar, Rory; Brown, Rosemary; Hoddinott, Graeme; Hesseling, Anneke C.; Marx, Florian M.
Background: A high risk of tuberculosis (TB), chronic lung disease, and mortality have been reported among people with a history of previous TB treatment, but data from high-incidence settings remain limited. The aim of this study was to characterize general morbidity and mortality among adults who had successfully completed TB treatment in the past 5 years in a high-incidence setting in South Africa. Methods: Adults ( 18 years) who had completed treatment for pulmonary TB between 2013 and 2017 were randomly selected from TB treatment registers. Household visits were conducted to locate and interview former TB (FTB) patients, and bacteriological testing for TB was offered. Additional data sources were used to ascertain the vitality status of FTB patients who could not be located. Results: Addresses were located for 200 of the 223 FTB patients sampled and 89 FTB patients were contacted of whom 51 agreed to be interviewed. Approximately half reported persistent respiratory symptoms, such as shortness of breath and wheezing, and repeated lung infections. One (3.6%) of 28 patients who provided a sputum sample had culture-positive TB and another two were currently on re-treatment for TB. Fifteen deaths post treatment were ascertained, resulting in a standardized mortality ratio of 3.8 (95% confidence interval 2.3–6.3) after successful TB treatment relative to the general population. Conclusions: In this high-incidence setting, locating and interviewing FTB patients was challenging. The study findings are consistent with a high rate of respiratory disease, including recurrent TB, and substantially elevated mortality among FTB patients.
Patient diagnostic rate as indicator of tuberculosis case detection, South Africa
(Centers for Disease Control and Prevention, 2016) Claassens, Mareli; Van Schalkwyk, Cari; Dunbar, Rory; Ayles, Helen; Beyers, Nulda
ENGLISH SUMMARY : To address the uncertainty of the indirectly measured tuberculosis case detection rate, we used survey data stratified by HIV status to calculate the patient diagnostic rate, a directly measurable indicator, in 8 communities in South Africa. Rates were lower among HIV-negative than HIV-positive persons. Tuberculosis programs should focus on HIV-negative persons.
The rate of sputum smear-positive tuberculosis after treatment default in a high-burden setting : a retrospective cohort study
(PLoS, 2012-09) Marx, Florian M.; Dunbar, Rory; Enarson, Donald A.; Beyers, Nulda
Rationale: High rates of recurrent tuberculosis after successful treatment have been reported from different high burden settings in Sub-Saharan Africa. However, little is known about the rate of smear-positive tuberculosis after treatment default. In particular, it is not known whether or not treatment defaulters continue to be or become again smear-positive and thus pose a potential for transmission of infection to others. Objective: To investigate, in a high tuberculosis burden setting, the rate of re-treatment for smear-positive tuberculosis among cases defaulting from standardized treatment compared to successfully treated cases. Methods: Retrospective cohort study among smear-positive tuberculosis cases treated between 1996 and 2008 in two urban communities in Cape Town, South Africa. Episodes of re-treatment for smear-positive tuberculosis were ascertained via probabilistic record linkage. Survival analysis and Poisson regression were used to compare the rate of smear-positive tuberculosis after treatment default to that after successful treatment. Results: A total of 2,136 smear-positive tuberculosis cases were included in the study. After treatment default, the rate of retreatment for smear-positive tuberculosis was 6.86 (95% confidence interval [CI]: 5.59–8.41) per 100 person-years compared to 2.09 (95% CI: 1.81–2.41) after cure (adjusted Hazard Ratio [aHR]: 3.97; 95% CI: 3.00–5.26). Among defaulters, the rate was inversely associated with treatment duration and sputum conversion prior to defaulting. Smear grade at start of the index treatment episode (Smear3+: aHR 1.61; 95%CI 1.11–2.33) was independently associated with smear-positive tuberculosis retreatment, regardless of treatment outcome. Conclusions: In this high-burden setting, there is a high rate of subsequent smear-positive tuberculosis after treatment default. Treatment defaulters are therefore likely to contribute to the pool of infectious source cases in the community. Our findings underscore the importance of preventing treatment default, as a means of successful tuberculosis control in highburden settings.
Retention in care and factors critical for effectively implementing antiretroviral adherence clubs in a rural district in South Africa
(Wiley Open Access, 2019-09-03) Bock, Peter; Gunst, Colette; Maschilla, Leonard; Holtman, Rory; Grobbelaar, Nelis; Wademan, Dillon; Dunbar, Rory; Fatti, Geoffrey; Kruger, James; Ford, Nathan; Hoddinott, Graeme; Meehan, Sue-Ann
Introduction: Differentiated models of care that include referral of antiretroviral treatment (ART) clients to adherence clubs are an important strategy to help clinics manage increased number of clients living with HIV in resource-constrained settings. This study reported on (i) clinical outcomes among ART clients attending community-based adherence clubs and (ii) experiences of adherence clubs and perceptions of factors key to successful adherence club implementation among clients and healthcare workers. Methods: A retrospective cohort analysis of routine data and a descriptive analysis of data collected through self-administered surveys completed by clients and healthcare workers were completed. Clients starting ART at the study clinic, between January 2014 and December 2015, were included in the cohort analysis and followed up until December 2016. The survey data were collected from August to September 2017. The primary outcome for the cohort analysis was a comparison of loss to follow-up (LTFU) between clients staying in clinic care and those referred to adherence clubs. Survey data reported on client experiences of and healthcare worker perceptions of adherence club care. Results: Cohort analysis reported on 465 participants, median baseline CD4 count 374 (IQR: 234 to 532) cells/ll and median follow-up time 20.7 (IQR 14.1 to 27.7) months. Overall, 202 (43.4%) participants were referred to an adherence club. LTFU was lower in those attending an adherence club (aHR =0.25, 95% CI: 0.11 to 0.56). This finding was confirmed on analysis restricted to those eligible for adherence club referral (aHR =0.28, 95% CI: 0.12 to 0.65). Factors highlighted as associated with successful adherence club implementation included: (i) referral of stable clients to the club, (ii) an ideal club size of ≥20 members, (iii) club services led by a counsellor (iv) using churches or community halls as venues (v) effective communication between all parties, and (vi) timely delivery of prepacked medication. Conclusions: This study showed good clinical outcomes, positive patient experiences and healthcare worker perceptions of the adherence club model. Factors associated with successful adherence club implementation, highlighted in this study, can be used to guide implementers in the scale-up of adherence club services across varied high-burden settings.
Understanding the time needed to link to care and start ART in seven HPTN 071 (PopART) study communities in Zambia and South Africa
(Springer, 2019) Seeley, Janet; Bond, Virginia; Yang, Blia; Floyd, Sian; MacLeod, David; Viljoen, Lario; Phiri, Mwelwa; Simuyaba, Melvin; Hoddinott, Graeme; Shanaube, Kwame; Bwalya, Chiti; De Villiers, Laing; Jennings, Karen; Mwanza, Margaret; Schaap, Ab; Dunbar, Rory; Sabapathy, Kalpana; Ayles, Helen; Bock, Peter; Hayes, Richard; Fidler, Sarah
To achieve UNAIDS 90:90:90 targets at population-level, knowledge of HIV status must be followed by timely linkage to care, initiation and maintenance of antiretroviral therapy (ART) for all people living with HIV (PLHIV). Interpreting quantitative patterns using qualitative data, we investigate time taken to link to care and initiate ART amongst individuals aware of their HIV-status in high HIV-prevalence urban communities in the HPTN 071 (PopART) study, a community-randomised trial of a combination HIV prevention package, including universal testing and treatment, in 21 communities in Zambia and South Africa. Data are drawn from the seven intervention communities where immediate ART irrespective if CD4 count was offered from the trial-start in 2014. Median time from HIV-diagnosis to ART initiation reduced after 2 years of delivering the intervention from 10 to 6 months in both countries but varied by gender and community of residence. Social and health system realities impact decisions made by PLHIV about ART initiation.

Browsing by Author "Dunbar, Rory"

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