Browsing by Author "Turnbull ER"

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A model of tuberculosis screening for pregnant women in resource-limited settings using Xpert MTB/RIF.
(2012) Turnbull ER; Kancheya NG; Harris JB; Topp SM; Henostroza G; Reid SE; Tuberculosis Department, Centre for Infectious Disease Research in Zambia, 5977 Benakale Road, P.O. Box 34681, Northmead, Lusaka, Zambia; Schools of Medicine and Public Health, University of Alabama at Birmingham, AL 35233, USA. eleanor.turnbull@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
Timely diagnosis and treatment of maternal tuberculosis (TB) is important to reduce morbidity and mortality for both the mother and child, particularly in women who are coinfected with HIV. The World Health Organization (WHO) recommends the integration of TB/HIV screening into antenatal services but available diagnostic tools are slow and insensitive, resulting in delays in treatment initiation. Recently the WHO endorsed Xpert MTB/RIF, a highly sensitive, real-time PCR assay for Mycobacterium tuberculosis that simultaneously detects rifampicin resistance directly from sputum and provides results within 100 minutes. We propose a model for same-day TB screening and diagnosis of all pregnant women at antenatal care using Xpert MTB/RIF. Pilot studies are urgently required to evaluate strategies for the integration of TB screening into antenatal clinics using new diagnostic technologies.
An evaluation of the performance and acceptability of three LED fluorescent microscopes in Zambia: lessons learnt for scale-up.
(2011) Turnbull ER; Kaunda K; Harris JB; Kapata N; Muvwimi MW; Kruuner A; Henostroza G; Reid SE; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. eleanor.turnbull@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
The World Health Organization recommends the roll-out of light-emitting diode (LED) fluorescent microscopes (FM) as an alternative to light microscopes in resource-limited settings. We evaluated the acceptability and performance of three LED FMs after a short orientation among laboratory technicians from government health centers in Zambia. Sixteen technicians with varied light microscopy experience were oriented to FMs and divided into groups; each group read a different set of 40 slides on each LED FM (Primo Star iLED™, Lumin™, FluoLED™) and on a reference mercury-vapor FM (Olympus BX41TF). Slide reading times were recorded. An experienced FM technician examined each slide on the Olympus BX41TF. Sensitivity and specificity compared to TB culture were calculated. Misclassification compared to the experienced technician and inter-rater reliability between trainees was assessed. Trainees rated microscopes on technical aspects. Primo Star iLED™, FluoLED™ and Olympus BX41TF had comparable sensitivities (67%, 65% and 65% respectively), with the Lumin™ significantly worse (56%; p<0.05). Specificity was low for trainees on all microscopes (75.9%) compared to the experienced technician on Olympus BX41TF (100%). Primo Star iLED™ had significantly less misclassification (21.1% p<0.05) than FluoLED™ (26.5%) and Lumin™ (26.8%) and significantly higher inter-rater reliability (0.611; p<0.05), compared to FluoLED™ (0.523) and Lumin™ (0.492). Slide reading times for LED FMs were slower than the reference, but not significantly different from each other. Primo Star iLED™ rated highest in acceptability measures, followed by FluoLED™ then Lumin™. Primo Star iLED™ was consistently better than FluoLED™ and Lumin™, and performed comparably to the Olympus BX41TF in all analyses, except reading times. The Lumin™ compared least favorably and was thought unacceptable for use. Specificity and inter-rater reliability were low for all microscopes suggesting that a brief orientation was insufficient in this setting. These results provide important data for resource-limited settings to consider as they scale-up LED FMs.
High prevalence of tuberculosis in newly enrolled HIV patients in Zambia: need for enhanced screening approach.
(2016-Aug) Henostroza G; Harris JB; Chitambi R; Siyambango M; Turnbull ER; Maggard KR; Krüüner A; Kapata N; Reid SE; Tuberculosis Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA; Tuberculosis Department, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; National Tuberculosis and Leprosy Control Programme, Ministry of Health of Zambia, Lusaka, Zambia.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
SETTING: Tuberculosis (TB) remains a leading cause of morbidity and mortality in sub-Saharan Africa. In Zambia, smear microscopy and chest radiography (CXR) are the primary TB diagnostic tools, and most cases are not bacteriologically confirmed. OBJECTIVE: We implemented enhanced screening to determine the TB burden among new human immunodeficiency virus (HIV) clinic enrollees. DESIGN: Consecutive adult HIV clinic enrollees were screened, regardless of symptoms. All underwent microscopy (Ziehl-Neelsen/fluorescence microscopy) on three sputum specimens, physical examination, and digital CXR. Sputum, blood and urine specimens were cultured. Xpert(®) MTB/RIF testing was performed retrospectively. RESULTS: From July 2011 to April 2012, 399 patients were enrolled. The median age was 34.4 years; body mass index was 20.8 kg/m(2), CD4 count was 202 cells/μl and 86% were symptomatic. Culture-confirmed TB was diagnosed in 72/399 (18%) patients; an additional 31/399 (8%) were culture-negative but diagnosed clinically. Symptom screening for any cough, fever, weight loss or night sweats had high sensitivity (95%) but low specificity (14%) for detecting culture-confirmed cases. Among culture-confirmed cases, 35/72 (49%) were missed clinically and detected only by culture. Xpert was 64% sensitive and 98% specific. CONCLUSIONS: High TB prevalence was found in Zambians newly enrolled into HIV care. Screening with sensitive diagnostics should be considered with culture when feasible in this population.
Tuberculosis and HIV control in sub-Saharan African prisons: "thinking outside the prison cell".
(2012-May-15) Reid SE; Topp SM; Turnbull ER; Hatwiinda S; Harris JB; Maggard KR; Roberts ST; Krüüner A; Morse JC; Kapata N; Chisela C; Henostroza G; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. stewart.reid@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
Tuberculosis is one of the fastest-growing epidemics in prison populations in sub-Saharan Africa (SSA), constituting a threat to both inmates and the wider community. Various factors have contributed to the breakdown of tuberculosis control in prison facilities in SSA, including slow and insensitive diagnostics, failing prison infrastructure, inadequate funding, and weak prevention and treatment interventions for human immunodeficiency virus (HIV). In this article, we describe the challenges inherent in current approaches to tuberculosis control in prisons and consider the alternatives. We argue that although improved implementation of conventional tuberculosis control activities is necessary, considerable investment in a broader range of public health interventions, including infrastructure and staffing upgrades, cutting-edge tuberculosis diagnostics, and combination prevention for HIV, will be equally critical. This combination response to tuberculosis in prisons will be essential for tackling existing and nascent prison tuberculosis epidemics and will require high-level political support and financing.