Browsing by Author "Krüüner A"

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Derivation of a tuberculosis screening rule for sub-Saharan African prisons.
(2014-Jul) Harris JB; Siyambango M; Levitan EB; Maggard KR; Hatwiinda S; Foster EM; Chamot E; Kaunda K; Chileshe C; Krüüner A; Henostroza G; Reid SE
SETTING: Lusaka Central Prison, Zambia. OBJECTIVE: To derive screening rules for tuberculosis (TB) using data collected during a prison-wide TB and human immunodeficiency virus (HIV) screening program. DESIGN: We derived rules with two methodologies: logistic regression and classification and regression trees (C&RT). We evaluated the performance of the derived rules as well as existing World Health Organization (WHO) screening recommendations in our cohort of inmates, as measured by sensitivity, specificity, and positive and negative predictive values. RESULTS: The C&RT-derived rule recommended diagnostic testing of all inmates who were underweight (defined as body mass index [BMI] < 18.5 kg/m(2)] or HIV-infected; the C&RT-derived rule had 60% sensitivity and 71% specificity. The logistic regression-derived rule recommended diagnostic testing of inmates who were underweight, HIV-infected or had chest pain; the logistic regression-derived rule had 74% sensitivity and 57% specificity. Two of the WHO recommendations had sensitivities that were similar to our logistic regression rule but had poorer specificities, resulting in a greater testing burden. CONCLUSION: Low BMI and HIV infection were the most robust predictors of TB in our inmates; chest pain was additionally retained in one model. BMI and HIV should be further evaluated as the basis for TB screening rules for inmates, with modification as needed to improve the performance of the rules.
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
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.
Performance of Xpert
(2020-Dec-21) Kasaro MP; Chilyabanyama ON; Shah NS; Muluka B; Kapata N; Krüüner A; Mwaba I; Kaunda K; Coggin WL; Wen XJ; Henostroza G; Reid S
SETTING: Peri-urban health facilities providing HIV and TB care in Zambia. OBJECTIVE: To evaluate 1) the impact of Xpert DESIGN: Quasi-experimental study design with the first cohort evaluated per standard-of-care (SOC; first sputum tested using smear microscopy) and the second cohort per an algorithm using Xpert as initial test (intervention phase; IP). Xpert testing was provided onsite in Chongwe District, while samples were transported 5-10 km in Kafue District. TB was confirmed using mycobacterial culture. RESULTS: Among 1350 PLHIV enrolled, 156 (15.4%) had confirmed TB. Time from TB evaluation to diagnosis ( CONCLUSION: Xpert improved time to diagnosis and treatment initiation, but there was no difference in all-cause mortality. High sensitivity of Determine TB-LAM Ag at lower CD4 count supports increased use in settings providing care to PLHIV, particularly with advanced HIV disease.