Performance of Xpert MTB/RIF Ultra for tuberculosis diagnosis in the context of passive and active case finding

We present a field evaluation of the diagnostic accuracy of Xpert MTB/RIF (Xpert) and Xpert MTB/RIF Ultra (Ultra), using two cohorts in a high TB/HIV burden setting in Southern Mozambique. Single respiratory specimens from symptomatic adults accessing health care services (passive case finding (PCF) cohort), and from household and community close contacts (active case finding (ACF) cohort), were tested by smear microscopy, culture, Xpert and Ultra. Liquid and solid culture served as a composite reference standard. We explored trace results’ impact on specificity via their recategorisation to negative (in all and just among those previously treated individuals) A total of 1419 and 252 participants were enrolled in the PCF and ACF cohorts, respectively. For the PCF cohort, Ultra showed higher sensitivity than Xpert overall (0.95 (95% CI: 0.90, 0.98) versus 0.88 (0.82, 0.93); p<0.001) and among smear negative patients (0.63 (0.48, 0.76) and 0.84 (0.71, 0.93). Ultra's specificity was lower than Xpert's (0.98 (0.97, 0.99) versus 0.96 (0.95, 0.97); p=0.008). For ACF, sensitivities were the same (0.67 (95% CI: 0.22,0.96) for both tests), although Ultra detected a higher number of microbiologically confirmed samples than Xpert (4.7% (12/252) versus 2.7% (7/252)). Conditional recategorisation of trace results among previously treated participants maintained differences in specificity in the PCF cohort. These results add evidence on the improved sensitivity of Ultra and support its use in different case finding scenarios.

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Are we missing ‘previously treated’ smear-positive pulmonary tuberculosis under programme settings in India? A cross-sectional study

F1000Research ◽

10.12688/f1000research.18353.1 ◽

2019 ◽

Vol 8 ◽

pp. 338

Author(s):

Hemant Deepak Shewade ◽

Vivek Gupta ◽

Srinath Satyanarayana ◽

Atul Kharate ◽

Lakshmi Murali ◽

...

Keyword(s):

Vulnerable Populations ◽

Past History ◽

National Level ◽

Previous History ◽

Case Finding ◽

Active Case Finding ◽

Active Case ◽

Tb Treatment ◽

History Of ◽

Previously Treated

Background: In 2007, a field observation from India reported 11% misclassification among ‘new’ patients registered under the revised national tuberculosis (TB) control programme. Ten years down the line, it is important to know what proportion of newly registered patients has a past history of TB treatment. Methods: A study was conducted among new smear-positive pulmonary TB patients registered between March 2016 and February 2017 in 18 randomly selected districts to determine the effectiveness of an active case-finding strategy in marginalised and vulnerable populations. We included all patients detected through active case-finding. An equal number of randomly selected patients registered through passive case-finding from marginalised and vulnerable populations in the same districts were included. Before enrolment, we enquired about any history of previous TB treatment through interviews. Results: Of 629 patients, we interviewed 521, of whom, 11% (n=56) had past history of TB treatment (public or private) for at least a month: 13% (34/268) among the active case-finding group and 9% (22/253) among the passive case-finding group (p=0.18). No factors were found to be significantly associated with misclassification. Conclusion: Around one in every ten patients registered as ‘new’ had previous history of TB treatment. Corrective measures need to be implemented, followed by monitoring of any change in the proportion of ‘previously treated’ patients among all registered patients treated under the programme at national level.

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Comparative Yield of Tuberculosis during Active Case Finding Using GeneXpert or Smear Microscopy for Diagnostic Testing in Nepal: A Cross-Sectional Study

Tropical Medicine and Infectious Disease ◽

10.3390/tropicalmed6020050 ◽

2021 ◽

Vol 6 (2) ◽

pp. 50

Author(s):

Suman Chandra Gurung ◽

Kritika Dixit ◽

Bhola Rai ◽

Raghu Dhital ◽

Puskar Raj Paudel ◽

...

Keyword(s):

Diagnostic Testing ◽

Scale Up ◽

Cross Sectional Study ◽

Case Finding ◽

Smear Microscopy ◽

Active Case Finding ◽

Community Based ◽

Cross Sectional ◽

Active Case ◽

And Control

This study compared the yield of tuberculosis (TB) active case finding (ACF) interventions applied under TB REACH funding. Between June 2017 to November 2018, Birat Nepal Medical Trust identified presumptive cases using simple verbal screening from three interventions: door-to-door screening of social contacts of known index cases, TB camps in remote areas, and screening for hospital out-patient department (OPD) attendees. Symptomatic individuals were then tested using smear microscopy or GeneXpert MTB/RIF as first diagnostic test. Yield rates were compared for each intervention and diagnostic method. We evaluated additional cases notified from ACF interventions by comparing case notifications of the intervention and control districts using standard TB REACH methodology. The project identified 1092 TB cases. The highest yield was obtained from OPD screening at hospitals (n = 566/1092; 52%). The proportion of positive tests using GeneXpert (5.5%, n = 859/15,637) was significantly higher than from microscopy testing 2% (n = 120/6309). (OR = 1.4; 95%CI = 1.12–1.72; p = 0.0026). The project achieved 29% additionality in case notifications in the intervention districts demonstrating that GeneXpert achieved substantially higher case-finding yields. Therefore, to increase national case notification for TB, Nepal should integrate OPD screening using GeneXpert testing in every district hospital and scale up of community-based ACF of TB patient contacts nationally.

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Challenges from Tuberculosis Diagnosis to Care in Community-Based Active Case Finding among the Urban Poor in Cambodia: A Mixed-Methods Study

PLoS ONE ◽

10.1371/journal.pone.0130179 ◽

2015 ◽

Vol 10 (7) ◽

pp. e0130179 ◽

Cited By ~ 26

Author(s):

Natalie Lorent ◽

Kimcheng Choun ◽

Shelly Malhotra ◽

Pichenda Koeut ◽

Sopheak Thai ◽

...

Keyword(s):

Mixed Methods ◽

Urban Poor ◽

Case Finding ◽

Mixed Methods Study ◽

Active Case Finding ◽

Community Based ◽

Active Case ◽

Tuberculosis Diagnosis

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Active case finding among marginalised and vulnerable populations reduces catastrophic costs due to tuberculosis diagnosis

Global Health Action ◽

10.1080/16549716.2018.1494897 ◽

2018 ◽

Vol 11 (1) ◽

pp. 1494897 ◽

Cited By ~ 15

Author(s):

Hemant Deepak Shewade ◽

Vivek Gupta ◽

Srinath Satyanarayana ◽

Atul Kharate ◽

K.N. Sahai ◽

...

Keyword(s):

Vulnerable Populations ◽

Case Finding ◽

Active Case Finding ◽

Active Case ◽

Tuberculosis Diagnosis

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High Yield of Active Tuberculosis Case Finding Among HIV-Infected Patients Using Xpert MTB/RIF Testing

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz233 ◽

2019 ◽

Vol 6 (6) ◽

Author(s):

Russell R Kempker ◽

Nikoloz Chkhartishvili ◽

Inga Kinkladze ◽

Marcos C Schechter ◽

Kristin Harrington ◽

...

Keyword(s):

Case Finding ◽

High Yield ◽

Molecular Diagnostic ◽

Smear Microscopy ◽

People Living With Hiv ◽

Active Case Finding ◽

Newly Diagnosed ◽

Pulmonary Tb ◽

Active Case ◽

Hcv Antibody

Abstract Objective Conduct an active case finding study in Tbilisi, Georgia, for pulmonary tuberculosis (TB) among people living with HIV (PLWH). Methods Newly diagnosed HIV patients were assessed for symptoms and asked to submit sputum samples for smear microscopy, culture, and molecular diagnostic testing (Xpert MTB/RIF). Results Among 276 PLWH, 131 agreed to participate and 103 submitted sputum samples. Most participants were male (70%) and mean age of 43 years. There were high rates of a positive hepatitis C virus (HCV) antibody test (46%) and the median CD4 count was 122 cells/mm3. A total of 15 (11.5%) persons were diagnosed with pulmonary TB, including 1 each with multidrug-resistant and isoniazid-resistant disease. Twelve had a positive culture for Mycobacterium tuberculosis and Xpert TB/RIF assay, and 4 had positive smear microscopy. Patients with pulmonary TB were more likely to use injection drugs (67% vs 36%, P = .02) and have a positive HCV antibody (73% vs 42%, P = .02). The presence and absence of any TB symptom had a sensitivity and negative predictive value for TB of 93% and 98%, respectively. Conclusion Our findings highlight the high prevalence of TB among newly diagnosed HIV-infected patients in an area with high rates of drug-resistant TB and the utility of an active case finding strategy for TB diagnosis.

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Are we missing ‘previously treated’ smear-positive pulmonary tuberculosis under programme settings in India? A cross-sectional study

F1000Research ◽

10.12688/f1000research.18353.2 ◽

2019 ◽

Vol 8 ◽

pp. 338

Author(s):

Hemant Deepak Shewade ◽

Vivek Gupta ◽

Srinath Satyanarayana ◽

Atul Kharate ◽

Lakshmi Murali ◽

...

Keyword(s):

Vulnerable Populations ◽

Past History ◽

National Level ◽

Previous History ◽

Case Finding ◽

Active Case Finding ◽

Active Case ◽

Tb Treatment ◽

History Of ◽

Previously Treated

Background: In 2007, a field observation from India reported 11% misclassification among ‘new’ patients registered under the revised national tuberculosis (TB) control programme. Ten years down the line, it is important to know what proportion of newly registered patients has a past history of TB treatment for at least one month (henceforth called ‘misclassification’). Methods: A study was conducted among new smear-positive pulmonary TB patients registered between March 2016 and February 2017 in 18 randomly selected districts to determine the effectiveness of an active case-finding strategy in marginalised and vulnerable populations. We included all patients detected through active case-finding. An equal number of randomly selected patients registered through passive case-finding from marginalised and vulnerable populations in the same districts were included. Before enrolment, we enquired about any history of previous TB treatment through interviews. Results: Of 629 patients, we interviewed 521, of whom, 11% (n=56) had past history of TB treatment (public or private) for at least a month: 13% (34/268) among the active case-finding group and 9% (22/253) among the passive case-finding group (p=0.18). No factors were found to be significantly associated with misclassification. Conclusion: Around one in every ten patients registered as ‘new’ had previous history of TB treatment. Corrective measures need to be implemented, followed by monitoring of any change in the proportion of ‘previously treated’ patients among all registered patients treated under the programme at national level.

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