Comparison of symptoms and treatment outcomes between actively and passively detected tuberculosis cases: the additional value of active case finding

SUMMARYPassive detection of tuberculosis (TB) cases may lead to delay in treatment which may contribute to increased severity of disease and mortality. Active case finding may be an alternative. In a community survey in Cape Town, South Africa, we actively detected 27 bacteriologically positive TB cases and compared those with 473 passively detected TB cases. Seven of 27 (26%) actively detected TB cases did not start treatment within 2 months and were considered initial defaulters. Those who did start treatment had similar treatment success rates as passively detected TB cases (both 80%) (OR 1·01, 95% CI 0·33–3·09). Passively detected cases reported the presence of the symptoms cough (OR 3·72, 95% CI 1·47–9·39), haemoptysis (OR 3·20, 95% CI 1·03–9·93), night sweats (OR 3·35, 95% CI 1·40–7·99), fever (OR 4·28, 95% CI 1·21–15·14), and weight loss (OR 11·14, 95% CI 4·17–29·74) more often than those detected actively. We conclude that although TB cases detected by a community survey are less symptomatic and are prone to a high initial default rate, active case finding can potentially identify a substantial portion of the existing caseload at an earlier stage of disease, thereby reducing the risk of transmission.

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Mobile community-based active case-finding for tuberculosis among older populations in rural Cambodia

The International Journal of Tuberculosis and Lung Disease ◽

10.5588/ijtld.18.0611 ◽

2019 ◽

Vol 23 (10) ◽

pp. 1107-1114 ◽

Cited By ~ 1

Author(s):

O. Camelique ◽

S. Scholtissen ◽

J.-P. Dousset ◽

M. Bonnet ◽

M. Bastard ◽

...

Keyword(s):

Risk Group ◽

Treatment Success ◽

Case Finding ◽

High Risk Group ◽

Active Case Finding ◽

Community Based ◽

Active Case ◽

Tb Treatment ◽

Mobile Community ◽

Older Populations

OBJECTIVE: To systematically screen older rural populations in Cambodia for tuberculosis (TB) and develop an effective active case-finding (ACF) model for this TB high-risk group.DESIGN: A retrospective study using routinely collected programmatic data on community-based ACF among people aged ≥55 years using TB symptoms and systematic chest radiography (CXR) screening, followed by Xpert® MTB/RIF testing for participants with positive screening results and TB culture for certain Xpert-negative specimens.RESULTS: Of 22 101 participants included in the analysis, 7469 (33.8%) were screening-positive and 5960 (27.0%) underwent Xpert testing. Pulmonary TB was identified in 482 (2.2%) individuals: 288 (1.3%) were bacteriologically confirmed (253 using Xpert, 35 using culture) and 194 (0.9%) were clinically diagnosed. Eighty-seven people needed to be screened in order to diagnose one Xpert-positive case. Among the Xpert-positive cases, only 31.6% (80/253) reported cough ≥2 weeks, and 39.9% (101/253) were asymptomatic but had a CXR suggestive of active TB. Treatment uptake was 97.3% (469/482), and treatment success was 88.0% (424/482).CONCLUSIONS: Community-based ACF was effective in detecting and successfully treating older TB patients, most of whom might otherwise have remained undiagnosed. Mobile CXR appears to be crucial in identifying a high number of asymptomatic, bacteriologically confirmed cases.

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The impact of active case finding on transmission dynamics of tuberculosis: A modelling study

PLoS ONE ◽

10.1371/journal.pone.0257242 ◽

2021 ◽

Vol 16 (11) ◽

pp. e0257242

Author(s):

Diepreye Victoria Ayabina ◽

M. Gabriela M. Gomes ◽

Nhung Viet Nguyen ◽

Luan Vo ◽

Suvesh Shreshta ◽

...

Keyword(s):

Reproduction Number ◽

Treatment Success ◽

National Level ◽

Case Finding ◽

Transmission Model ◽

Active Case Finding ◽

Active Case ◽

Incidence Data ◽

Country Level ◽

The Impact

Background In the last decade, active case finding (ACF) strategies for tuberculosis (TB) have been implemented in many diverse settings, with some showing large increases in case detection and reporting at the sub-national level. There have also been several studies which seek to provide evidence for the benefits of ACF to individuals and communities in the broader context. However, there remains no quantification of the impact of ACF with regards to reducing the burden of transmission. We sought to address this knowledge gap and quantify the potential impact of active case finding on reducing transmission of TB at the national scale and further, to determine the intensification of intervention efforts required to bring the reproduction number (R0) below 1 for TB. Methods We adopt a dynamic transmission model that incorporates heterogeneity in risk to TB to assess the impact of an ACF programme (IMPACT TB) on reducing TB incidence in Vietnam and Nepal. We fit the models to country-level incidence data using a Bayesian Markov Chain Monte Carlo approach. We assess the impact of ACF using a parameter in our model, which we term the treatment success rate. Using programmatic data, we estimate how much this parameter has increased as a result of IMPACT TB in the implementation districts of Vietnam and Nepal and quantify additional efforts needed to eliminate transmission of TB in these countries by 2035. Results Extending the IMPACT TB programme to national coverage would lead to moderate decreases in TB incidence and would not be enough to interrupt transmission by 2035. Decreasing transmission sufficiently to bring the reproduction number (R0) below 1, would require a further intensification of current efforts, even at the sub-national level. Conclusions Active case finding programmes are effective in reducing TB in the short term. However, interruption of transmission in high-burden countries, like Vietnam and Nepal, will require comprehensive incremental efforts. Complementary measures to reduce progression from infection to disease, and reactivation of latent infection, are needed to meet the WHO End TB incidence targets.

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