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

PLoS ONE ◽  
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.

scholarly journals The impact of active case finding among high-risk populations on the decline of tuberculosis incidence

2021 ◽  
Author(s):  
Aleksandra Tomczak ◽  
Dominika Warmjak ◽  
Aneta Wiśniewska
Keyword(s):  
High Risk ◽  
Disease Transmission ◽  
Reproduction Number ◽  
Case Finding ◽  
Transmission Risk ◽  
Active Case Finding ◽  
Disease Dynamics ◽  
Active Screening ◽  
Active Case ◽  
The Impact

Introduction: Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis. In 2019 the WHO reported approximately 10 million TB cases and 1.4 million deaths worldwide. TB still remains one of the leading causes of death in humans. Brazil is one of 30 countries with the highest TB burden with 96,000 new cases and 6,700 deaths reported in 2019. From 2015 the TB incidence is increasing by 2%–3% annually. It means that TB control programs need to be improved. Aim: Our aim is to show the impact of active case finding of TB cases among a high-risk subpopulation on decline of the incidence in the general population. Material and methods: We use a SIS-type compartmental mathematical model to describe the disease dynamics. We consider the population as a heterogeneous population which differ in disease transmission risk. Using best-fit techniques we compare the actual data with the model. For the fitted parameters we calculate the basic reproduction number and estimate the TB trends for the next few years applying several preventative protocols. Results and discussion: Using numerical simulations we examine the impact of ACF on the disease dynamics. We show that active screening among high risk subpopulations can help to reduce TB spread. We show how the reproduction number and estimated incidence decline depend on the detection rate. Conclusions: Active screening is one of the most effective ways for reducing the spread of disease. However, due to financial constraints, it can only be used to a limited extent. Properly applied detection can limit the spread of the disease while minimizing costs.

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

2019 ◽  
Vol 23 (10) ◽  
pp. 1107-1114 ◽  
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.

scholarly journals A Multi-Faceted Approach to Tuberculosis Active Case Finding among Remote Riverine Communities in Southern Nigeria

2021 ◽  
Vol 18 (18) ◽  
pp. 9424
Author(s):  
Andy Samuel Eyo ◽  
Valerie Okon Obot ◽  
Okezie Onyedinachi ◽  
Nathaly Aguilera Vasquez ◽  
Jacob Bigio ◽  
...  
Keyword(s):  
Community Outreach ◽  
Case Finding ◽  
Control Population ◽  
Active Case Finding ◽  
Access To Health Services ◽  
Historical Trends ◽  
Active Case ◽  
Southern Nigeria ◽  
Community Volunteers ◽  
The Impact

Nigeria accounts for 11% of the worldwide gap between estimated and reported individuals with tuberculosis (TB). Hard-to-reach communities on the Southern Nigeria coast experience many difficulties accessing TB services. We implemented an active case finding (ACF) intervention in Akwa Ibom and Cross River states utilizing three approaches: house-to-house/tent-to-tent screening, community outreach and contact investigation. To evaluate the impact, we compared TB notifications in intervention areas to baseline and control population notifications, as well as to expected notifications based on historical trends. We also gathered field notes from discussions with community volunteers who provided insights on their perspectives of the intervention. A total of 509,768 individuals were screened of which 12,247 (2.4%) had TB symptoms and 11,824 (96.5%) were tested. In total, 1015 (8.6%) of those identified as presumptive had confirmed TB—98.2% initiated treatment. Following implementation, TB notifications in intervention areas increased by 112.9% compared to baseline and increased by 138.3% when compared to expected notifications based on historical trends. In contrast, control population notifications increased by 101% and 49.1%, respectively. Community volunteers indicated a preference for community outreach activities. Multi-faceted, community-based interventions in Nigeria’s coastal areas successfully increase TB detection for communities with poor access to health services.

Should active case-finding projects increase the number of tuberculosis cases notified at national level?

2017 ◽  
Vol 21 (4) ◽  
pp. 475-475 ◽  
Author(s):  
L. Blok ◽  
M. I. Bakker ◽  
M. Straetemans ◽  
L. Gerstel ◽  
M. Brouwer ◽  
...  
Keyword(s):  
National Level ◽  
Case Finding ◽  
Active Case Finding ◽  
Active Case

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

F1000Research ◽  
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.

scholarly journals Do community-based active case-finding interventions have indirect impacts on wider TB case detection and determinants of subsequent TB testing behaviour? A systematic review

2021 ◽  
Vol 1 (12) ◽  
pp. e0000088
Author(s):  
Helena R. A. Feasey ◽  
Rachael M. Burke ◽  
Marriott Nliwasa ◽  
Lelia H. Chaisson ◽  
Jonathan E. Golub ◽  
...  
Keyword(s):  
Indirect Effect ◽  
Controlled Trial ◽  
Case Finding ◽  
Case Detection ◽  
Active Case Finding ◽  
Community Based ◽  
Active Case ◽  
Attitudes And Practices ◽  
The Impact ◽  
Case Notification

Community-based active case-finding (ACF) may have important impacts on routine TB case-detection and subsequent patient-initiated diagnosis pathways, contributing “indirectly” to infectious diseases prevention and care. We investigated the impact of ACF beyond directly diagnosed patients for TB, using routine case-notification rate (CNR) ratios as a measure of indirect effect. We systematically searched for publications 01-Jan-1980 to 13-Apr-2020 reporting on community-based ACF interventions compared to a comparison group, together with review of linked manuscripts reporting knowledge, attitudes, and practices (KAP) outcomes or qualitative data on TB testing behaviour. We calculated CNR ratios of routine case-notifications (i.e. excluding cases identified directly through ACF) and compared proxy behavioural outcomes for both ACF and comparator communities. Full text manuscripts from 988 of 23,883 abstracts were screened for inclusion; 36 were eligible. Of these, 12 reported routine notification rates separately from ACF intervention-attributed rates, and one reported any proxy behavioural outcomes. Two further studies were identified from screening 1121 abstracts for linked KAP/qualitative manuscripts. 8/12 case-notification studies were considered at critical or serious risk of bias. 8/11 non-randomised studies reported bacteriologically-confirmed CNR ratios between 0.47 (95% CI:0.41–0.53) and 0.96 (95% CI:0.94–0.97), with 7/11 reporting all-form CNR ratios between 0.96 (95% CI:0.88–1.05) and 1.09 (95% CI:1.02–1.16). One high-quality randomised-controlled trial reported a ratio of 1.14 (95% CI 0.91–1.43). KAP/qualitative manuscripts provided insufficient evidence to establish the impact of ACF on subsequent TB testing behaviour. ACF interventions with routine CNR ratios >1 suggest an indirect effect on wider TB case-detection, potentially due to impact on subsequent TB testing behaviour through follow-up after a negative ACF test or increased TB knowledge. However, data on this type of impact are rarely collected. Evaluation of routine case-notification, testing and proxy behavioural outcomes in intervention and comparator communities should be included as standard methodology in future ACF campaign study designs.

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

2008 ◽  
Vol 136 (10) ◽  
pp. 1342-1349 ◽  
Author(s):  
S. DEN BOON ◽  
S. VERVER ◽  
C. J. LOMBARD ◽  
E. D. BATEMAN ◽  
E. M. IRUSEN ◽  
...  
Keyword(s):  
Treatment Success ◽  
Case Finding ◽  
Community Survey ◽  
Active Case Finding ◽  
Success Rates ◽  
Similar Treatment ◽  
Active Case ◽  
Night Sweats ◽  
Default Rate ◽  
Additional Value

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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