Contact tracing strategies in household and congregate environments to identify cases of tuberculosis in low- and moderate-incidence populations

Drug-Resistant Tuberculosis Case-Finding Strategies: Scoping Review

BACKGROUND

Finding individuals with drug-resistant tuberculosis (DR-TB) is important to control the pandemic and improve patient clinical outcomes. To our knowledge, systematic reviews assessing the effectiveness, cost-effectiveness, acceptability, and feasibility of different DR-TB case-finding strategies to inform research, policy, and practice, have not been conducted and the scope of primary research is unknown.

OBJECTIVE

We therefore assessed the available literature on DR-TB case-finding strategies.

METHODS

We looked at systematic reviews, trials, qualitative studies, diagnostic test accuracy studies, and other primary research that sought to improve DR-TB case detection specifically. We excluded studies that included patients seeking care for tuberculosis (TB) symptoms, patients already diagnosed with TB, or were laboratory-based. We searched the academic databases of MEDLINE, Embase, The Cochrane Library, Africa-Wide Information, CINAHL (Cumulated Index to Nursing and Allied Health Literature), Epistemonikos, and PROSPERO (The International Prospective Register of Systematic Reviews) using no language or date restrictions. We screened titles, abstracts, and full-text articles in duplicate. Data extraction and analyses were carried out in Excel (Microsoft Corp).

RESULTS

We screened 3646 titles and abstracts and 236 full-text articles. We identified 6 systematic reviews and 61 primary studies. Five reviews described the yield of contact investigation and focused on household contacts, airline contacts, comparison between drug-susceptible tuberculosis and DR-TB contacts, and concordance of DR-TB profiles between index cases and contacts. One review compared universal versus selective drug resistance testing. Primary studies described (1) 34 contact investigations, (2) 17 outbreak investigations, (3) 3 airline contact investigations, (4) 5 epidemiological analyses, (5) 1 public-private partnership program, and (6) an e-registry program. Primary studies were all descriptive and included cross-sectional and retrospective reviews of program data. No trials were identified. Data extraction from contact investigations was difficult due to incomplete reporting of relevant information.

CONCLUSIONS

Existing descriptive reviews can be updated, but there is a dearth of knowledge on the effectiveness, cost-effectiveness, acceptability, and feasibility of DR-TB case-finding strategies to inform policy and practice. There is also a need for standardization of terminology, design, and reporting of DR-TB case-finding studies.

Outcomes of TB contact tracing and predictors of success: a 10-year retrospective cohort analysis in Birmingham, UK

BACKGROUND: Contacts of TB cases in Birmingham and Solihull, UK, are offered screening for TB infection. Between 1990 and 2010, only 59.1% of contacts completed screening. The service has since increased screening staff numbers, changed screening locations and increased screening follow-up. Our primary aim was to identify whether screening completion rates have improved. Our secondary aim was to identify predictors of screening completion.METHODS: This was a retrospective analysis of all contacts of TB patients in Birmingham and Solihull between 1 January 2011 and 31 December 2020, stratified by pulmonary and extrapulmonary TB (PTB or EPTB) index infection. Multiple logistic regression analysis for predictors of screening completion was performed.RESULTS: A total of 3,255 index cases and 27,820 contacts were identified. TB incidence has declined, in keeping with national trends. Screening completion has improved from 59.1% of contacts to 74.9% overall since service improvements were made, with improvement in screening completion for contacts of both PTB and EPTB index cases (OR 1.087, 95% CI 1.074-1.101; P < 0.001) and (OR 1.048, 95% CI 1.019-1.078; P = 0.001), respectively.CONCLUSIONS: Changes made to the TB service have improved screening outcomes over the last decade. Significant predictors of screening completion have been identified, highlighting areas for targeted resource allocation.

Contact tracing strategies in household and congregate environments to identify cases of tuberculosis in low- and moderate-incidence populations

BACKGROUND

Tuberculosis is an infectious bacterial disease that is spread via respiratory droplets from infected individuals to susceptible contacts. To eliminate this disease from low- and medium-incidence settings, people who are most likely to be infected (contacts) must be identified. Recently, study authors have examined alternate approaches to contact tracing methods that demonstrate improved detection and prioritization of contacts. The comparative benefit of these methods has not been established.

OBJECTIVES

To assess the effectiveness of novel methods of contact tracing versus current standard of care to identify latent and active cases in low- to moderate-incidence settings.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS, Web of Science, and CINAHL up to 15 July 2019. We also searched for clinical trials and examined reference lists and conference proceedings.

SELECTION CRITERIA

Randomized controlled trials (RCTs) and cluster-RCTs of contact tracing strategies that included alternate approaches (other than standard practice).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed identified articles for eligibility and quality using prespecified criteria.

MAIN RESULTS

No trials met the inclusion criteria of this review. Several study authors described an alternate method for examining contacts and performing social network analysis but did not compare this with the current contact tracing approach.

AUTHORS' CONCLUSIONS

This Cochrane Review highlights the lack of research in support of the current contact tracing method and the need for RCTs to compare new methods such as social network analysis to improve contact tracing processes.