Contact Investigation: A Priority for Tuberculosis Control Programs

The Lancet Infectious Diseases

Collier

et al. 2019

Summary Background Active case-finding among contacts of patients with tuberculosis is a global health priority, but the effects of active versus passive case-finding are poorly characterised. We assessed the contribution of active versus passive case-finding to tuberculosis detection among contacts and compared sex and disease characteristics between contacts diagnosed through these strategies. Methods In shanty towns in Callao, Peru, we identified index patients with tuberculosis and followed up contacts aged 15 years or older for tuberculosis. All patients and contacts were offered free programmatic active case-finding entailing sputum smear microscopy and clinical assessment. Additionally, all contacts were offered intensified active case-finding with sputum smear and culture testing monthly for 6 months and then once every 4 years. Passive case-finding at local health facilities was ongoing throughout follow-up. Findings Between Oct 23, 2002, and May 26, 2006, we identified 2666 contacts, who were followed up until March 1, 2016. Median follow-up was 10·0 years (IQR 7·5–11·0). 232 (9%) of 2666 contacts were diagnosed with tuberculosis. The 2-year cumulative risk of tuberculosis was 4·6% (95% CI 3·5–5·5), and overall incidence was 0·98 cases (95% CI 0·86–1·10) per 100 person-years. 53 (23%) of 232 contacts with tuberculosis were diagnosed through active case-finding and 179 (77%) were identified through passive case-finding. During the first 6 months of the study, 23 (45%) of 51 contacts were diagnosed through active case-finding and 28 (55%) were identified through passive case-finding. Contacts diagnosed through active versus passive case-finding were more frequently female (36 [68%] of 53 vs 85 [47%] of 179; p=0·009), had a symptom duration of less than 15 days (nine [25%] of 36 vs ten [8%] of 127; p=0·03), and were more likely to be sputum smear-negative (33 [62%] of 53 vs 62 [35%] of 179; p=0·0003). Interpretation Although active case-finding made an important contribution to tuberculosis detection among contacts, passive case-finding detected most of the tuberculosis burden. Compared with passive case-finding, active case-finding was equitable, helped to diagnose tuberculosis earlier and usually before a positive result on sputum smear microscopy, and showed a high burden of undetected tuberculosis among women. Funding Wellcome Trust, Department for International Development Civil Society Challenge Fund, Joint Global Health Trials consortium, Bill & Melinda Gates Foundation, Imperial College National Institutes of Health Research Biomedical Research Centre, Foundation for Innovative New Diagnostics, Sir Halley Stewart Trust, WHO, TB REACH, and IFHAD: Innovation for Health and Development.

Section: Introductionmentioning

confidence: 99%

Active and passive case-finding in tuberculosis-affected households in Peru: a 10-year prospective cohort study

Saunders

The Lancet Infectious Diseases

Collier

et al. 2019

“…Trials have shown that preventive therapy decreases the risk of progression to tuberculosis disease by 60 to 90% 2 – 4 . Nevertheless, globally the impact of preventive therapy on tuberculosis control is limited because people with a latent tuberculosis infection are seldom identified 5 and, therefore, seldom take preventive therapy 6 – 9 . In addition, many people have difficulty adhering to treatment 7 , 8 , 10 and tuberculosis patients who do not take adequate treatment are more likely to experience adverse outcomes, such as treatment failure, tuberculosis recurrence and death 11 .…”

Section: Introductionmentioning

confidence: 99%

“… 2 – 4 Nevertheless, globally the impact of preventive therapy on tuberculosis control is limited because people with a latent tuberculosis infection are seldom identified 5 and, therefore, seldom take preventive therapy. 6 – 9 In addition, many people have difficulty adhering to treatment 7 , 8 , 10 and tuberculosis patients who do not take adequate treatment are more likely to experience adverse outcomes, such as treatment failure, tuberculosis recurrence and death. 11 They are also more likely to transmit the infection, especially to household contacts 12 and to develop multidrug-resistant tuberculosis, 13 an increasing global public health threat.…”

Section: Introductionmentioning

confidence: 99%

A randomized controlled study of socioeconomic support to enhance tuberculosis prevention and treatment, Peru

Wingfield¹,

Bull. World Health Organ.

Huff

et al. 2017

Self Cite

109

ObjectiveTo evaluate the impact of socioeconomic support on tuberculosis preventive therapy initiation in household contacts of tuberculosis patients and on treatment success in patients.MethodsA non-blinded, household-randomized, controlled study was performed between February 2014 and June 2015 in 32 shanty towns in Peru. It included patients being treated for tuberculosis and their household contacts. Households were randomly assigned to either the standard of care provided by Peru’s national tuberculosis programme (control arm) or the same standard of care plus socioeconomic support (intervention arm). Socioeconomic support comprised conditional cash transfers up to 230 United States dollars per household, community meetings and household visits. Rates of tuberculosis preventive therapy initiation and treatment success (i.e. cure or treatment completion) were compared in intervention and control arms.FindingsOverall, 282 of 312 (90%) households agreed to participate: 135 in the intervention arm and 147 in the control arm. There were 410 contacts younger than 20 years: 43% in the intervention arm initiated tuberculosis preventive therapy versus 25% in the control arm (adjusted odds ratio, aOR: 2.2; 95% confidence interval, CI: 1.1–4.1). An intention-to-treat analysis showed that treatment was successful in 64% (87/135) of patients in the intervention arm versus 53% (78/147) in the control arm (unadjusted OR: 1.6; 95% CI: 1.0–2.6). These improvements were equitable, being independent of household poverty.ConclusionA tuberculosis-specific, socioeconomic support intervention increased uptake of tuberculosis preventive therapy and tuberculosis treatment success and is being evaluated in the Community Randomized Evaluation of a Socioeconomic Intervention to Prevent TB (CRESIPT) project.

“…This policy is consistent with the apparent protective effect of chemoprophylaxis in our study. However, in most high-TB-prevalence settings, resources are insufficient for comprehensive contact tracing within and outside the home [ 43 ]. Provision of chemoprophylaxis to all household contacts may be appropriate in some settings.…”

Section: Discussionmentioning

confidence: 99%

Sputum Microscopy With Fluorescein Diacetate Predicts Tuberculosis Infectiousness

Datta

Sherman

The Journal of Infectious Diseases

et al. 2017

Self Cite