Knowledge about tuberculosis transmission and prevention and perceptions of health service utilization among index cases and contacts in Brazil: Understanding losses in the latent tuberculosis cascade of care

Abstract

Introduction: Tuberculosis contacts are candidates for active and latent tuberculosis infection screening and eventual treatment. However, many losses occur in the different steps of the contacts' cascade of care. Reasons for this are poorly understood.

Objective: To describe the different steps where losses in the contact cascade occur and to explore knowledge and attitudes regarding tuberculosis transmission/prevention and perceptions about tuberculosis services in order to understand the reasons for losses from the tuberculosis service users' perspective.

Design: We collected routine data from the index case and contact registry books and from patients' records to build the cascade of care of contacts in 12 health facilities in three Brazilian cities with high tuberculosis incidence rates. During a knowledge, attitudes and practices (KAP) survey, trained interviewers administered a semi-structured questionnaire to 138 index cases and 98 contacts.

Results: Most of the losses in the cascade occurred in the first two steps (contact identification, 43% and tuberculin skin testing placement, 91% of the identified contacts). Among KAP-interviewed contacts, 67% knew how tuberculosis is transmitted, 87% knew its key symptoms and 81% declared they would take preventive therapy if prescribed. Among KAP-interviewed index cases, 67% knew they could spread tuberculosis, 70% feared for the health of their families and 88% would like their family to be evaluated in the same services.

Conclusion: Only a small proportion of contacts are evaluated for active and latent tuberculosis, despite their-and their index cases'-reasonable knowledge, positive attitudes towards prevention and satisfaction with tuberculosis services. In these services, education of service users would not be a sufficient solution. Healthcare workers' and managers' perspective, not explored in this study, may bring more light to this subject.

Fig 1. Cascade of latent tuberculosis infection care on the twelve participant health units in the Brazilian capitals, January-June 2014.

Flowchart displaying the cascade of care of tuberculosis contacts in 12 clinics in Brazil, January-June 2014. * Expected contacts calculated multiplying the number of index cases by 4.2; TST = Tuberculin Skin Test.