Determinants of losses in the latent tuberculosis cascade of care in Brazil: A retrospective cohort study

Abstract

Background: The present study evaluated factors associated with losses in the latent tuberculosis infection (LTBI) cascade of care in contacts of tuberculosis (TB) patients, in a referral center from a highly endemic region in Brazil. Methods: Contacts of 1672 TB patients were retrospectively studied between 2009 and 2014. Data on TB screening by clinical investigation, radiographic examination and tuberculin skin test (TST) were extracted from medical records. Losses in the cascade of care and TB incidence within 2-year follow-up were calculated. Results: From a total of 1180 TB contacts initially identified, only 495 were examined (58% loss), and 20 were diagnosed with active TB at this stage. Furthermore, 435 persons returned for TST result interpretation and 351 ($81%) were TST positive. Among those with positive TST, 249 (73%) were treated with isoniazid for 6 months whereas 51 abandoned therapy early. Three individuals who did not receive LTBI treatment, one with incomplete treatment and another who completed treatment developed active TB. A logistic regression analysis revealed that increases in age were associated with losses in the LTBI cascade independent of other clinical and epidemiological characteristics. Conclusions: Major losses occur at initial stages and older patients are at higher risk of not completing the LTBI cascade of care.

Tuberculosis Burden and Determinants of Treatment Outcomes According to Age in Brazil: A Nationwide Study of 896,314 Cases Reported Between 2010 and 2019

“…In case of p δ = 0, the delta-gap (Δ) was calculated, which is defined as the distance between the intervals in δ units. The delta-gap value was directly related with the difference in distribution of values between the groups; the higher the delta value, the greater the effect size ( 14 ).…”

Determinants of losses in the latent tuberculosis infection cascade of care in Brazil: a prospective multicenter cohort study

“…A similar result was found in a previous study by our group in a different cohort of 1,264 TB contacts and using TST instead of IGRA. The study found a LTBI prevalence of 41.9% and the incidence of active TB of 2/100,000 inhabitants [19]. LTBI was significantly more common in women, black/ pardo , older individuals, and active and secondhand smokers.…”

Increased Frequency of Memory CD4+ T-Cell Responses in Individuals With Previously Treated Extrapulmonary Tuberculosis

“…The parent study also included participants who were asymptomatic contacts of pulmonary TB index cases. All TB contacts were actively screened for TB through clinical, radiologic, and microbiologic investigation (32). At the time of study enrollment, individuals not living with HIV who tested positive for QuantiFERON TB Gold-in-Tube (QFT) enzymelinked immunosorbent assay (Qiagen) and also exhibited a positive tuberculin skin test (TST) result (> 5 mm) were considered to have latent TB infection (LTBI), and individuals who were QFT-negative and had negative TST result (< 5 mm) were considered uninfected controls (30).…”