Prevalence and Incidence of Latent Tuberculosis Infection in Georgian Healthcare Workers

Abstract

BackgroundTuberculosis is a major occupational hazard in low and middle-income countries. Limited data exist on serial testing of healthcare workers (HCWs) with interferon-γ release assays (IGRAs) for latent tuberculosis infection (LTBI), especially in low and middle-income countries. We sought to evaluate the rates of and risk factors for LTBI prevalence and LTBI test conversion among HCWs using the tuberculin skin test (TST) and QuantiFERON-TB Gold In-tube assay (QFT-GIT).MethodsA prospective longitudinal study was conducted among HCWs in the country of Georgia. Subjects completed a questionnaire, and TST and QFT-GIT tests were performed. LTBI testing was repeated 6-26 months after baseline testing.ResultsAmong 319 HCWs enrolled, 89% reported prior BCG vaccination, and 60% worked in TB healthcare facilities (HCFs). HCWs from TB HCFs had higher prevalence of positive QFT-GIT and TST than those from non-TB HCFs: 107/194 (55%) vs. 30/125 (31%) QFT-GIT positive (p<0.0001) and 128/189 (69%) vs. 64/119 (54%) TST positive (p = 0.01). There was fair agreement between TST and QFT-GIT (kappa = 0.42, 95% CI 0.31–0.52). In multivariate analysis, frequent contact with TB patients was associated with increased risk of positive QFT-GIT (aOR 3.04, 95% CI 1.79–5.14) but not positive TST. Increasing age was associated with increased risk of positive QFT-GIT (aOR 1.05, 95% CI 1.01–1.09) and TST (aOR 1.05, 95% CI 1.01–1.10). High rates of HCW conversion were seen: the QFT-GIT conversion rate was 22.8/100 person-years, and TST conversion rate was 17.1/100 person-years. In multivariate analysis, female HCWs had decreased risk of TST conversion (aOR 0.05, 95% CI 0.01–0.43), and older HCWs had increased risk of QFT-GIT conversion (aOR 1.07 per year, 95% CI 1.01–1.13).ConclusionLTBI prevalence and LTBI test conversion rates were high among Georgian HCWs, especially among those working at TB HCFs. These data highlight the need for increased implementation of TB infection control measures.

Infección Latente por Tuberculosis en Trabajadores de Salud en Guayaquil, Ecuador

“…Se ha constatado la utilidad de esta técnica en poblaciones con las características mencionadas ( Pai, Dendukuri, et al, 2008) y las observaciones obtenidas coinciden con lo reportado en otras investigaciones con similar metodología (Nienhaus, Schablon, Preisser, Ringshausen, & Diel, 2014 La prevalencia encontrada fue 29,80%, valor que se asemeja a lo reportado en investigaciones de diversos países en similares condiciones. Joshi et al realizó una revisión sistemática en la que se reportó una prevalencia de LTBI entre 33% a 79% en países con ingresos de bajos a medios (Joshi, Reingold, Menzies, & Pai, 2006); así mismo, Whitaker et al reportó una prevalencia de 31% en Georgia, en TS no expuestos a pacientes con TB prioritariamente, mientras que en aquellos expuestos a pacientes con TB activa fue del 55% (Whitaker et al, 2013). Legesse et al estimó una prevalencia de 63.7% usando QTF-GIT (Legesse et al, 2011).…”

Prevalence of Latent Tuberculosis Infection in Type 2 Diabetic and NonDiabetic Individuals

“…in the latent phase. Few studies have investigated the prevalence of LTBI in healthcare workers, prisons [4][5][6][7][8][9] . Many research questions regarding association between diabetes and LTBI remains unanswered because of inadequate studies, furthermore none in India have considered diabetic population which is a high risk group.…”

Role of QuantiFERON-TB Gold In-Tube test in detection of latent tuberculosis infection in health care contacts in Alexandria, Egypt

“…TB transmission in healthcare facilities can be significantly reduced with the implementation of effective TB infection control measures. While most high income countries have successfully implemented TB infection control measures, TB infection control measures are limited or virtually non-existent in most resource-limited countries (Whitaker et al, 2013).…”

“…Most high-income countries screen HCWs periodically for LTBI as part of their TB infection control programs (Whitaker et al, 2013), in an effort to identify new infections that can be targeted for preventive therapy (Zwerling et al, 2012a), but this practice is unusual in most low and middle-income countries (Whitaker et al, 2013).…”

“…Two commercially available IGRAs have been approved for use: the Quanti-FERON-TB Gold In-Tube (QFT-GIT) assay (Cellestis Inc., Valencia CA) and the T-SPOT.TB assay (Oxford Immunotec, Abingdon, UK). IGRAs have several advantages over the TST: they require only one visit, are not affected by BCG vaccination, have less cross-reaction with non-tuberculous mycobacteria, are less subjective in measuring results, and can be repeated without boosting (Whitaker et al, 2013). In comparison with TST, the IGRA reduces the number of x-rays and the amount of chemoprevention needed (Nienhaus et al, 2013).…”