Tuberculosis infection among primary health care workers / Infecção por tuberculose entre profissionais de saúde da atenção básica

ABSTRACT Objective: To estimate the prevalence of and determine the risk factors associated with latent Mycobacterium tuberculosis infection (LTBI) among primary health care workers in the city of Vitória, Brazil. Methods: This was a cross-sectional study with data collected through a survey regarding socio-demographic, occupational, clinical, and exposure characteristics, as well as knowledge about tuberculosis, conducted between 2011 and 2012. All participants underwent a tuberculin skin test (TST), and TSTs were read at 72 h by a trained professional. Results: A total of 218 primary health care workers participated in the study. The prevalence of TST positivity at the ≥ 10-mm and ≥ 5-mm cut-off points was, respectively, 39.4% (95% CI: 32.9-45.9) and 54.1% (95% CI: 47.4-60.7). Regarding occupational categories, community health agents had the highest proportion of TST positivity, regardless of the cut-off point (≥ 10 mm: 47.5%; and ≥ 5 mm: 60.5%). Regarding factors associated with TST results, "having had a previous TST" showed a statistically significant association with TST positivity at the ≥ 10-mm and ≥ 5-mm cut-off points (OR = 2.5 [95% CI: 1.17-5.30] and OR = 2.18 [95% CI: 1.23-3.87], respectively). Conclusions: The prevalence of LTBI was found to be high among the primary health care workers in this sample. Therefore, we recommend the establishment of a periodic screening program for LTBI and implementation of effective biosafety policies for the prevention of this infection among primary health care workers.

RESUMO Objetivo: Estimar a prevalência de infecção latente pelo Mycobacterium tuberculosis (ILTB) e identificar os fatores de risco associados a essa infecção entre profissionais de saúde da atenção básica no município de Vitória (ES). Métodos: Estudo transversal cujas informações foram obtidas por meio de inquérito sobre dados sociodemográficos, ocupacionais, clínicos, de exposição e de conhecimento sobre tuberculose, realizado entre 2011 e 2012. Todos os participantes foram submetidos ao teste tuberculínico (TT), e a leitura do resultado foi realizada após 72 h por um profissional capacitado. Resultados: Participaram do estudo 218 profissionais de saúde. A prevalência de positividade ao TT foi de 39,4% (IC95%: 32,9-45,9) e de 54,1% (IC95%: 47,4-60,7), respectivamente, para os pontos de corte do TT ≥ 10 mm e ≥ 5 mm. Em relação às categorias profissionais, os agentes comunitários de saúde apresentaram a maior proporção de positividade ao teste, independentemente do ponto de corte considerado (≥ 10 mm: 47,5%; e ≥ 5 mm: 60,5%). Em relação aos fatores associados ao resultado do teste, "ter feito TT anteriormente" apresentou associações estatisticamente significativas com o resultado positivo ao TT para os pontos de corte ≥ 10 mm e ≥ 5 mm [OR = 2,5 (IC95%: 1,17-5,30) e OR = 2,18 (IC95%: 1,23-3,87), respectivamente]. Conclusões: Os profissionais de saúde da atenção básica dessa amostra apresentaram uma alta prevalência de ILTB. Logo, recomendam-se a instituição de um programa de triagem periódica para ILTB e a implantação de políticas efetivas de biossegurança para a prevenção dessa infecção nos profissionais de saúde na atenção básica.

Tuberculosis infection among primary health care workers.

OBJECTIVE: To estimate the prevalence of and determine the risk factors associated with latent Mycobacterium tuberculosis infection (LTBI) among primary health care workers in the city of Vitória, Brazil. METHODS: This was a cross-sectional study with data collected through a survey regarding socio-demographic, occupational, clinical, and exposure characteristics, as well as knowledge about tuberculosis, conducted between 2011 and 2012. All participants underwent a tuberculin skin test (TST), and TSTs were read at 72 h by a trained professional. RESULTS: A total of 218 primary health care workers participated in the study. The prevalence of TST positivity at the ≥ 10-mm and ≥ 5-mm cut-off points was, respectively, 39.4% (95% CI: 32.9-45.9) and 54.1% (95% CI: 47.4-60.7). Regarding occupational categories, community health agents had the highest proportion of TST positivity, regardless of the cut-off point (≥ 10 mm: 47.5%; and ≥ 5 mm: 60.5%). Regarding factors associated with TST results, "having had a previous TST" showed a statistically significant association with TST positivity at the ≥ 10-mm and ≥ 5-mm cut-off points (OR = 2.5 [95% CI: 1.17-5.30] and OR = 2.18 [95% CI: 1.23-3.87], respectively). CONCLUSIONS: The prevalence of LTBI was found to be high among the primary health care workers in this sample. Therefore, we recommend the establishment of a periodic screening program for LTBI and implementation of effective biosafety policies for the prevention of this infection among primary health care workers.

Comparison of interferon-γ release assay to two cut-off points of tuberculin skin test to detect latent Mycobacterium tuberculosis infection in primary health care workers.

BACKGROUND: An interferon-γ release assay, QuantiFERON-TB (QFT) test, has been introduced an alternative test for the diagnosis of latent Mycobacterium tuberculosis infection (LTBI). Here, we compared the performance of QFT with tuberculin skin test (TST) measured at two different cut-off points among primary health care work (HCW) in Brazil. METHODS: A cross-sectional study was carried out among HCWs in four Brazilian cities with a known history of high incidence of TB. Results of the QFT were compared to TST results based on both ≥5 mm and ≥10 mm as cut-off points. RESULTS: We enrolled 632 HCWs. When the cut-off value of ≥10 mm was used, agreement between QFT and TST was 69% (k = 0.31), and when the cut-off of ≥5 mm was chosen, the agreement was 57% (k = 0.22). We investigated possible factors of discordance of TST vs QFT. Compared to the TST-/QFT- group, risk factors for discordance in the TST+/QFT- group with TST cut-off of ≥5 mm included age between 41-45 years [OR = 2.70; CI 95%: 1.32-5.51] and 46-64 years [OR = 2.04; CI 95%: 1.05-3.93], BCG scar [OR = 2.72; CI 95%: 1.40-5.25], and having worked only in primary health care [OR = 2.30; CI 95%: 1.09-4.86]. On the other hand, for the cut-off of ≥10 mm, BCG scar [OR = 2.26; CI 95%: 1.03-4.91], being a household contact of a TB patient [OR = 1.72; CI 95%: 1.01-2.92] and having had a previous TST [OR = 1.66; CI 95%: 1.05-2.62], were significantly associated with the TST+/QFT- group. No statistically significant associations were found among the TST-/QFT+ discordant group with either TST cut-off value. CONCLUSIONS: Although we identified BCG vaccination to contribute to the discordance at both TST cut-off measures, the current Brazilian recommendation for the initiation of LTBI treatment, based on information gathered from medical history, TST, chest radiograph and physical examination, should not be changed.

[Prevalence of latent infection of mycobacterium tuberculosis among healthcare students in a public university in Vitória, state of Espírito Santo, Brazil]. / Prevalência de infecção latente pelo Mycobacterium tuberculosis entre estudantes da área da saúde de uma universidade pública em Vitória, ES, Brasil.

This article seeks to determine the prevalence of Mycobacterium tuberculosis infection in medical and nursing students of the Federal University of Espirito Santo (UFES) This is a cross-sectional study in which data were collected through a questionnaire assessing personal characteristics, information about tuberculosis, use of preventive measures, etc. This was followed by the application of the tuberculin skin test, with readings after 72 hours by trained nurses, the positive cutoff point for the TST being 10 mm of induration in the 72-hour reading. Participants in the study included 225 volunteers, namely 98 Medical students and 127 Nursing students. A positive tuberculin skin test was found in 54 students of both courses, resulting in a prevalence of 24%. Among Nursing Students the result of a positive TST was obtained in 24% and in 23%, of Medical Students, such that this difference was not statistically significant. It is necessary to carry out a routine program of tuberculin testing, for confirmation, combined with interventions to reduce the risk of nosocomial transmission in the workplace, as well as further studies to evaluate the effectiveness of new tests to detect latent tuberculosis infection.

Prevalência de infecção latente pelo Mycobacterium tuberculosis entre estudantes da área da saúde de uma universidade pública em Vitória, ES, Brasil / Prevalence of latent infection of mycobacterium tuberculosis among healthcare students in a public university in Vitória, state of Espírito Santo, Brazil

Este artigo tem por objetivo determinar a prevalência da infecção pelo Mycobacterium tuberculosis em acadêmicos de enfermagem e medicina da Universidade Federal do Espírito Santo. Estudo de corte transversal no qual os dados foram coletados através de questionário, composto de questões abertas e fechadas sobre características pessoais; informações a respeito da tuberculose; utilização de medidas preventivas, etc. Aplicou-se teste tuberculínico, com leitura após 72h por enfermeiros treinados, considerando como ponte de corte positivo 10 mm de enduração. Participaram 225 voluntários, sendo 98 estudantes da Medicina e 127 da Enfermagem. A positividade ao teste tuberculínico fora encontrada em 54 estudantes de ambos os cursos, resultando uma prevalência de 24%. Entre os Estudantes de Enfermagem o resultado do TST positivo foi obtido em 24% e nos Estudantes de Medicina em 23%, sendo esta diferença não significativa estatisticamente. Faz-se necessário um programa de realização de teste tuberculínico, de rotina, para confirmação de viragem tuberculínica, combinado com intervenções para reduzir o risco de transmissão nosocomial no local da prática, bem como a realização de outros estudos para avaliar a eficácia de novos testes para detecção de tuberculose latente.

This article seeks to determine the prevalence of Mycobacterium tuberculosis infection in medical and nursing students of the Federal University of Espirito Santo (UFES) This is a cross-sectional study in which data were collected through a questionnaire assessing personal characteristics, information about tuberculosis, use of preventive measures, etc. This was followed by the application of the tuberculin skin test, with readings after 72 hours by trained nurses, the positive cutoff point for the TST being 10 mm of induration in the 72-hour reading. Participants in the study included 225 volunteers, namely 98 Medical students and 127 Nursing students. A positive tuberculin skin test was found in 54 students of both courses, resulting in a prevalence of 24%. Among Nursing Students the result of a positive TST was obtained in 24% and in 23%, of Medical Students, such that this difference was not statistically significant. It is necessary to carry out a routine program of tuberculin testing, for confirmation, combined with interventions to reduce the risk of nosocomial transmission in the workplace, as well as further studies to evaluate the effectiveness of new tests to detect latent tuberculosis infection.