Prevalence and incidence of Mycobacterium tuberculosis infection in nursing students in Vitória, Espírito Santo

Abstract

This prospective study evaluated the incidence of Mycobacterium tuberculosis infection among nursing students at the Federal University of Espírito Santo, using the purified protein derivative test. In parallel, we evaluated whether knowledge on tuberculosis transmission mechanisms had any impact on nursing students' attitudes in relation to the risk of tuberculosis infection. The incidence of tuberculin conversion was 10.5% per year (p=0.035, 95% CI = 3.63-17.43), whereas the expected conversion rate in the overall population in Brazil is 0.5% per year. These results indicate nursing students as a group at risk for TB infection. Among the risk factors studied only the use of NIOSH95 masks was associated with protection against infection (RR=0.2). Furthermore there was no statistical difference among students that PPD converted and those who remained negative regarding disease knowledge and the existence of adequate facilities for patient hospitalization. Our data reinforces the need for implementing special biosafety programs targeting this professional group. Key-words: Nursing students. Tuberculosis. Purified protein derivative. RESUMOAtravés de estudo prospectivo, avaliou-se a incidência de infecção pelo Mycobacterium tuberculosis entre estudantes de enfermagem da Universidade Federal do Espírito Santo, usando o teste do derivado de proteína purificado. Paralelamente, avaliamos se o conhecimento sobre mecanismos de transmissão da tuberculose teve algum impacto nas atitudes dos estudantes em relação ao risco de infecção por tuberculose. A incidência da conversão tuberculínica foi de 10,5% ao ano (p=0,035, 95% CI = 3,63 -17,43), quando a taxa de conversão para a população geral no Brasil é de 0,5% ao ano. Estes resultados indicam que os estudantes de enfermagem são um grupo de risco para infecção por tuberculose. Dentre os fatores de risco estudados somente o uso da máscara NIOSH95 estava associado à proteção contra a infecção (RR=0,2). Não houve diferença estatisticamente significativa entre os estudantes que converteram o PPD e aqueles que permaneceram negativos em relação ao conhecimento sobre tuberculose e existência de condições específicas para hospitalização dos pacientes com tuberculose. Nossos dados reforçam a necessidade de implementação programas de biosegurança especiais visando este grupo de profissionais. Palavras-chaves: Estudantes de enfermagem. Tuberculose. Derivado protéico purificado.

Knowledge as a factor in vulnerability to tuberculosis among nursing students and professionals

“…Those efforts may benefit both students and professionals, contributing to broaden nurses' awareness about their vulnerability to the disease (17)(18)(19) . Moreover, adequate knowledge of TB may also directly impact nursing practice, as the individual and collective aspects of appropriate biosafety measures could be addressed.…”

Risco de infecção tuberculosa em agentes comunitários de saúde

“…The tuberculin response (study outcome) was defi ned as an increase in the tuberculin response of at least 10 mm. 6 Subjects who presented a tuberculin result < 4 mm (weakly reactive) were considered to be negative.…”

“…Some studies 3,6,7,9,10,13,17,18,a have dealt with healthcare professionals' risk of infection and becoming ill with Mycobacterium tuberculosis. However, in Brazil, only one study has looked into this risk among community health agents (CHAs).…”

“…This problem, which had been neglected for a long time, has now come back into discussion through several studies that have emphasized the increased risk of infection by M. tuberculosis among health professionals or students working in this fi eld. 6,16 Studies 3,4,13,19 have indicated that there is a greater risk of infection among professionals acting in healthcare establishments, and have drawn attention to length of service, delays in diagnosis and laboratory proof, professional category, working in certain locations (such as emergency services, hospital admission units and laboratories) and lack of respiratory protection (masks), as factors that may infl uence the degree of contagion. However, none of these studies evaluated the risk of infection among CHAs.…”

Prevalência e fatores associados à infecção pelo Mycobacterium tuberculosis entre agentes comunitários de saúde no Brasil, usando-se a prova tuberculínica

“…Considerando-se os grupos de risco para IL-TB, os profissionais da área da saúde estão entre os mais vulneráveis, como demonstram várias publicações 12,13,14,15,16,17,18,19,20 . Uma revisão sistemática encontrou que a incidência de ILTB, demonstrada por meio da conversão da prova tuberculínica (PT), pode chegar a 14% nesses profissionais, e o risco de evoluir para TB doença é de 5.361 casos/100 mil profissionais de saúde a cada ano, em virtude da exposição nosocomial 21 .…”