Latent Tuberculosis Infection among Healthcare Students and Postgraduates in a Mediterranean Italian Area: What Correlation with Work Exposure?

Abstract

Background: Tuberculosis screening is part of the standard protocol for evaluating the risk of infection in healthcare workers. The aim of this study was to evaluate the prevalence of latent tuberculosis infection (LTBI) among students attending various healthcare profession degree courses and postgraduate medical courses at the School of Medicine of the University of Palermo, Italy, and assess the possible professional origin of infection. Methods: In total, 2946 students (2082 undergraduates and 864 postgraduates) took part in a screening program for LTBI between January 2014 to April 2019 using the tuberculin skin test (TST). Students with a positive TST result underwent a Quantiferon-TB test (QFT). Results: Among the 2082 undergraduates, 23 (1.1%) had a positive TST; the result was confirmed with QFT for 13 (0.62%) of them. Among the 864 postgraduate students, 24 (2.78%) had a positive TST and only 18 (2.08%) showed a positive QTF. Latent tuberculosis infections were significantly more frequent among postgraduates than undergraduates (2.08% > 0.62%, p < 0.0001). There was a higher number of subjects previously vaccinated for TB (18.87% > 0.24%, p < 0.0001), and of vaccinated subjects found positive for TST and QTF (66.67% > 7.69%, p = 0.001) in the postgraduate group. Conclusion: Latent TB is relatively low among medical school students in our geographic area. Nevertheless, this infectious disease must be regarded as a re-emerging biohazard for which preventive strategies are required to limit the risk of infection, especially among exposed workers.

Tuberculosis Infection Screening in 5468 Italian Healthcare Students: Investigation of a Borderline Zone Value for the QFT-Test

“…In fact, this low prevalence was confirmed by other studies that found prevalence rates from 2.1% to 9.9% in German trainees [ 23 , 24 ] and by two studies from Denmark [ 25 ] and Norway [ 26 ] (1% and 3.4%, respectively). Our results are also in agreement with those of several Italian studies conducted among health professionals, in which the prevalence of subjects with LTBI was very low: 0.4% in a study carried out in Northern Italy by Durando et al, 1.5% in a study by Lamberti et al, and 0.62% in a study conducted by Verso et al with both of these latter studies carried out in Southern Italy [ 27 , 28 , 29 , 30 ].…”

To study the prevalence of latent tuberculosis infection among medical students

“…Al 2015). (20,21) Overestimation of the incidence of latent tuberculosis infection with TST was probably due to BCG booster dose vaccination at birth. (16) In our study, the prevalence of LTBI in dental students was higher than in a study by Lamberti et.al in 2017.…”

Occupational Infections among Dental Health Workers in Germany—14-Year Time Trends

“…A study among dental students in Italy found a prevalence of 2.9% when they were tested with a tuberculin skin test (TST) and/or an interferon-y release assay (IGRA) [ 52 ]. Studies among other healthcare students showed values between 0.1% and 2.1% [ 53 , 54 , 55 , 56 ], suggesting that dental students have a higher risk of contracting tuberculosis. The fact that occupational LTBI has only been recorded since 2009 can be attributed to a change in the perception of TB as an OD, rather than to an actual increase in infections.…”