Volume 186 - Issue 2
Should medical students be routinely offered BCG vaccination?
Authors: David N Durrheim and Michael J Hensley
Med J Aust 2007; 186 (2): 98-99. || doi: 10.5694/j.1326-5377.2007.tb00815.x
Published online: 15 January 2007
Published online: 15 January 2007
To the Editor: Graham and colleagues correctly assert that medical students are at increased risk of infection with Mycobacterium tuberculosis in settings where they are treating patient groups with a high prevalence of active pulmonary tuberculosis (TB).1 This is well illustrated by the increasing prevalence of latent TB infection among medical students in their later clinical years in countries where community TB incidence markedly exceeds that of Australia.2
Their case for a standard approach to screening of medical students at course entry has great merit, and their arguments in favour of using an interferon gamma release assay to screen for latent TB infection would bring Australia into line with current international best practice.
However, the data presented do not substantiate a policy of offering BCG vaccination to all Australian medical students whose screening test result for latent TB infection, whether by interferon gamma or tuberculin skin testing (TST), is negative. Although BCG offers definite benefits in reducing the risk of life-threatening disseminated disease in children under 2 years of age, it does not offer dependable protection against pulmonary TB in adults.4 Medical students who are vaccinated with BCG may be lulled into a false sense of security, and neglect other more effective infection control measures that would reduce their risk of TB exposure and infection. Although BCG is a relatively safe vaccine, there is a small but well defined risk of local and systemic adverse events.5
We therefore support a standardised approach to screening medical students with TST or, preferably, interferon gamma at course entry and exit. Screening for latent TB infection should be offered whenever merited during the course of study, after exposure to active TB disease in Australia or abroad. The benefits of chemoprophylaxis on conversion outweigh the risks associated with isoniazid use, and the risks associated with BCG may not be acceptable where the risk of TB exposure for many Australian medical students is currently negligible.
References
- Graham M, Howley TM, Pierce RJ, Johnson PD. Should medical students be routinely offered BCG vaccination? Med J Aust 2006; 185: 324-326.
- Teixeira EG, Menzies D, Comstock GW, et al. Latent tuberculosis infection among undergraduate medical students in Rio de Janeiro State, Brazil. Int J Tuberc Lung Dis 2005; 9: 841-847. 0_pgfId-1162356
- Jensen PA, Lambert LA, Iademarco MF, Ridzon R; CDC. Guidelines for preventing the transmission of Mycobacterium tuberculosis in health-care settings, 2005. MMWR Recomm Rep 2005; 54(17): 1-141. 0_pgfId-1162364
- Fine PEM. Immunities in and to tuberculosis: implications for pathogenesis and vaccination. In: Porter JDH, McAdam KPWJ, editors. Tuberculosis: back to the future. Chichester: John Wiley & Sons, 1994. 0_CBBBACEA
- Talbot EA, Perkins MD, Silva SF, Fotheringham R. Disseminated bacille Calmette-Guerin disease after vaccination: case report and review. Clin Infect Dis 1997; 24: 1139-1146. 0_CBBDHCAA