Evaluation of tuberculin skin test in children younger than 2 years who presented an adverse event to the BCG vaccine

• Grant number: 17/01124-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): November 01, 2017
• Effective date (End): October 31, 2018
• Field of knowledge: Health Sciences - Medicine - Maternal and Child Health
• Principal Investigator: Maria Isabel de Moraes Pinto
• Grantee: Susana Artiaga Dias Maciel
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Tuberculosis is an infectious illness of great importance to Public Health. In Brazil, it is estimated that there are at least 73.000 new cases reported every year. The World Health Organization (WHO) advises that vaccinating with Calmette-Guérin bacillus (BCG) is the best strategy to prevent the infection and the severe forms of tuberculosis. Nonetheless, it is known that administrating BCG vaccine may interfere with an important screening test: the tuberculin skin test. The intensity of the tuberculin skin test response in individuals with localized BCG adverse event is still unknown. The objective of this study is to evaluate the diameter of induration after the application of tuberculin test in children under the age of 2 who have not been exposed to tuberculosis and who exhibit a localized BCG adverse event. Candidates will be selected at the Reference Center for Special Immunobiologicals linked to the Federal University of São Paulo (CRIE-UNIFESP), where an average of 30 new cases of children with localized BCG adverse events are referred to every year. As soon as a consent form is signed by the candidates' legal guardians, a form with demographic and clinical data about the children is filled in. They will also be submitted to a physical examination. Afterwards, the tuberculin skin test will be applied and after 72 hours, the induration will be read. On the same day of the tuberculin skin test application, 4 ml of peripheral blood will be collected for an interferon gamma release assay (Quantiferon 4G). Data will be analyzed aiming to establish an average size for the induration after the tuberculin skin test and to maintain a confidence interval of 95%, as well as to provide the percentage of children without any known contact with active pulmonary tuberculosis adults who show an induration equal to or greater than 10mm wide. The results of tuberculin skin test will be compared with those of the interferon gamma release assay (Quantiferon) in order to exclude the possibility of an earlier exposure to tuberculosis. (AU)