Risk of tuberculosis transmission by healthcare workers to children - a comprehensive review.

Background: Children <15 years are at elevated risk of becoming infected with M. tuberculosis complex (Mtbc).

Objective: To assess the magnitude of Mtbc transmission by healthcare workers (HCW) to children.

Methods: Medline, Google Scholar and Cochrane library were searched to select primary studies in which HCW was the presumed index case and exposed infants and children aged below 15 years were screened for latent TB infection (LTBI).

Results: Of 4,702 abstracts, 19 original case reports covering one HCW each as presumed source case of Mtbc transmission to children, were identified. In sum, 11,511 children, of those 5,881 infants (51.1%), mostly in newborn nurseries, were considered contact persons and underwent tuberculin skin (TST) or Interferon gamma release assay (IGRA) testing. Test positivity was reported in 492/11,511 children (4.3%) coming from 14 studies. When test results considered falsely positive were excluded, the number of latently infected children decreased to 365/10,171 (3.6%). In all studies, the presumed duration of infectivity of the source case was, but the actual intensity and duration of exposure were not, decisive for the initiation of contact investigations. In only two of the studies, the contact time of the children towards the corresponding source case was estimated.

Conclusions: The results of our review suggest that the risk of Mtbc transmission from HCW to children in healthcare setting is considerably lower than reported in household settings. However, as the preselection of pediatric contacts appeared in most cases to be vague, the data found in the literature probably underestimates the actual risk.