Quantiferon for Detection of Latent Tuberculosis in Healthcare Workers

The accuracy of tuberculin skin test (TST) for detecting latent tuberculosis is limited in countries with a high proportion of population having received vaccination with the BCG. We aim to determine the cost-effectiveness of Quantiferon gold (QTFG), compared to BCG vaccine to detect latent tuberculosis in exposed healthcare workers (HCWs)

The QUANTIPS study includes two components:

1. survey of HCWs working in high-risk units (respiratory diseases or infectious diseases with at least 5 case of smear-positive pulmonary tuberculosis par year) from 14 University hospitals in France 2. Follow-up of HCWs with unexpected exposure to a patient with contagious tuberculosis (delay in respiratory isolation of a smear-positive patient) in 4 University hospitals Main objective: Therapeutic impact of tuberculosis screening using TST compared to QFTG. The impact is defined by the decision to treat of not a HCW with latent tuberculosis using QFTG, compared to the decision which would have been based on TST alone

Secondary objectives:

* Cost-effectiveness of replacing TST by QFTG * Prevalence and incidence of latent tuberculosis in exposed HCWs (Part 1) * Incidence of latent tuberculosis in HCWs exposed to an index case (part 2) Inclusion: HCWs who volunteer to participate in units with at least 5 patients with smear-positive tuberculosis each year (Group 1), HCWs exposed to a smear-positive patient non isolated at hospital admission (Group 2) Study population: 2000 (Group 1) and 600 (Group 2) HCWs Study duration: inclusion during 3 months, follow-up of one year (Group 1 ); Inclusion for one year, with a 3-month follow up (Group 2)

Study exams:

* Group 1 : TST, QFTG, chest radiography at baseline and after one year * Group 2 : TST, QFTG, chest radiography at baseline (within 3 weeks after exposure) and after 3 months

Endpoints:

* therapeutic decision regarding tuberculosis treatment, with a cost-effectiveness analysis (Markov's modelling) * prevalence and incidence of latent tuberculosis