Quantiferon for Detection of Latent Tuberculosis in Healthcare Workers

Cost-effectiveness of Quantiferon Gold in VITRO Test of T-lymphocytic Response for Detection of Latent Tuberculosis in At-risk 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

INCLUSION CRITERIA:

Group 1:

• Healthcare worker volunteering for the study
• Stable (expected employment in the unit > one year)
• Working in a high-risk units for tuberculosis (at least 5 cases of smear-positive pulmonary tuberculosis per year)

Group 2 :

• Healthcare worker volunteering for the study
• With an unexpected exposure to a patient with contagious tuberculosis (delay in respiratory isolation of a smear-positive patient)

EXCLUSION CRITERIA:

• No informed consent
• Age < 18 years
• Employment in this unit < one year