Erkens C.G.M.,KNCV Tuberculosis Foundation |
Dinmohamed A.G.,KNCV Tuberculosis Foundation |
Dinmohamed A.G.,Erasmus Medical Center |
Kamphorst M.,Public Health Service Rotterdam Rijnmond |
And 11 more authors.
International Journal of Tuberculosis and Lung Disease | Year: 2014
BACKGROUND: Interferon-gamma release assays (IGRAs) are reported to be more specific for the diagnosis of latent tuberculous infection (LTBI) than the tuberculin skin test (TST). The two-step procedure, TST followed by an IGRA, is reported to be cost-effective in high-income countries, but it requires more financial resources. OBJECTIVE: To assess the added value of IGRA compared to TST alone in the Netherlands. METHODS: Test results and background data on persons tested with an IGRA were recorded by the Public Municipal Health Services in a web-based database. The number of persons diagnosed with LTBI using different screening algorithms was calculated. RESULT S : In those tested with an IGRA, at least 60% of persons who would have been diagnosed with LTBI based on TST alone had a negative IGRA. Among those with a TST reaction below the cut-off for the diagnosis of LTBI, 13% had a positive IGRA. For 41% of persons tested with an IGRA after TST, the IGRA influenced whether or not an LTBI diagnosis would be made. CONCLUSION: With the IGRA as reference standard, a high proportion of persons in low-prevalence settings are treated unnecessarily for LTBI if tested with TST alone, while a small proportion eligible for preventive treatment are missed. Incremental costs of the two-step strategy seem to be balanced by the improved targeting of preventive treatment. © 2014 The Union. Source