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Updated: Mar 24, 2026
Application of Long-term cultured Interferon-γ Enzyme-linked Immunospot Assay for Assessing Effector and Memory T Cell Responses in Cattle
Published on: July 11, 2015
Interferon-gamma release assays can effectively screen migrants for the tuberculosis infection, but urgent, active
1Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden.
Aim:
Increasing numbers of migrants to Sweden are screened for tuberculosis (TB), and a rational approach to screening is required. We evaluated positive tuberculin skin tests (TSTs) and interferon-gamma release assays (IGRAs) on paediatric migrants in relation to the TB incidence in the corresponding foreign-born populations in Stockholm.
Methods:
This study examined the characteristics of migrants under the age of 18 who were referred to a paediatric TB clinic at Karolinska University Hospital from 2008 to 2014 by primary care centres in Stockholm County.
Results:
We saw 943 TST-positive children with a median age of 14 years at the TB clinic and performed IGRAs on 557. IGRA positivity ranged from 64% in migrants from Somalia to 20% in those from the former Soviet Union and eastern Europe, with an estimated population level prevalence of 18.8% and 4.2%, respectively. These were significantly correlated to TB incidence in foreign-born Stockholm children. We diagnosed active TB in 20 screened migrants, and advanced, symptomatic TB was diagnosed in 10 recently arrived migrants without screening.
Conclusion:
IGRAs showed higher specificity than TST in identifying tuberculosis. TB screening should focus on migrants from high-incidence countries, but this may be inadequate to detect advanced TB cases.
