Tuberculosis Infection and Disease Among Pregnant People Living in Sweden With Origin in Tuberculosis-Endemic Countries

Background: Pregnancy has been associated with elevated incidence of tuberculosis (TB) disease. Since 2014, people living in Sweden with origin in TB-endemic countries have been offered screening for TB infection in antenatal care (ANC) using Quantiferon-TB assays. We assessed factors associated with TB infection in this population and determined the incidence of TB disease during pregnancy and postpartum periods with regard to ANC Quantiferon-TB results.

Methods: Quantiferon-TB results obtained during ANC in Sweden, 2014-2018, were linked to data from national registers (Pregnancy Register, Patient Register and Tuberculosis Register). Factors associated with TB infection (defined as Quantiferon-TB ≥0.35 IU/mL) were identified using logistic regression analysis. Incidence of TB disease was determined with regard to pregnancy, postpartum and subsequent periods, and ANC Quantiferon-TB results.

Results: Among 7638 screened individuals, 1424 (18.6%) had TB infection. Tuberculosis infection was independently associated with higher age at immigration (adjusted odds ratio, 1.04 [95% confidence interval, 1.03-1.05]; < .001), and was more common among people originating from Africa compared to other world regions (845/3088 [27.4%] vs 579/4550 [12.7%]; < .001). In total, 16 participants were diagnosed with TB disease (10 during pregnancy, 4 at <6 months after delivery, 2 at >6 months after delivery); among these, all diagnosed during pregnancy/postpartum had positive ANC Quantiferon-TB results (constituting 14/1424 [1%] of people with TB infection).

Conclusions: Among pregnant people screened in Swedish ANC, TB infection was associated with higher age and African origin. All cases of TB disease reported in persons with TB infection at ANC screening occurred during pregnancy or postpartum.