Open AccessTransmission of tuberculosis between foreign-born and Finnish-born populations in Finland, 2014–2017
Author(s) -
Pirre E. Räisänen,
Marjo Haanperä,
Hanna Soini,
Petri Ruutu,
J. Pekka Nuorti,
Outi Lyytikäinen
Publication year - 2021
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0250674
Subject(s) - epidemiology , foreign born , tuberculosis , transmission (telecommunications) , medicine , population , mycobacterium tuberculosis , demography , cluster (spacecraft) , pediatrics , environmental health , pathology , sociology , computer science , electrical engineering , programming language , engineering
We describe the epidemiology of tuberculosis (TB) and characterized Mycobacterium tuberculosis (M . tuberculosis) isolates to evaluate transmission between foreign-born and Finnish-born populations. Data on TB cases were obtained from the National Infectious Disease Register and denominator data on legal residents and their country of birth from the Population Information System. M . tuberculosis isolates were genotyped by spoligotyping and Mycobacterial Interspersed Repetitive Unit Variable Number Tandem Repeat (MIRU-VNTR). We characterized clusters by age, sex, origin and region of living which included both foreign-born cases and those born in Finland. During 2014–2017, 1015 TB cases were notified; 814 were confirmed by culture. The proportion of foreign-born cases increased from 33.3% to 39.0%. Foreign-born TB cases were younger (median age, 28 vs. 75 years), and had extrapulmonary TB or multidrug-TB more often than Finnish-born cases (P<0.01 for all comparisons). Foreign-born cases were born in 60 different countries; most commonly in Somalia (25.5%). Altogether 795 isolates were genotyped; 31.2% belonged to 80 different clusters (range, 2–13 cases/cluster). Fourteen (17.5%) clusters included isolates from both Finnish-born and foreign-born cases. An epidemiological link between cases was identified by (epidemiological) background information in two clusters. Although the proportion of foreign-born TB cases was considerable, our data suggests that transmission of TB between foreign and Finnish born population is uncommon.