title: Tuberculosis Outbreak in an Educational Institution in Norway.
abstract: Within 1 week in April 2013, three cases of pulmonary tuberculosis (TB) were reported among students attending training sessions at an educational institution in Oslo, Norway. By the end of October 2013, a total of nine epidemiologically linked cases had been reported. The outbreak encompassed a total of 24 cases from 2009 to 2014, among which all of the 22Mycobacterium tuberculosisisolates available had identical mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) profiles (MtbC15-9 code 10287-189) belonging to the Beijing lineage. Whole-genome sequencing (WGS) of theM. tuberculosisisolates revealed 20 variable nucleotide positions within the cluster, indicating a clonal outbreak. The most likely index case was identified and diagnosed in Norway in 2009 but was born in Asia. WGS analyses verified that all of the cases were indeed part of a single transmission chain. However, even when combining WGS and intensified contact tracing, we were unable to fully reconstruct the TB transmission events.
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway gunnstein.norheim@fhi.no.
authors.forename: Gunnstein
authors.initials: G
authors.lastname: Norheim
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Siri
authors.initials: S
authors.lastname: Seterelv
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Trude M
authors.initials: TM
authors.lastname: Arnesen
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.|Oslo University Hospital, Oslo, Norway.
authors.forename: Anne Torunn
authors.initials: AT
authors.lastname: Mengshoel
authors.affiliation: Oslo University Hospital, Oslo, Norway.|University of Oslo, Oslo, Norway.
authors.forename: Tone
authors.identifier: 0000-0002-1709-6921
authors.initials: T
authors.lastname: Tønjum
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Janne O
authors.initials: JO
authors.lastname: Rønning
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Vegard
authors.initials: V
authors.lastname: Eldholm
mesh_terms: D000293:Adolescent; D000328:Adult; D016000:Cluster Analysis; D004196:Disease Outbreaks / Q000706:statistics & numerical data; D016680:Genome, Bacterial / Q000235:genetics*; D006801:Humans; D058889:Molecular Typing; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D009664:Norway / Q000453:epidemiology; D013334:Students / Q000706:statistics & numerical data; D020080:Tandem Repeat Sequences / Q000235:genetics; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000453:epidemiology* / Q000382:microbiology; D055815:Young Adult
keywords: Mycobacterium tuberculosis; Norway; genotyping; outbreak; whole-genome sequencing