title: Molecular epidemiology of drug-resistant tuberculosis in Sweden.
abstract: Drug-resistant tuberculosis (TB), including the more severe forms of multidrug- and extensively drug-resistant forms, is an increasing public health concern globally. In Sweden the majority of patients with TB are immigrants from countries with a high incidence of TB including the drug-resistant forms. In this study, the spread of resistant TB in Sweden was investigated by molecular fingerprinting. Isolates resistant to at least one of the drugs, isoniazid, rifampicin, ethambutol or streptomycin, from 400 patients collected between 1994 and 2005, were studied by restriction fragment length polymorphism (RFLP) and by spoligotyping. Thirty-five clusters of patients infected with strains with identical RFLP and spoligotyping patterns (2-96 patients per cluster), comprising a total of 203 patients, were found. One large outbreak of isoniazid resistant tuberculosis was identified, involving 96 patients, mainly from the Horn of Africa. To identify chains of transmission, molecular epidemiological characterization of TB isolates should, if possible, be performed on isolates from all new TB patients.
authors.affiliation: Department of Bacteriology, Swedish Institute for Infectious Disease Control, S-17182 Solna, Sweden.
authors.forename: Solomon
authors.initials: S
authors.lastname: Ghebremichael
authors.forename: Ramona
authors.initials: R
authors.lastname: Petersson
authors.forename: Tuija
authors.initials: T
authors.lastname: Koivula
authors.forename: Alexandra
authors.initials: A
authors.lastname: Pennhag
authors.forename: Victoria
authors.initials: V
authors.lastname: Romanus
authors.forename: Ingela
authors.initials: I
authors.lastname: Berggren
authors.forename: Björn
authors.initials: B
authors.lastname: Petrini
authors.forename: Sven
authors.initials: S
authors.lastname: Hoffner
authors.forename: Gunilla
authors.initials: G
authors.lastname: Källenius
mesh_terms: D000995:Antitubercular Agents / Q000627:therapeutic use; D015373:Bacterial Typing Techniques; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007538:Isoniazid / Q000627:therapeutic use; D008297:Male; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D013548:Sweden / Q000453:epidemiology / Q000208:ethnology; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy / Q000453:epidemiology*
chemical_list: D000995:Antitubercular Agents; D007538:Isoniazid