title: Infections preceding early arthritis in southern Sweden: a prospective population-based study.
abstract: OBJECTIVE
  To detect evidence of infections preceding early arthritis in Southern Sweden and to compare the clinical outcome of remission during a 6-month followup for patients with and without signs of prior infection.
  
  
  METHODS
  Adult patients with arthritis of less than 3 months' duration were referred from primary health care centers to rheumatologists. All patients were systematically screened for infections caused by Salmonella typhimurium and Salmonella enteritidis, Yersinia enterocolitica, Campylobacter jejuni, Borrelia burgdorferi, Chlamydia trachomatis, Chlamydia pneumoniae, and parvovirus B19.
  
  
  RESULTS
  Seventy-one patients were included in this study. Twenty-seven (38%) patients had reactive arthritis (ReA), 17 (24%) undifferentiated arthritis, 15 (21%) rheumatoid arthritis (RA), 4 (6%) psoriatic arthritis, and the rest (11%) other diagnoses. Of all the patients, 45% had evidence of a recent infection preceding the arthritis, as indicated by laboratory tests and/or disease history. C. jejuni dominated the ReA group. The occurrence of recent C. trachomatis, B. burgdorferi, C. pneumoniae, and parvovirus B19 infections was low. Overall, 58% of the patients went into remission during the 6-month followup. Of the patients with a preceding infection, 69% went into remission as compared to 38% of the patients without a preceding infection (p = 0.011). Thirty-three percent of the patients with RA were in remission after 6 months.
  
  
  CONCLUSIONS
  In this population-based cohort, 45% of the patients presenting with a new-onset arthritis had had a prior infection. Campylobacter ReA dominated the ReA group. There were only a few cases preceded by infections by C. trachomatis, B. burgdorferi, C. pneumoniae, and parvovirus B19 infections. Remission during the first 6 months was especially frequent in the group of patients with a prior infection, but the remission rate was relatively high even for arthritis without prior infection.
authors.affiliation: Department of Internal Medicine, Växjö Central Hospital, Växjö, Sweden. maria.soderlin@ltkronoberg.se
authors.forename: Maria K
authors.initials: MK
authors.lastname: Söderlin
authors.forename: Hannu
authors.initials: H
authors.lastname: Kautiainen
authors.forename: Mirja
authors.initials: M
authors.lastname: Puolakkainen
authors.forename: Klaus
authors.initials: K
authors.lastname: Hedman
authors.forename: Maria
authors.initials: M
authors.lastname: Söderlund-Venermo
authors.forename: Thomas
authors.initials: T
authors.lastname: Skogh
authors.forename: Marjatta
authors.initials: M
authors.lastname: Leirisalo-Repo
mesh_terms: D000293:Adolescent; D000328:Adult; D016918:Arthritis, Reactive / Q000453:epidemiology* / Q000382:microbiology / Q000821:virology; D002169:Campylobacter Infections / Q000453:epidemiology*; D016123:Campylobacter jejuni; D002690:Chlamydia Infections / Q000453:epidemiology*; D016993:Chlamydophila pneumoniae; D005260:Female; D015796:HLA-B27 Antigen / Q000032:analysis; D006801:Humans; D015994:Incidence; D008193:Lyme Disease / Q000453:epidemiology; D008297:Male; D010322:Parvoviridae Infections / Q000453:epidemiology*; D016732:Parvovirus B19, Human; D010352:Patient Dropouts; D000091402:Prohibitins; D011446:Prospective Studies; D013548:Sweden / Q000453:epidemiology
chemical_list: D015796:HLA-B27 Antigen; C000717331:PHB2 protein, human; D000091402:Prohibitins