title: Incidence and antibiotic treatment of erythema migrans in Norway 2005-2009.
abstract: The first stage of Lyme borreliosis (LB) is mainly the typical skin lesion, erythema migrans (EM), which is estimated to comprise 80-90% of all LB cases. However, the reporting of, and the actual incidence of LB varies throughout Europe. Studies from Sweden and Holland have found EM incidences varying from 53 to 464 EM/100,000 inhabitants/year. Under-reporting of LB is common and a coefficient of three to reach a realistic estimate is suggested. In Norway, it is mandatory to report only the second and third LB stages to the National Institute of Public Health. To find the Norwegian incidence of EM, we extracted data from the electronic medical records of regular general practitioners and out-of-hours services in the four counties with the highest rates of registered LB in the 5 years from 2005 to 2009. We found an EM incidence of 448 EM/100,000 inhabitants/year in these counties, which yields a national incidence of 148 EM/100,000 inhabitants/year. Our findings show that solitary EMs comprised almost 96% of the total LB incidence in Norway. Older females have the highest rates of EM. Phenoxymethylpenicillin is the most commonly used drug to treat EM in Norway, which complies with the national guidelines for antibiotic use. Antibody tests are performed in 15% of cases. Less than 1% of patients are referred to secondary care. The study also shows a high number of patients seeking care for tick bites without signs of infection and there is an overuse of antibiotics in these patients.
authors.affiliation: Norwegian Antibiotic Centre for Primary Care, Department of General Practice, University of Oslo, PO box 1130 Blindern, N-0318 Oslo, Norway. Electronic address: k.e.eliassen@medisin.uio.no.
authors.forename: Knut Eirik
authors.initials: KE
authors.lastname: Eliassen
authors.affiliation: Department of Infectious Diseases, Oslo University Hospital, Faculty of Medicine, University of Oslo, Kirkeveien 166, N-0460 Oslo, Norway. Electronic address: dag.berild@medisin.uio.no.
authors.forename: Dag
authors.initials: D
authors.lastname: Berild
authors.affiliation: Norwegian National Advisory Unit on Tick-borne Diseases, Sorlandet Hospital, PO box 783 Stoa, N-4809 Arendal, Norway. Electronic address: harald.reiso@medisin.uio.no.
authors.forename: Harald
authors.initials: H
authors.lastname: Reiso
authors.affiliation: Department of Medical Microbiology, Vestfold Hospital Trust, Halfdan Wilhelmsens allè 17, N-3116 Tonsberg, Norway. Electronic address: nigrud@siv.no.
authors.forename: Nils
authors.initials: N
authors.lastname: Grude
authors.affiliation: Tarnasen GP Office, Valhallaveien 70, N-1413 Tarnasen, Norway. Electronic address: karen.sofie.christophersen@gmail.com.
authors.forename: Karen Sofie
authors.initials: KS
authors.lastname: Christophersen
authors.affiliation: Asker and Baerum Primary Care Out-of-hours Service, Sogneprest Munthe-kaas vei 100, N-1346 Gjettum, Norway. Electronic address: cecilie.finckenhagen@gmail.com.
authors.forename: Cecilie
authors.initials: C
authors.lastname: Finckenhagen
authors.affiliation: Norwegian Antibiotic Centre for Primary Care, Department of General Practice, University of Oslo, PO box 1130 Blindern, N-0318 Oslo, Norway. Electronic address: morten.lindbak@medisin.uio.no.
authors.forename: Morten
authors.initials: M
authors.lastname: Lindbæk
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008193:Lyme Disease / Q000188:drug therapy* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents
keywords: Antibiotic use; Clinic; Epidemiology; General practice; Lyme borreliosis; Tick-borne diseases