Sammendrag
Abstract
Background
Tick-borne infections transmitted by the sheep tick, Ixodes ricinus, are emerging diseases in Norway. Today both physicians and the general population are more and more aware of the consequences that may follow a tick bite, mainly because of the increasing incidence, the media, and the experience that almost all Norwegians know of someone who fell “dramatically” ill due to a tick bite. This assignment has emphasized on both an epidemiological and a clinical aspect to assess a wide perspective on these challenging zoonoses.
Material and methods
The epidemiological data were collected from the registers of the Norwegian Surveillance System for Communicable Diseases (MSIS) and from relevant literature.
189 medical records with tick-related infections at Ullevaal University Hospital (UUS), 2000-2005, were retrospectively studied.
Results
In Norway, Lyme borreliosis is the most common tick-transmitted infection. 311 cases were registered in Norway, 2006. However, tick-borne encephalitis, human granulocytic anaplasmosis and tularemia may also be possible outcomes from a Norwegian tick bite.
The UUS-review resulted in an investigation of 19 cases of African tick bite fever (ATBF) caused by Rickettsia africae, endemic in rural sub-Saharan Africa, and 153 cases of Lyme borreliosis. 48 % of the patients infected with Borrelia burgdorferi had recognized a tick bite, and 38 % had observed the characteristic rash of early infection, namely erythema migrans (EM).
Interpretation
Several microorganisms may be transmitted by I. ricinus, and coinfections could be clinically relevant.
With regards to Lyme borreliosis, clinicians should all year around think of the possibility of disseminated or chronic Lyme borreliosis in patients living in endemic regions presenting with neurological, dermatological or rheumatic complaints compatible with the infection, even if the patient has not noticed any tick bites or EMs. To prevent chronic manifestations early treatment is crucial.
All cases of ATBF were successfully treated with ciprofloxacin or doxycycline.