title: [Are domestic Cryptosporidium and Giardia infections in Norway underdiagnosed?].
abstract: BACKGROUND
  Cryptosporidium and Giardia are recognised as common causes of waterborne disease in several countries. In order to describe investigative practices for these protozoan parasites in Norway, we surveyed medical microbiology laboratories nationwide for faecal screening policies and methods used for detection of Cryptosporidium and Giardia.
  
  
  METHODS
  All medical microbiology laboratories in Norway received questionnaires on laboratory methods, indications for screening, and numbers of samples investigated over the 1998-2002 period.
  
  
  RESULTS
  Of the 22 laboratories that receive faecal samples, 17 had established diagnostic routines for Giardia detection, 14 for Cryptosporidium. Examination for Giardia cysts was standard procedure in all 17 laboratories, mainly in specimens from immigrants and travellers returning from abroad. Examination for Cryptosporidium was, on the other hand, infrequent. Ten of the 14 laboratories reported less than 10 examinations per year. Giardia was frequently detected, with 1 to 6% positive samples in the various laboratories. Cryptosporidium was seldom detected; all laboratories reported only 0-1 positive sample per year.
  
  
  CONCLUSIONS
  While laboratories frequently screen faecal samples for Giardia, screening for Cryptosporidium is rare. Little is known about the public health significance of domestic infections with these parasites in Norway; further investigation is needed in order to estimate the burden of disease they cause and to implement control measures if required.
authors.affiliation: Division for smittevern, Nasjonalt forkehelseinstitutt, Oslo. karin.nygard@fhi.no
authors.forename: Karin
authors.initials: K
authors.lastname: Nygård
authors.forename: Line
authors.initials: L
authors.lastname: Vold
authors.forename: Lucy
authors.initials: L
authors.lastname: Robertson
authors.forename: Jørgen
authors.initials: J
authors.lastname: Lassen
mesh_terms: D000818:Animals; D003457:Cryptosporidiosis / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology; D003458:Cryptosporidium / Q000302:isolation & purification; D003967:Diarrhea / Q000469:parasitology; D005243:Feces / Q000469:parasitology; D016829:Giardia lamblia / Q000302:isolation & purification; D005873:Giardiasis / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology; D006801:Humans; D009664:Norway / Q000453:epidemiology; D011795:Surveys and Questionnaires