The reason for this latest revision was the introduction of the new Health Register Act of 2001(2), which made it necessary to base the statutory notification system on this Act and not as previously on the Communicable Disease Control Act of 1994. The other registers covered by the new Health Register Act are the Medical Birth Register, the Death Register, the Vaccination Register, and the Cancer Register. The Central Tuberculosis Register was established in 1964 and has, mostly for historical reasons, until recently been a separate body outside the NIPH. As a consequence of the Government Health Authorities reorganisation in 2002, the National Tuberculosis Register is now a part of NIPH and is administrated by the Department of Infectious Disease Epidemiology. A separate Tuberculosis Register has, however, been retained within the new statutory notification system.

The new statutory notification system is based on the traditional reporting of selected notifiable diseases. As a supplement to this reporting and as a response to new challenges in infectious disease control, a whole range of early warning systems has been introduced in the new legislation. This constitutes a major change from the old system.

Reporting of notifiable diseases
The number of notifiable disease has now been reduced from 68 to 58. Infections such as amoebic dysentery, HTLV-infections, hepatitis D and E, and rare sexually transmitted infections (STIs) such as chancroid and lymphogranuloma are among the infections that are no longer notifiable. New notifiable diseases are echinococcosis, severe acute respiratory syndrome (SARS), and smallpox. Echinococcosis has been included as a result of recent findings of Echinococcus multilocularis in mice, polar foxes, and domestic cats and dogs on Svalbard archipelago outside mainland Norway (3).

The notifiable diseases are now divided into three main categories: group A covers most of the infections; group B covers HIV infection, gonorrhoea, and syphilis; and group C covers influenza and genital chlamydial infections. Group A and group B diseases are notified, case by case, by both clinicians and laboratories, while group C diseases are reported as aggregated data from laboratories (chlamydia) and as sentinel data from selected clinicians (influenza). Group A diseases are reported with full patient identification, while the STIs in group B are reported anonymously using a non-unique identifier linking reports from clinicians and laboratories. At the moment, all notifications are sent by ordinary post, but it is hoped that electronic reporting from laboratories will be introduced before the end of 2003. All doctors and all the laboratories in the country are obliged to report notifiable diseases. Case definitions are in use for all notifiable diseases and will soon be revised to comply with common European case definitions (4).

Patient consent is not necessary for reporting a notifiable disease, but the reporting clinicians are obliged to inform the patient of the reporting system and what the data will be used for. The patient also has the right to be given information on the use of his/her own data in the register.

Early warning systems
Early warning is defined in the new legislation as immediate reporting (usually by telephone) to local, regional, or central health authorities on clinical suspicion of a number of selected diseases, outbreaks, etc. In the following situations, health personnel are obliged to give such an early warning: