[Considerations on surveillance of HIV infections. The experience of Navarre (Spain)]

The number and proportion of cases in the HIV registry of Navarre (Spain) that were residents of this region were quantified, according to the census and the healthcare card database.

Of the 2,385 persons diagnosed with HIV infection to 2003, only 1,610 (67.5%) were residents of Navarre. The rate of HIV cases diagnosed among residents in Navarre was over 90 cases per million between 1994 and 1998, with values similar to those of Switzerland. In contrast with the time-trend in other European countries, the time-trend in Navarre decreased from 1994 to 2003. Since 2000 the rate of new HIV cases in Navarre has been lower than rates in Portugal, Switzerland, Luxembourg, Belgium, Ireland, and the United Kingdom.

To prevent overestimation of the number of HIV infections, cases duplicated between regions should be excluded. This could be achieved by a national HIV surveillance system.