Allergy to ragweed in northern Italy and prevention strategies.

Ragweed is spreading in Europe and in northern Italy, particularly in the Lombardia and Friuli areas. It constitutes a cause of significant morbidity for asthma and rhinoconjuntivitis involving as much as 12% of the general population in those countries most at risk. The public campaign to fight ragweed promoted in 1999 by the Lombardia Region failed to achieve significant results since the count of ragweed pollen in the subsequent years is similar to the previous and reached peaks of 700 pollens per m3.