Epidemiological data on listeriosis in Portugal: 2003 – 2008

Listeria monocytogenes is a ubiquitous Gram-positive facultative intracellular food-borne pathogen that causes invasive listeriosis that is an uncommon infection. There are some high-risk groups of individuals, which include the elderly, immunocompromised individuals, pregnant women and their neonates. Because of its clinical severity and the high rate of fatality, listeriosis is an infection of considerable public health concern. The invasive illness, which clinical manifestations include meningitis, encephalitis, late-term spontaneous abortion, and septicemia, although rare has a high fatality rate, between 20 and 30 %. In Portugal the available data of cases of listeriosis are limited as it is not a notifiable disease and is likely to be under-reported.