Dar seafood ppp standard

Pathology of illness: There are two main clinical forms of infection with L. monocytogenes, namely listerial gastroenteritis, where usually only mild, flu-like symptoms are reported, and the classic invasive listeriosis, where the bacteria penetrate the gastrointestinal tract and invade normally sterile sites within the body (FDA 2003).
Invasive listeriosis can be very severe, and in some cases, life-threatening. Invasive listeriosis is an opportunistic infection and a relatively rare illness, with a wide range of symptoms including meningoencephalitis and septicaemia. Mild or asymptomatic infections in pregnant women may lead to infection of the foetus (Sutherland & Porritt 1997). The incubation period prior to individuals becoming symptomatic with listeriosis can be long (up to 3 months) but most commonly in the region of several days, and for the gastrointestinal form less than 24 hours (Sutherland & Porritt 1997).
It is estimated that approximately 2–6 per cent of the healthy population harbours L monocytogenes in their intestinal tract, which suggests that people are frequently exposed to L. monocytogenes (Rocourt & Bille 1997; Farber & Peterkin 1991). This may also suggest that most people have tolerance to infection by L. monocytogenes, and given the relatively low number of reported cases, exposure rarely leads to serious illness (FDA 2003; Marth 1988; Hitchins 1996). However, a number of high-risk groups for listeriosis have been identified, including pregnant women and their foetuses, neonates, elderly, and the immunocompromised (Sutherland & Porritt 1997).