Unlike other seafood, the mercury level in mussels is not the problem, since that is relatively low. The real issues are the toxins and bacteria in it that need to be destroyed before the shellfish can be considered completely safe for consumption. One such bacteria that is sometimes found in mussels is the Vibrio vulnificus. It can enter the mother’s gastrointestinal track and cause food poisoning. It can even cross the placenta and damage or kill the developing baby. Under cooked mussel also harbours the virus Hepatitis A which can cause an infection in the mother’s liver and lead to preterm birth. Thus, in order to eliminate all risks, it is important to clean and cook mussels thoroughly before eating it.