Prosciutto is an Italian dry-cured ham, prepared by salting and air-drying a pig’s hind leg for many months. Since it is served without being cooked, it is categorized as an uncooked, ready-to-eat meat. During pregnancy, consuming prosciutto that has not been thoroughly heated is cautioned against due to potential foodborne pathogens. The concern relates to the processing method, which does not use high heat, rather than the meat itself.
The Primary Pathogens of Concern
The two main infectious agents of concern in uncooked, cured meats like prosciutto are the parasite Toxoplasma gondii and the bacterium Listeria monocytogenes.
Toxoplasma gondii
Toxoplasma gondii is transmitted through the ingestion of tissue cysts, often found in raw or undercooked meat. If a pregnant person acquires toxoplasmosis for the first time, the parasite can cross the placenta. This infection poses serious risks to the fetus, including neurological damage and vision loss.
Listeria monocytogenes
Listeria monocytogenes is particularly dangerous because it can multiply even in cold temperatures, such as inside a refrigerator. Pregnant individuals are estimated to be ten to twenty times more likely to contract listeriosis than the general population. Listeriosis can result in severe outcomes, including miscarriage, stillbirth, premature delivery, and serious infections in the newborn.
Why Curing Does Not Guarantee Safety
Prosciutto is preserved through dry-curing, which involves heavily salting and air-drying the meat for an extended period. This process reduces the meat’s water activity and increases salt concentration, inhibiting the growth of many bacteria. However, salt and drying do not achieve the same level of pathogen destruction as high-heat cooking. Studies show that some pathogens, including Listeria monocytogenes and Toxoplasma gondii, can survive the curing steps. Curing is a preservation method, not a sterilization method, meaning it reduces the risk without eliminating it entirely.
Making Prosciutto Safe to Eat
The only way to consume prosciutto safely during pregnancy is to heat it thoroughly until it reaches a specific internal temperature. Heating the meat to a sufficient temperature effectively kills the Toxoplasma parasite and the Listeria bacterium. The recommended internal temperature to ensure pathogen destruction is 165°F (74°C). This temperature must be reached throughout the meat, which can be verified using a food thermometer. Heating the cured meat until it is visibly steaming hot is a practical way to achieve the necessary temperature without a thermometer.
Other Cured and Deli Meats to Limit
The food safety risks associated with prosciutto extend to many other ready-to-eat cured and deli meats. Products like salami, pepperoni, and capicola carry a similar risk of Toxoplasma gondii and Listeria monocytogenes contamination because their dry-curing or fermentation process does not reliably eliminate all harmful organisms. The guidance also covers pre-packaged and counter-sliced cold-cut deli meats, such as ham, turkey, and roast beef. These primarily pose a risk of Listeria contamination, as re-contamination can occur during slicing or packaging, even if the meat was cooked during production. To consume any deli or cured meat safely, the recommendation is to heat it until it is steaming hot, or to an internal temperature of 165°F, before eating.