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Harmful bacteria and parasites

Among the microorganisms that are normally associated with food poisoning, there are two that pregnant women should be extra careful about: listeria and toxoplasm. These microorganisms can damage the fetus without causing particularly severe symptoms in the mother. Examples of signs of illness in the mother may be flu-like symptoms. In the worst case, an infection can lead to miscarriage or congenital damage to the child.

Harmful bacteria and parasites

Listeria (Listeria monocytogenes) is a bacterium found naturally in water, soil and raw materials. The bacterium grows rapidly at room temperature, but also - unlike many other bacteria - at low temperatures, such as in refrigerators. Usually, a very high number of bacteria per gram of food is required for it to cause disease. The bacterium dies upon heating, but survives freezing. Listeria first and foremost enters the body via foods that are stored in a refrigerator for a long time and are eaten without heating. You can read about the food below.

Toxoplasma (Toxoplasma gondii) is a parasite found in the intestinal tract of cats. People can be infected in two different ways:

  • In direct or indirect contact with feces from cats. Direct infection from cat feces, for example, can be done by cleaning the litter box or patting infected cats. Indirectly, one can also become infected through food and drink that is contaminated with cat feces, for example through unwashed vegetables or fruits. You can also become infected through contact with soil and sand where cats have buried their feces.
  • By eating raw meat from animals infected with toxoplasm. The parasite is found in the flesh of such animals, although the animals themselves show no signs of disease. The parasite is killed by boiling or frying the meat well. It can also be killed by freezing for at least -18 C for several days. However, it probably survives digging and cold smoking of meat.

If a pregnant woman is infected for the first time during pregnancy, the parasite can be transmitted to the fetus and cause miscarriage, malformation or other serious damage to the baby, if the disease is not treated in time. For more information about pregnancy and maternity fashion, please see BESTAAH.COM maternity sweatshirts & hoodies. People who have been infected earlier in life have antibodies to the parasite that protect the fetus from infection. In Sweden, between 10 and 28% of the population has antibodies to toxoplasma. Caregivers can check if a pregnant woman has such antibodies using a blood test. The advice regarding the toxoplasmic parasite applies first and foremost to pregnant women who do not know for sure that they have protective antibodies.

In Sweden, it is not considered necessary to routinely examine pregnant women for antibodies against toxoplasmosis.


In raw meat, both toxoplasm and listeria can be present. Make sure all the meat you eat is well cooked, cooked or grilled. This also applies to hamburgers, pan steaks and the like. Do not taste raw meat when cooking. Cooking utensils that have been in contact with raw meat should be washed before being used for other foods. Ground meat poses a greater risk than other meat when it comes to toxoplasm. Sliced ​​meats also pose a greater risk than whole meat when it comes to listeria. Therefore, avoid eating cut, vacuum-packed meatloaf towards the end of the shelf life. Vacuum-packed meatloaf has a durability of several weeks. If the spread contains listeria, the amount of bacteria can increase to harmful levels.


All cheeses that are heat treated well - such as cheese on pizza, hot sandwiches, lasagna or sauces - can be eaten by pregnant women.

Listeria has been found in soft / semi-soft stored cheeses of unpasteurized milk. Unpasteurized milk is not heat-treated enough, and the risk of listeria bacteria is therefore relatively high. In Sweden, some cheese made from unpasteurized milk is sold.

Listeria is also found in soft and semi-soft cheeses - such as brie and camembert - and in soft cheeses such as gorgonzola, although these have been made from pasteurized milk. The reason is that these cheeses can get infected at some point in the production process. Listeria is very rare in these cheeses, but to be on the safe side, pregnant women should eat these cheeses when they are as fresh as possible, avoiding them towards the end of their shelf life. Namely, the amount of possible listeria bacteria is at its highest towards the end of the shelf life.

All other types of cheese are considered safe in terms of the amount of listeria. Melted cheese of all types is considered safe. These are usually sold on a tube. Listeria also does not thrive in hard cheeses such as "Gouda", "Jarlsberg", "Norvegia", or in mesost and parmesan cheese. These cheeses can therefore be safely eaten by pregnant women.

Fish and seafood

Pregnant women should not eat sour fish as the special conditions in their production involve an increased risk of Listeria.

Listeria can also be found in small quantities in buried or smoked fish. If the bacterium is allowed to grow, for example in vacuum-packed products with a long shelf life, the bacteria level may become too high. Therefore, eat dug and smoked fish when it is as fresh as possible. So, to be on the safe side, you should avoid buried and smoked fish that are nearing the end of their shelf life.

If raw fish, such as sushi, is treated hygienically, there is little risk of high levels of listeria.

Out of country

In many countries, the risk of being infected with toxoplasma is much higher than in Sweden. The incidence of toxoplasmosis varies greatly geographically. The infection is common in mild and humid climates, rare in dry and warm areas. Countries with a high risk of infection include France, Italy, Portugal, Spain and the Canary Islands - where about 60-80% of the younger population is infected. The risk of being infected is about 20 times higher in southern countries, compared to Sweden. In southern Germany and Austria, 40-60% of the younger population is infected. The British Isles, Northern Germany and the Nordic countries have about the same risk of infection as us and travel to these places does not pose any increased risk.

Pregnants who choose to travel to countries with a high risk of infection should be careful with their eating habits, avoid contact with cats and take new blood tests three weeks after returning home. If you cannot follow these tips, you should consider staying at home better.


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