Historically, infectious diseases have been
a major cause of maternal and fetal morbidity and mortality worldwide.
Although improvements have been achieved due
to better hygienic standards and vaccinations,
infections still continue to represent
a major public health problem during pregnancy until today.
One cause are foodborne infections that can induce
infection in both the mother and the unborn child and can induce miscarriage,
premature labor, severe congenital disease,
and even fetal death.
Therefore, it is important that pregnant women
take precautionary measures to reduce the risk of
foodborne infections by selecting
appropriate foods and by introducing proper food handling.
Prevention is the main focus in the management of foodborne diseases during pregnancy.
There are three major groups of pathogens that pose
the greatest threat of causes of foodborne illnesses to a pregnant woman and her child.
These include listeria, salmonella, and toxoplasmosis.
Listeriosis, caused by the bacteria Listeria monocytogenes,
is a predominantly foodborne illness.
Listeria can contaminate a variety of raw foods such as uncooked vegetables and meats,
unpasteurized milk, and soft cheeses.
Research suggests that pregnant women seem to be more
susceptible to listeria infection than the general population,
although the infection itself does not appear to be more severe.
However, listeria tend to invade the placenta and the fetus,
and they may cause severe fetal and neonatal infection.
Fetal infection can be lead to preterm labor,
neonatal sepsis, meningitis, and death.
Evidence has shown that one in five,
or about 20% of pregnancies,
complicated by listeria infection,
resulted in spontaneous abortion or stillbirth.
Prevention of foodborne listeria infection during pregnancy is a key priority.
All pregnant women should be informed during their normal prenatal care about
proper food preparation practices and about
avoiding foods with a high risk of contamination.
The four cornerstones of safe food preparation should be followed which include clean,
separate, cook, and chill.
High-risk foods should be avoided.
This includes, in particular,
raw and not-fully-cooked meat or sausage such as salami,
raw ham, and other raw animal foods.
Only meat that is thoroughly cooked is really safe.
Also, soft cheese, smoked fish,
and prepared and pre-packed salads should be avoided.
Fresh fruits, vegetables, and salad must be thoroughly washed,
freshly prepared, and soon consumed.
Thereby, the risk of listeria infections can be greatly minimized.
Infections caused by salmonella species are the most common cause of foodborne diseases.
In the United States, the CDC estimates that 1.2 million
cases of illness are caused by nontyphoidal salmonella every year in the U.S. alone.
Salmonella is often contracted through contaminated food.
Pregnant women are no more susceptible to salmonella than the general population,
but there are specific complications
that are associated with the infection during pregnancy.
Septic infection of the mother can result in spontaneous abortion.
If transmission to the fetus occurs,
this can cause preterm births and neonatal infection of the brain and meningitis.
Again, prevention is important to avoid foodborne salmonella infection.
The most common sources of salmonella are foods of animal origin.
Pregnant women should avoid raw or undercooked eggs, poultry, and meats.
Many foods contain raw eggs of which people are not often aware.
These can include hollandaise sauce made at home or in some restaurants, mayonnaise,
caesar and other salad dressings made at home or in some restaurants,
tiramisu, homemade ice cream,
cookie dough, and frostings.
All of these products and other foods containing raw eggs should be strictly
avoided by pregnant women to reduce the risk of salmonella infection.
It is important to adhere to
proper hygiene precautions when handling raw meat or poultry.
These include washing hands,
work surfaces, and utensils immediately after contact.
Toxoplasmosis is the third major cause of foodborne disease deaths in the world.
It is caused by the intracellular parasite Toxoplasma gondii.
Transmission to the fetus can occur.
The overall risk of developing congenital toxoplasmosis ranges
from 20-50% of untreated infected pregnant women.
Maternal infections in later stages of the pregnancy are more likely to be transmitted.
Toxoplasmosis vertical transmission increases from 10-15% in the first trimester to
44% in the second trimester and to
more than 71% when the maternal infection occurs in the third trimester.
At the same time maternal disease severity actually decreases with gestational age.
This means that there's a higher chance of pregnancy loss and
severe sequelae when infection occurs in the first trimester.
While congenital toxoplasmosis is rare, when it does occur,
infection of the unborn child can have
devastating neurological and ophthalmological consequences,
and it can induce cardiac malformation.
That is why prevention of
toxoplasmosis infections should be at the forefront of pregnancy care.
In all cases, the screening policy and information on prevention of
Toxoplasma gondii infection should be made available to
all pregnant women and women in the preconception phase.
As with all other foodborne disease,
prevention can be carried out with specific hygienic and dietary recommendations.
Examples of such have already been given for avoidance
of listeriosis and salmonellosis.
Cats have been identified as additional important transmitters of Toxoplasma gondii.
Therefore, there are additional recommendations on contact with cats during pregnancy.
These include wearing gloves and thoroughly cleaning hands and
nails when handling material potentially contaminated by cat feces,
such as sand or soil,
or after working in the garden.
Change litter and get rid of cat feces with
wearing gloves on a regular basis usually every 24 hours.
It is even better if the pregnant woman can get another family member to do this.
Disinfect emptied cat litter tray with
near-boiling water for five minutes before refilling.
Freeze meat to at least -20 degrees Celsius or
-4 degrees Fahrenheit which kills Toxoplasma gondii easily.
In all the three instances of the foodborne diseases that we discussed,
awareness of the causes of infection by
foodborne illnesses is the best means of preventing infection.
Therefore, healthcare professionals need to adequately inform pregnant women of
these potential risks and how to avoid them during their first consultation.