Food Poisoning During Pregnancy

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Food poisoning during pregnancy can mean a lot of things.  There are several different categories of food poisoning that can strike pregnant women. These include botulism, E. coli, Salmonella, cholera, listeriosis, and numerous others. Anybody can be hit with food poisoning, but pregnancy makes you particularly vulnerable to listeriosis, a condition resulting from consumption of food that is contaminated with the bacterial species Listeria monocytogenes. This can happen, especially, if you consume packaged foods designed for long shelf-lives, notoriously soft cheeses, deli meats, and raw seafood, including sushi. Listeria poisoning is rare overall, but pregnancy raises your risk to 10-18 times that of non-pregnant people. Furthermore, Hispanic women who are pregnant have 24 times the risk of the non-pregnant population, and so listeriosis is really the main food poisoning concern during pregnancy. Other factors raising your risk include anything that weakens your immunity, include AIDS and certain medications.

Salmonella infection is a type of food poisoning that develops in people who have eaten food contaminated with either of two species of bacteria. One species is called Salmonella enterica and other is called Salmonella bongori. The foods most likely to be contaminated with Salmonella are undercooked eggs, followed by seafood, especially shellfish, that is undercooked, or raw. In the United States, an estimated 1-3 per 30,000 eggs are contaminated with one type or another of Salmonella. Infection with Salmonella strikes pregnant women more often than it strikes anyone else. Cooking eggs well goes a long way in reducing the danger.

Escherichia coli is a bacterial species that lives inside your large intestine. Certain E. coli strains that contaminate food can cause a kind of food poisoning that can be extremely dangerous. Vibrio cholera is a species of bacteria that can contaminate water and produces a toxin that cause serious disease with severe diarrhea and vomiting as the principal symptoms. The disease is known commonly as ‘cholera’. An estimated 1.3-4.0 million people develop cholera each year around the globe, resulting in 21 000 – 143 000 deaths. The disease comes in outbreaks, often due to contamination of water and food supplies. Mostly, this happens in developing countries, in locations where there is inadequate access to clean water and facilities for sanitation.

Botulism is an extremely dangerous, but fortunately very rare, condition resulting from a toxin produced by a bacterial species called Clostridium botulinum.

Diagnosis of food poisoning is based on the history of what you have eaten and the development of food poisoning symptoms, and often on laboratory tests for presence of the suspected contaminant organism in your body or in the food. Diagnosis is of listeriosis, for example, is achieved by finding that L. monocytogenes can be cultured from samples of your blood.

In cases of food poisoning, typically you develop gastrointestinal disturbances and/or flu-like symptoms, such as fever, headache, muscle aches, back pain, and a sore throat. With listeria, this situation can lead to sepsis, infection throughout the body which is life-threatening to the mother. As for the fetus, the effects can be indirect. If the mother suffers from dehydration, for instance, this is dangerous to the fetus as well. Certain food poisoning, such as listeriosis, threatens the health of the fetus directly as well. Listeriosis can cause spontaneous abortion (miscarriage), premature labor and delivery, infection of the membranes that surround the fetus (chorioamnionitis), and stillbirth. Problems occurring in the newborn after birth can include neonatal sepsis (infection throughout the newborn’s system) pneumonia, and meningitis.

Treatment of pregnant women with listeriosis includes antibiotic medicines. This is to protect the fetus as much as to protect the mother. The same antibiotics are given to infants who have the disease, so there is little concern about exposure to the medications in the womb. As for breast feeding mothers with listeriosis, there is no concern about exposure to the medications (antibiotics) through breast milk. However, if you have listeriosis to the point that you require antibiotics, you may not feel up to breastfeeding, and so using infant formula might be the more prudent course. At the point of the writing of this post, however, there is an infant formula shortage in the United States, so the formula option may be more challenging for many mothers.

Apart from medications such as antibiotics, various supportive treatments also play an important role. Such measures include fluid replacement, which normally can be by mouth, but in some cases may be intravenous.

David Warmflash
Dr. David Warmflash is a science communicator and physician with a research background in astrobiology and space medicine. He has completed research fellowships at NASA Johnson Space Center, the University of Pennsylvania, and Brandeis University. Since 2002, he has been collaborating with The Planetary Society on experiments helping us to understand the effects of deep space radiation on life forms, and since 2011 has worked nearly full time in medical writing and science journalism. His focus area includes the emergence of new biotechnologies and their impact on biomedicine, public health, and society.

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