Listeria in pregnancy, symptoms and prevention

Infection by listeria It is acquired by eating contaminated food and is a bacteria resistant to low temperatures. Once the contaminated food is ingested, the listeria is absorbed in the digestive system and reaches the placenta, one of its favorite tissues. From there it can harm the fetus as we will see later. The incidence of this infection has increased in recent years and in our environment it has increased from 0.2 to 0.8 per thousand deliveries since 2002. Its appearance is somewhat more frequent in summer.

Symptoms of listeria

The symptoms of this infection are nonspecific, giving discomfort, some of fever, similar to a. In 20% of the cases a picture of gastrointestinal symptoms Previous, such as nausea, abdominal pain ... In some cases it is completely asymptomatic.

In a non-pregnant patient it is a non-specific condition without further importance, but in pregnant women it is serious due to its fetal impact. If the infection is acquired in the first or second trimester of pregnancy (20% of cases), one or more fetal death occurs in the uterus. Of the 80% of cases in which it occurs in the third trimester, one third is totally asymptomatic for the mother and the fetus and in two thirds there is an infection of the bag of waters and a premature labor with a fetus mortality of around 20%. Fetuses born to mothers who contract listeria in late pregnancy can get infected in two different ways:

• By hematogenous route, that is, Through the blood. It is the most frequent form and appears on the second or third day of life. They are usually children born prematurely and who have respiratory failure with pneumonia. The prognosis is fatal in 20-30% of cases.
• By contagion in the birth canal. It appears later, on the seventh day of life and the most frequent is that they present meningitis.

Diagnosing listeriosis in pregnant women

Sometimes it is very difficult to diagnose since the symptoms are very common to many diseases. In the first and second trimesters of pregnancy it can give flu-like symptoms, with fever above 38ºC and in 20% of cases preceded by gastrointestinal symptoms. In the third trimester it usually presents as a picture of fever, uterine pain, contractions ...

If there is suspicion of a possible infection by listeria in a pregnant woman We must perform an analysis of maternal blood for nonspecific determinations of infection, but also make a culture of maternal blood to specifically look for the bacteria. Sometimes one will also be done to make a culture and be able to determine if it is contaminated by listeria or not.

What can we do if we have listeriosis?

Being a bacterium and not a virus, we can use antibiotics as a treatment. But since it is a bacterium that is inside the cells, intracellular, we must administer high doses of antibiotics intravenously, that is, in a serum, for at least seven days and can last up to 14 days. Specialist in gynecology and obstetrics