LISTERIOSIS AS AN INFECTION OF PREGNANCY MANIFESTED IN THE NEWBORN
Authors: Hood Marion 
Published: December 2021

Twenty-nine listeric infections have been recognized at Charity Hospital in New Orleans in approximately a 5-year period. This represents more cases than have been reported from any other area in the United States.
Two questions concerning Listeria monocytogenes infections are posed.
1. Is Louisiana an actual endemic area of this disease?
2. Can this infection be prevented or its mortality reduced?
The following studies were pursued in an attempt to answer the first question.
As the majority of infections have been in pregnant women and newborn infants, studies were devised to test whether or not this group has latent infections that are manifested clinically under certain conditions.
Listeria monocytogenes was recovered only twice from a total of 605 cultures made on pregnant women, newborn children, stillborn infants and immature dead fetuses.
Four out of some 7,000 blood cultures made on obstetrical patients during this period showed Listeria monocytogenes; two were obtained during pregnancy and two at time of delivery.
Listeria was recovered 29 times from a total of approximately 100,000 cultures made in the bacteriology laboratory during this 5-year period, from material that might be expected to yield this organism.
These data indicate that the cases of listeriosis in this area represent incidental infections rather than clinical manifestations of an underlying endemic center of disease. Listeriosis as a general problem rather than a special one of certain endemic areas offers a challenge to all clinicians.
Answers are proposed to the second question: "Can this infection be prevented or its mortality be reduced?"
The infection in adults (other than pregnant women) and children over 1 month old is usually manifested as meningitis and should be treated accordingly. Listeria moncytogenes is almost uniformly sensitive to the antibiotics commonly used, so cure can be anticipated in uncomplicated cases.
The infection may be acquired by infants either transplacentally or from the birth canal during delivery. Transplacental infection is highly fatal and must be prevented.
A practical approach is illustrated by the two cases described in which listeria septicemia was recognized in the pregnant women before the fetuses were damaged in utero. Adequate treatment permitted one woman to deliver a normal, well, term child. Inadequate therapy given the second woman probably prevented transplacental infection of the fetus but allowed organisms to remain in the birth canal permitting infection during delivery.
Infants infected with Listeria monocytogenes during the birth process develop symptoms, usually of meningitis, in the 8-to-12-day period following delivery. If all infants born of parturient women who show signs of endometritus or sepsis could be carefully watched during this period, early infection might be recognized, cultures taken for diagnosis and antibiotic therapy instituted at once.
These procedures should prevent transplacental passage of the organism and cure infections acquired during delivery. If this could be accomplished it would materially reduce the presently high mortality of listeriosis.