Epidemiological investigation of a maternal Listeria monocytogenes ST2 infection case

Abstract

On September 26, 2024, a municipal hospital in Jiaxing City reported a maternal case of Listeria monocytogenes infection. In order to clarify the source of infection, the Jiaxing Center for Disease Control and Prevention immediately conducted the epidemiological investigation, laboratory testing and related disposal work. The case presented with fever (37.9 ℃), gradually intensifying paroxysmal abdominal pain without obvious cause, and went to hospital on the day of onset. Due to fetal intrauterine distress, a male infant was delivered by cesarean section on the same day. The epidemiological investigation identified that the case usually consumed fruits, often store fruits such as watermelon and grapes in the refrigerator alongside raw meat, and the refrigerator had never been cleaned or disinfected, posing a risk of cross contamination. Laboratory tests on amniotic fluid sample from the pregnant woman, infant blood sample showed positive results for Listeria monocytogenes infection. One strain of Listeria monocytogenes was detected in a smear sample from the inner wall of the refrigerator, and all the strains were ST2 type. Consuming fruits contaminated with Listeria monocytogenes may be the main source of infection. Food safety education for pregnant women and their family members should be strengthened to reduce the risk of infection.

Keywords

• listeria monocytogenes
• pregnant woman
• cross contamination
• epidemiological investigation