Listeriosis is a foodborne infectious disease mainly due to ingestion of food contaminated by Listeria monocytogenes. Clinical manifestations in human listeriosis can range from gastroenteritis to serious systemic infections, such as septicemia, central nervous system invasion, and maternal–fetal infection. The fatality rate of listeriosis is high, ranging from 20% to 35%, despite of antimicrobial therapy.

To early detect outbreaks of listeriosis, Centers for Diseases Control and Prevention (CDC) in USA added L. monocytogenes into surveillance under PulseNet ( 1998. Listeriosis has become a notifiable infectious disease in Taiwan since 2018. In USA, approximately 2,500 people become seriously ill with listeriosis annually, and about 500 die. In 2014, 2,194 confirmed cases of listeriosis were reported by 28 European Union (EU)/European Economic Area (EEA) countries. Recently, the listeriosis outbreak in South Africa, approximately 1000 confirmed cases and 180 deaths, is the largest ever of the disease linked to food poisoning. The infection is most likely to sicken pregnant women and their newborns, elderly, and people with weakened immune systems.