Pregnant women: Pregnant women typically experience only a mild, flu-like illness. However, infections during pregnancy can lead to miscarriage, stillbirth, premature delivery, or life-threatening infection of the newborn. Previously healthy people: People who were previously healthy but were exposed to a very large dose of Listeria can develop a non-invasive illness (meaning that the bacteria have not spread into their blood stream or other body sites). Symptoms can include diarrhea and fever.If an animal has eaten food contaminated with Listeria and does not have any symptoms, most experts believe that no tests or treatment are needed, even for people at high risk for listeriosis. Cause
Listeria monocytogenes is ubiquitous in the environment. The main route of acquisition of Listeria is through the ingestion of contaminated food products. Listeria has been isolated from raw meat, dairy products, vegetables, fruit and seafood. Soft cheeses, unpasteurized milk and unpasteurised pâté are potential dangers; however, some outbreaks involving post-pasteurized milk have been reported.Rarely listeriosis may present as cutaneous listeriosis. This infection occurs after direct exposure to L. monocytogenes by intact skin and is largely confined to veterinarians who are handling diseased animals, most often after a listerial abortion.It can be more common in patients with hemochromatosis. Diagnosis
In CNS infection cases, L. monocytogenes can often be cultured from the blood or from the CSF (Cerebrospinal fluid). Prevention
The main means of prevention is through the promotion of safe handling, cooking and consumption of food.
As of 4 March 2018, with 967 people infected and 180 deaths, this was the largest listeriosis outbreak in history. The source was traced to processed meat products produced at a Tiger Brands Enterprise plant in Polokwane. 2018 Australia listeriosis outbreaks
On 2 March 2018 the New South Wales Food Authority confirmed that investigations into a listeriosis outbreak in rockmelons (cantaloupes) began in January. The cantaloupes had infected people from Victoria, Queensland, New South Wales and Tasmania, after being grown on a farm in the Riverina region of NSW.As of 2 March 2018, 13 of 15 cases had been confirmed as originating from listeria infected cantaloupes, and of the 15 people infected, 3 had died. Later victims included a fourth person on 7 March and a Victorian man in his 80s on 16 March. A miscarriage was also linked to listeriosis. Seventeen cases had been confirmed as of 7 March.In July 2018, a number of countries, including Australia, issued recalls of frozen vegetables due to Listeria. 2019 Spain listeriosis outbreak
In August 2019, an outbreak was declared in several provinces in Andalusia, southern Spain, as a result of consumption of a contaminated batch of processed-meat products. As of 19 August 2019, 80 people had been diagnosed and 56 were hospitalized (43 of them in the province of Seville),
As of 20 August, 114 people were diagnosed, and 18 pregnant woman in hospital, and the first confirmed death (a 90-year-old woman);

although the total figure of hospitalised reduced to 53. In addition, eight miscarriages have been related to the outbreak.