Neonatal listeriosis presenting in the first week has a high mortality. About 20% of fetuses infected with Listeria (Listeria monocytogenes) are stillborn.
The liquor can be stained, and this can be mistaken for meconium.
Reservoir:
- gastrointestinal tracts of humans, birds, cattle, sheep and other animals
- widespread in the environment: soil, vegetation, water, silage/sewage, mammal/fish/bird faeces
- occurs in raw foods, food components and ready-to-eat foods: most commonly in foods because of contamination from sites in food production environments
Epidemiology:
- listeriosis is a rare but severe systemic infection that includes bacteraemia, meningitis and encephalitis and in pregnant women can lead to miscarriage and stillbirth
- most often affects those who have a weakened immune system including pregnant women, their unborn and newborn infants, the elderly and individuals who are immunocompromised by a pre-existing medical condition or treatments for an existing illness
- occasionally, healthy people can become infected
- listeriosis has a high mortality rate of 20-30% and in the UK is the most common cause of death from a foodborne illness. The annual number of laboratory-confirmed cases of listeriosis averaged 180 a year between 2005-14
Transmission:
- majority of cases are foodborne. Cases and outbreaks have been associated with a variety of foodstuffs, the most common in England and Wales being pre-prepared sandwiches but other foods have included soft cheeses, cooked and processed meats (e.g. pâté and sliced meat), smoked fish, butter, olives and melon in the US
- mother-to-baby transmission is important:
- in utero transmission,
- vertical transmission during birth, or
- person-to-person spread soon after delivery
- direct contact with infected animals can occasionally cause infection
- pregnant women, individuals who are immunocompromised and those (< 1 month and >60 years of age) are more susceptible to infection
- L. monocytogenes can be present in the faeces of approximately 5% of the population but is likely to be transitory
Incubation period
- For invasive disease, the incubation period ranges from 1-70 days
Infectivity:
- Not applicable except at and shortly after delivery due to contact (hand or fomites) from an infected infant to an apparently healthy infant who develops meningitis
Guidance for management of meningitis if the causative organism has been identified as Listeria monocytogenes (2)
- for meningitis caused by Listeria monocytogenes:
- give intravenous amoxicillin or ampicillin for 21 days
- get advice from an infection specialist on adding intravenous co-trimoxazole for the first 7 days
- after 21 days, stop antibiotics if the person has recovered, or get advice from an infection specialist if they have not
Reference:
- PHE (2019). Recommendations for the Public Health Management of Gastrointestinal Infections
- NICE (March 2024). Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management