BPSU - Listeria infection in infants <90 days

Surveillance of listeria infection in infants <90 days is due to commence in September 2017. The study aims to define the incidence of listeria infection in young infants, define whether some ethnic groups or geographical areas are more affected and describe the management and clinical outcome of the infected babies in the UK and Ireland. Data will be cross checked with the national public health laboratories to ensure all cases are captured. Results from the study will inform national antibiotic policy for young infants.

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Lead investigator

Dr Stefania Vergnano
Bristol Royal Hospital For Children

Level 6, UBHT Education Centre
Upper Maudlin Street, 
Bristol BS2 8AE
Professor Paul T Heath,
Professor of Paediatric Infectious Diseases,
Paediatric Infectious Diseases Research Group, Division of Clinical Sciences, Jenner Wing, Level 2, Room 2.213
St Georges, University of London,
London, SW17 0RE


Listeria is a rare bacterial infection that affects mostly immunocompromised individuals, including young babies. Pregnant women can become infected by eating contaminated food, such as fresh cheese and unpasteurised milk, and may then pass on the infection to their unborn babies, causing miscarriages, stillbirths or severe disease with high mortality and neurodevelopmental consequences in newborns. Currently the exact epidemiology and clinical outcome are not clear and it is possible that the infection is becoming more common in selected ethnic groups.

Current national guidelines (e.g. the NICE guidelines), advising doctors on antibiotic treatment for babies younger than 3 months, recommend an antibiotic combination that will treat listeria infection. However, a recent national study of meningitis showed listeria only in babies younger than 1 month, raising the possibility that the current guidelines may be exposing thousands of babies between 2 and 3 months of age to unnecessary additional antibiotics.

The study aims to establish the incidence of proven and possible listeria, age, geographical, and ethnic distribution, management and outcome at diagnosis and at one year follow up. This data will inform national antibiotic policies for infants under 90 days and prevention strategies in pregnancy.

Case definition

Please report any infant of 90 days of age or less with a clinical diagnosis of invasive listeria infection according to the treating clinician or with suspected listeria infection treated for at least 5 days with appropriate antibiotics.


September 2017 to September 2019 (25 months of surveillance). Follow-up until September 2020 (12 month follow-up).


This study is being funded through St George’s University of London. 

Ethical approval

This study has been approved by Yorkshire and the Humber – South Yorkshire REC (REC reference: 16/YH/0491) and has been granted Section 251 HRA-CAG permission (CAG Reference: 17/CAG/0029).

This study has been granted Public Benefit and Privacy Panel for Health and Social Care (PBPP) approval in Scotland (PBPP reference: 1516-0292).

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