Enhanced surveillance of Guillain-Barré syndrome during the influenza pandemic

In collaboration with:
Association of British Neurologists (British Neurological Surveillance Unit)
British Society for Clinical Neurophysiology
GBS Support Group
British Paediatric Surveillance Unit

An increased risk of Guillain-Barré syndrome (GBS) after influenza-like illness has been identified and it is essential that this risk is assessed during the current pandemic.  Although it has been shown that there is no risk of GBS after seasonal influenza vaccines, one swine flu vaccine used in the United States in 1976 saw one extra case of GBS with every 100,000 doses of vaccine. Due to this, GBS has been highlighted as a possible adverse event needing enhanced surveillance.

In order to rapidly inform national and international policy on the risks of the disease and safety profile of swine influenza vaccines, a 'real time' surveillance system is needed. Reporting every case of GBS irrespective of vaccination or disease history is essential for conducting robust epidemiological analyses capable of identifying whether there is an increased risk of GBS in defined time periods after vaccination, or after influenza itself, compared with the background risk.

If swine influenza itself causes GBS, the onset is likely to be too late to be able to confirm cases by detecting virus in a throat swab. However, antibody tests taken some weeks after infection can be informative. If negative, they can exclude prior swine flu infection and if positive we can compare the proportion positive among GBS patients and age-matched controls to identify the contribution, if any, that swine flu has made to GBS occurring during the winter months.

We therefore request that from August onwards a blood sample is taken from all GBS cases and sent to the Respiratory Virus Unit for swine flu antibody testing, at no cost to your hospital.

Letter explaining the process of serum sample collection (PDF, 34 KB)

Request Form E15: Swine-Lineage Influenza A (H1N1) Serology (PDF, 82 KB)

Last reviewed: 25 November 2009