Saturday, January 28, 2012

Guillain-Barré syndrome

First, a pregnancy update:

Last week I went with Holly to her appointment with the midwife where we heard the baby's heartbeat for the first time. Holly is starting to show a little, and this morning I was able to feel the top of her womb. She'll have another ultrasound in a few weeks. Holly has had some occasional queasiness, but no serious morning sickness. So, everything is going very well!

Guillain-Barré syndrome:

Guillain-Barré syndrome (GBS) is an inflammatory disorder of peripheral nerves, causing muscle weakness and sensory changes (tingling or burning sensation and/or pain). About 70% of cases are preceded by a ‘trigger’ event, usually occurring 1 to 3 weeks before the onset of symptoms. One of the most common trigger events is an upper respiratory infection - including influenza.

The incidence (number of new cases) of GBS is estimated to be 1.8 per 100,000 population per year. In the United States, there around 6,000 new cases of GBS every year.

In 1976, there was an increase in the incidence of GBS among the recipients of the 'swine flu' vaccine of about 1 case per 100,000 vaccine recipients. In 2004 the Institute of Medicine concluded that there was sufficient evidence of a causal relationship between the 1976 'swine flu' vaccine and GBS, but the reason has not been determined.

Since 1976, vaccine production methods have changed, resulting in fewer side effects. Most studies have found no association between GBS and influenza vaccines manufactured after 1976, but a few studies suggest that there may be an additional one case of GBS per one million influenza vaccine recipients. Since influenza is a trigger event for GBS, a protective effect from the vaccine against GBS cannot be ruled out.

When considering the possible side effects of a vaccine, it's important to consider the risk versus the benefits. The attack rate for influenza during flu season is 10% to 40%. In contrast to a possible 1 additional case of GBS per one million vaccine recipients, the hospitalization rate for 2009 H1N1 was 222 per one million and the death rate was 9.7 per one million cases. Pregnant women are at much higher risk for hospitalization and death from influenza than the general population. GBS is a condition from which most people completely recover.

I've never bought a lottery ticket because the probability of winning is low. I don't worry about GBS when I take a flu vaccine because the probability of developing GBS as a result is either nonexistent or extremely low. I'm much more likely to miss work or be hospitalized because of the flu.

References:

Centers for Disease Control and Prevention. (2010). Preliminary results: surveillance for Guillain-Barré syndrome after receipt of influenza A (H1N1) 2009 monovalent vaccine – United States, 2009-2010. Morbidity and Mortality Weekly Report, 59(21), 657-661. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5921a3.htm.
Centers for Disease Control and Prevention. (2011). Guillain-Barré syndrome (GBS): questions & answers. http://www.cdc.gov/flu/protect/vaccine/guillainbarre.htm.
Haber, P., DeStefano, F., F., Angulo, F. J., Iskander, J., Shadomy, S. V., Weintraub, E. et al. (2004). Guillain-Barré syndrome following influenza vaccination. JAMA, 292(20), 2478-2481. http://jama.ama-assn.org/content/292/20/2478.full.
Harati, Y. & Bosch, E. P. (2008) Disorders of peripheral nerves. In W. G. Bradley, R. B. Daroff, G. M. Fenichel, & J. Jankovic (Eds.) Neurology in clinical practice (5th Ed.) [Electronic version].
Hughes, R. A., Charlton, J., Latinovic, R., & Guilliford, M. C. (2006). No association between immunization and Guillain-Barré syndrome in the United Kingdom 1992 to 2000. Archives of Internal Medicine, 166(12), 1301-1304. http://archinte.ama-assn.org/cgi/content/full/166/12/1301.
Grimaldi-Bensouda, L., Alpérovitch, A. Besson, G.,Vial, C. Cuisset, J. M., Papeix,C. et al. (2011). Guillain-Barré syndrome, influenzalike illness, and influenza vaccination during seasons with and without circulating A/H1N1 viruses. American Journal of Epidemiology, 174(3), 326-335. http://aje.oxfordjournals.org/content/174/3/326.full.
Juurlink, D. N., Stukel, T. A., Kwong, J., Kopp, A., McGeer, A., Upshur, R. E. et al. (2006). Guillain-Barré syndrome after influenza vaccination in adults. Archives of Internal Medicine, 166(20), 2217-2221. http://archinte.ama-assn.org/cgi/content/full/166/20/2217.
Lasky, T., Terracciano, G. J., Magder, L., Koski, C. L., Ballesteros, M., Nash, D. et al. (1998). The Guillain-Barré syndrome and the 1992 – 1993 and 1993 – 1994 influenza vaccines. New England Journal of Medicine, 339(25), 1797-1802. http://www.nejm.org/doi/full/10.1056/NEJM199812173392501.
National Research Council. (2004). Immunization safety review: influenza vaccines and neurological complications. Washington, DC: The National Academies Press. http://www.iom.edu/Reports/2003/Immunization-Safety-Review-Influenza-Vaccines-and-Neurological-Complications.aspx.
Sivadon-Tardy, V., Orlikowski, D., Porcher, R., Sharshar, T., Durand, M-C., Enouf, V. et al. (2009). Guillain-Barré syndrome and influenza virus infection. Clinical Infectious Diseases, 48(1), 48-56. http://cid.oxfordjournals.org/content/48/1/48.full.
Stowe, J., Andrews, N., Wise, L., & Miller, E. (2009). Investigation of the temporal association of Guillain-Barré syndrome with influenza vaccine and influenzalike illness using the United Kingdom General Practice Research Database. American Journal of Epidemiology, 169(3), 382-388. http://aje.oxfordjournals.org/content/169/3/382.full.
Tam, C. C., O'Brien, S. J., Petersen, I., Islam, A., Hayward, A., & Rodrigues, L. C. (2007). Guillain-Barré syndrome and preceding infection with Campylobacter, influenza, and Epstein-Barr virus in the General Practice Research Database. PLoS ONE 2(4), e344. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0000344.
Vellozzi, C., Burwen, D. R., Dobardzic, A., Ball, R., Walton, K., & Haber, P. (2009). Safety of trivalent inactivated influenza vaccines in adults: background for pandemic influenza vaccine safety monitoring. Vaccine, 27(15), 2114-2120. doi.org/10.1016/j.vaccine.2009.01.125


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2 comments:

  1. Don PlummerJanuary 28, 2012 at 4:00 PM

    My wife has had GBS symptoms before; therefore, nobody will give her a flu shot. Is there an additional risk of a recurrence of GBS that rules out giving her a shot?

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    Replies
    1. Matthew RollossonJanuary 28, 2012 at 5:45 PM

      Thanks Don - that's a great question.

      A history of GBS is a precaution, but not an absolute contraindication, to receiving a flu vaccine.

      It is not known whether a flu vaccine increases the risk of a recurrence of GBS but, as a precaution, people who have had GBS within 6 weeks of receiving a flu vaccine and are not at high risk for severe flu complications should usually not receive a flu vaccine.

      The CDC recommendation does not advise against giving a flu vaccine to someone who had GBS that did not occur within 6 weeks of receiving a flu vaccine.

      For people who are at high risk for complications of the flu, the benefits of receiving a flu vaccine may outweigh the risks.

      An alternative for people who cannot receive a flu vaccine is antiviral prophylaxis.
      http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5908a1.htm
      http://www.cdc.gov/flu/about/qa/flushot.htm#whoshouldnot

      People at high risk for complications of flu include pregnant women, children under 5 years of age, adults over 65 years of age, and people with chronic medical conditions.
      http://www.cdc.gov/flu/about/qa/flushot.htm#high-risk

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