• Open Access

Parkinson’s disease or Parkinson symptoms following seasonal influenza

Authors

  • Stephen Toovey,

    1. Division of Infection and Immunity, Royal Free and University College Medical School, Academic Centre for Travel Medicine and Vaccines, London, UK
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  • Susan S. Jick,

    1. Boston Collaborative Drug Surveillance Program, Boston University Medical Center, Lexington, MA, USA
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  • Christoph R. Meier

    1. Boston Collaborative Drug Surveillance Program, Boston University Medical Center, Lexington, MA, USA
    2. Basel Pharmacoepidemiology Unit, Division of Clinical Pharmacy and Epidemiology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
    3. Hospital Pharmacy, University Hospital Basel, Basel, Switzerland
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  • This work was funded by an unrestricted grant from F. Hoffmann – La Roche.

Professor Christoph R. Meier, PhD, MSc, Basel Pharmacoepidemiology Unit, Hospital Pharmacy, University Hospital Basel, Spitalstrasse 26, CH - 4031 Basel, Switzerland. E-mail: meierch@uhbs.ch

Abstract

Please cite this paper as: Toovey S et al. (2011) Parkinson’s disease or Parkinson symptoms following seasonal influenza. Influenza and Other Respiratory Viruses 5(5), 328–333.

Background  Influenza may cause neurological sequelae and has been associated with encephalitis lethargica, an entity displaying Parkinson’s disease (PD) signs and symptoms that followed the 1918 influenza pandemic. We studied the association between diagnosed influenza and idiopathic PD or Parkinson symptoms (PS) not followed by a firm PD diagnosis.

Methods  We used the UK-based General Practice Research Database to perform a case–control analysis. We identified cases who developed an incident diagnosis of PD or PS between 1994 and March 2007, and we matched four controls on age, gender, general practice, calendar time, and history in the database to each case. We calculated odds ratios (OR) with 95% confidence intervals (CI) using conditional logistic regression to assess the relative risk of developing PD or PS in association with previous influenza diagnoses.

Results  We identified 3976 PD cases and 18 336 PS cases. The risk of developing PD was not associated with previous influenza infections. However, PS was associated with recent influenza (last infection 0–29 days: OR 3·03, 95% CI 1·94–4·74; 30–364 days: OR 1·36, 95% CI 1·14–1·63), number of influenza episodes (1 attack: OR 1·20, 95% CI 1·12–1·28; 2 attacks: OR 1·52, 95% CI 1·28–1·81; ≥3 attacks: OR 2·00, 95% CI 1·45–2·75), and severity of preceding influenza infections (≥1 severe attack: OR 1·45, 95% CI 1·25–1·68).

Conclusions  Influenza is associated with PD-like symptoms such as tremor, particularly in the month after an infection, but not with an increased risk of developing idiopathic PD.

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