Incidence of <i>Campylobacter</i> -Associated Guillain-Barré Syndrome Estimated from Health Insurance Data

Abstract

Guillain-Barré syndrome (GBS) is sometimes preceded by <i>Campylobacter</i> infection. We estimated the cumulative incidence of <i>Campylobacter</i>-associated GBS in the United States using a retrospective cohort design. We identified a cohort of patients with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis code of "intestinal infection due to <i>Campylobacter</i>" (008.43) using MarketScan Research Databases for 2004-2013. <i>Campylobacter</i> patients with an encounter for "acute infective polyneuritis" (AIP; ICD-9-CM 357.0) were identified. Patients with an inpatient encounter having AIP as the principal diagnosis were considered probable GBS cases. Patients with probable GBS ≤8 weeks after the <i>Campylobacter</i> encounter were considered probable <i>Campylobacter</i>-associated GBS cases. For comparison, we repeated this analysis for patients with "other <i>Salmonella</i> infections" (ICD-9-CM: 003). Among 9315 <i>Campylobacter</i> patients, 16 met the case definition for probable GBS. Two were hospitalized with probable GBS ≤8 weeks after the encounter listing a <i>Campylobacter</i> diagnosis (9 and 54 days) and were considered probable cases of <i>Campylobacter</i>-associated GBS; this results in an estimated cumulative incidence of 21.5 per 100,000 <i>Campylobacter</i> patients (95% confidence interval [CI]: 3.7-86.6), or 5% of all estimated GBS cases. The remaining 14 patients were diagnosed with probable GBS on the same encounter (<i>n</i> = 12) or 1-3 days (<i>n</i> = 2), before the encounter listing the <i>Campylobacter</i> diagnosis. Including these cases increased the cumulative incidence to 172 per 100,000 <i>Campylobacter</i> cases (95% CI: 101.7-285.5), 41% of estimated GBS cases. This study, using a method not previously applied to United States data, supports other data that <i>Campylobacter</i> is an important contributor to GBS, accounting for at least 5% and possibly as many as 41% of all GBS cases. These data can be used to inform estimates of the burden of <i>Campylobacter</i> infections, including economic cost.