Risk of Guillain-Barre syndrome following herpes zoster, United States, 2010-2018

Epidemiologic data regarding the risk of Guillain-Barre syndrome (GBS) following herpes zoster (HZ) are limited. We conducted a self-controlled case series analysis using two large national data sources to evaluate the risk of GBS following HZ among U.S. adults. We analyzed medical claims from the IBM (R) MarketScan (R) Commercial Claims and Encounters (persons 18-64 years during 2010-2018) and Centers for Medicare and Medicaid Services Medicare (persons >= 65 years during 2014-2018) databases. HZ cases were defined as persons with an outpatient claim with a primary or secondary ICD-9 or ICD-10 diagnostic code for HZ. GBS cases were defined as persons with an inpatient claim with a principle diagnostic code for GBS and an associated procedural code. We compared the rates of GBS following HZ in the 1-42-day risk window versus primary (100-365-day) or secondary (43-99-day) control windows. We identified 489,516 persons 18-64 years of age and 650,229 persons >= 65 years of age with HZ, among whom 11 and 41, respectively, developed GBS 1-365 days following HZ. The risk of GBS following HZ was increased during the risk window as compared to the primary control window for both groups, with a rate ratio of 6.3 (95% CI, 1.8-21.9) for those 18-64 years and 4.1 (95% CI, 1.9-8.7) for those >= 65 years. This study provides new and methodologically rigorous epidemiologic support for an association between HZ and GBS, and useful context regarding the benefits versus potential risks of zoster vaccination.