Reactive Arthritis Incident Estimates from Four Foodborne Pathogens

Introduction:   Reactive Arthritis (ReA) is an inflammatory arthritis caused by certain Gram-negative foodborne and venereal infections. While foodborne illness associated ReA affects males and females with the same frequency, the postvenereal form occurs at a male to female ratio of 9:1. These bacteria, or their DNA components, have been found in the synovial tissue or fluid of persons suffering with ReA. Gastrointestinal infections, even minor, precede arthritis symptoms usually by 1 – 6 weeks.

Purpose: The incidence of ReA post-enteric infection is not well understood or defined, the overall attack rate of foodborne illness associated ReA ranges from 1.5% to 30%. Lack of a clear disease definition and specific diagnostic criteria for ReA makes epidemiologic studies problematic. 

Methods: This analysis looked at published studies of ReA for four bacterial foodborne infections. Shigella, Yersinia, Salmonella, and Campylobacterincident rates are estimated for 2010 through data collected by FoodNet sites. Incidence of ReA for 2010 are approximated using: census estimates for 2010, FoodNet incident rates of illness, and studied outcomes of specific cohorts infected with those 4 bacterial infections.

Results:   Results approximate that ReA is a public health burden of significant consequence affecting as few as 4,616 individuals annually in the United States or upwards of 19,257. Given that ReA can affect 50% of cases chronically, 12,000 people may annually contract the chronic form. This is a conservative estimate, since some studies suggest 63% will develop chronic complications of ReA.

Significance: Increased recognition of the severity and incidence of ReA following foodborne infection, may prompt improved treatment of the initial infection with antibiotics, thus dramatically alter the subsequent attack rate of ReA.