High prevalence of streptococcal or Epstein-Barr virus infections in children with acute non-septic monoarthritis.

To investigate associations between infections and acute monoarthritis, we performed a prospective study on 32 children consecutively hospitalized and 32 age-matched controls. Among 26 (81%) children having infections, the most frequent agents were Group A ?-hemolytic Streptococcus (GAS: 53%) and Epstein-Barr virus (EBV: 37.5%). Among controls, only 5 (16%) were infected with GAS and 2 (6%) with EBV (P<0.005). The most frequently involved joints were hip in 15 children and ankle in 10 children. Our study showed that acute monoarthritis in children may be frequently associated with streptococcal or EBV infections.