Serratia marcescens endophthalmitis associated with intravitreal injections of bevacizumab

Purpose To report two cases of Serratia marcescens endophthalmitis related to presumed aliquot drug contamination, and to determine the incidence of acute endophthalmitis after intravitreal injection of bevacizumab. Methods A retrospective chart review of 2020 consecutive intravitreal bevacizumab injection (IVBI) cases at the three affiliated hospitals of Seoul National University (A, B, and C) was carried out between 12 October 2006, and 31 January 2008. Bevacizumab was retrieved multiple times from a single original vial as needed and then discarded on the same day at hospital A and C, or prepared as a single dose aliquot vial at a compounding pharmacy in the hospital B. Results The incidence of endophthalmitis after IVBI was 2/2020 (0.099%). Two patients receiving IVBI on the same day, but by different surgeons in different sites in hospital B, developed acute endophthalmitis. S. marcescens was isolated from the vitreous sample of the two patients. Molecular typing with pulsed field gel electrophoresis showed that the organisms were of the same strain, which suggested that the drug was contaminated at the pharmacy. Conclusions Endophthalmitis is a rare complication after IVBI and can be caused by contaminated aliquot drug. Serratia is one of the causative organisms of acute endophthalmitis, which can have devastating consequences, despite the treatment. A compounding pharmacy in a hospital might not be able to guarantee that aliquoted drug is free of contamination for the IVBI.