News of Streptococcus endophthalmitis contamination following the intravitreal injection of Avastin (bevacizumab, Genentech) seemed to keep popping up last year, but no clear cause had been identified.

However, a recent study by researchers at the Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, seems to be hot on the trail of the culprit, at least in the Florida outbreak cases.¹

Avastin, used off-label, is as effective at treating AMD as FDA-approved Lucentis (ranibizumab, Genentech), but costs significantly less per dose.² The cost-cutting, compounding procedure is common at VA hospitals across the nation.

A lawsuit against the U.S. Department of Veterans Affairs claimed that five individuals received a bacteria-tainted shot of the drug at the VA hospital in Nashville in March 2011. The complaint asserted that bacteria-tainted bevacizumab caused blindness and brain damage in one of the patients who received the injection. At least one doctor stated that the medication became contaminated while being mixed inside the hospital pharmacy.

Other reports indicate that five patients with macular degeneration were blinded last August at the VA Sepulveda Ambulatory Care Center in California after receiving injections of Avastin believed to have come from the pharmacy at the main campus of the VA Greater Los Angeles Healthcare System.

Later that month, the FDA issued a warning that at least 12 patients in the Miami area had been infected with Streptococcus endophthalmitis from injections of the drug. Investigators traced the tainted injections to a single pharmacy that had distributed the Avastin to multiple eye clinics.

A recent report investigated the 12 patients who presented with endophthalmitis after intravitreal bevacizumab injection.¹ The injections occurred at four different locations in south Florida during one week in early July 2011. While none of the infections originated at the Bascom Palmer Eye Institute, nine patients presented to its tertiary-care ophthalmic emergency room for treatment, and three were seen in consultation.

Microbiology cultures for 10 of the patients were positive for Streptococcus mitis/oralis and seven unused syringes of bevacizumab prepared by the compounding pharmacy at the same time as those prepared for the affected patients also were positive for S. mitis/oralis. After four months of follow-up, all but one patient had counting fingers or worse visual acuity, and three required evisceration or enucleation.

Local, state and federal health department officials have been investigating the source of the contamination, but the study authors believe the most likely cause was contamination during syringe preparation at the compounding pharmacy.

1. Goldberg RA, Flynn HW, Isom RF, et al. An outbreak of Streptococcus endophthalmitis after intravitreal injection of bevacizumab. Am J Ophthalmol. 2012 Feb;153(2):204-08.
2. CATT Research Group, Martin DF, Maguire MG, et al. Ranibizumab and bevacizumab for neovascular age-related macular degeneration. N Engl J Med. 2011 May 19;364(20):1897–1908.