2011 Acanthamoeba Keratitis Outbreak Investigation

Acanthamoeba keratitis (AK) is a rare and debilitating eye infection that can result in permanent visual impairment or blindness. CDC has been monitoring AK infections since a 2007 AK outbreak investigation that resulted in a recall of a contact lens solution 1.

As a response to reports of elevated numbers and unusual clusters of AK infections, CDC and other federal, state, and local public health partners started an investigation in March 2011. The purpose of this investigation was to identify common risk factors for AK that could be modified to prevent new AK infections from occurring.

CDC staff, state health officials, and local health officials conducted standardized telephone interviews of 167 people with AK from 36 states and Puerto Rico, their treating ophthalmologists, and their primary eye care providers. Additionally, 163 contact lens users 12 years of age and older who never had AK were also interviewed to better understand why some people get AK and others do not.

Preliminary analyses identified an association with wearing contact lenses and contact lens hygiene practices but did not reveal the need to recall any particular contact lens-associated products. At this time, CDC has communicated these findings to regulatory agencies (e.g., FDA). Based on these findings, public health and clinical professionals should increase awareness among the general public and healthcare providers about the disease, treatment, and important contact lens hygiene practices to prevent new infections and improve the health outcomes of those with current infections. Contact lens wearers can reduce their risk for AK by practicing appropriate contact lens hygiene.

More Information

1. Yoder JS, Verani J, Heidman N, Hoppe-Bauer J, Alfonso EC, Miller D, Jones DB, Bruckner D, Langston R, Jeng BH, Joslin CE, Tu E, Colby K, Vetter E, Ritterband D, Mathers W, Kowalski RP, Acharya NR, Limaye AP, Leiter C, Roy S, Lorick S, Roberts J, Beach MJ. Acanthamoeba keratitis: The Persistence of Cases Following a Multistate Outbreak. Ophthalmic Epidemiol. 2012;19(4):221-5.