Health officials scramble to find source of fungal keratitis cases

Atlanta-With a growing list of states reporting suspected cases of an uncommon fungal keratitis, the Centers for Disease Control and Prevention (CDC) and other U.S. health authorities continue to search for the cause of an apparent outbreak of the rare fungal infection among soft contact-lens wearers.

As of late April, the CDC had confirmed 54 cases of keratitis caused by the Fusarium fungus over the past 10 months, with eight possible cases and 114 more still under investigation. The total of 176 suspected cases are being reported from 26 states and Puerto Rico. Eight patients have required corneal transplants.

The outbreak is baffling medical experts because it seems to have appeared suddenly-in the United States, Singapore, and Hong Kong-with little indication as to its cause.

The majority of confirmed cases are being linked to the use of Bausch & Lomb's ReNu with MoistureLoc Multi-Purpose Solution, although some have involved other brands. Of the first 30 confirmed cases, 28 patients wore soft contact lenses, and 26 of those remembered using Bausch & Lomb's ReNu brand contact lens solution in the month before infection. The most current figures were unavailable at press time.

However, thorough testing of the ReNu bottles used in confirmed cases-as well as the Greenville, SC, plant where the product is manufactured-has failed to find the source for the fungal keratitis.

"We have gone to the point of retrieving open bottles from consumers who have had complications, who have had a Fusarium infection. We have tested that product, and in every case the open product is still efficacious," Zarella said.

Meanwhile the FDA and the CDC are continuing joint inspections of the Green-ville plant, which ships ReNu with MoistureLoc to the United States, Southeast Asia, and Korea. FDA officials cautioned in an April 21 update that extensive microbiological testing might take up to 1 month to analyze fully. A CDC researcher said the situation is receiving intense scrutiny by his agency.

Dr. Chang urged ophthalmologists to consider fungal keratitis early on when presented with symptoms of an ocular infection and called this apparent outbreak "the largest I have personally experienced."