OT:Occ-Env-Med -Acanthamoeba Keratitis - US, 2005-7

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Acanthamoeba Keratitis - US, 2005-7

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm56d526a1.htm?

s_cid=mm56d526a1_e

http://www.cdc.gov/mmwr/PDF/wk/mm56d526.pdf

Acanthamoeba Keratitis --- Multiple States, 2005--2007

In May 2006, the Illinois Department of Public Health (IDPH) informed

CDC about a possible increase in Acanthamoeba keratitis (AK) at an

ophthalmology center in Illinois during the preceding 3 years. The

University of Illinois at Chicago (UIC) was investigating this

possible increase. In October 2006, IDPH updated CDC about the

ongoing

UIC investigation. At that time, CDC informally contacted multiple

ophthalmology centers in the United States to assess whether the

potential increase in cases extended beyond Illinois. Responses from

the ophthalmology centers were inconclusive. In January 2007, CDC

initiated a retrospective survey of 22 ophthalmology centers

nationwide to assess whether cases were increasing throughout the

United States. In March 2007, data received from 13 centers

demonstrated an increase in culture-confirmed cases of AK with wide

geographic distribution. The increase in cases had begun in 2004 and

continued to the present. On March 16, 2007, CDC initiated a

multistate investigation to look for risk factors associated with

this

increase in AK cases. This report summarizes recent preliminary

results of that investigation, which, indicated an association with

AK

in soft contact lens wearers who used Advanced Medical Optics (Santa

Ana, California) Complete® MoisturePlus™ (AMOCMP) multipurpose

cleaning solution. CDC and the Food and Drug Administration (FDA) are

taking steps to notify the public and the medical and public health

communities of this preliminary association. The manufacturer has

undertaken a voluntary recall of the product.

AK, a rare but potentially blinding infection of the cornea, is

caused

by a ubiquitous, free-living ameba (Acanthamoeba) that is found

commonly in the environment, including water (e.g., tap and

recreational water), soil, sewage systems, cooling towers, and

heating/ventilation/air conditioning (HVAC) systems. AK primarily

affects otherwise healthy persons who wear contact lenses; an

estimated 85% of U.S. cases occur in contact lens wearers (including

wearers who follow recommended contact lens-care practices) (1).

Persons who improperly store, handle, or disinfect their lenses

(e.g.,

by using tap water or homemade solutions for cleaning); swim, use hot

tubs, or shower while wearing lenses; come in contact with

contaminated water; have minor damage to their corneas; or have

previous corneal trauma are at increased risk for infection (2).

Based

on an analysis of cases reported to CDC during 1985--1987, the

incidence of AK in the United States has been estimated at one to two

cases per million contact lens users (3,4). An estimated 30 million

persons in the United States wear soft contact lenses (5).

Initial case finding for this investigation was facilitated through

postings on the Epidemic Information Exchange (Epi-X), on

ophthalmology/optometry/infection control listservs and websites, and

through queries of clinical microbiology laboratories. As of May 24,

2007, a total of 138 patients with onset of symptoms on or after

January 1, 2005, and positive Acanthamoeba cultures from corneal

specimens had been reported to CDC by public health authorities and

ophthalmologists from 35 states and Puerto Rico. Standardized

telephone interviews of patients, ophthalmologists, and primary

eye-care providers are being conducted by state and local health

officials and CDC. Laboratory testing of clinical specimens, contact

lenses, bottles of solution, and contact lens cases received from AK

patients, including typing of Acanthamoeba spp. isolates, is ongoing.

An initial analysis was conducted using data from the first 46

completed patient interviews.

Among the 46 culture-confirmed patients who were interviewed, the

median age was 40 years (range: 15--77 years); six (13%) were aged

<18

years. Twenty-seven (59%) were female. Of the 37 of these patients

for

whom clinical data were available, medical therapy was unsuccessful

for nine (24%), and they were required or expected to undergo corneal

transplantation. Of the 46 patients, 39 (85%) wore soft contact

lenses, three (7%) wore rigid lenses, and four (9%) reported no

contact lens use. Among the 42 contact lens users, 16 (38%) reported

swimming while wearing contact lenses and 35 (83%) reported showering

while wearing contact lenses during the month before symptom onset.

Among the 39 soft contact lens users, 36 reported using one or more

specific types of contact lens solution, 21 of these (58%) reported

any use of AMOCMP in the month before symptom onset, 20 (56%)

reported

using AMOCMP as their primary solution, and 14 (39%) reported using

AMOCMP as their exclusive solution. Exposure data from the 36

patients

who wore soft contact lenses and used any type of contact lens

solution were compared with exposure data from controls who were

interviewed as part of the 2006 CDC Fusarium keratitis outbreak

investigation (6). These controls, who were selected as

geographically

matched controls for the Fusarium keratitis cases, represented a

sample of adult soft contact lens wearers from different U.S. states

who were asked about product use and behaviors during March 2006 (6).

The 14 AK soft contact lens--wearing case-patients with symptom onset

dates before April 1, 2006 (the period most comparable to Fusarium

controls), who reported use of a single solution were compared with

115 controls from the Fusarium investigation who reported using a

single solution. The results indicated that four (29%) of the 14 AK

case-patients had used AMOCMP, compared with six (5%) of the 115

Fusarium controls (odds ratio: 7.3 [95% confidence interval (CI) =

1.7--30.1]). In a separate comparison, 36 soft contact lens--wearing

AK case-patients with symptom onset dates before May 24, 2007, who

reported use of one or more solutions were compared with 124 Fusarium

controls who reported using one or more solutions. The results

indicated that 21 (58%) of the 36 AK case-patients had used AMOCMP,

compared with eight (6%) of the 124 Fusarium controls (odds ratio:

20.3; [CI = 7.6--53.9]). AMOCMP lot numbers were available for 10

patients who reported using the solution; no single lot number was

repeated, suggesting that AMOCMP was not intrinsically contaminated.

Analysis of the reported use of other brands of contact lens solution

did not reveal any statistically significant associations.

The AK investigation by CDC, state and local health departments, FDA,

and other partners, is continuing, and interviews of the remaining

patients with culture-confirmed AK, their treating ophthalmologists,

and their primary eye-care providers are ongoing. Although the

results

of initial analyses are preliminary, they suggest that use of AMOCMP

increases the risk for AK. Additional studies will provide a more

definitive assessment of the risk associated with use of AMOCMP.

However, based on the preliminary findings, persons who wear soft

contact lenses and who use AMOCMP should 1) stop using the product

immediately and discard all remaining solution, including partially

used or unopened bottles; 2) choose an alternative contact lens

solution; 3) discard current lens storage container; 4) discard their

current pair of soft lenses; 5) see a health-care provider if they

experience any signs of eye infection, including eye pain or redness,

blurred vision, sensitivity to light, sensation of something in the

eye, or excessive tearing.

Contact lens users with questions regarding which solutions are best

for them should consult their eye-care provider. Patients should also

consult their eye-care provider if they have any of the following

symptoms: eye pain or redness, blurred vision, sensitivity to light,

sensation of something in the eye, and/or excessive tearing. AK

symptoms, which can last several weeks to months, vary among

patients.

Early in the infection, symptoms can be similar to the symptoms of

other more common eye infections; however, AK can result in vision

loss or blindness if untreated.

All contact lens wearers should follow established guidelines to help

reduce the risk for eye infections, including AK (Box). Primary-care

clinicians evaluating contact lens users with symptoms of eye pain or

redness, tearing, decreased visual acuity, discharge, sensitivity to

light,Ep: or foreign body sensation should consider the diagnosis of

AK and refer patients to an ophthalmologist, if appropriate.

Diagnosis

of AK requires a high degree of suspicion, especially in a contact

lens wearer with a recent diagnosis of another form of keratitis,

such

as herpes simplex virus keratitis, who is not responding to therapy.

Diagnosis of AK is based on clinical presentation and isolation of

organisms from corneal culture or detection of trophozoites and/or

cysts on histopathology. However, a negative culture does not

necessarily rule out Acanthamoeba infection. Confocal microscopy and

polymerase chain reaction assays to detect Acanthamoeba can also

assist with diagnosis. Early diagnosis can greatly improve treatment

efficacy.

Clinicians should consider obtaining clinical specimens (e.g.,

corneal

scrapings) for culture before initiating treatment. Clinicians or

microbiology laboratories should report cases of AK to state and

local

health departments or directly to CDC at telephone, 770-488-7775.

Acanthamoeba isolates should be submitted to state laboratories

according to instructions provided by local and state public health

laboratories. Public inquiries should be made via telephone

800-CDC-INFO. Further information regarding Acanthamoeba infections

is

available at http://www.cdc.gov/ncidod/dpd/parasites/acanthamoeba

/index.htm

Reported by: K , J Bugante Los Angeles County Health Dept; T

Chang, DVM, S Chen, MPH, J Rosenberg, MD, California Dept of Health

Svcs. R Hammond, PhD, K McConnell, MPH, R on, MA, Florida Dept

of Health. J Elm, MS, M Nakata, C Wakida, Hawaii Dept of Health. C

Austin, DVM, J Bestudik, MG Bordson, C Conover, MD, Illinois Dept of

Public Health. L Granzow, MPH, Indiana Dept of Health. A Pelletier,

MD, V Rea, MPH, Maine Dept of Health and Human Svcs. A Chu, MHS, E

Luckman, MPH, land Dept of Health and Mental Hygiene. K Signs,

DVM, Michigan Dept of Community Health. J Harper, MS, Minnesota Dept

of Health. T Damrow, PhD, E Mosher, Montana Dept of Public Health and

Human Svcs. K Kruger, North Dakota Dept of Health. E Saheli, MPH,

Ohio

Dept of Health. M Cassidy, J Hatch, Oregon Public Health Div, Dept

Human Svcs. A Weltman, MD, Pennsylvania Dept of Health. EJ

, MD, Y , MPH, Puerto Rico Dept of Health. MA Kainer, MD,

Tennessee Dept of Health. J Archer, MS, Wisconsin Dept of Health and

Family Svcs. C Joslin, OD, Univ of Illinois Chicago. P Cernoch,

Methodist Hospital of Houston; D MD, M Hamill MD, A Matoba MD,

S

Pflugfelder MD, K Wilhelmus, MD, Baylor College of Medicine, Texas. S

Beavers, MD, T Chen, MD, K Christian, DVM, M , MD, D Dufficy,

DVM, M Gershman, MD, M Glenshaw, PhD, A Hall, DVM, S Holzbauer, DVM,

A

Huang, MD, A Langer, DVM, Z , MD, AS Patel, PhD, LR Carpenter,

DVM, J Schaffzin, MD, J Su, MD, I Trevino, DVM, T Weiser, MD, P

Wiersma, MD, S Lorick, DO, JR Verani, MD, EIS officers, CDC.

Acknowledgments

The findings in this report are based, in part, on contributions by M

Bonhomme, N Pressly, M Robboy, OD, J Saviola, OD, E Woo, Food and

Drug

Admin. MJ Beach, PhD, C Braden, MD, S Brim, MA, D Chang, MD, F Chow,

A

daSilva, PhD, AJ Deokar, MPH, R Greco Kone, MPH, S ston, MS, AS

Kusano, MS, B Park, Y Qvarnstrom, PhD, MD, S Persaud, S Roy, MD, G

Visvesvara PhD, D Wagner, K Wannemuehler, MS, JS Yoder, MPH, National

Center for Zoonotic, Vector-Borne, and Enteric Diseases, CDC.

References

1. Stehr-Green JK, TM, Brandt FH, Carr JH, Bond WW, Visvesvara

GS. Acanthamoeba keratitis in soft contact lens wearers: a

case-control study. JAMA 1987;258:57--60.

2. Parmar DN, Awwad ST, Petroll WM, Bowman RW, McCulley JP, Cavanagh

HD. Tandem scanning confocal corneal microscopy in the diagnosis of

suspected Acanthamoeba keratitis. Ophthalmology 2006;113:538--47.

3. Schaumberg DA, Snow KK, Dana MR. The epidemic of Acanthamoeba

keratitis: where do we stand? Cornea 1998;17:3--10.

4. Stehr-Green JK, TM, Visvesvara GS. The epidemiology of

Acanthamoeba keratitis in the United States. Am J Ophthalmol

1989;107:331--6.

5. US Environmental Protection Agency. Do you wear contact lenses?

There's something you should know. Available at

http://www.epa.gov/waterscience/acanthamoeba.

6. Chang DC, Grant GB, O'Donnell K, et al. Multistate outbreak of

Fusarium keratitis associated with use of a contact lens solution.

JAMA 2006;296:953--63.

BOX. Guidelines for contact lens users to help reduce their risk for

eye infections

• Visit your eye-care provider for regular eye examinations.

• Wear and replace contact lenses according to the schedule

prescribed

by your eye-care provider.

• Remove contact lenses before any activity involving contact with

water, including showering, using a hot tub, or swimming.

• Wash hands with soap and water and dry before handling contact

lenses.

• Clean contact lenses according to the manufacturer's guidelines and

instructions from your eye-care provider.

— Use fresh cleaning or disinfecting solution each time lenses are

cleaned and stored. Never reuse or top off old solution.

— Never use saline solution and rewetting drops to disinfect lenses.

Neither solution is an effective or approved disinfectant.

• Store reusable lenses in the proper storage case.

— Rinse storage cases with sterile contact lens solution (never use

tap water) and leave open to dry after each use.

— Replace storage cases at least once every 3 months.