Fear of vCJD transmission causes U.K. to tighten sterilization codes

The stricter standards imposed by the United Kingdom are designed to prevent medical practitioners, ophthalmologists and other eye care professionals from transferring the deadly disease among patients.

LONDON — The “remote chance” of transferring the deadly variant Creutzfeldt-Jakob disease through surgical instruments, contact lenses and tonometer prisms has led the United Kingdom to tighten its regulations on eye care decontamination.

In January 2001, the Department of Health (DH) here issued a nationwide alert highlighting the possible risk of transmitting variant Creutzfeldt-Jakob disease (vCJD) through inadequately sterilized surgical instruments, specifically those used in operations on the central nervous system and the lymphatic system.

Next to neurosurgery, ophthalmology poses the greatest risk of transmission. According to a study by John Collinge, MD, a renowned expert on spongiform encephalopathies, the climate of the retina and optic nerves provides a refuge for the pathological organisms called proteinaceous infectious particles (prions) of vCJD, which can remain infective for years.

In order to prevent the spread of the disease via prion-contaminated instruments, the National Health Service (NHS) began an aggressive campaign to upgrade sterilization standards in hospitals and private practices. The program is called ProCure21. According to Health Minister John Denham, $285 million (£200 million) will be spent on improving decontamination services by 2003.

According to a press release from the NHS, the investment will fund a major overhaul to provide the most up-to-date decontamination services available and modernize sterile service departments by providing fully automated sterilizers and washer disinfectors.

It is hoped that the ProCure21 plan will help prevent the risk of transmitting the disease, but the help of surgeons and physicians is needed to conform with new codes and stricter standards in the operating room.

Getting back to standard regulations

“What this means now, during a string of procedures, is the device — like a microkeratome — will have to be manually sterilized by medical equipment personnel for an extended length of time,” said Julian Stevens, FRCOphth, of Moorfields Eye Hospital. “This procedure will take between 2 to 3 hours, but would normally take only about 20 minutes.”

In the past, hospitals have been able to save time in busy operating rooms by recycling frequently used instruments in just a few minutes. However, with the reinforcement of standards, a quick cleaning will be impossible.

According to Dr. Stevens, the law will mean a tremendous effort and expense for hospitals and practices throughout Europe.

“You’ll either have to buy more instruments for phacoemulsification and other surgeries or you’ll have to find effective disposable instruments,” he said. “Either way you look at it, it’s a totally new way of managing — a completely new cost issue.”

This sterilization method is nothing new, however, said Roger J. Buckley, MA, FRCS, FRCOphth, also of Moorfields Eye Hospital. “It’s just going back to the methods that we should have been using all along. We can’t use any abbreviated sterilization programs anymore,” he said. For the time being, shortened sterilization methods have been outlawed.

Remote risk

Mr. Denham stressed that the strict enforcement and new standards are based on the “remote chance” that vCJD may be passed from one individual to another from improperly sterilized surgical instruments.

As of March 2002, 116 deaths linked to vCJD have been reported to the DH. The first case was diagnosed in 1994. Variant CJD is the human form of bovine spongiform encephalopathy (BSE), first diagnosed in cattle in 1986.

Sporadic, or classic, CJD pathology reflects the development of vacuoles in the brain, which create a spongiform pattern in the affected brain tissue. In both sporadic CJD and vCJD, the brain-tissue degeneration leads to rapidly progressing dementia and death. Distinguishing pathological elements, however, led scientists to the conclusion that European residents contracted vCJD, or the human form of “mad cow disease,” after eating beef infected with BSE during 1985 to 1989.

Deaths have not been conclusively been linked to the ingestion of BSE-contaminated beef, and there is no proof of transmission from medical devices, or specifically from eye care instruments.

“We have no evidence of any patient being infected with vCJD in any hospital,” Mr. Denham said, “but we are still learning about the progress of the disease.”

According to Prof. Buckley, there are three potential instrument-related cases of CJD found in the ophthalmological literature, which are “not very convincing.”

“There is only one probable case, and two possible cases,” Prof. Buckley said. “But even the probable case could have been spontaneous, due to the fact that sporadic CJD can arise in one out of every 1 million people.”

Even with a small chance of contraction, it is clear that compliance with more stringent sterilization techniques is necessary to ensure that all surgeons and medical workers prevent the introduction of the fatal disease.

Slow uptake of practices

In December 2001, an audit of hospitals found that 109 of 249 surgical centers in England were employing inadequate disinfecting practices. A number of these centers were refractive surgery clinics and ophthalmology units.

“Threats of closure were made, to focus people’s minds,” Prof. Buckley said. “To a certain extent, [sterilization practices] had slipped — as many things do unless they are being constantly watched.”

Clinics are being forced to comply with the new sterilization procedures, but their practice has been slow to start, Dr. Stevens said. “Often, the issue is met with either denial or hysteria.”

According to Dr. Stevens and Prof. Buckley, many ophthalmologists, optometrists and opticians are currently reviewing their procedures.

However, there has been resistance. “People have not perceived this as a problem and find it difficult to accept as a reality,” Prof. Buckley said.

Corneal contact standards

In October 2001, the College of Optometrists and the Association of British Dispensary Opticians Medical Devices Agency issued guidance on the reuse of contact lenses and other devices that come into contact with the cornea. By law, the optometrists and dispensing opticians are now required to follow new codes when using reusable contact lenses and reusable tonometer heads.

According to the Medical Devices Agency (MDA), contact lenses should be used on one individual only. However, this is not possible for corneal and scleral diagnostic contacts, which are often reused in clinics. In these instances, medical personnel should cleanse and disinfect lenses with 2% sodium hypochlorite solution. Lenses should be soaked for 1 hour, followed by thorough rinsing in sterile saline. Lenses should then be disinfected by conventional methods — with disinfection solution storage or dry storage.

Similarly, tonometer prisms, used for measuring eye pressure, have now fallen under stricter sterilization codes. Most prisms allow for reuse 100 times before they are discarded. However, between uses, disinfection with 2% sodium hypochlorite solution at room temperature, for 1 hour, should follow cleansing with standard methods of hygiene. After soaking for 1 hour, the guidance advises rinsing the prism thoroughly in saline solution or boiled water and wiping it dry.

Lack of prion-killing agents

Sodium hypochlorite solution, the required decontamination agent for both reusable contact lenses and tonometer heads, is the only chemical agent proven to eliminate vCJD prions, according to Prof. Buckley.

“It’s actually bleach, just a household cleaner used for baby bottles and counter tops,” Prof. Buckley said. “Fortunately, it’s much more effective in destroying prions than conventional methods of sterilization like autoclaving, dry heat and irradiation.”

This is good news for optometrists and dispensing opticians. Unfortunately for ophthalmologists, sodium hypochlorite cannot be used for sterilizing metal surgical instruments.

“Many instruments will dissolve in this solution,” Prof. Buckley said. Therefore, surgical instruments are subjected to the conventional methods, which are unable to destroy CJD prions.

“We can reduce the level by a certain amount, but we can’t completely eliminate the agent,” Prof. Buckley said.

In the meantime, the government is actively searching for other compositions and methods of sterilizing metal instruments that will allow them to be reused safely, according to the NHS.

Strict codes for surgery

Fortunately, improvements can be made upon the status of sterile surgical instruments in the operating room.

“It’s possible to envision a good, safe practice, which may not be technically ideal, but is the best that we can do for the time being,” Prof. Buckley said.

The DH advises clinics to meticulously keep track of instruments and reinforce the length of sterilization time, which is often shortened in busy clinics.

According to the Royal College of Ophthalmologists in London, “All instruments that penetrate the optic nerve sheath, enucleation snares or scissors and evisceration spoons should be traceable to individual patients.” Clinics should keep a record of these instruments and never transfer them out of the building or surgical department.

Should there be any question or confirmation of a deceased or living patient having CJD or vCJD, all instruments used on that patient should be destroyed by incineration. This guidance comes from a Health Service Circular on vCJD, distributed by the NHS in December 2001.

Subsequently, all patients who were inadvertently treated with the instruments used on a sporadic CJD or vCJD patient should be identified before reports are made to a National CJD Surveillance Unit.

Between uses in healthy patients, all surgical instruments in vitreoretinal surgery, keratoplasty, cataract and refractive surgery should endure a traditional sterilization process that can be 10 or more times longer than what has become standard in operating rooms with a high patient turnover.

Future may include disposables

In order to comply with the stricter regulations, clinics will need to purchase more instruments.

Under the ProCure21 plan, at least 3,000 hospitals will be “substantially refurbished or replaced” and equipped to handle their regular amount of patients by 2004. This figure does not include practicing ophthalmologists and optometrists’ private centers.

“This money will fund the modernization of NHS decontamination facilities, but not private practices,” Mr. Denham said.

Unfortunately, there is no guarantee that every medical clinic or hospital will be adequately reimbursed for the additional tools, products and manpower needed to prevent the transmission of vCJD.

As a result, the government has turned to disposable instruments in hopes of preserving cost efficiency.

“The government is actively pursuing this route,” Prof. Buckley said. “We are currently doing a cost analysis to see how much single-use instruments would cost against the standard ones.”

In December 2001 the NHS announced that a tonsillectomy that had been performed with single-use electrosurgical diathermy forceps to avoid prion transference had led to complications that resulted in a fatal hemorrhage. This came after the government mandated that tonsil and adenoid surgery be performed with single-use instruments in January 2001.

The mandate has since been lifted, but the government remains committed to conducting pilot studies on the efficiency of single-use eye instruments.

According to the NHS, ophthalmic devices with replaceable components that come into contact with the eye will be restricted to single use as soon as additional supplies are available.

Surgeons are optimistic that some reusable instruments will be approved, thereby reducing the risk of vCJD transmission through surgical tools.

“We are hopeful, but can’t pretend that the problem has been solved yet, because it hasn’t,” Dr. Stevens said.

Prof. Buckley added, “Unfortunately, this problem is no longer a British problem. The World Health Organization has acknowledged vCJD as a global problem, so we’ve all got to deal with it now.”

For Your Information:

• Roger J. Buckley, MA, FRCS, FRCOphth, can be reached at Moorfields Eye Hospital, 162 City Road, London, UK, EC1V2PD; +(44) 207- 253-3411; fax: +(44) 207-566-2019; email: RJBcity@aol.com.
• Julian Stevens, FRCOphth, can be reached at Moorfields Eye Hospital, 162 City Road, London, UK, EC1V2PD; +(44) 207-251-4835; fax: +(44) 207-431-8622; e-mail: julianstevens@compuserve.com.
• For more information on UK sterilization regulations, contact the National Health Service’s CJD Policy Unit, Skipton House, Room 630B, 80 London Road, London SE1 6LH, England; +(44) 207-972-5238; e-mail: dhmail@doh.gov.gsi.uk. Information is also available at the NHS Department of Health Estates Web site: www.decontamination.nhsestates.gov.uk.; or the Medical Devices Agency’s Web site: www.medical-devices.gov.uk.