Infection Control Today - 11/2003: Clinical Update

Isolation Protocol Takes On New Meaning in SARS Era

By Kathy Dix

It used to be called paranoia. But now being a sticklerfor isolation guidelines is just good sense.

If SARS (severe acute respiratory syndrome), Norwalk-like virusand smallpox represent the Big Bad Wolf, consider isolation protocol to be theWoodcutter. The fall of 2002 brought several diseases to the forefront ofAmerican consciousness, and in response, the Centers for Disease Control andPrevention (CDC) released additional guidelines on proper isolation practicesspecific to these diseases. Terri Rearick, RN, BS, CIC, head of infection control at Illinois ChildrensMemorial Hospital, the educational facility for Northwestern UniversitysFeinberg School of Medicine, says that her own facility has responded withadaptations in construction. We have adapted to isolation changes by adding two new negative airpressure rooms to our emergency department in light of SARS and thesmallpox/bioterrorism preparedness efforts, she says.

Not only that, but the hospital has updated its isolation categories; theynow rank patients according to six different classifications: the standard Airborne, Droplet and Contact Isolation, but also two combinedcategories of Airborne/Contact and Droplet/Contact. We also use protectiveisolation for our stem cell and bone marrow transplant patients, sheclarifies.

Fear has not been a motivating factor in changing basic hospital policy; instead, Rearick says, We try not to be reactionary and be proactivewhenever possible.

Like other hospitals, Childrens Memorial has instituted its own SARSpolicy, and has increased fit testing for personal respirator use.

Childrens Memorial has also purchased three positive air pressurerespirators and is working with the city of Chicago in our bioterrorismplanning, notes Rearick. This planning also covers biological challenges that arenaturally occurring/emerging infectious diseases.

In general, there have been no paradigm shifts in infection control due toillnesses such as SARS or smallpox, says Peter R. Wolfe, MD, vice chief ofmedical staff at Century City Hospital in West Los Angeles, a specialist ininternal medicine and infectious diseases, and an associate clinical professorof medicine at the University of California at Los Angeles.

Certainly the bioterrorism issue has been important in infection controlthe past two years; I would say that the greatest effect has been on emergencyrooms, which will be the first line of defense against potential terroristattacks. Much of this is educating the front line personnel about what theagents are and how to recognize them, adds Wolfe.

It is true that the increasing prevalence of VRE (vancomycin-resistant enterococcusand multidrug-resistant gram negative enterics in the hospital setting hasled CDC and JCAHO (Joint Commission on Accreditation of HealthcareOrganizations) to focus more attention on limiting the spread of these and othernosocomial pathogens, he explains. However, its interesting that somehospitals in the local area have stopped isolating MRSA patients.

The real changes to infection control procedures have been obvious ones suchas the new guidelines from the CDC emphasizing the magnitude of handwashing,says Wolfe. The addition of alcohol-based hand rubs as an alternative tosoapand- water handwashing has been the biggest modification, followed by otherrecommendations to continue using gloves and to utilize traditional handwashingwhen hands are visibly soiled.

CDC guidelines also recommend that healthcare workers in contact withhigh-risk patients avoid artificial nails, and wear only short natural nails,and that healthcare facilities monitor improvements in adherence to hand hygieneguidelines.

The CDCs HICPAC committee has appointed a small group to update itsexisting isolation guidelines, says Rita McCormick, RN, CIC, senior infectioncontrol practitioner for the University of Wisconsin Hospitals and Clinics, butthe new guidelines will not be published until 2004 or 2005. However, the CDChas addressed Norwalk virus, SARS and smallpox in separate publications; ofnote, any of the existing viral gastroenteritis diseases (including Norwalk-likeviruses) can readily be handled using existing guidelines addressing acutediarrhea of unknown etiology until the infectious etiology is determined, says McCormick, and then the specific precautions can be utilized ifdifferent. Typically, contact precautions are used for various types of diarrhea inyoung children or incontinent adults.

Norwalk Virus or Norwalk-like Virus

In 2002, thousands of travelers were felled by the Norwalk virus or one ofits close norovirus relatives. Cruise ships especially were prime havens for the virus that causes acute gastroenteritis lasting one to two days. Transmitted through fecal-oral contact, Norwalk virus appears to be easily transmitted from person to person, especially in the close quarters associated with a ship or a nursing home.

First linked with gastroenteritis in 1972, Norwalk virus was associated withan epidemic of gastroenteritis that occurred in 1968 in Norwalk, Ohio. Over justtwo days, 50 percent of an elementary schools population developed acutegastroenteritis.¹

Norwalk virus is cunning it can be found in contaminated food or water,or be transmitted by touching an infected persons hand, even a stair railing,doorknob or salad tongs at the buffet. And, strangely enough, it appears that susceptibility to infection may begenetically determined, with people of O blood group being at greatest risk for severe infection, says the CDC.²

The best means of preventing the spread of infection is to follow handhygiene guidelines and dispose of infectious materials; in an inpatient setting,contact isolation precautions should be taken. Notify the state board ofhealth for all epidemic outbreaks of Norwalk virus (two or more people whoshared a common meal) so it can investigate potential outbreak centers andprevent further transmission, recommend two physicians in an e-article about Norwalk virus.¹

SARS

SARS, a recently discovered coronavirus that appears to have jumped fromanimals to humans in the late summer or early fall of 2002, has been surprisingin its sporadic ability to spread rapidly. So-called superspreaders who either expose many others to the disease before they are diagnosedand treated, or who happen to have a particularly vigorous strain of the disease have been capable of spreading the disease to hundreds, while others notwearing masks or washing their hands infect few.

In response to the SARS outbreak of late 2002 and early 2003, the CDCreleased specific guidance on appropriately dealing with SARS patients. First,when a suspect SARS patient is admitted, infection control personnel should benotified immediately; second, standard precautions are necessary, in addition to eye protection for all patient contact.³

Not only that, but contact and airborne precautions should be observed, andall healthcare workers in contact with the patient should have a qualitative fittest for their N-95 respirators. If N-95 respirators are not available,personnel should wear surgical masks.

Persons seeking medical care for an acute respiratory infection should beasked about possible exposure to someone with SARS or recent travel to an areawith SARS, say the guidelines. If SARS is suspected, the patient should beprovided with a surgical mask, or asked to cover the mouth with a disposabletissue while coughing, talking or sneezing. This patient should be kept separatefrom others in the reception area, and the CDC recommends removing him or her toa private room with negative pressure. Healthcare workers in contact with suchpatients should wear N-95 respirators, follow standard and contact precautionsand wear eye protection.

In the home setting, such patients should wear surgical masks, or, if this isimpossible, housemates should wear surgical masks when in close contact, andshould utilize careful hand hygiene with soap and water, or alcohol-based hand rubs if the hands are not visiblysoiled.

Suspected Smallpox

In its Guidelines for Environmental Infection Control in Health CareFacilities, the CDC recommends that patients with smallpox be placed innegative-pressure rooms at illness onset; specific suggestions in the subsectionon ventilation requirements indicate that air pressure should be monitoreddaily, with audible manometers or smoke tubes at the door, or permanent visualmonitoring mechanisms.⁴

Such rooms should be well-sealed, have proper air intake and exhaust ports,and should have self-closing devices on all exit doors. Air should be exhaustedoutside, away from air-intake and populated areas, or recirculated after beingpassed through a HEPA filter.

In addition, healthcare workers exposed to the patient should be properlyshielded with personal respiratory protection.