Infection Control Today - 07/2003: SARS: It May Be Here to Stay

July 1, 2003

SARS: It May Be Here to Stay

By Linda L. Spaulding, RNC, CIC

Severe acute respiratory syndrome (SARS) hasemerged as a new, sometimes fatal respiratory illness. China identified thefirst cases in the fall of 2002, when the Guangdong Province reported 305 casesof a highly contagious and very severe atypical pneumonia. Cases were prevalentamong healthcare workers (HCWs) and their household contacts; many cases wererapidly fatal. In February 2003 the Centers for Disease Control and Prevention (CDC)named this illness severe acute respiratory syndrome (SARS) and issued aclinical case definition. In March 2003, the World Health Organization (WHO)issued a global alert about the China outbreak and instituted worldwidesurveillance.

SARS is believed to be caused by a virus known asthe coronavirus and as of April 19, 2003, more than 3,547 cases have beenreported, including 182 deaths. Presenting as an atypical pneumonia, the viruswas first recognized in Hanoi, Vietnam in February 2003, but the epidemic beganin the province of Guangdong in November 2002. Transmission occurred inGuangdong and Shaxi provinces and the Special Administrative Region of Hong Kongin China, Taiwan in China, Hanoi in Vietnam, Singapore and Toronto, Canada.Thirteen other countries have now reported imported cases.

Currently, officials believe the coronavirus isthe major causative agent of SARS. The main signs and symptoms include highfever (greater than 38 degrees Celsius, 100.4 Fahrenheit), cough and shortnessof breath or breathing difficulties. Ten percent of patients presenting withSARS develop severe pneumonia; of those half will require ventilator support.

HCWs are at particular risk, noting that as ofApril 9, 2003, the majority of cases have occurred in people who have closecontact with SARS cases.

Description of the Disease

Symptoms begin with fever for one to two days,then a dry cough or dyspnea for two to three days. Atypical pneumonia developson days four to five in most cases. Initially the pneumonia is unilateral butwith one to three days it often becomes bilateral, progressing to white-outon the chest X-ray.

From this point, the patient improves (80 to 90percent of cases) and recovers in the next four to 76 days; or the patientdeteriorates on days six or seven with respiratory distress (10-20 percent ofcases). Fifty percent of patients in category B will require mechanicalventilation.

The mortality rate in this group is high. Most ofthe SARS cases have been reported in individuals between 20 and 70 years of age.Very few cases have occurred in children.

It appears at this time that the mode oftransmission is by aerosol and/or droplet spread. Respiratory isolation in anegative-pressure room and standard precautions are recommended for all cases.

Communicability

The period of communicability is not currentlyknown but individuals are thought to be infectious once respiratory symptomsappear. The incubation period is thought to be two to 11 days, most commonlythree to five days.

Population at Risk

Currently, household contact and friends of SARScases as well as healthcare workers appear at highest risk of contracting SARS.

Secondary cases from air travel have beenreported. There is no information at this stage to determine who is at risk ofbecoming severely ill and dying. It is thought that the worst outcome may beamong those with underlying respiratory and cardiac illnesses such as heartdisease, asthma and COPD.

SARS Case Definition Recommended by WHO

Suspect Cases:A person presenting after Feb. 1, 2003 with history of:

  • High fever (greater than 38 degrees C) and

  • One or more respiratory symptoms including cough, shortness of breath, difficulty breathing and one or more of the following:

1. Close contact with a person who had beendiagnosed with SARS (defined as having cared for, having lived with, or havinghad direct contact with respiratory secretions and body fluids of a person withSARS).

2. Recent history of travel to areas reportingcases of SARS Probable Cases: A suspect case with chest X-ray findings ofpneumonia or respiratory distress syndrome or a person with an unexplainedrespiratory illness resulting in death, with an autopsy examinationdemonstrating the pathology of respiratory distress syndrome without anidentifiable cause.

Management of Severe Acute Respiratory Syndrome

Management of suspect cases:

  • Patients with symptoms of SARS should be triaged immediately to designated examination rooms or wards

  • Issue a surgical mask to patients (if the patient can tolerate wearing a mask, an N-95 is preferred)

  • Obtain and record detailed clinical, travel and contact history including occurrence of any respiratory diseases in contact persons during the last 10 days

  • Obtain a chest X-ray (CXR) and full blood count (FBC)

  • If CXR is normal, provide advice on personal hygiene, avoidance of crowded areas and public transportation and to remain at home until well. Discharge with advice to seek medical care if respiratory symptoms worsen

  • If CXR demonstrates uni- or bi-lateral infiltrates with or without interstitial infiltration, manage as a probable case Management of contacts of suspected and probable cases:

The implementation of standard precautions isrecommended when handling any clinical wastes, including wearing gloves andprotective clothing when handling clinical waste. Manual handling of wasteshould be avoided.

Other symptoms may be muscular stiffness, loss ofappetite, confusion, rash and diarrhea.

All waste should be disposed of as biohazard, andensure that healthcare workers observe proper sharps disposal in apuncture-resistant container.

Management of probable cases:

  • Hospitalize under isolation or cohorted with other SARS cases

  • Sample for laboratory investigation and exclusion of known causes of atypical pneumonia:

1. Throat and/or nasopharyngeal swabs and coldagglutinins (Weli-Felix reaction: Widals test) 2. Blood for culture andserology 3. Urine 4. Bronchoalveolar lavage 5. Postmortem examination asappropriate It is advised that specimens are collected on alternate days. Anumber of reference labs are able to receive and process samples. This should becoordinated through your public health authority. Samples should be investigatedin laboratories with proper containment facilities (BL3).

  • Monitor FBC alternate days

  • CXR as clinically indicated

  • Treat as clinically indicated Broad-spectrum antibiotics have not appeared to be effective in stopping the progression of this disease. IV ribavirin and steroids may have stabilized one patient.

Care of Patients With Probable SARS

Patients with probable SARS should be isolatedand accommodated in negative-pressure rooms with the door closed, in singlerooms with their own bathroom facilities, or cohort placement in an area with anindependent air supply and exhaust system.

Turning off air conditioning and opening windowsfor good ventilation is recommended if an independent air supply is unfeasible.Whenever possible, the patient under investigation for SARS should be separatedfrom those diagnosed with the syndrome. Ensure that if windows are opened theyare away from public places.

Disposable equipment should be used whereverpossible in the treatment and care of patients with SARS. If devices are to bereused, they should be sterilized in accordance with manufacturersinstructions. Surfaces should be cleaned with broad-spectrum (bactericidal,fungicidal and viricidial) disinfectants of proven efficacy.

Patient movement should be avoided as much aspossible. Patients being moved should wear masks to minimize dispersal ofdroplets. National Institutes of Occupational Safety and Health (NIOSH) standardmasks (N95), often used to protect other highly transmissible respiratoryinfections such as tuberculosis, are preferred if tolerated by the patient. Allvisitors, staff, students and volunteers should wear a N95 mask on entering theroom of a patient with confirmed or suspected SARS. Surgical masks are a lesseffective alternative to the N95.

Handwashing is the most important hygiene measurein preventing the spread of infection. Gloves are not a substitute forhandwashing. Hands should be washed before and after significant contact withthe patient, after activities likely to cause contamination and after removinggloves.

Alcohol-based hand disinfectants formulated foruse without water may be used in certain limited circumstances. HCWs are advisedto wear gloves for all patient handling. Gloves should be changed between andafter any contact with items likely to be contaminated with respiratorysecretions (masks, tubing, nasal prongs or tissues).

Gowns (waterproof aprons) and head covers shouldbe worn during procedures and patient activities that are likely to generatesplashes or sprays of respiratory secretions.

HCWs must wear protective eyewear or face-shieldsduring procedures where there is potential splashing, splattering or spraying ofblood or other body substances.

HCWs are advised to wear masks whenever there isa possibility of splashing or splattering of body substances, or where airborneinfection may occur. Particulate filter personal respirator protection devicescapable of filtering 0.3um particles (N95) should be worn at all times whenpatients with suspected or confirmed SARS.

Discharge From the Hospital and Follow-Up

The period of communicability of SARS currentlyis unknown but is thought to be up to 10 days after symptoms have resolved. TheWHO recommends the following for discharge and follow-up:

Clinical symptoms/findings:

  • Afebrile for 48 hours

  • Resolving cough Laboratory tests: if done and previously abnormal:

  • White cell (lymphocyte) count returning to normal

  • Platelet count returning to normal

  • Creatinine phosphokinase returning to normal

  • Liver function tests returning to normal

  • Plasma sodium returning to normal

  • C reactive protein returning to normal Radiological findings:

  • Improving chest X-ray changes

Follow-up for Convalescent Cases

Discharged convalescent patients should be askedto return to the hospital if they have an elevated temperature of 38 degrees Cand above on two consecutive occasions. Follow-up is recommended at one week (orbefore if decided so by the clinician) at which time they should have a repeatchest X-ray, full blood count and any other blood tests that were previouslyabnormal. The patient should be followed up by the healthcare facility fromwhich they were discharged. Subsequent follow-ups are recommended until thechest X-ray and the patients health return to normal.

As part of the follow-up, convalescent serologyshould be taken at three weeks (if an acute serum specimen was taken) after thedate of the presenting symptoms and provided to the healthcare facility fromwhich they were discharged. Until more is known about the etiological agent andthe potential for continued carriage (and hence the risk of continuingtransmission) a cautious approach is warranted. WHO advises that followingdischarge from the hospital convalescent cases should be advised to wait for aminimum of 14 days, before considering returning to work or school. This istwice the known maximum incubation period. During this period they should stayindoors, keeping contact with others to a minimum. Clear instructions should begiven to convalescent cases to return to the healthcare facility from which theywere discharged if their condition deteriorates and any further symptomsdevelop.

The good news about SARS is that even though itis a killer, it doesnt pose the same threat as a full-blown flu epidemic. Themortality rate for SARS is currently 4 percent. Influenza causes more deathsannually than SARS has to date. The CDC is working closely with WHO and otherpartners as part of a global effort to address the SARS outbreak. Whether thisvirus is here to stay is yet to be determined. It is important for all HCWs tostay up to date with developing news.

Linda L. Spaulding, RN, CIC, is Infection ControlTodays 2003 Educator of the Year and an independent infection controlconsultant in Hawaii.