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

SARS: It May Be Here to Stay

By Linda L. Spaulding, RNC, CIC

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

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

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

HCWs are at particular risk, noting that as of April 9, 2003, the majority of cases have occurred in people who have close contact 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 develops on days four to five in most cases. Initially the pneumonia is unilateral but with one to three days it often becomes bilateral, progressing to white-out on the chest X-ray.

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

The mortality rate in this group is high. Most of the 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 of transmission is by aerosol and/or droplet spread. Respiratory isolation in a negative-pressure room and standard precautions are recommended for all cases.

Communicability

The period of communicability is not currently known but individuals are thought to be infectious once respiratory symptoms appear. The incubation period is thought to be two to 11 days, most commonly three to five days.

Population at Risk

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

Secondary cases from air travel have been reported. There is no information at this stage to determine who is at risk of becoming severely ill and dying. It is thought that the worst outcome may be among those with underlying respiratory and cardiac illnesses such as heart disease, 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 been diagnosed with SARS (defined as having cared for, having lived with, or having had direct contact with respiratory secretions and body fluids of a person with SARS).

2. Recent history of travel to areas reporting cases of SARS Probable Cases: A suspect case with chest X-ray findings of pneumonia or respiratory distress syndrome or a person with an unexplained respiratory illness resulting in death, with an autopsy examination demonstrating the pathology of respiratory distress syndrome without an identifiable 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 is recommended when handling any clinical wastes, including wearing gloves and protective clothing when handling clinical waste. Manual handling of waste should be avoided.

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

All waste should be disposed of as biohazard, and ensure that healthcare workers observe proper sharps disposal in a puncture-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 cold agglutinins (Weli-Felix reaction: Widals test) 2. Blood for culture and serology 3. Urine 4. Bronchoalveolar lavage 5. Postmortem examination as appropriate It is advised that specimens are collected on alternate days. A number of reference labs are able to receive and process samples. This should be coordinated through your public health authority. Samples should be investigated in 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 isolated and accommodated in negative-pressure rooms with the door closed, in single rooms with their own bathroom facilities, or cohort placement in an area with an independent air supply and exhaust system.

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

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

Patient movement should be avoided as much as possible. Patients being moved should wear masks to minimize dispersal of droplets. National Institutes of Occupational Safety and Health (NIOSH) standard masks (N95), often used to protect other highly transmissible respiratory infections such as tuberculosis, are preferred if tolerated by the patient. All visitors, staff, students and volunteers should wear a N95 mask on entering the room of a patient with confirmed or suspected SARS. Surgical masks are a less effective alternative to the N95.

Handwashing is the most important hygiene measure in preventing the spread of infection. Gloves are not a substitute for handwashing. Hands should be washed before and after significant contact with the patient, after activities likely to cause contamination and after removing gloves.

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

Gowns (waterproof aprons) and head covers should be worn during procedures and patient activities that are likely to generate splashes or sprays of respiratory secretions.

HCWs must wear protective eyewear or face-shields during procedures where there is potential splashing, splattering or spraying of blood or other body substances.

HCWs are advised to wear masks whenever there is a possibility of splashing or splattering of body substances, or where airborne infection may occur. Particulate filter personal respirator protection devices capable of filtering 0.3um particles (N95) should be worn at all times when patients with suspected or confirmed SARS.

Discharge From the Hospital and Follow-Up

The period of communicability of SARS currently is unknown but is thought to be up to 10 days after symptoms have resolved. The WHO 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 asked to return to the hospital if they have an elevated temperature of 38 degrees C and above on two consecutive occasions. Follow-up is recommended at one week (or before if decided so by the clinician) at which time they should have a repeat chest X-ray, full blood count and any other blood tests that were previously abnormal. The patient should be followed up by the healthcare facility from which they were discharged. Subsequent follow-ups are recommended until the chest X-ray and the patients health return to normal.

As part of the follow-up, convalescent serology should be taken at three weeks (if an acute serum specimen was taken) after the date of the presenting symptoms and provided to the healthcare facility from which they were discharged. Until more is known about the etiological agent and the potential for continued carriage (and hence the risk of continuing transmission) a cautious approach is warranted. WHO advises that following discharge from the hospital convalescent cases should be advised to wait for a minimum of 14 days, before considering returning to work or school. This is twice the known maximum incubation period. During this period they should stay indoors, keeping contact with others to a minimum. Clear instructions should be given to convalescent cases to return to the healthcare facility from which they were discharged if their condition deteriorates and any further symptoms develop.

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

Linda L. Spaulding, RN, CIC, is Infection Control Todays 2003 Educator of the Year and an independent infection control consultant in Hawaii.

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