Severe Acute Respiratory Syndrome (SARS) Somsak Lolekha MD, PhD

SARS Mid November-February, >300 people in China’s Guangdong province had the same disease with 5 deaths. February 26, 2003, a business man (index case) was admitted to hospital in Hanoi. He was referred to Hong Kong and died on March 13, 2003 March 5, seven health care workers who had cared for the index case also became ill in Hanoi. March 12, 20 health care workers developed influenza like symptoms in Hong Kong. March 11, a health care traveled to Thailand from Hanoi had been unwell and was sent to hospital for isolation. He died on March 29,2003. No evidence of transmission of SARS in Thailand.

Index case in Hong Kong outbreak A visitor from Mainland China was sick a week before staying at the Metropole hotel in Kowloon. 7 people who contracted SARS recently stayed or visited the ninth floor of the hotel between 12 February and March 2. The 7 persons investigated include 3 visitors from Singapore, 2 from Canada, one China mainland visitor and a local Hong Kong resident. The local Hong Kong resident is believed to be the index case had visit an acquaintance staying at the hotel from February,2003. He was an index case in the outbreak in the Prince of Wales Hospital in Hong Kong

Summary of reported cases of SARS 28 Mar 2003 CountryTotal No. No. of deaths Local transmission of cases German40None Canada373Yes China, Guangdong 80634Yes Singapore892Yes Hong Kong47010Yes Taiwan100Yes Thailand31None United Kingdom30None United States590 Viet Nam584Yes Other110Yes Total

Reported Cases of SARS

Reported Cases of SARS in Hong Kong

Countries with SARS Affected countries: country with the evidence of transmission of the disease e.g. Hong Kong, Hanoi, Guangdong province in China, Singapore, Taiwan Countries with few imported cases but do not transmit any further.

MMWR 2003;52:241-55

Guideline for presumptive diagnosis of SARS Onset of illness after February 1, 2003 Fever (>38 C) and One or more signs and symptoms of respiratory illness including cough, shortness of breath, difficulty breathing, hypoxia, radiographic finding of pneumonia, or respiratory distress and History of travel to Hong Kong, Mainland China, Hanoi or Singapore within 10 days of symptom onset or Close contact with persons with SARS within 10 days of onset of symptoms March 30, 2003

SARS Incubation period: 3-5 days (range 2-10 days) Etiology: likely to be virus in family Coronaviridae CBC: normal, leucopenia(by day 3-4), thrombocytopenia (less common) Signs and symptoms: fever, headache, malaise, coughing, shortness of breath Transmission: man to man, close contact, secondary attack rate >50% Fatality: 54 out of 1550 (3.5%) Over 90% of the early cases occur in healthcare workers Most of the patients involve family members and other close contacts of infected people and health care workers.

Family Paramyxoviridae Sub-family Paramyxovirinae Genus Morbillivirus Measles virus Genus Paramyxovirus Parainfluenza virus Genus Rubulavirus Mumps virus Sub-family Pneumovirinae Genus Pneumovirus Respiratory Syncytial virus Genus Metapneumovirus RNA-containing virus with helical symmetry and enveloped sensitive to ether, acid, and heat. Co-infected.

Family Coronaviridae Structure: non-segmented, linear, single strand RNA+ helical, enveloped Diseases: Common cold, pneumomia, gastroenteritis Virulent factors: E2 glycoprotein Mode of transmission: inhalation of aerosols; respiratory transmission from person-to-person, indirect through fomites hand contamination, particle aerosols. Incubation period: 2-5 days (2-10 days) Communicability: during acute and convalescent stages Drug susceptibility: no specific antivirals Susceptibility to disinfectants: 1% sodium hypochlorite, 2% glutaraldehyde Physical inactivation: sensitive to heat Survival outside host: up to 3 hours on environmental surface

Coronavirus

Clinical Features of SARS Symptoms Per cents Fever100 Malaise100 Chills97 Headache84 Myalgia81 Dizziness61 Rigors55 Cough39 Sore throat23 Runny nose23

Clinical course of SARS Incubation period: 3-7 days The illness generally begins with a prodrome of fever >38 o C, chill, malaise, headache, myalgias. Normal CBC After 3-7 days, a lower respiratory phase begins with the onset of a dry, non-productive cough or dyspnea that may be accompanied by or progress to hypoxia. There are 2 groups of patients –Group one: the majority (80%-90%), characteristic symptoms will progress to about day 6 or 7 and then will spontaneously start getting slowly better. –Group two: 10%-20% has a more severe form of the disease and progress to acute respiratory distress syndrome, many of them will require mechanical ventilatory support.

Clinical Course of SARS Infected by Corona virus Incubation period 2-10 days Fever >38 C, malaise, headache, chill Respiratory symptoms, nonproductive cough Difficulty breathing, 3-7 days Recover slowly after 7 days Progressively worse on days and died on days 90%

Radiological finding in SARS Chest X-ray (CXR) may be normal during the first few days of illness Patchy CXR changes are sometimes noted in the absence of chest symptoms CXR findings typically begin with a small unilateral patchy shadowing, and progress over 1- 2 days to become bilateral and generalized, with interstitial/confluent infiltrates. Adult Respiratory Distress Syndrome (ARDS) has been observed in a number of patients in the end stages.

Management of suspect case of SARS Send the patient to designated examination room or ward Issue patients with special mask Obtain and record detailed clinical, travel and contact history during the last 10 days Chest X-ray (CXR) and CBC If CXR is normal Provide advice on personal hygiene, avoidance of crowded areas and public transportation, remain at home until well If CXR demonstrate uni- or bilateral infiltration hospitalize under isolation

Management of probable case of SARS Hospitalize under isolation or cohorted with other SARS cases Sample for laboratory investigation and exclusion of known causes of atypical pneumonia –Throat and nasopharyngeal swabs and cold agglutinin –Blood culture and serology –Urine –Broncho alveolar lavage CBC alternate days CXR as clinically indicated Treat as clinically indicated

Screening questions for SARS We should ask the patients or passengers 2 questions. First question relates to symptoms, asking about fever, cough or difficult in breathing. Second question asks about possible exposure, whether you know you have been in contact with a case of SARS, whether you have worked or visited or been a patient in a hospital where there is SARS, or whether you have member of your family has been a suspect or probable case of SARS.

Advice for Airline and Traveler Alert the destination airport of any passengers meeting the case definition criteria Arriving passengers who are symptomatic should be referred to health authorities for assessment and care Aircraft passengers and crew should be informed of the person’s status as a suspect case of SARS The passengers and crew should provide all contact information for how passengers can be reached for the subsequent 14 days to airport health authorities. Persons planning elective or nonessential travel to Hong Kong, Guangdong province, Singapore, Hanoi may wish to postpone their trips.

Hospital Infection Control Guidance Airborne precautions –Negative pressure rooms with the door closed –Single rooms with their own bathroom facilities –Cohort placement in an area with an independent air supply and exhaust system –Turning off air conditioning and open windows for good ventilation is recommended if an independent air supply is unfeasible

Hospital Infection Control Guidance Contact precautions –Use gown and gloves for contact with the patient or their environment All visitors, staff and students should wear a N95 mask (or surgical mask) on entering the room Patient movement should be avoided as much as possible. Patients being moved should wear a surgical mask to minimize dispersal of droplets.

Management of Exposures to SARS for Healthcare and other Institution Settings Exclusion from duty, if fever or respiratory symptoms develop during the 10 days following an unprotected exposure to SARS until 10 days after the resolution of fever. Surveillance (active and passive) Close contacts of SARS with either fever or respiratory symptoms should not be allowed to enter the healthcare facility as visitors. Educate all visitors