Sars

Main article: Progress of the SARS outbreak

The epidemic appears to have originated in Guangdong Province in November 2002 ("Patient #0" -- first reported symptoms -- has been attributed to Charles Bybelezar of Montreal, Canada) and, despite taking some action to control it, Chinese government officials did not inform the World Health Organization of the outbreak until February 2003, restricting media coverage in order to preserve public confidence. This lack of openness caused delays in efforts to control the epidemic, resulting in criticism of the People's Republic of China (PRC) from the international community. The PRC has since officially apologized for early slowness in dealing with the SARS epidemic.[2]

In early April, there appeared to be a change in official policy when SARS began to receive a much greater prominence in the official media. However, it was also in early April that accusations emerged regarding the undercounting of cases in Beijing military hospitals. After intense pressure, PRC officials allowed international officials to investigate the situation there. This revealed problems plaguing the aging mainland Chinese healthcare system, including increasing decentralization, red tape, and inadequate communication.

In late April, revelations occurred as the PRC government admitted to underreporting the number of cases due to the problems inherent in the healthcare system. Dr. Jiang Yanyong exposed the coverup that was occurring in China, at great personal risk. He reported that there were more SARS patients in his hospital alone than were being reported in all of China. A number of PRC officials were fired from their posts, including the health minister and mayor of Beijing, and systems were set up to improve reporting and control in the SARS crisis. Since then, the PRC has taken a much more active and transparent role in combating the SARS epidemic.

[edit] Spread to other countries

The epidemic reached the public spotlight in February 2003, when an American businessman traveling from China became afflicted with pneumonia-like symptoms while on a flight to Singapore. The plane stopped at Hanoi, Vietnam, where the victim died in a hospital. Several of the medical staff who treated him soon developed the same disease despite basic hospital procedures. The severity of the symptoms and the infection of hospital staff alarmed global health authorities fearful of another emergent pneumonia epidemic. On March 12, 2003, the WHO issued a global alert, followed by a health alert by the United States Centers for Disease Control and Prevention (CDC). Local transmission of SARS took place in Toronto, Vancouver, Ulaan Bator, Manila, Singapore, Hanoi, Taiwan, the Chinese provinces of Guangdong, Jilin, Hebei, Hubei, Shaanxi, Jiangsu and Shanxi, the Chinese municipality of Tianjin, the Chinese Autonomous Region of Inner Mongolia, and the Chinese Special Administrative Region of Hong Kong.

In Hong Kong the first cohort of affected people were discharged from the hospital on March 29, 2003. The disease spread in Hong Kong from a mainland doctor on the 9th floor of the Metropole Hotel in Kowloon Peninsula, infecting 16 of the hotel visitors. Those visitors traveled to Singapore and Toronto, spreading SARS to those locations. Another, larger, cluster of cases in Hong Kong centred around the Amoy Gardens housing estate. Its spread is suspected to have been facilitated by defects in the sewage system of the estate.

[edit] Clinical information

[edit] Symptoms

Initial symptoms are flu-like and may include: fever, myalgia, lethargy, gastrointestinal symptoms, cough, sore throat and other non-specific symptoms. The only symptom that is common to all patients appears to be a fever above 38 oC (100.4 oF). Shortness of breath may occur later. Symptoms usually appear 2-10 days following exposure, but up to 13 days has been reported. In most cases symptoms appear within 2-3 days. About 10-20% of cases require mechanical ventilation.

[edit] Physical signs

Early physical signs are inconclusive and may be absent. Some patients will have tachypnea and rales on auscultation. Later, tachypnea and lethargy become more prominent. Rashes may develop in some areas of the body.

[edit] Investigations

The Chest X-ray (CXR) appearance of SARS is variable. There is no pathognomonic appearance of SARS but is commonly felt to be abnormal with patchy infiltrates in any part of the lungs. The initial CXR may be clear.

White blood cell and platelet counts are often low. Early reports indicated a tendency to relative neutrophilia and a relative lymphopenia -- relative because the total number of white blood cells tends to be low. Other suggestive laboratory tests are raised lactate dehydrogenase and slightly raised creatine kinase and C-Reactive protein levels.

[edit] Diagnostic tests

With the identification and sequencing of the RNA of the coronavirus responsible for SARS on April 12, 2003, several diagnostic test kits have been produced and are now being tested for their suitability for use.

Three possible diagnostic tests have emerged, each with drawbacks. The first, an ELISA (enzyme-linked immunosorbent assay) test detects antibodies to SARS reliably but only 21 days after the onset of symptoms. The second, an immunofluorescence assay, can detect antibodies 10 days after the onset of the disease but is a labour and time intensive test, requiring an immunofluorescence microscope and an experienced operator. The last test is a PCR (polymerase chain reaction) test that can detect genetic material of the SARS virus in specimens ranging from blood, sputum, tissue samples and stools. The PCR tests so far have proven to be very specific but not very sensitive. This means that while a positive PCR test result is strongly indicative that the patient is infected with SARS, a negative test result does not mean that the patient does not have SARS.

The WHO has issued guidelines for using these diagnostic tests.[1]

There is currently no rapid screening test for SARS and research is ongoing.

[edit] Diagnosis

A chest x-ray showing increased opacity in both lungs, indicative of pneumonia, in a patient with SARS.

A chest x-ray showing increased opacity in both lungs, indicative of pneumonia, in a patient