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Global Update Indian Pediatrics 2003; 40:447-448 |
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News in Brief |
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SARS- severe acute respiratory syndrome Suspected etiological agent: A new strain of the corona virus as identified by scientists in the Chinese University of HongKong. Coinfections with a paramyxovirus or a human metapneumovirus have not been ruled out. Chlamydia was isolated from some of the cases who died in China. Epidemiology The origin of the epidemic is suspected to be in Guangzhou, in Guangdong province in China in November 2002. A semi-retired doctor from Guangzhou is believed to be the index case who transmitted the disease to Hong Kong. From the Metropole Hotel where he stayed, the disease spread by droplet infection via the lift lobby to various guests who in turn transmitted the disease to other countries. Another Chinese American businessman who was unwell when he went from Shanghai to Hanoi in Vietnam where he deteriorated and was admitted to a hospital in Hanoi. He is considered the index case in Vietnam where many health care workers were infected. He was then transferred to Prince of Wales Hospital hospital in Hong Kong where hundreds of people have since got infected. Other countries which have been affected include Canada, Germany, USA, Taiwan, Thailand, and Singapore. By 7 April, 2601 probable and suspected cases worldwide, including 98 deaths, had been reported to WHO in 18 countries of which 1268 cases and 53 deaths were in China. WHO case definitions for severe acute respiratory syndrome: Case definitions are updated as new information accumulates, and the following are those updated on March 16. Suspect case A person presenting after Feb 1, 2003 with history of: high fever (>38º C); and one or more respiratory symptoms including cough, shortness of breath, difficulty breathing, and one or more of the following: * close contact, within 10 days of onset of symptoms, with a person who has been diagnosed with SARS * history of travel, within 10 days of onset of symptoms, to an area in which there are reported foci of transmission of SARS. Probable case 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 a necropsy examination demonstrating the pathology of respiratory distress syndrome without an identifiable cause. Pattern of transmission WHO has reported that as of March 15, most cases have been close contacts of other cases, and more than 90% of cases have occurred in health-care workers. Close contact means having cared for, lived with, or had direct contact with respiratory secretions and body fluids of a person with SARS. (Source: http://www.who.int/) Attack rate More than 50% people exposed to patients with SARS. Clinical features The most common early systemic symptoms in Hong Kong and Hanoi included fever, malaise, myalgia, headache, and dizziness. Sore throat and rhinorrhea occurred early in fewer than 25% of cases, and cough occurred early in only 39% of cases. After 3-7 days of fever the lower respiratory phase begins, with a non-productive cough, which may be accompanied by dyspnoea and chest pain. Breathlessness requiring oxygen occurred in many cases after about five days and progressed to hypoxaemia requiring ventilatory support in around 15%, a rate similar to the 10-20% observed elsewhere. Investigations The university of Hong Kong is providing a PCR test for local hospitals for the corona virus. Early chest X-ray findings typically show small focal unilateral diffuse interstitial infiltrates, which may be overlooked initially and peripheral air space consolidation on thoracic computed tomographic scanning. The appearance evolves rapidly, often becoming more generalised and affecting both lung fields. Chest radiographs may, however, be normal during the febrile prodrome and throughout the illness. Other common findings include lymphocytopenia (69.6%), thrombocytopenia (44.8%), elevated LDH (71%) and elevated creatine kinase (32.1%). Treatment Doctors in Hong Kong are using a combination of ribavarin and steroids and 85% have shown improvement. The influenza neuraminidase inhibitor oseltamivir and antibiotics targeted at known bacterial pathogens causing atypical pneumonia have been used without evident benefit. Outcome Overall case fatality is about 4%. Predictors of adverse outcome are advanced age (OR per decade of life 1.8, CI 1.6 to 2.8; p = 0.009), high LDH ( OR OR per 100 U/L, 2.09; CI 1.28- 3.42; p = 0.003) and a high absolute neutrophil count (OR 1.6; CI 1.03-2.5 ; p = 0.04). Prevention Until the route(s) has been clearly established infection control measures should include both airborne precautions (including a negative pressure isolation room, use of full respiratory protection for people entering the room, and eye protection for all contacts) and contact precautions (gowns and gloves and hand hygiene). People who were exposed to patients or have symptoms suggesting SARS are being quarantined in for 10 days. People flying in from high risk countries are being screened for symptoms. WHO has issued unprecedented travel advice, recommending that people postpone any planned trips to Hong Kong and Guangdong province. Gouri Rao Passi,
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