Castro-Sansores CJ, Góngora-Biachi RA

Language: Spanish
References: 29
Page: 89-100
PDF size: 63.77 Kb.

ABSTRACT

During the fall of 2003, more than 300 cases of an atypical pneumonia were reported in a province in the southeast of China. By the end of February 2003, cases of this syndrome had already been reported on Hong Kong, Indonesia, the Phillapines, Vietnam and Canada. The Centers for Disease Control and Prevention (CDC) in the United States of America called this pathology Severe Acute Respiratory Syndrome (SARS). In April 2003, an international cooperative study resulted in the isolation of a new coronavirus associated with SARS (SARS-CoV). It is a RNA virus, with a diameter of between 60 and 130 nM, wich reaches high concentrations of more than 100 million molecules/mL of viral RNA in sputum. However it is extremely low in plasma during the acute phase and in faeces during convalescense. It remains stable in faeces and urine at room temperature for 1-2 days. It quickly becomes inactive at temperatures over 56°C and loses its infectious capacity when exposed to desinfectants and common fixatives.
The majority of the patients reported are adults. In Toronto, Canada, the average age was 45, ranging between 34 and 57. 61% were women. In Hong Kong, 57% of the 1425 cases were women. In all the cases 228 (16%) were £15. There is still no explanation for the low incidence of pediatric cases and the more bening clinical course with lower lethality. The incubation period of SARS-CoV is 6 days on average, with a range from 3 to 10. A temperature over 38°C is present in almost 100% of cases and is accompanied by other symptoms like shivers, stiffness, myalgias, general malaise and migraines. Some patients have diarrhoea during the symtomal phase. A cough, usually dry, and dyspnoea appear between 3 and 7 days after the symptoms have in 10 to 20% of the cases; this can be serious enough to require ventilatory assisstance. At the beginning of the diseases, the most common laboratory finding is lymphocytopenia (‹1000); when the respiratory symptom stage begins, leukocytopenia (‹3500) if found at frequencies between 33% and 68% and thrombocytopenia (‹150,000) in almost 50% of the cases. An increase in the transaminases (‹4 times their maximum value) and the creatinfosfoquinase is observed between 23% and 70%. Radiological studies are often normal during the symptomal phase. However during the febril period up to 70% of the cases are abnormal. Histological findings of the pulmonary tissues commonly show diffuse alveolar damage with of varying degrees of severity. Secundary bacterial pneumonia can be identified in 10% of cases and the electronic microscope shows viral particles in the cytoplasm or epilethial cells, corresponding to SARS-CoV. The disease evolutions a serious respiratory insufficiency in 20% of the cases and 9% of the cases are lethal. The contagion route of SARS-CoV is by way of coughing, sneezing or talking. Up to the present, there is no recognised efficient treatment for curing SARS.

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