Free Essay On Sars

Severe Acute Respiratory Syndrome

Severe acute respiratory syndrome (SARS), also known as purple death is atypical pneumonia. The first case of the disease was registered in November 2002 in the Chinese province of Guangdong. At the moment, it is known that the causative agent of SARS is the SARS coronavirus (SARS-CoV), a new type of coronavirus. In the process of breeding the virus destroys the cells of the pulmonary alveoli. The death rate from SARS was about 10%.
Initially, the PRC authorities hid the message of an outbreak of a new infection, but the epidemic quickly spread to neighboring Hong Kong and Vietnam in late February 2003 and further to other countries and continents. The last case of SARS was recorded in June 2003. A total of 8437 cases observed, of which 813 were fatal.
Scientists have discovered two types of molecules that stop reproduction of the SARS virus, which will help create a cure for this dangerous disease, according to a paper published in the Journal of the American scientists Proceedings of the National Academy of Sciences.
SARS is a disease, which appeared at the beginning of the twenty-first century and in 2002-2003 spread to several countries in Southeast Asia.
The term "atypical pneumonia" appeared long before the development of the pandemic and the latter used to describe lung disease caused by not ordinary pneumonia and atypical pathogens such as Legionella, Mycoplasma, Chlamydia, viruses. More accurately reflect the uniqueness of the disease worldwide accepted the designation "Severe Acute Respiratory Syndrome" (SARS) and its English synonym for "Severe Acute Respiratory Syndrome" (SARS). SARS is an acute respiratory disease, a disease very similar once on influenza, measles, mumps, dog distemper and bronchopneumonia chickens.
SARS symptoms are fever, dry cough, and shortness of breath or palpitations. Chest x-ray shows a picture of pneumonia. Also, there may be other symptoms - fever, headache, loss of appetite, malaise, and muscle aches, dry skin and diarrhea.
Feature of this disease is the prevalence of symptoms of general intoxication, which overshadow pulmonary manifestations. For such pneumonia unpredictable: they may occur as hard, with the development of life-threatening complications. The disease is difficult to diagnose in the early stages, whereby patients come to the hospital later under the supervision of a specialist.
The incubation period for SARS is three to six, rarely ten days. Studies have shown that during the SARS does not depend on sex, and 70% of the infected are a relatively young person The overall mortality rate is about 4%, with sharp fluctuations in different age groups.
The causative agent of SARS - one of the representatives of coronaviruses. He was identified by 17 March 2003 on materials WHO it was found that the causative agent of SARS is a new type of coronavirus.
Coronaviruses are large RNA-containing viruses that can cause disease in humans and animals. Antigenic properties are divided into three groups. The first group of human respiratory coronavirus 229E, coronaviruses of cats, dogs, pigs. The second - human virus OS43, mouse hepatitis virus and coronavirus calves. The third group includes the enteric coronavirus, human and avian infectious bronchitis virus.
Officially established that the SARS coronavirus is a new, previously never met in humans and animals. A new virus called SARS-associated coronavirus. Its image obtained by electron microscopy.
Virions are spherical in shape with a diameter of 80-160 nm. Virion surface is covered with clavate processes, a length of about 20 nm, giving a crown shape virions.
The virions contain a plus-polyadenylated RNA chain length 16-30 kb (coronaviruses have the largest genome gene of other viruses exceeding three times). Genomic thread (+) RNA coronaviruses, consisting of a single chain, can be broadcast on the ribosomes of the host cell. Virions are produced by budding from the membrane of the rough endoplasmic reticulum and Golgi apparatus. Mature virions are formed inside the cells, before viral proteins are expressed on the cell surface. Released virions are capable of re-adsorbed on the surface of cells, causing them to merge and stimulating the immune response of the host. The main target cells are cells of the alveolar epithelium.
The virus is found in the sputum, plasma (in the acute period); in the faeces - during convalescence. Has a relatively high resistance to the environment. Stored on the exposed surfaces of up to three hours. Rapidly inactivated by disinfectants. Officially, the SARS epidemic began in February 2003. By April 2003 foci of infection have been reported in 32 countries. The total number of cases is about 8.5 thousand. And five thousand p atients registered in China. Although by the end of May 2003 officially ended the epidemic, but sporadic cases are still recorded. The main route of transmission of airborne, but not ruled out the possibility of transmission by direct contact. Susceptibility is low, as evidenced by the small number of cases. The disease was registered only among adults. Most at risk are subject to the elderly.
There are still not exist highly effective treatment methods to cure SARS. Persons with symptoms of SARS are being treated in hospital under constant supervision of a physician and complete isolation from the other patients. Because of the severity of the disease, treatment should begin as soon as possible, according to symptomatic indicators, to confirm the diagnosis.
Antiviral drugs (ribavirin orally or intravenously). Ribavirin is a purine nucleoside with a broad spectrum of activity and antiviral activity is similar to guanosine. Activity of the drug is proved for a large number of RNA-containing viruses. Due to the relatively high toxicity of ribavirin its use should be avoided in persons with impaired immune system (babies, people older than 65 years, recipients of organ and bone marrow, are HIV-positive patients), and in patients undergoing therapy with other drugs - nucleoside analogues (acyclovir, ganciclovir, and so on. d.).
Antimicrobials. Antibiotics have no effect on coronavirus - the etiological agent of SARS, but prevents secondary bacterial flora, and can also affect the bacteria causing pneumonia atypical non-viral origin, these agents may be used up to the final diagnosis.

Inducers of interferon tsikloferon particularly recommended for the prevention and treatment of SARS.

Steroid hormones are used intravenously or orally to relieve the symptoms of inflammation, and the prevention of pulmonary edema.
May be appointed as pulmonary surfactant BL.
Combination therapy with ribavirin and corticosteroids based on a clinical benefit from their use. The best result was obtained by hospital doctors in Hong Kong when administered to patients large doses of combination therapy with ribavirin and corticosteroids.

The most effective recognized the following regimen of patients with confirmed and presumptive diagnosis of severe acute respiratory syndrome.

In the U.S., SARS treatment is carried out in specialized intensive care units, use antivirals, antibiotics of last generation, glucocorticosteroid preparations. Against most viruses - causative agents of pneumonia to date there are no drugs. Use a combination of corticosteroids and antiviral agents such as ribavirin. Commonly used to treat pneumonia antibiotics are not active on the "atypical" pathogens. Drugs of choice for the treatment of SARS are macrolides, which are most active against Legionella, Mycoplasma, Chlamydia, also used some quinolones, tetracyclines.
Given the known routes of transmission of SARS US experts have developed lists of restrictive measures for medical and public institutions. This implies compliance with certain restrictive measures in respect of patients with suspected or confirmed SARS SARS: 1) Standard precautions (hand hygiene); 2) Precautions for direct contact (use of gowns, goggles, gloves); 3) Measures to limit the spread of airborne infection (negative pressure in the room where the patients, the use of disposable respirators N 95).
The international community managed to achieve the first victory over SARS. However, it remains unclear number of questions concerning the epidemiology and pathogenesis of SARS. The main conditions of victory over SARS obvious is the creation of an effective vaccine, the development of highly specific and sensitive diagnostic tests and interrupt the chain of transmission.

References

Alan DL Sihoe; Randolph HL Wong; Alex TH Lee; Lee Sung Lau; Natalie Y. Y. Leung; Kin Ip Law; Anthony P. C. Yim (June 2004). "Severe acute respiratory syndrome complicated by spontaneous pneumothorax". Chest 125 (6): 2345–51. doi:10.1378/chest.125.6.2345. PMID 15189961.
SARS: Chronology of the Epidemic Martin Enserink, Science 15 March 2013: 1266–1271. In 2003, the world successfully fought off a new disease that could have become a global catastrophe. Here's what happened from the first case to the end of the epidemic.
"Remembering SARS: A Deadly Puzzle and the Efforts to Solve It". Centers for Disease Control and Prevention. April 11, 2013. Retrieved August 3, 2013.