Running head: MICROBIOLOGY 100 MODULE 5 Microbiology 100 Module 5 July 29, 2009 Microbiology 100 Module 5 Severe acute respiratory Syndrome (SARS) is the respiratory disease caused by the SARS-associated coronavirus SARS-CoV, however, there are assumptions that other infectious agents can have a role in some cases of SARS viral infection (Peiris, Yuen, & Osterhaus, 2003).
There are few major characteristics of SARS which account for its spread and the severity: infectivity (the ability of the virus to cause infection by entering the host and multiplying to an infectious dose), resistance (the ability of the virus to survive under adverse environmental conditions), and virulence (the ability of the virus to cause mortality).
In order to justify your reasons for selecting the characteristics of SARS as described above it is important to gain more knowledge about the virus. The SARS associated coronavirus has specific shape, a core is surrounded by spherical protein shell, which is covered with extruding surface proteins forming a halo (corona) that is typical for coronavirus. The resistance level of SARS is quite high, as the virus remains stable in feces and urina at room temperature for minimum 1-2 days and can remain more stable in stool from diarrhea patients (as diarrhea patients have higher pH in their stool than normal) for at least 4 days (Pang, Zhu, & Xu, 2003).
Running head: MICROBIOLOGY MODULE 1 Microbiology Module I July 14, 2009 Microbiology Module I Microbiology Module 1 Part A Dear Editor, Few days ago I have read the article published in a local newspaper claiming that Edward Jenner was the greatest microbiologist of all time and made the greatest contribution to public health. Although I do honor Edward Jenner and do consider him to be one of the ...
Although SARS loves its infectivity when it is exposed to various commonly used fixatives and disinfectants, its survival rate in cell-culture supernatant is very high, as there is an insignificant reduction in concentration of the SARS coronavirus after 21 days at 4C and -80C temperature.
As far as the reduction in concentration of SARS virus is by 1 log at a stable room temperature for two days, SARS is considered one of the most stable human coronaviruses. The virus has high level of resistance to high temperatures, as exposure to heat at 56C eradicates SARS at around 10,000 units/15 minutes (Jernigan, Low, & Helfand, 2004).
Finally, in laboratory conditions the virus exposed to fixatives (fixation on glass sides for immunofluorescence assays at a stable room temperature) does not eradicate SARS unless the acetone is cooled to -20C (S., Chang, & Cheung, 2003).
In addition, according to the first scientific studies conducted by the scientists in the WHO network of collaborating laboratories that were aimed to determine survival time of SARS virus in different environmental conditions, the virus is able to survive after drying on plastic surfaces for up to 2 days (Public Health Guidance for Community-Level Preparedness and Response to severe acute respiratory syndrome (SARS) Version 2/3).
The studies conducted in Japan, Hong Kong and Germany report similar results (Severe Acute Respiratory Syndrome (SARS)).
According to them, SARS cornavirus survives in faeces for at least 48 hours, and in urine for at least 1 day. Yet, the exact dose of SARS coronavirus required to cause infection still remains unknown.
The researchers consider that further research is required before they can assert about faecal-oral transmission of SARS virus (SEVERE ACUTE RESPIRATORY SYNDROME (SARS)).
All scientific studies place emphasis on the importance of proper cleaning, frequent handwashing and proper disinfection control in hospital and other medical settings with patients suffering from SARS virus. The major way of SARS transmission remains spread by infected droplets (What Everyone Should Know About SARS).
Overview In the following report, "computer viruses" will be explained in detail. A lengthy and informative description of the evolution and history on microcomputer viruses will be given, to give you a background of their origin for some understanding of how they came to be. The next segment in the report is on how to combat computer viruses with the development of anti-virus applications. The ...
Frequent handwashing and proper personal hygiene is important in all locations where contact with SARS transmitters is possible because shedding of SARS virus in respiratory secretions, faeces and urine is confirmed by the results of numerous scientific studies. Therefore, due to high level of virus resistance SARS poses a significant threat to population. SARS has a high level of infectivity. Recent outbreaks of SARS coronavirus lead to 4280 probable SARS cases and 206 deaths in China, which accounts for 65% of the worlds total number of SARS infection cases and 44% of all reported deaths.
As far as SARS coronavirus is transmitted through close contact with respiratory droplets containing virus, the major way of transmission of close person-to-person contact. Therefore, the patient suffering from SARS transmits virus and infects healthy people (Guan, Zheng, & He, 2003).
Basically, spread of SARS coronavirus occurs through deposition of respiratory droplets onto the mucous membranes of the nose, mouth or eyes that were released by infected person through airborne transmission after a sneeze or cough. Respiratory droplets are able to spread over 3 feet (Xu, He, & Evans, 2004).
The person who lived with the infected patient or the one who had direct contact with the respiratory secretions or body fluids of SARS infected person can get infected with SARS. The examples of close contact include but not limited to hugging, kissing, directly touching infected person, talking to the infected person within three feet, sharing eating utensils or sharing drinking utensils, to mention a few. Therefore, tourists can easily get infected in a country with high rates of SARS infection (e.g., China).
In addition, the spread of SARS occurs through feces, sewage, food, air, water and other possibilities, therefore, infectivity is the most significant factor that causes people to worry and cancel their travel plans (especially to China, as China remains the leading country in terms of SARS cases and deaths).
Smallpox Smallpox was a disease that was caused by a virus. The virus spread when an uninfected person came in direct contact with a sick person and breathed in the virus. Usually, the virus was in tiny drops that were coughed up by the sick person. After about two weeks the infected person would develop a high fever and muscle aches and pains. After about three days of fever the person would ...
References Guan, Y., Zheng, B., & He, Y. (2003).
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The severe acute respiratory syndrome. N Engl J Med , 349, 2431-41. Public Health Guidance for Community-Level Preparedness and Response to Severe Acute Respiratory Syndrome (SARS) Version 2/3. (n.d.).
Retrieved July 29, 2009, from http://www.cdc.gov/ncidod/sars/guidance/index.htm S., O., Chang, H., & Cheung, T. (2003).
Transmission of the severe acute respiratory syndrome on aircraft. N Engl J Med. , 349, 2416-22.
Severe Acute Respiratory Syndrome (SARS).
Retrieved July 29, 2009, from http://www.who.int/csr/sars/en/ SEVERE ACUTE RESPIRATORY SYNDROME (SARS).
Retrieved July 29, 2009, from http://enhs.umn.edu/current/5103/SARS/transmission .html What Everyone Should Know About SARS. (n.d.).
Retrieved July 29, 2009, from http://www.cdc.gov/ncidod/sars/basics.htm Xu, R., He, J., & Evans, M. (2004).
Epidemiologic clues to SARS origin in China. Emerg Infect Dis. , 10, 1030-7..