Introduction
Severe acute respiratory syndrome (SARS) is a communicable disease that is caused by the virus SARS corona virus (SARS-CoV) (Coronavirus Research and SARS, 2004) The disease started in South China in early 2002. During the outbreak, mortality was highly dependent on age. Older people succumbed to the disease more than younger people did. The disease has not yet been eliminated from the human population. Scientists claim that it exists in natural reservoirs and may return to the human population any time.
Pathogen involved
SARS is caused by a virus in the coronavirus family known as SARS corona virus (SARS-CoV) (Coronavirus Research and SARS, 2004).
The defense-host disease
Both adaptive and innate immune responses are involved in SARS infections. However, adaptive responses are more involved because replication of the virus outpaces innate immune responses (Overview of the SARS, 2004). Both responses are involved because their interaction is very important.
Adaptive responses cannot be elicited without innate responses. After infection, the immune system uses nonspecific immune defenses to contain the spread of the virus in the body. In addition, it uses antigen specific immune responses to fight the virus. The main aim of these immune responses is to eradicate both host cells and virus particles involved.
Infection and transmission
SARS is transmitted through person-to person contact (Overview of the SARS, 2004). Transmission involves exposure of individuals to infectious droplets from infected people. In addition, it is transmitted through direct physical contact with body fluids of infected individuals (‘Overview of the SARS Epidemic’, 2004). Infectious agents are transmitted when the mucous membrane of the nose, eyes or mouth comes into direct contact with infected respiratory droplets or fomites.
Particles of the virus contained in transmitted respiratory droplets are the main cause of the disease. The particles attack epithelial cells and the lining of the mucosal membrane (‘The public health response to SARS’ 2004). With the aid of the synthetic mechanisms of host cells, the virus cells replicate and release new virus particles that attack other cells.
Clinical manifestations
The disease manifests itself through symptoms and signs that are typical to flu-like infections. These symptoms include chills, muscle and body aches, fever, and in some cases, diarrhea (The public health response to SARS 2004). After a week of infection, symptoms include dry cough, fever of 38 degree Celsius, and shortness of breath. If the disease is not diagnosed and treated early enough, it may progress to pneumonia or respiratory failure. In severe cases, it progresses to death.
Diagnosis and control
Diagnosis of SARS involves different types of tests. These tests include blood clotting tests, complete blood count (CBC), chest X-ray or chest CT scan, and blood chemistry tests (Denison, 2004). These tests take time to give results. However, health professionals use other tests that give quick results.
These tests include antibody tests, direct isolation of the virus, and rapid polymerase chain reaction (PCR) for the virus (Coronavirus Research and SARS, 2004). These tests have limitations because they cannot identify the virus during the first week of infection when the disease is most critical.
Control of SARS involves avoiding contact with infected people, avoiding travel to areas with outbreaks, and cleaning hands with alcohol-based disinfectants (Denison, 2004). In addition, avoiding sharing things such as utensils and food, wearing masks and goggles are also effective control methods (‘The public health response to SARS’ 2004). It is also advisable to close one’s mouth and nose when sneezing to avoid transmitting the virus to others in case one is infected.
References
‘Coronavirus Research and SARS‘ 2004, in S Knobler, A Mahmoud, S Lemon, A Mack, L Sivitz, and K Oberholtzer (eds.), Learning from SARS: Preparing for the Next Disease Outbreak, National Academies Press, Washington, pp. 19-22. Web.
Denison, M 2004, ‘Coronavirus Research: Keys to Diagnosis, Treatment, and Prevention of SARS‘, in S Knobler, A Mahmoud, S Lemon, A Mack, L Sivitz, and K Oberholtzer (eds.), Learning from SARS: Preparing for the Next Disease Outbreak, National Academies Press, Washington, pp. 149 – 157. Web.
‘Overview of the SARS Epidemic‘, 2004, in S Knobler, A Mahmoud, S Lemon, A Mack, L Sivitz, and K Oberholtzer (eds.), Learning from SARS: Preparing for the Next Disease Outbreak, National Academies Press, Washington, pp. 2-13. Web.
‘The public health response to SARS‘ 2004, in S Knobler, A Mahmoud, S Lemon, A Mack, L Sivitz, and K Oberholtzer (eds.), Learning from SARS: Preparing for the Next Disease Outbreak, National Academies Press, Washington, pp. 13-19. Web.