There are several causes to pneumonia including viruses, bacteria, mycoplasmas (small, free-living particles with characteristics of both bacteria and viruses), and fungi. Infection with the Streptococcus pneumoniae bacterium, also called pneumococcus, is the most common cause of bacterial pneumonia. Streptococcus Bacteria This scanning electron micrograph shows disease-causing Streptococcus bacteria, commonly found in the human mouth, throat, respiratory tract, bloodstream, and wounds. Often airborne in hospitals, schools, and other public places, Streptococcus bacteria are responsible for infections such as strep throat, scarlet fever, and some types of pneumonia.
b. Transmission Since pneumonia is a disease which attacks the human ventilation system, it is most commonly spread through sneeze and or cough droplets. The droplets from coughing or sneezing from people who has been infected by pneumonia contain bacteria (pathogens). Another person can be infected easily if they breathe in the droplets, because then the bacteria would have enter the lungs and starts to grow and divide there.
c. Effects (Symptoms) Pneumonia causes inflammation of one or both lungs. In people with pneumonia, air sacs in the lungs fill with fluid, preventing oxygen from reaching blood cells and nourishing the other cells of the body. In bacterial pneumonia, the usual symptoms include a shaking chill followed by a fever of about 40�C (104�F), pain in the chest while breathing, a cough, and blood-streaked sputum. In bronchopneumonia, the inflammation occurs in scattered patches in the tissue around the ends of the bronchioles, the smallest air tubes in the lungs. In lobar pneumonia, the inflammation is widespread and involves an entire lobe of the lung. In the United States about 5 million cases of pneumonia are reported each year and about 63,500 people die from the disease.
Antibiotics Antibiotics are agent that destroys bacteria: a substance that is able to kill or inactivate bacteria in the body. Antibiotics are derived from microorganisms, especially fungi, or are synthetically produced. a. Antibiotics are commonly prescribed with to help the body to fight bacterial diseases. Antibiotics such as has been used to treat bacterial pneumonia. b. Antibiotics are useless against viruses because virus does not carry out the process of growth and reproduction themselves. They rely on host cells to carry out the process for them. Thus it is not possible to block these processes without also harming the host cells, and therefore viruses cannot be treated by antibiotics.
II. Defense against Infectious Disease: Non Specific Immunity & Specific Immunity 6. Non-specific and specific immunity Non Specific immunity is a quick-response system, which is present from birth. It is very effective against a wide range of pathogens and foreign substances, and it always gives the same type of response. Specific immunity is an immunity system which is effective against specific pathogens, but reacts slowly. This includes cells and protein within the blood and lymph, which attack, disarm, destroy and remove foreign bodies. 7. Barriers to infection (features of the human body which prevent micro-organism from entering the body)
Feature Role Skin Form membranes that prevent most cells from entering the body. The outer layer of the skin is tough and rough forms a physical barrier. The sebaceous gland secretes lactic and fatty acids, which prevents the growth of most pathogenic bacteria. Mucous Lysozyme, an enzyme found in mucous membranes, kills bacteria. Cilia Cilium/cilia are microscopic projections on cell. Tears The tear fluid lubricates the eyes, and protects them from foreign matter and infection-the latter because it contains salt and lysozyme, an enzyme that kills microorganisms. Stomach Acid Hydrochloric acid in the stomach kills microorganisms that may have been ingested in the food. + Mucin coats the stomach, protecting it from the effects of the acid and pepsin.