Chapter 14 Infection Control

14.1
Classes of microorganisms
A microorganism, or microbe, is a small living organism that is not visible to the naked eye. It has to be viewed under a microscope. Microorganisms that are beneficial in maintaining certain body processes are called nonpathogens. Microorganisms that cause infection and disease are call pathogens, or germs. The five classes of microorganisms are bacteria, protozoa, fungi, rickettsiae, and helminths. Bacteria is a one celled organism that multiplies rapidly. They are classified by shape and arrangement. Cocci are round or spherical. Diplococci means that the cocci are in pairs so diplococci bacteria casues gonorrhea, meningitis, and pneumonia. If cocci occur in clusters, then it is called staphylococci. Staphylococci causes infections like boils, urinary tract infections, wound infections, and toxic shock. Protozoa is a one celled animal like organism often found in decayed materials, animal or bird feces, insect bites, and contaminated water. Some protoza are pathogenic and cause diseases such as malaria, amebic, dysentery, trichomonas, and African sleeping sickness. Fungi is a simple, plant like organism that live on dead organic matter. Yeasts and molds are two common forms that can be pathogenic. Antibiotics do not kill fungi. Rickettsiae is a parasitic microorganisms which means they cannot live outside the cells of another living organism. Found in fleas, lice, ticks, and mites, and are trasmitted to humans by the bites of these insects. Antibiotics are effective against many different rickettsiae. Viruses are the smallest microorganisms, visible on using an elctron microscope. Viruses cannot reproduce unless they’re inside another living cell. Spread from human to human by blood and other body secretions. It can cause many diseases such as common cold, measles, influenza, mumps, chicken pox, herpes, warts and polio. Hepatits B or serum hepatits is caused by the HBV virus is transmitted by blood, and serum. Hepatits C is caused by the hepatitis C virus, or HCV and is transmitted by blood and blood-containing body fluids. Helminths are multicellular parasitic organisms commonly called worms or flukes. They are transmitted to humans when humans ingest the eggs or larvae in contaminated food,ingest meat contaminated with the worms, or get bitten by infected insects. Worms can penetrate the skin to enter the body.

Chain of Infection
There are six parts that belong under chain of infection. They are causative agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host. Causative agent is a pathogen, such as bacterium or virus that can cause a disease. Causative agent can be broken down by early recognition of signs of infection and rapid, accurate identification of organisms. Reservoir is an area where the causative agent can live. Reservoir can be broken down by medical asepsis, standard precautions, employee health, environmental sanitation, and disinfection/sterilization. Portal of exit is a way for the causative agent to escape from the reservoir in which it has been growing. It can be broken down by medical asepsis, personal protective equipment, handwashing, control of excretions and secretions, trash and waste disposal, and standard precautions. Mode of transmission is a way that the causative agent can be transmitted to another reservoir or host where it can live. The pathogen can be transmitted by direct contact (physical or sexual contact) or indirect contact when the pathogen is transmitted by air, food, soil and insects. Mode of transmission can be broken down by transmission-based precautions, food handling, air flow control, medical asepsis, sterilization, handwashing, and standard precautions. Portal of entry is a way for the causative agent to enter a new reservoir or host. Pathogens can enter the is through breaks in the skins, breaks in the mucous membrane, the respiratory tract and the circulatory