infection prevenion and control

INFECTION PREVENTION AND CONTROL
Infection cycle
An infection is a disease state that results from the presence of pathogens in or on the body. A pathogen is a disease producing microorganism. A infection occurs as a result of a cycle process, as shown in figure 28-1. the six components in the infection cycle are as follows :
- Infectious agent
- Reservoir
- Portal of exit
- Means og transmission
- Portal of entry
- Susceptible host
Infectious agent. Some of the more prevalent agent that are capable of causing infection include bacteria, virus and fungi. Bacteria are the most significant and most commonly observed infection causing agents in healthcare institutions. Bacteria can be categorized is various ways. According to shape, they are classified as spherical (cocci), rod-shaped (bacilli), or corkscrew (spirochetes). Based on their reaction to the gram stain bacteria may be either gram positive or gram negative. Gram positive bacteria have a tick cell wall that resists decolonization (loss of color) and are stained violet. Gram negative bacteria have chemically more complex cell walls and can be decolorized by alcohol. This difference is vital information when the physician is selecting an antibiotic to prevent or treat an infection. Antibiotic may be either specifically effective against only gram positive organism or classified as broad-spectrum and be effective against several groups of microorganisms.
Another distinguishing characteristic of bacterial is their need for oxygen. Most bacteria require, oxygen to live and grow and are referred to as aerobic. Those that can live without oxygen are anaerobic bacteria.
A virus is the smallest of all microorganism and can be seen only by using an electron microscope. Many infections are caused by viruses, including the common cold and the deadly disease acquired immunodeficiency syndrome (AIDS)
Fungi are plantlike organism (molds and yeasts) that also can caused by infection. They are present in the air, soil, and water, and many are resistant to treatment. An organism’s potential to produce disease depends on a variety of factors including the following :
- number of organisms
- virulence of the organism, or its ability to cause disease
- competence of person’s immune system
- length and intimacy of the contact between a person and the microorganism
Under normal conditions, an organism may not produce disease. Microorganism that commonly inhabit various body sites and are part of the body’s natural factors may intervene and cause this relatively harm less organism to become the source of an infection. Bacteria that may potentially be harmful are referred to opportunists.