114 Unit 1 Introduction to Healthcare Copyright Goodheart-Willcox Co., Inc. The Chain of Infection During a hospital stay, a patient does not expect to acquire an infection. Unfortunately, patients often do acquire new infections while in the hospital. Hospital-acquired infections are called nosocomial infections, also known as healthcare-acquired infections or healthcare-associated infections. Nosocomial infec- tions can cause pneumonia and infections of the bloodstream, the urinary tract, and other parts of the body. The reduced infection resistance of hospital- ized patients contributes to the rate of nosocomial infections. Learning the various aspects of infection can help you prevent nosocomial infections. There are many modes of transmission of infection. As a healthcare worker, you should be familiar with all of them. One mode is direct contact, such as per- son-to-person contact or contact with infectious body secretions (contamination on hands). Another is indirect contact, in which a pathogen comes from food, air, soil, feces, instruments, equipment, clothing, and so on. Vectors, such as insects, rodents, or other small animals, can spread pathogens by biting a host. As part of a team working continually to prevent the spread of infection, you need to understand the various ways that infection can be transmit- ted from person to person. The chain of infection is used to visualize the sequence of events that allows infection to invade the human body. This sequence consists of an infectious agent, reservoir or host, portal of exit, mode of transmission, portal of entry, and susceptible host (Figure 4.12). The infection control department of a healthcare facility focuses on interrupting the chain of infection before the infection spreads throughout the hospital. Once it becomes clear that an infection has developed, the clinical laboratory must identify the infectious agent as soon as possible. Appropriate treatment must be started immediately. Several methods are used to break the chain of infection to control the spread of infection. The remaining sections of the chapter examine the most common and important methods. Hand Hygiene Employees must maintain excellent hygiene, which includes hand hygiene. Hand hygiene is considered the single most important way to prevent the spread of infection. It can be accomplished through hand washing with a detergent or antimicrobial soap and water, or by applying an alcohol-based hand rub. Hand sanitizers do not kill the microorganisms that cause severe gastrointestinal infec- tions such as Clostridium diffi cile (or C. diffi cile) or the Norovirus. Alcohol-based hand wipes have been found to be useless against any viruses not coated in lipid envelopes. In an effort to prevent the spread of infection, the CDC has issued hand hygiene guidelines for healthcare workers. These guidelines state that hands should be washed 1. before and after eating 2. after the restroom has been used and 3. when dirt or body fl uids such as blood, mucus, urine, and feces are visible on the hands. nosocomial infections infections acquired in hospitals and other healthcare facilities also known as healthcare- acquired infections direct contact a type of infection transmission in which the pathogen travels directly from one host to another, such as in person-to-person transmission indirect contact a type of infection transmission in which the pathogen takes an indirect path—such as through food, air, or clothing—to its next host vectors carriers—such as insects, rodents, or other small animals—that spread pathogens from host to host chain of infection the sequence of events that allows infection to move from one source or host to another hand hygiene hand washing with a detergent or antimicrobial soap and water, or by applying an alcohol-based hand rub considered the single most important way to prevent the spread of infection