Infection Unit 12

Adonis K. Lomibao, R.N.12/19/11

Objectives

Spell & Define key terms Identify most common microbes &

characteristics List links in chain of infection List the ways infectious disease are spread Name & describe 5 serious diseases

Objectives Cont.

Identify cause of important infectious disease Define spores & explain how they differ from

other pathogens Describe common treatments for infectious

disease. List natural body defenses against infection Explain why patients are at risk for infection.

Introduction

Organisms-living beings Microorganisms or microbes-tiny organisms Nonpathogens-microbes that do not cause

disease Pathogens- disease causing microbes

-Grow best at body temp, limited light, moisture,food supply, & oxygen.

Infection- pathogens invade the body & cause disease.

Microbes

4 types

-Bacteria

-Viruses

-Fungi

-Protozoa

Bacteria

Simple one-celled organisms Named according to shapes & arrangement Shapes:

-Coccus- round or spherical

-Bacillus-straight rod

-Spirillum-spiral, corkscrew,slightly curved

Bacteria Cont.

Arrangements:

-single

-pairs:diplo-

-chains:strepto-

-clusters:staphylo- Colonies-groups of growing bacteria

Fungi

2 kinds:

-yeast:single cell budding forms of a fungus. Can affect mouth, skin, & feet

-molds:can cause infections in the lung Parasite: an organism that lives in or on

another organism without benefiting the host. Immuno-suppressed patients at risk

Virus

The smallest microbe Come in a variety of shapes Classified by:

-type of DNA or RNA

-clinical properties Common viruses include:

Hepatitis,Herpes,HIV/AIDS,chickenpox, influenza, common cold,p.156

Protozoa

Once-celled organisms that live on living matter

Classified by how the move...i.e. Whiplike tails, hairlike projections.

i.e. Malaria S&S:Diarrhea, Dysentery(lower bowel

infection), encephalitis

The Chain of Infection

Certain conditions exist for infection to occur COI Includes:

-Causative agent:pathogen that causes disease

-Reservoir or source: where the pathogen can live & reproduce

-Portal of exit: manner in which the pathogen leaves the body

COI Cont.

Method or mode of transmission:manner in which the pathogen is carried to another person

Portal of Entry: manner in which the pathogen enters the body

Susceptible host: a person who will become ill from the entry of pathogens into the body

Object of Infection control is to DISRUPT the chain of infection!!

Causative agent

Microorganism that can produce the disease in humans

Most common causes:

-Bacteria

-Viruses

-Fungi

-Protozoa

Reservoir or source

Where pathogens can survive May or may-not multiply in reservoir Four common reservoirs:

-Humans

-Insects & animals

-Environment

-Fomites:objects that can be contaminated with infectious material that contains the microbe.

Human Reservoirs

2 types;

-Cases:people with acute illness with S&S

-Carriers: persons who can give a disease to others. May not have S&S or know of infections.

Portals of Entry

Organisms enter through:

-breaks in skin or mucous membranes

-respiratory tract

-genitourinary tract

-gastrointestinal tract

-circulatory system

-transplacental

Portals of Exit

Leave the reservoir of host through body secretions

POE Include:

-excretions or resp. tract or genital tract

-draining wounds

-urine

-feces

-blood & body fluids

-Saliva & Tears

Transmission of Disease

Spread of infectious organisms may happen in 3 ways:

-Airborne Transmission

-Droplet Transmission

-Contact Transmission

-Vector Transmission

Host

The person who harbors infectious organisms. Person does not have enough resistance to

agent Infection develops when organism penetrates

the body, begins to multiply, & causes damage Risk factors are conditions that indicate a

problem may develop.

Types of Infections

Local: confined to one area..i.e. Boil or abscess

Generalized: i.e. pneumonia in the lungs Systemic: widespread through bloodstream

Body Flora

Microbes that live in and on our body surfaces Healthy individuals lives in harmony with flora Balance may be disturbed by:

-pathogens

-normal flora that become pathogenic

-flora from on body area to another

-drugs that upset balance and allow one to flourish

How Pathogens Affect the Body

Microbes act in different ways to produce disease:

-Attack & destroy cells they invade

-produce toxins that harm the body

-cause sensitivity responses called allergies

Body Defenses

Intact skin Mucous membranes-sticky & trap foreign

materials Cilia-propel mucus out of body Coughing & sneezing Hydrochloric acid Tears

Internal Defenses

Fever Phagocytes Inflammation Temperature Immune response

Immunity The ability to fight of disease caused by

microbes Antigen- pathogenic microbe that enters the

body Antibodies- provide immunity to disease

caused by that antigen Immunization: Vaccines protect against

specific pathogens Immunosupression: the body's immune

system is inadequate...more likely to develop infections.

Bacterial Infections

Diagnositic: Culture & Sensitivity Antibiotic-antibacterial drug. Common bacterial infections include:

-MRSA & VRE

-Tuberculosis

-Streptococcus A

-Escherichia coli

-Pseudomembranous Colitis(C. Diff)

Spores

Microscopic reproductive bodies that are responsible for the spread of some diseases.

Can survive in a dormant form until conditions are ideal for reproduction

Difficult to eliminate Examples:

-Norovirus

-C. Difficile

Viral Infections

Examples:

-Shingles

-Influenza

-AIDS

-Hantavirus

-Sever Acute Resp. Syndrome

-Smallpox

Parasites

Survive by feeding off another human or animal

Examples:

-Head Lice:spread by direct contact.--Nits(eggs)

-Scabies:caused my microscopic mite.Spread by in/direct contact

-Bedbugs:bites cause painful rash

Self-Care

Healthy diet Get enough sleep Keep your body clean Live in a clean environment Avoid smoking & substance abuse Learn how to cope with stress