Chapter 3
Preventing Disease Transmission
Pathogen – an extremely small disease causing agent. The most common types are bacteria and
viruses. Pathogens can be found in the environment and in:
 Blood
 Semen
 Vaginal secretions
 Cerebrospinal fluid (fluid that flows through the brain and spinal cord)
 Synovial fluid (fluid that lubricates many joints and tendons)
 Pleural fluid (fluid that lubricates the lungs)
 Pericardial fluid (fluid that lubricates the heart and the space it is in)
 Amniotic fluid (fluid that surrounds the fetus during pregnancy)
 Peritoneal fluid (fluid that lubricates the abdominal cavity)
Terms:
1. Communicable disease – an infectious disease that can be transmitted from people,
objects, animals, or insects, directly or indirectly. Some can be transmitted more easily
than others.
2. Infectious diseases – are caused by invasion of the body b a pathogen such as a bacterium,
virus, fungus, or parasite. A disease can be infectious, but not communicable.
3. Infection – occurs when pathogens enter the body and overpower the body’s defense
system.
4. Bacteria – one-celled organisms that live everywhere in our environment. They do NOT
depend upon other organisms for life and can live outside of the body. Examples of
diseases caused by bacteria: TB, meningitis, scarlet fever, tetanus. Can be treated with
antibiotics.
5. Virus – depend upon other organisms to live. Once they become established in the body,
they are difficult to eliminate since few medications will treat them. The body’s immune
system is the primary defense against viral infections.
Conditions Necessary for Disease Transmission:
 Pathogen present
 Sufficient quantity of pathogen to cause disease
 Person vulnerable to the disease
 Transmission at correct entry site
How Pathogens Enter the Body
 Direct contact
 Indirect contact
 Airborne
 Vector-borne
Direct contact transmission – occurs when a person touches an infected person’s body fluids.
Indirect contact transmission – occurs when a pe4son touches objects that have been
contaminated by the blood or another body fluid of an infected person. Examples – dressings,
anything with blood on it, contaminated sharp objects.
Airborne transmission – occurs when a person inhales infected droplets that have been airborne as
an infected person coughs or sneezes.
Vector transmission – occurs when an animal, such as a dog or raccoon, or an insect, such as a
tick, transmits a pathogen into the body through a bite.
Diseases that cause concern
1 – Herpes simplex - virus
 Symptoms – lesions, general ill feeling, sore throat
 Transmission – direct contact (highly contagious)
 Infective material – broken skin, mucous membranes
2 – Meningitis – virus or bacteria
 Symptoms – respiratory illness, sore throat, nausea, vomiting, headache, stiff neck
 Transmission – airborne, direct and indirect contact
 Infective material – food and water; mucus
3 – Tuberculosis – bacteria
 Symptoms – coughing, weight loss, night sweats, occasional fever, general ill feeling
 Transmission – airborne
 Infective material – saliva, airborne droplets
4 – Hepatitis – alcohol abuse, drubs, or other chemicals – this form cannot be transmitted. There
are types that are caused by viruses: A, B, & C
 Symptoms – flu-like, jaundice
 Transmission – direct and indirect contact
 Infective material – blood, saliva, semen, feces, food, water, other products
5 – HIV infection – virus
 Symptoms – fever, night sweats, weight loss, chronic diarrhea, severe fatigue, shortness of
breath, swollen lymph nodes, lesions
 Transmission – direct and indirect contact
 Infective material – blood, semen, vaginal fluid, breast milk
If an exposure occurs:
 Wash any area of contact as quickly as possible
 Document the situation in which the exposure occurred
 Follow work place protocols. They should include:
o Type of exposure covered
o List of immediate actions to be taken
o When or how quickly to report incident
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Where and to whom to report incident
Which forms should be completed
Directives for incident investigation
Medical follow up to be completed
If you think you have been exposed to a communicable disease, it is YOUR responsibility
to notify your superiors
The medical facility may test to see if the victim has a communicable disease
If there is a disease present, you will be notified
Summary - Exposure Control Plan
 Exposure determination
 Schedules and methods for implementing OSHA standards
 Procedures for evaluating exposures
 Immunizations
Standard Precautions (BSI-body substance isolation) to Prevent Disease Transmission
 Protective equipment
 Personal hygiene practice
 Engineering controls
 Work practice controls