Which microorganisms are responsible for causing disease?
Control of Disease in Healthcare:
-how can microorganisms be moved
from place to place in a predictable and cyclic manner
Pathogens can cause disease in a _________ of manners
What is the CHAIN OF INFECTION?
- Six links present in a cyclic format that illustrate the manner in which pathogens are spread potentialy causing disease.
- 1) Causative Agent
- 2) Reservoir
- 3) Portal of Exit
- 4) Method of Transmission
- 5) Portal of Entry
- 6) Susceptible Host
Chain of Infection 1: CAUSATIVE AGENT
A pathogenic organism such as a bacteria, virus or fungus
Chain of Infection 2: Reservoir
- Place where pathogen hides, grows & multiplies
- This is the resevoir host
- May be an animal, human, an object, an insect or virtually anything in the environment including food & water
Chain of Infection 3: Portal of Exit
- The way the pathogen leaves resevoir/host (generally body secretions)
- Various ways of exitting
- Blood, semen, vaginal secretions, breast milk, tears, urine, feces and wound drainage
Chain of Infection 4: Method of Transmission
-what is it
-what are the three types
- Once the pathogen leaves the host, it must be transmitted to another host via..
- Body surface to body surface (body fluids/hands)
- Heard most commonly in health care
Contact with contaminated food, water, items or equipment (whirpool water, reused electrodes)
Infection by cough/sneeze (droplets containing microorganisms are propelled a short distance )
Three Types of Non-Contact Transmission
- Vehicle-contaminated items
- Airborne-evaporated droplets that remain suspended in air for a period of time
- Vectorborne: transmitted through insects or rodents (lime disease)
Chain of Infection 5: Portal of Entry
- Pathogens require a means to enter a new host
- --Digestive tract
- --Reproductive tract
- --Respiratory tract
Chain of Infection 6: Susceptible Host
--what is this
--what are 3 factors which decrease immune system response?
- Low or Limited systemic resistance to the organisms
- --increased stress
- --decreased sleep
- --poor nutrition
Standard Precautions (3 things to know about these)
- Care of ALL patients in health care setting
- Applied to ALL body fluids, secretions, and excretions regardless of infection or diagnosis
- Application varies depending upon nature of interaction between patient and provider
What are some Standard Precautions (6)
- Hand Washing
- Special Attension for Blood Borne Pathogens (Hepatits & HIV primarily)
What are the two minor additions to existing Standard Precautions recommended during course of outbreak investigations such as SARS & H1N1?
- Cough Etiquette
- Hand Hygiene (hand washing before and after everytime you see a patient)
Transmission-Based Precautions for Airborne Pathogens (evaporated droplets in air or contaminated dust that is infectious over a long distance)
- Private Room w/ air pressure control (chicken pox/tiburculosis)
- Patient should remain in room
- Personnel should war respiratory protection (N-95 mask) when entering the room -- custom fit pressure mask that covers the nose & mouth
Transmission Based Precautions for Droplets
--contamination through sneezing, coughing, & talking-- close contact transmission
- Visitors and staff should keep a greater than 3 feet distance or wear mask
- Patients may share a room with another patient with the same infection
--direct & indirect contact--
- Gloves required
- Use of personal protective equipment
- Dedicated equipment whenever possible; disposables recommended
- Prioritized cleaning of patient areas
- Procedures used for a patient with an unusualy high risk of becoming infected through contact with another person
- Bone Marrow Transplant
- Organ Transplant
- Severe and Extensive Burns
- Any person who enters the room must apply protective garments such as gloves, gown and mask
Techniques used to eliminate all pathogens in the area
Techniques used to keep pathogens confined to specific areas
Infections that develop in a health care setting--HAI-Healthcare Associated Infection
Health Associated Infection
What is the most effective method to reduce the transmission of pathogens?
- Routinely perform hand hygiene
- --Start & end of day
- --Before & after each patient contact
- --Before & after application of gloves
What are the 3 antibiotic resistant Infections?
- MRSA (Methicillan Resistant Staphylococcus Aureus)
- VISA (Vancomycin Intermediate S. Aureus)
- VRE (Vancomycin Resistant Enterococcus)
Two Blood Borne Pathogens
Methicillan Resistant Staphylococcus Aureus
Vancomycin Intermediate S. Aureus
Vancomycin Resistant Enterococcus
Wounds that result from venous insufficiency most commonly occure where?
Over the medial malleolus
What do the veins lack that the arteries have which provides a problem for venous blood return to the heart?
Veins do not have an intrisic pumping system like the arteries.
In which type of patients would we most likely see a wound resulting from venous insufficiency due to the inability of the cardiovascular system to pump blood back to the heart?
Usually cancer patients who have adema in the lower extremities, but they have normal pulses
In which position would a patient normally feel most comfortable if they have a would which was the result of venous insufficiency?
What is a wound?
A discontinuity in the skin and underlying tissues that may result from a variety of sources
Scrape, scratch; outer layers of the skin are scraped away
A small but deep wound as in trauma
A slice type cute
A purposeful cut as in surgery
Wearing down of tissue
The process of inflammation and healing occurs in overlapping phases differentiated by specific cell populatons and ativities. These cellular activities are dependent on a number of factors including...
- Enzyme Activity
- Optimal PH
- Temperature of the tissue
- Moisture is a key element in a positive would healing environment (not dry, but not too wet)
Three Stages of Wound Healing
The stages of wound healing are ______________ with _____________ time frames
Two results of wound healing
Regeneration & Repair
Complete restoration of the original state of a tissue (for small wounds)
Results in a scar (traumatic healing)
Wounds heal with edges that are closely approximated or surgically repaired with sutures, staples, steri-strips
Wounds that are large with significant tissue loss and edges that may be retracted. These wounds heal by the gradual filling in of the wound with granulation tissue. Heal from the bottom up
Common Types of Wounds--Pressure Ulcer
Caused by excessive pressure to soft tissue that exceeds local capillary pressure and by friction and shearing forces