Infection Control

• Understanding basic principles is essential for health care agencies to control / prevent the spread of infection

Microorganisms

• Small living plant or animal

• Not visible to the naked eye

• Viewed by microscope• Everywhere in our

environment• Many are a natural part

of our body

Significance of the Normal Flora

The normal flora influences the anatomy, physiology, susceptibility to pathogens, and morbidity of the host.

    Skin Flora

The varied environment of the skin results in locally dense or sparse populations, with Gram-positive organisms (e.g., staphylococci, micrococci, diphtheroids) usually predominating.  Oral and Upper Respiratory Tract Flora

A varied microbial flora is found in the oral cavity, and streptococcal anaerobes inhabit the gingival crevice. The pharynx can be a point of entry and initial colonization for Neisseria, Bordetella, Corynebacterium, and Streptococcus spp.  Gastrointestinal Tract Flora

Organisms in the stomach are usually transient, and their populations are kept low by acidity. Helicobacter pylori is a potential stomach pathogen that apparently plays a role in the formation of certain ulcer types. In normal hosts the duodenal flora is sparse. The ileum contains a moderately mixed flora (106 to 108/g of contents). The flora of the large bowel is dense and is composed predominantly of anaerobes. These organisms participate in bile acid conversion and in vitamin K and ammonia production in the large bowel. They can also cause intestinal abscesses and peritonitis.    Urogenital Flora

The vaginal flora changes with the age of the individual, the vaginal pH, and hormone levels. Transient organisms frequently cause vaginitis. The distal urethra contains a sparse mixed flora; these organisms are present in urine specimens unless a clean-catch, midstream specimen is obtained

Benefits of Flora• Normal flora takes up space and nutrients that

would otherwise be used by pathogens• Actively antagonize pathogens by producing

substances that inhibit or kill them• Provide constant stimulation of the immune

system that will react with pathogenic species• Aids in development of gut-associated lymphoid

tissue which increases immune response• Enhances capillary development• Synthesize Vit K & B absorption which has been

shown to aid in immune response

• Pathogens

• Disease producing microorganisms

• Non-pathogens

• Non disease producing microorganisms

• Microbes

Microorganisms

The Five Classifications of Microorganisms

• Bacteria• Simple, one-celled organism• Have no nucleus• Neither plant nor animal• Multiply rapidly• Classified by their shape /

configuration• Treated with antibiotics

• Shape of Bacteria/ Naming

• Cocci - sphere

• Bacilli - rods

• Spirilla - spirals

• Staph - in clusters

• Strep - in chains

• Google Image Result for http://www.aenvirocure.com/DB_DATA/contams/organic/images/bacteria_pili.jpg

Protozoa

• One celled animals• Smallest of all animals• Live in water or in moist

areas• Found in abundance in

contaminated water– Malaria– Amebic dysentery– African sleeping sickness

• low access to clean water has had many health implications in Uganda

• according to a study carried out in 2002, diarrhoea alone accounted for approximately 19% of infant mortalities in the country

• statistics indicate that malaria is the leading cause of child morbidity

• approximately 70,000 to 100,000 children in Uganda die every year from malaria

• this represents 30% of the country’s child mortality rates (between the ages of 2 and 4), and accounts for 23% of total disability

• the average expenditure on malaria-related treatments are as high as US $300 million annually.

Fungi / Fungus

• Simple plant like organisms

• Some good / some bad• Live on dead organic

matter• Yeast / Mold• Ringworm • Athletes foot• Jock Itch• Thrush

Rickettsiae

• Between a bacteria & Virus

• Cannot live outside a living organism

• Many can be treated with antibiotic

• Usually transmitted to humans by vectors

Vectors

Bite to obtain blood

Spread pathogens with this bite

Virus

• Types of Microbes: Viruses• Smallest of all Microorganisms• Cannot reproduce outside another living cell• Literally takes over the host cells functions• Spread human to human by blood and body

secretions• Difficult to kill , resistant to disinfectants, not

affected by antibiotics• Common cold, HIV, mumps, chickenpox,

herpes, warts, flu, and polio

• The Origin of HIV and the First Cases of AIDS• HIV• Human immunodeficiency syndrome• a condition in humans in which the immune system begins to fail, leading to life-

threatening opportunistic infections • Infection with HIV occurs by the transfer of blood, semen, vaginal fluid, pre-ejaculate, or

breast milk. Within these bodily fluids, HIV is present as both free virus particles and virus within infected immune cells

• The four major routes of transmission are unprotected sexual intercourse, contaminated needles, and transmission from an infected mother to her baby at birth, or through breast milk

• World Health Organization (WHO) estimate that AIDS has killed more than 25 million people since it was first recognized on December 1, 1981, making it one of the most destructive pandemics in recorded history

• At the end of 2003, an estimated 1,039,000 to 1,185,000 persons in the United States were living with HIV/AIDS

• In 2005, 37,331 cases of HIV/AIDS in adults, adolescents, and children were diagnosed in the 33 states

Two viruses of major concern to HC workers

• No, mosquito bite can not cause AIDS. When a mosquito transmits a disease agent from one person to another, the infectious agent must remain alive inside the mosquito until transfer is completed. If the mosquito digests the parasite, the transmission cycle is terminated and the parasite cannot be passed on to the next host. Studies with HIV clearly show that the virus responsible for the AIDS infection is regarded as food to the mosquito and is digested along with the blood meal. As a result, mosquitoes that ingest HIV-infected blood digest that blood within 1-2 days and completely destroy any virus particles that could potentially produce a new infection. Since the virus does not survive to reproduce and invade the salivary glands, the mechanism that most mosquito-borne parasites use to get from one host to the next is not possible with HIV. AIDS is spread by direct contact with infected blood and sexual secretions. Direct contact includes having sex with an infected person, sharing needles with an infected person, receiving HIV-infected blood or organ transplants, or transfer from an infected mother to newborn baby.

Can a mosquito spread AIDS ?

Why is HIV dangerous to HC workers?

• Cannot live outside host cell for more than a few seconds

• Is not easily spread human to human• Spread through contact w/ blood & body fluids• HC workers handle blood / body fluids constantly

HIV - Wikipedia, the free encyclopedia

Hep B

• Transmitted through infected blood and body fluids

• Lives outside the body for at least 7 days• 200 x easier to become infected with Hep

B than with HIV• Vaccine exists• 500 healthcare workers hospitalized

annually • 200-300 healthcare workers die annually • Look at this fact sheet

Microorganisms

• Warm – Dark – Moist – Food Source

• Internal Body is perfect environment

•kimicontrol educational LEGIONELLA PNEUMOPHILASTAPHYLOCOCCUS AUREUS BACILLUS ANTHRACIS ESCHERICHIA COLI SALMONELLA LISTERIA MONOCYTOGENES CLOSTRIDIUM BOTULINUM BACILLUS CEREUS YERSINIA ENTERCOLITICA PSEUDOMONAS AERUGINOSA PAROTITIS VARICELLA ZOSTER VIRUS SARS

Nosocomial Infections• Infections acquired in a health care

facility• Most often transmitted by a health care

worker• Most often preventable• Prolong hospitalization• Increase cost of hospitalization• May not be covered by insurance• Many are antibiotic resistant which

cause serious infection • Infection control departments

– Educate employees and patients– Establish and monitor guidelines r/t

infection control– Track infections– Track / Treat exposures

• Most common Nosocomial– Urinary tract infection - Why?

Health-care-associated infections affect nearly 2 million individuals annually in the United States, and are responsible for approximately 80,000 deaths each year, according to a guide published by the Centers for Disease Control

Opportunistic Infection• Caused by an organism

that usually do not cause disease in a person with a health immune system

• Who would that be?• Organ transplant• Chemo therapy• HIV / AIDS• Anorexic• Cancer

Communicable Diseases

• Easily spread from person to person

• Common Cold is an example

• Mobile County Health Department:251-690-8158:Promoting, improving and protecting the health of Mobile County.

OSHA

• Occupational Safety and Health Administration• Concerned with worker safety• What puts health care workers at risk ???• SEE HANDOUT - BLOODBORNE PATHOGENS - Write 3 paragraphs explanation

• In 1991 OSHA determined that HC employees face a significant risk as a result of their occupational exposure to potentially hazardous materials

• They realized that risks can be minimized by following some guidelines for the handling of these materials

• UNIVERSAL PRECAUTIONS

Universal Precautions• System of infection control that assumes that every direct contact

with body fluids is infectious• Requires every employee exposed to blood / body fluids to be

protected• ALL PATIENTS ARE CONTAGIOUS & ALL BODY FLUIDS ARE

INFECTIOUS • Wash hands frequently• Wear gloves if there is even a possibility you might have contact

with body fluids• Wash hands with antibacterial soap after removal of gloves or

exposure to potentially infectious materials• Wear gloves once and discard• Place contaminated clothing or supplies in proper containers per

facility policy• Used needles or sharp instruments MUST be discarded in a

biohazzard sharps container

Body Fluids

• body fluids of concern include• semen• vaginal secretions• cerebrospinal fluid• synovial fluid / pleural fluid / peritoneal fluid / pericardial

fluid / amniotic fluid (fluids that surround internal organs)• saliva in dental procedures• any body fluids visibly contaminated with blood• unfixed tissue or organ from a human is potentially

infectious• cell or tissue cultures / organ cultures• culture medium or other solutions from experimental

animals infected with HIV or hepatitis B.

Sources of Infectious Organisms in Body Fluids

Source Organism Transmission

Blood HBV - cuts/abrasions HCV

Contact with broken

skin or membrane - nosebleeds HIV/AIDS

- menses Cytomegalovirus

- needles

- human bites

Feces HAV Salmonella bacteria

Oral inoculation from

hands or food Shigella bacteria

Rotavirus

Urine Cytomegalovirus

Bloodstream, oral, and

mucus membrane

inoculation from hands

Respiratory Secretions HBV - saliva Tuberculosis

Bloodstream, oral, and

mucous membrane - nasal discharge Mononucleosis V

Influenza V Common cold V

Meningitis

Source Organism Transmission

Vomitus Gastrointestinal V - may contain blood (Rotavirus)

Oral from contaminated hands (see "blood")

See "blood"

Semen HBV Sexual contact HIV/AIDS (unprotected) Venereal Disease

The body’s defense

Physical Barrier - The Body’s Main Line of defenseSkin - The first line of defense.Lysozyme secreted by sweat glands break down cell walls of microbes.Mucous membraneUrinaryReproductiveEyeLysozyme (antimicrobial substance) secreted in tears

Mechanical FactorsLachrymal Apparatus- lysozyme in tearsSaliva- helps to wash down microbes into the stomach where their killed by the acidic environment Mucous- Found in upper respiratory tract. The thick mucous traps microbes and then flows downward and eventually swallowed and killed in the acidic environment of the stomach.Mucous-coated hairs- Cilia flush & trap bacteriaFlow of Urine- flush out bacteriaVaginal Secretions- flush out Peristalsisin GI tract flush out

Chemical FactorsOil Glands- produce sebum (protective film) Low pH- of the skin help to inhibit microbial growth Sweat Glands- produce lysozyme (Antimicrobial substance)- flush- high concentration NaCl inhibit Microbial growth.Gastric Juices- in GI tract- too acidic for most microbial growthResident Flora - allows immune system to establish- Normal Flora - Microorganisms which normally inhabit the healthy human body or other naturalenvironments.

Work Practice Controls• Mandatory employee educations• Exposure procedures• Regulations of treatment and disposal of

biohazzardous materials• Use of Personal Protective Devices /Equipment

(PPE)• Hep B vaccination• Warning signs and labels• Medical surveillance – Infection control Departments

• Principle of Universal Precautions

• ALL PATIENTS ARE CONTAGIOUS – ALL BODY FLUIDS ARE INFECTIOUS

• Treat all patients equally

• Treat all body fluids equally

• No worry about who / what is a potentially hazardous

Personal Protective Equipment

Patient Isolation

• Transmission Based Precautions / Isolation

• Pt is isolated according to how their dz/infection is transmitted

• Airborne

• Contact

• Droplet

• Reverse

• Airborne Precautions• Airborne transmission occurs by dissemination of

either airborne droplet nuclei (small particle residue of evaporated droplets that can remain suspended in the air for long periods of time) or dust particles containing the infectious agent

• Organisms transmitted in this manner can be widely dispersed by air currents and may be inhaled or deposited on a susceptible host within the same room or a long distance from the source patient

• Special air handling and ventilation systems are required to prevent airborne transmission

• Isolation rooms used & must have negative airflow (own A?C system)

• All personnel entering the isolation room must wear a mask

• Gloves are required when touching infective material. Gowns are required when caring for a patient with chickenpox

• Patients must wear a surgical mask during transport when outside the negative flow isolation room.

• Contact Precautions• Direct contact involves skin-to-skin contact and

physical transfer of organisms from an infected/colonized source to a susceptible host.

• The hands of healthcare workers are most often implicated when direct contact transmission is suspected

• Direct contact transmission can also occur between two patients

• Indirect contact involves contact of a susceptible host with a contaminated intermediate object, usually some inanimate object in the environment

• Contact precautions apply to specified patients known or suspected to be infected or colonized with significant organisms that can be transmitted by direct contact

• Gloves are required when entering the patient's room• Gowns must be worn when entering the patient's room

if contact with the patient, equipment, or furnishings is anticipated

• Gowns are also required if the patient has diarrhea, ileostomy or colostomy. A private room is required

• The patient should be transported only when necessary for diagnosis or treatment

• The risk of infection transmission must be weighed against the need for transport

• The patient should wear a clean long sleeved gown if transport is necessary.

• Droplet Precautions• Droplet transmission involves contact of the

conjunctivae or the mucous membranes of the nose or mouth of a susceptible person with large particle droplets.

• Droplets are generated from the source patient primarily during coughing, sneezing or talking, or during procedures such as suctioning or bronchoscopy

• Transmission of infection by large particle droplets requires close contact between the source patient and the susceptible host

• Droplets do not remain suspended in the air and generally travel only short distances, usually three feet or less, through the air

• Special air handling and ventilation systems are not required to prevent transmission

• A surgical mask must be worn when within three feet of the patient

• Gloves are required when touching infective material

• A gown is required if soiling is likely• A private room is desirable; however, patients

with the same disease may share a room if necessary

• The patient should wear a surgical mask during transport.

Reverse Isolation

• Protective Isolation• Protects the patient

from the environment

• Immumo-compromised persons

• Ca / HIV• Transplant• Chemo therapy• Newborns /

especially premature

A regular isolation unit is designed to protect other patients and staff from a

patient’s infection, such as a respiratory virus or

chickenpox reverse isolation unit is

designed to protect patients from getting an infection

caused by germs – bacteria, viruses or fungus – that may

be in the environment or carried by staff and visitors.

 

• Asepsis

• Absence of disease-producing organisms / pathogens

• Aseptic techniques

• Maintaining cleanliness and eliminating or preventing contamination

• Hand washing

• Using disposable gloves

• Proper cleaning of instruments/equipment

• Antiseptic• Prevents / Inhibits growth of pathogens• Not effective on spores & viruses• Used on the skin• Betadine / Alcohol• Disinfectant• Destroys / Kills pathogenic organisms• Not effective on spores and viruses• Used on objects / damages skin• Boiling water and chemical disinfectants

• Sterilization• Destroys all microorganisms• Pathogens and nonpathogens• Effective on spores and

viruses• Surgical equipment is sterilized• Steam under pressure, gas

radiation• Autoclave

• Chain of Infection