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Communicable Disease Basics. Objectives. Describe three ways infectious agents can be transmitted Describe at least three ways to decrease risk of infections in public settings List three examples of common infectious diseases and how to reduce risk of infection . Chain of Infection.
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Objectives • Describe three ways infectious agents can be transmitted • Describe at least three ways to decrease risk of infections in public settings • List three examples of common infectious diseases and how to reduce risk of infection
Chain of Infection • Model used to understand the infection process • Each link represents step in transmission of infection • Each link has to be present and in order for an infection to occur
1 - The Infectious Agent -any disease causing microorganism (pathogen)
Infectious agents are: • Bacterial • Viral • Fungal • Parasitic
2 - The Reservoir -Where a microorganism normally lives and reproduces
Examples of reservoirs: • Humans • Animals • Water • Food
3 - The Portal of Exit -route of escape of the pathogen from the reservoir.
Examples of portals of exit: • Flu or cold - mucous secretions • West Nile Virus - when the mosquito bites and feeds on the bird’s blood • Hepatitis A - stool • SARS - droplet, contact
4 - The Route of Transmission (Spread) -the way the pathogen gets from the reservoir to the new host
Transmission:Respiratory Droplets • From respiratory tract (i.e., nose, mouth) secretions of infected person • E.g. cough, sneeze • Do not circulate in air for long time or travel far (mostly < 3 feet) • Many diseases spread by respiratory droplets; e.g. flu, cold, pertussis, SARS • Can spread germs directly or indirectly
Droplet Transmission Agent is coughed or sneezed out into the air and floats on droplets
Direct Spread by Droplets • Close contact with infected person (<3 ft) • Infected person coughs, sneezes, talks, sings • Droplets land directly on mucous membranes (eyes, nose, mouth) of susceptible person
Indirect Spread by Droplets Droplets with the infectious agent land on a table, doorknob etc.
Indirect Spread by Droplets Someone touches contaminated object
Indirect Spread by Droplets Touch nose, mouth, eyes with contaminated hand
Airborne Transmission • Germs stay suspended in air on small particles • Uncommon method of transmission • Only occurs for certain germs, such as tuberculosis • Less commonly for flu, SARS
Airborne Transmission • Germs stay suspended in air on small particles • Uncommon method of transmission • Only occurs for certain germs, such as tuberculosis • Less commonly for flu, SARS
Other Methods of Transmission • Food/water/hands contaminated with stool from infected person; e.g., norovirus • Blood exposures, sexual contact • a.k.a. blood-borne; e.g. HIV, hepatitis B and C • Vector-borne • E.g. Mosquitoes and West Nile virus, malaria • Unlikely methods of spread in courtroom
What Do You Need to Do? • Make sure that you have available for staff and patient use an adequate supply of: • surgical masks • tissues • alcohol hand rub • trash cans with foot pedals to lift lid for disposing of tissues/masks
5 - The Portal of Entry -route through which the pathogen enters its new host
Respiratory System • Inhale germs
Other Portals of Entry Sexual contact Ingestion Breaks in Protective Skin Barrier
6 - TheSusceptible Host -A person who can get sick when they are exposed to a disease causing pathogen
What Is the Purpose of Respiratory Hygiene? • To reduce the transmission of airborne diseases
Hand Hygiene • Wash hands frequently with soap and warm water for at least 20 seconds • Alcohol hand gels
Use gloves where contact with body secretions and excretions is taking place
Cough Etiquette • Limit close contact (<3 feet) with coughing clients • Cover cough/sneeze with tissue • Offer mask to coughing clients
Keep a clean environment • Clean contaminated surfaces with commercial germicidal cleanser or wipes
Maintain vaccinations for employees • Flu shot- every year for age >50 and high-risk groups • Tetanus shot every 10 years • Hepatitis B for persons who may contact objects contaminated with blood • Pneumovax (“pneumonia” vaccine) for age ≥65 • Hepatitis A
What Are Some of the Airborne Diseases of Concern? • Pertussis • Tuberculosis • Influenza • Common colds
Pertussis (Whooping Cough) • Droplet and contact transmission • Runny nose and prolonged severe cough • A bacterial infection • Most dangerous for babies • Vaccine preventable for children aged 7 and under
Tuberculosis Agent • Caused by bacterium, Mycobacterium tuberculosis Reservoir • Humans
Latent TB Infection • Person infected with TB bacteria • Bacteria kept dormant by person’s immune system • Not sick or contagious • 10% develop TB disease over life time • Infection detected by TB skin test
Active TBDisease • Usually involves lung infection • Cough >3 weeks, fevers, weight loss, night sweats • Can cause serious illness but is treatable with antibiotics • Contagious until appropriately treated
Preventing Spread of TB • Patients with TB disease should delay court appearance until appropriate duration of therapy • Patients with active TB are no longer contagious after 2-3 weeks of appropriate therapy • should be cleared by doctor
Influenza(Flu) Agent • Virus Reservoir • Humans • Animals (e.g. birds, pigs) • Generally different strains
Flu Transmission:Respiratory Droplets • Direct: Close contact (<3 feet) • Droplets from cough/sneeze enter mouth, nose, eyes of susceptible person • Indirect: Contaminated surfaces • Cases peak each winter in U.S.
How Do I Protect Myself From the Flu? • Flu Vaccine Recommended for: • Persons >50 years old • Anyone with a chronic illness, such as asthma or diabetes • Children age 6-23 months • Women who will be pregnant during flu season
Habits for Good Health • Avoid close contact with people who are sick • Stay home when sick • Cover mouth/nose with tissue when coughing/sneezing • Avoid touching nose, mouth, eyes • Wash hands often with soap/water or alcohol rub
What Can You Do to Reduce Your Chances of Getting Sick? • Encourage coughing clients to wash their hands (or use alcohol hand rub) • Wash your own hands frequently • Wipe down counters, pens, phones, computer keyboards, etc. with disinfectant cleaner as needed • Cough etiquette- cover with tissue • Offer mask to coughing clients
Recommendations • Staff and clients should have access to: • Hand washing facilities • Tissues • Trash cans for disposing of tissues • Consider having alcohol hand rub available