WEEK 1 TEST FINAL

Different types of pathogenic organisms are: viruses, bacteria, fungi, protozoa and other organisms that can cause infectious disease.

Endemic - expected levels of disease in a region
Epidemic - a rapid increase in cases higher than expected in a population within a region
SARS - it's an example of an epidemic
Pandemic - when an epidemic is widespread and crosses borders
Outbreak - is a small scale epidemic
A small scale epidemic is called an outbreak.
Virulence is an organisms ability to cause infectious disease
If some infectious agents are not very likely to cause disease we can say that they are not very virulent
An example of A disease that is not very virulent is polio
How are pathogens able to cause infection?

They have flagella
Pilai
Capsules
Endospores
biofilms
endotoxins
Exotoxins

Flagella are protein filaments that help bacteria to move around
another name for fimbriae is pilli
pilai resemble a porcupine
a pathogen that binds to cells or grabs hold of them to infect them is Pillai
protective walls that surround some cell membranes of pathogens are capsules
A pathogen that makes macrophages and neutrophils is a capsule
a type of pathogen that is resistant to hot and cold and also resistant to drying and chemical agents are endospores
a bunker that is impermeable to our host antibody reaction is called biofilm
is it true or false that some pathogens use exotoxins and endotoxins to make themselves more virulent
proteins released by bacteria that cause disease manifestations are called exotoxins
A neurotoxin that acts on the nerves or motor end plates that can cause paralysis is an example of an exotoxin or an endotoxin
What type of toxin acts on the gastrointestinal tract to cause diarrhea. The answer is enterotoxin
Cytokines can cause rashes and fevers
the type of toxin that stimulates the release of cytokines is called pyrogenic exotoxin
endotoxins are found on gram negative bacteria
endotoxins are responsible for causing host defects
host defects are things like fever, changes in blood pressure, inflammation and lethal shock
once an agent infects a host the degree and severity of the infection will depend on the hosts ability to fight off the infectious agent
virulence and host susceptibility cannot be separated
The things that make a host susceptible to infection are

Immune system
Age
Nutrition
genetic defects
Medication

the ability of the host to prevent an infection from occurring is dependent on:

Barriers
Chemicals
Immunity

at common effect of aging is that it weakens our specific and nonspecific defenses
Why are infants susceptible to infection and disease? Because their immune systems are not fully developed
Genetic defects happen because people may not have neutrophil that kill the bacteria
Chemicals in tears and saliva provide resistance to invading pathogens
some ways that host resistance can be compromised and make an individual susceptible to an infection are:

if the skin or mucosa is breached
cystic fibrosis patients who have poor ciliary function
intubation and catheterization

A patient with poor ciliary function may have cystic fibrosis.
A reservoir is the habitat where an Organism lives grows and multiplies.
Infectious diseases result from the interaction of agent, host, and environment
The sequence of the chain of infection is reservoir, portal of exit, mode of transmission, portal of entry, infection of a susceptible host.
How can we interrupt transmission at the reservoir? We can eliminate the disease or inactivate it so that it is unable to survive in the reservoir.
Pathogens leave the host in materials that the body secrets and excretes.
Proper hand hygiene and disposal of waste is a prevention technique at the portal of exit
When a pathogen is transmitted from a source to a susceptible host through a fomite this is a vehicle borne mode of transmission
a vector borne mode of transmission is through animal or insect
the portal of entry refers to how a pathogen enters a susceptible host.

Link	Function	prevention
Reservoir	Habitat in which the Organism normally lives grows and multiplies	transmission may be interrupted when the infectious agent is eliminated, inactivated or cannot survive. for example, rapid identification and management of organisms
portal of exit	Pathogens often leave hosts in materials the body secrets or excretes	Managed through good infection prevention and control practices. For example, good hand hygiene, appropriate use of PPE, proper food packaging and disposal of waste
mode of transmission	physical contact - person to person contact skin to skin contact, kissing. Example: STIs, cold sores, HPV vehicle borne- where the pathogen is transmitted from source to host via fomites Airborne- occurs when infectious agents are carried by dust or droplet nuclei suspended in the air Droplets- large spray with short range aerosols produced by sneezing, coughing or talking Vectorborne - animal or insect	good infection prevention and control practices. For example, good hand hygiene, isolation of infected patients, air flow control.
portal of entry	how a pathogen enters a susceptible host. It must provide access to tissues in which the pathogen can multiply, or a toxin can act	aseptic non touch technique, safe catheter care, wound care
host susceptibility	depends on genetic or constitutional factors, specific immunity and nonspecific factors that affect an individual's ability to resist infection or to limit pathogenicity	reducing the susceptibility of patients receiving health care. For example, treatment of underlying disease, recognizing high risk patients oh

Emerging barriers to decreasing disease transmission:

increases in host susceptibility due to changes in demographics
drug resistance and pathogen mutation
new diseases
breakdown of public measures
Travel
more changes in environment technology and industry practices

when inequities are high and community assets are low then health outcomes are worse
Bacteria are the number one pathogen that cause serious human infection