ch26 Communicable Diseases

The increasing number of people who choose not to get vaccinated can lead to the _____________

reemergence of disease

A _______ disease is a contagious one - it is infectious and can be transmitted from person to person.

communicable

If someone catches the illness(communicable), they can get sick and spread the pathogen - it could be: ________________onto the next person.

This can become a small isolated outbreak or even a full pandemic.

cold, virus, other disease causing agent

An ______ disease is an infection.

infectious

While all communicable diseases are infectious …….

not all infections are communicable

__________, for example, can cause an infection, but a person with _____can't spread it to another person meaning it's noncommunicable

Tetanus

A ___________ disease is a disease that is not transmissible directly from one person to another.

noncommunicable

Non-communicable diseases include

1. parkinsons

2. autoimmune

3. stroke

4.  most heart diseases

5. cancers

6. diabetes

7.CKD

8.Osteoarthritis

9. osteoporosis

10. alzhiemers

11. cataracts

Additional examples of non-communicable diseases are caused by toxins in:

1. food

2.enviorment

Today, it is understood that disease etiology is: _____________________.

complex and multicasual agent

According to the Epidemiological Triangle, infectious disease is the result of interaction amongst the ____, _____,_____.

host, agent, enviornment

The principle of multi-causation stresses that one infectious agent alone is not sufficient enough to cause disease; the agent must be transmitted within a _________ to a susceptible host.

favorable enviorment

Not all contact with an infectious agent leads to infection and not all infection leads to an

infectious disease

An infectious agent may contaminate the skin or mucous membranes of a host, ____________- this is what not all contact with an infectious agent leads to infection means.

but not invade the host

An infectious disease is a communicable disease meaning it can spread from _____ to _____

person to person

A person could become infected with something, but it could be a non-communicable disease meaning it ________ such as tetanus

cannot be spread

OR you may have an infectious agent that invades & multiplies within the host and produces either a _____________infection

subclinical or clinical

A subclinical infection is an infection that is _____________ - the person does not know that they have it because they are not showing noticeable symptoms of disease.

aysmptomatic

The host could also respond in an opposite way - it could produce noticeable symptoms of an infectious disease meaning a _______.

clinical infection

Infection simply is an entry in multiplication __________

of an infectious agent in a host.

When a person is diagnosed with disease, it is considered a ____.

case

Once infectious agents replicate in a host, they can be transmitted from that host regardless of ___________. This means that they are_______.

precense of diease symptoms, carriers

Some people become carriers and continue to shed the infectious agent without ever _________. Example is what?

showing symtpoms, covid 19

In the _____ period, the person has been exposed.

latency

In the communicable_ period, this is the time during which an _______________from an infected person to another person, also known as the infectious period

nfectious agent may be transferred directly or indirectly

Communicable period normally begins before the patient experiences symptoms.

The _____ period, may overlap with the communicable period.

incubation

Meaning when it's incubating, you're________ experiencing any symptoms and you are spreading

not

Control of infectious diseases in a population requires _______ ______  the occurrence of new cases.

1. indenitfying

2. monitoring

the number of new cases

incidence

Some infectious diseases are endemic and occur at a consistent, expected level in a geographic area. This could be the case with

1. STD

2. PNEUOMONIA

An _________ is an unexpected occurrence of an infectious disease in a limited geographic area.

_OUTBREAK

Examples of an outbreak

salmonella, pretesses

An ___________ is an unexpected increase of an infectious disease in a geographic area over an extended period of time. For example:

epidemic, ex. measles

A _________ is a steady occurrence of a disease over a large geographic area or worldwide.

For example: covid 19, bubonic plague, Spanish  flu

pandemic

Disease spreads from person to person through a series of events known as the

chain of transmission

In order to prevent infecting more people, we must ___the chian of infectio.

There are_____links in the chain of transmission that can be broken

break, 6

Steps of the chain of transmission

infectious agent—-reservoir——portal of exit—mode of transmission——portal of entry——susceptible host

An _______ agent is an organism capable of producing an infection or infectious disease.

infectious agent

An infectious agent could be a

1. bacteria

2. fungus

3. parasite

4. virus

Infectious agents act differently depending on their ___________ properties and ________ with their human host.

intrinsic, interactions

For example, an agent's _________ all have an impacton the transmission and the type of relationship it establishes with its host

1. size

2. shape

3. chemical make up

4. growth requirement

5. viability

. Remember _______ has an important impact on the transmission and the type of relationship it establishes with its host!

viability

The power to invade and infect a large number of people is ._____ is an organism’s (which could be a bacteria, virus, fungus, parasite) ability to infect you

infectivity

You can be infected but not sick, and there are plenty of times when you're infected, but the organism does not ______

cause disease

_________ is the agent’s ability to cause disease.

Pathogenicty

Some organisms are harmless and can live on you or in you without you even noticing. But, if they do cause some sort of disease process, then they are called "_________." Some pathogens are less pathogenic than others

_pathogens (ex. ecoil, hoc)

_______ is their ability to produce serious disease in their host

virulence

_______ is very infectious, very pathogenic (because most people who are infected do develop the disease) and very virulent (because it causes a severe, often fatal disease

ebola

__________has a high infectivity, high pathogenicity, but a very low virulence.

chickenpox

_____ has a very low infectivity, low pathogenicity, but a high virulence if it's left untreated

TB

RESERVOIR is an environment in which a pathogen lives and multiplies.This caninclude:

1. HUMAN

2. ANIMALS

3. BUGS          

4. PLANTS

5. SOIL

6. WATER

Some agents have more than ____ reservoir.

one

Knowing reservoirs is important because in some cases, transmission can be controlled when you eliminate the reservoir.For example:

mosquitos breed in standing water,

A portal of exit is the mean by the which the infectious agent is transported from the host. Therefore, agents leave the human host through a portal of exit.

Portal of exits include

1. respiratory secretions

2. vaginal secretions

3. semen

4. saliva

5. lesion exudates

6. blood

7. feces

A mode of transmission is a method where by the infectious agent is transmitted from one host to another host. This can be through _____ transmission

direct or indirect

Direct transmission is person to person. This can be through

1.touching

2. kissing

3. biting

4. sexual contact

Direct projections of mucus secretions by droplet to another person' s mucous membranes of the eyes or mouth during

1. coughing

2. sneezing

(also considered direct transmission.)

Direct contact is responsible for many communicable diseases such as

1.STD

2.INFLUENZA

INDIRECT transmission is the spread of infection through a vehicle of transmission outside the host. The transmission of pathogens from the environment to humans is referred to as indirect contact infection examples of this include:

1. NEEDLE PRICK INJURIES

2. HEP B

In addition, indirect transmission could be contaminated:

1.FOAMITES

2.VECTORS

Fomites are______that act as transport agents for microbe. For example, TELEPHONES

1.INANIMATE OBJECTS

2.MATERIALS

3.SUBSTANCES

It’s important to do what, especially in the hospital setting?

sanitize

Vectors can be

bugs, animals

Transmission from a vector to the human host usually occurs through (ex. zika, west nile)

1.BITE

2. STING

______, this could be DIRECT OR INDIRECT

Fecal oral

When a disease spreads through the fecal-oral route, it means that contaminated feces from an infected person is somehow ingested by another person. It could occur indirectly through

CONSUMING CONTAMINATED FOOD (ex. not handwashing)

One of the easiest ways to prevent fecal oral trasnmission from occurring in the first place is what?

SIMPLE HAND HYGIENE

DIRECT transmission of the fecal-oral route occurs through _______.

oral sex

A portal of entry is a means by which an infectious agent enters a new host. Agents invade the host through portal of entry. Portals of entry include:

respiratory passages, mucous membranes, skin, and blood vessels, oral cavity, placenta.

Not all humans are equally susceptible to, or at risk for, contracting an infection or development of an infectious disease. _____________ play a huge role.

Biological and personal characteristics

older adults are at greater risk for _______

pneumonia

A fetus is at greater risk for harm from ____ as opposed to the pregnant woman herself.

zika virus

Technology and medicine can be effective in controlling an agent. Inactivating an agent is the principle behind

disinfection, sterilization, and radiation of fomites.

Anti-infective drugs can control infectious disease. These include:

1. antibiotics, antivirals, antiretrovirals, and anti malarial

Not only do drugs permit recovery in the infected person, but they also play a role in preventing transmission of the pathogens to ________

another person.

Early treatment of HIV with anti retroviral suppresses the virus and has the potential to ________

reduce the transmission

Treating or eliminating nonhuman reservoirs is an effective method of preventing replication of pathogens and thus preventing

transmission

Nonhuman reservoirs include:

water, food, milk, animals, insects, and sewage

___ is an enforced isolation or restriction of movement of those who have been exposed to an infectious agent during the incubation period. This is a method of controlling the reservoir.

 Quarantine

Quaratine was used for

SARS, COVID 19

The transmission chain may be broken at the portal of exit by properly disposing of:

secretions, excretions and exudates from infected persons. AND ALSO ISOLATION

The portal of entry can be controlled by using barrier precautions such as PPE

masks, gloves, gowns, protective eyewear

In addition, what else can control the portal of entry?  

Avoiding unnecessary invasive procedures and protecting oneself from vectors

_________ were developed to prevent the transmission of diseases found in blood and other bodily fluids.

universal precautions

Healthcare workers should assume every patient is infectious and _____ themselves.

must protect (like IV blood draws)

Many factors such as _____contribute to a host’s resistance, or ability to ward off infections.

1.age, health status, nutriton, health behvaiors

____ is a defense against infection

Immunity

______ immunity is innate resistance to a specific antigen or toxin. How is this

obtained?

natural, You are born with it

The types of white blood cells involved in innate immunity are ________ which develop into _________ such as . neutrophils, basophils, natural killer cells

monocytes, macrophages

Acquired immunity comes from actual exposure to

1. agent

2.toxin

3. vaccine

There are two types of acquired immunity:

1. active

2. passive

active_immunity is when the body produces its own antibodies against an antigen, either from:

1. infection of pathogen

2.introduction

passive immunity is the temporary resistance that has been donated to the host either through:

1.plasma proteins, immunoglobulins, antitoxins or transplacental

Administering _____ to a patient is a form of passive immunity. It is a type of antibody

immunoglobulin

Passive immunity can be induced artificially when antibodies are given as a medication to a _______

nonimmune individual.

antibodies may come from where?

Pooled and purified blood products of immune people

Passive immunity lasts only as long as what?

substances remain in the bloodstream

_________vaccine failure is the failure of the vaccine to stimulate any immune response.

This could be caused by:

_____________

Primary, 1. improper storage 2. improper administration ,3.  exposure of a light snesitive vaccine

_____ vaccine failure is the waning of immunity after an initial immune response.

This occurs more with immunosupressed.

secondary

Secondary vaccine failure is where the patient develops an initial immune response, but

when they come in contact with that specific infection, the protective response is _____ to prevent the disease.

inadequate