Chapter 2.1 Different types of disease

Infectious Disease

Diseases caused by pathogens that can be transmitted from person to person.

Non-infectious Disease

Diseases not caused by pathogens and cannot be transmitted; often result from environmental, lifestyle, and genetic factors.

Pathogen

A microorganism or infective agent that can cause disease in a host organism.

Types of Pathogens

Includes bacteria, fungi, protists, viruses, parasites, and prions.

Bacteria

B - binary fission

R - releases toxins

E - effects host

A - alone (single celled)

K - keep multiplying

eg - salmonella

Fungi

F - feed on nutrients

U - uses spores

N - need moisture

G - grow on/in host

I - infect tissue/skin

eg - athletes foot

Protists

P - parasites often

R - reproduce in host

O - one celled usually

T - target tissue/blood

eg - malaria

Virus

V - very tiny

I - inject genetic material

L - live only in host

L - lock onto host

I - invade cells

A - aren’t living

N - need host machinery

eg - influenza

Parasitic Worms

W - work in host

O - obtain food

R - rely on host

M - multicellular

S - steal nutrients

eg - intentional worms

Prion

P - protein only

R - replicate abnormally

I - infect nervous system

O - oddly folded

N - no DNA

eg - mad cow disease

Examples of Infectious Diseases caused by Bacteria

Include food poisoning (E. Coli), syphilis (Treponema pallidum), tuberculosis (Myobacterium tuberculosis).

Examples of Infectious Diseases caused by Viruses

Include influenza (Influenza viruses), common cold (over 200 types), AIDS (HIV).

Examples of Non-infectious Diseases

Include obesity, type 2 diabetes, cardiovascular disease, certain types of cancer.

Transmission Mechanisms of Pathogens

Airborne transmission, direct/indirect contact, or vectors.

Host Interaction of Pathogens

Pathogens must be able to cross protective barriers, multiply inside, and avoid the immune system.

Autoimmune Diseases

Diseases triggered by some pathogens that cause an excessive immune response.

Chemical Carcinogens

Chemicals like cigarette smoke that can cause mutations leading to cancer.

Physical Carcinogens

High energy radiation that can damage DNA and lead to cancer.

Lifestyle Non-infectious Disease Factors

Unhealthy choices such as poor diet and lack of exercise that increase disease risk.

Genetic Factors in Diseases

Diseases that can be inherited or have a genetic predisposition.