CHAPTER 14: PRINCIPLES OF DISEASE AND EPIDEMIOLOGYPage421 in textbook

LET’S GET STARTED

•We are going to the Computer Lab on Wednesday and Thursday to research a specific disease caused by Bacteria or Viruses

•Start thinking of a disease you might be interested in

• We are going to be talking about different diseases caused by pathogens

• Pathogens are disease causing microorganisms

• Can be bacteria, fungi, viruses, protozoa, helminthes (worms)

You will be responsible for lots of vocab this chapter

VOCAB

• Pathology

• Etiology

• Pathogenesis

• Infection

• Disease

• Normal microbiota

• Acute disease

• Chronic disease

• Latent infection

• Predisposing factor

• Carriers

• Reservoir of infection

• Vectors

• Emerging infectious diseases

• Commensalism

• Mutualism

• Parasitism

• Opportunistic pathogen

• Koch’s postulate

• Symptoms

• Sporadic disease

• Endemic disease

• Epidemic disease

• Pandemic disease

PATHOLOGY, INFECTION, DISEASE

• Infections can be undetectable

• Infections can lead to diseases but do not have to

• Few microorganisms are pathogenic when you compare to the vast number of microorganisms

NORMAL MICROBIOTA• Microorganisms are introduced to a newborn baby from the environment and when

breathing begins

• Lactobacilli

• E. coli

• A typical human body contains 1 x 1013 body cells and 1 x 1014 bacterial cell

• 1,000,000,000,000 vs 100,000,000,000,000• 10 x more bacterial cells than human cells!!!!!

• Microorganisms are usually concentrated in specific areas of the body

• Reproductive organs, mouth, intestines, anus, skin, etc.

CONDITIONS

• Chemical and physical requirements are important to microorganisms

• Temperature

• pH

• Oxygen

• CO2

• Salt

• Sunlight

COMMENSALISM + / O

MUTUALISM + / +

PARASITIC + / -

KOCH’S POSTULATES (PAGE 426)

•Microorganisms can cause specific diseases

•1877-Bacillus anthracis

ETHICAL ISSUES

• What ethical issues can you think of dealing with Koch’s postulates?

• What if you accidentally inoculated someone or something with a virus?

• What if you knowingly inoculated someone or something?

• How would your life be forever changed if you had a transmissible disease?

CLASSIFYING INFECTIOUS DISEASES

• Communicable diseases are diseases that spread from one host to another directly or indirectly

• Examples: chickenpox, measles, typhoid fever

• Non-communicable disease is not spread from one host to another. It occasionally causes a disease if it gets outside its natural habitat

• Cancer, Leukemia, Lupus, Diabetes

•Compare and contrast pandemic, epidemic, and endemic.

SEVERITY OF A DISEASE

• Herd immunity is when many people in a population are immune from the disease

•How can herd immunity by achieved?

•What are the benefits of herd immunity?

•What are the disadvantages of herd immunity?

PREDISPOSING FACTORS

• Gender

• Genetic background

• Climate

• Nutrition

• Age

• Environment

• Lifestyle habits

STAGES OF A

DISEASE

• Incubation period is the time interval between the initial infection and the first appearance of any signs or symptoms

•Prodomal period is period where early and mild symptoms of disease

•Period of illness is the most severe part of the disease

•Period of decline is when the signs and symptoms subside

•Period of convalescence is when the person regains strength

RESERVOIR•Humans, animals and nonliving things can be reservoirs

•Diseases that occur primarily in wild and domestic animals and can be transmitted to humans is called zoonoses

• Zoonotic diseases

•Fomite = a nonliving object involved in the spread of infection

•Hand washing is the single most important means of preventing the spread of infection

EMERGING INFECTIOUS DISEASES

•EIDs are new or changing diseases

•Epidemiology is the science that studies when and where diseases occur and how they are transmitted

You will be researching an EID and its epidemiology