Micrbiology 265 unit 1 Epidemiology continued

What do Predisposing Factors mean?

things that make body more susceptible to disease

What are the steps to disease? (5)

1) enter body

2) adhere specific host cells

3) multiplication of pathogen

4) invade and colonize host tissues

5) inflict damage to those tissues

what 2 ways can microbes evade the Immune System?

1) covering the bacterium around a sugary coat called the capsule

2) hiding inside of cells

What are the 2 types of toxins?

Endotoxin and Exotoxin

What are exotoxins

made in bacteria cytoplasm, moves out and makes contact with endotoxins

what are endotoxins

regular component of bacterium, like the cell wall

What do the two toxins do?

impair normal functions of host and damage tissues and cells

what are the stages of disease (5)

1) incubation - no symptoms

2) prodromal - signs and symptoms

3) period of illness - being sick

4) period of decline - going away

5) period of covalenscence - recovery

What are the classification of disease based on severity and duration?

Acute

Chronic/persistent

Subacute

Latent

What is acute?

rapid but short (1 month)

What is chronic/persistent?

slow, less severe, longer periods (3 months)

Subacute

Intermediate (3 months)

Latent

Inactive, but can activate if the host is weak

What are the classifcations based on extent of host involvement?

Local Infection — >one spot
Systemic Infection —> spread throughout body by blood or lymph

Focal Infection —> systemic but starts in one spot

What is sepsis? What can it lead to?

a toxic inflammatory condition from microbes that is systemic. It is also a infection in the bloodstream that leads to septic shock

What is septicemia

blood poisoning; systemic infection from organisms growing in blood

Bacteriemia

bacteria in blood

Toxemia

Toxins in bloodVi

Viremia

Virus in blood

What are the terms for disease occurence

Incidence, Prevalence, frequency of occurence

What does incidence mean

# of new cases in a population that get disease over a time period

What does prevalence mean>

# of people affected by the disease over a time period

Sporadic

A disease the occurs occassionally

Endemic

A disease that is constantly in a population

Epidemic

A disease that spreads to many people in an area over a short amount of time

Pandemic

Epidemic disease thats worldwide

What is a nosocomial infection

A hospital acquired infection

Statistics of a nosocomial infection

5-15% get it

rate increased 36%

8th leading cause of death

What are factors that cause nosocomial infection

Microbes in hospital environment

Compromised status of host

• resistance impaired

  • broken skin

  • supressed immune system

Chain of transmission

• direct and indirect contact

What 2 ways can you control nosocomial infections

washing hands and disinfection of equipment