What is Pathology?
The study of disease
What is Etiology?
The study of the cause of a disease
What is pathogenesis?
The development of disease
What is Infection?
Colonization of the body by pathogens
What is a Disease?
An abnormal state in which the body is not functioning normally.
What is transient microbiota?
it can be present for days, weeks or months
-can be washed off
What is normal microbiota?
Bacteria on the body that permanently colonizze the host.
What is Symbiosis?
The relationship between normal microbiota and the host.
What is Commensalism?
When one organism benefits and the other is unaffected
What is mutualism?
When both organisms benefit
What is Parasitism?
When one organism benefits at the expense of the other.
Some normal microbiota are opportunistic pathogens
What is microbial antagonism?
A competition between microbes.
How does normal microbiota protect the host?
- it protects the host by:
- -occupying niches that pathogens might occupy
- -producing acids
- -producing bateriocins
What are probiotics?
They are live microbes applied to or ingested into the body, intended to exert a beneficial effect
What are Koch's Postulates?
- 1-The same pathogen must be present in every case of the disease.
- 2-The pathogen must be isolated from the disease's host and grown in pure culture.
- 3-The pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible lab animal.
- 4-The pathogen must be isolated from the inoculated animal and must be shown to be the orginal pathogen.
What is the purpose of Koch's postulates?
- Koch's postulates are used to prove the causse of an infectious disease.
- -some pathogens can cause several disease conditions
- -some pathogens cause disease only in humans
What is a symptom?
A change in body function that is felt by a patient as a result of a disease.
What is a sign?
A change in a body that can be measured or observed as a result of the disease?
What is a Syndrome?
A specific group of signs and symptoms that accompany a disease.
What is a communicable disease?
A disease that is spread from one host to another.
What is a contagious disease?
A disease that is easily spread from one host to another
What is a noncommunicable disease?
A disease that is not transmitted from one host to another.
What is an incidence?
Fraction of a population that contracts a disease during a specific time.
What is prevalence?
Fraction of a population havig a specific disease at a given time.
What is a sporadic disease?
Disease that occuurs occasionally in a population.
What is an endemic disease?
Disease constantly present in a population
What is a Epidemic disease?
Disease acquired by many hosts in a given area in a short time.
immunity in most of a population
What is an acute disease?
Symptoms develop rapidly
Disease develops slowly
Symptoms between acute and chronic
Disease with a period of no symptoms when the causative agent is inactive
Pathogens are limited to a small area of the body
An infection throughout the body
Systemic infection that began as a local infection
Toxic inflammatory condition arising from the spread of microbes, especially bacteria or their toxins, from a focus of infection.
Bacteria in the blood
Growth of bacteria in the blood
Toxins in the blood
Viruses in the blood
Acute infection that cuases the initial illness
Opportunistic infection after a primary (predisposing) infection
No noticeable signs or symptoms (inapparent infection)
What are Predisposing factors?
- -make body more susceptible to disease
- *Short urethra in females
- *Inherited traits, such as the sickle cell gene
- *Climate and weather
What are Reservoirs of infection
- Continual sources of infection
- -Human: AIDs, gonorrhea
- -Carriers may have inapparent infections or latent diseases
- -Animal: Rabies, Lyme disease
- -some zoonoses may be transmitted to humans
- -Nonliving: Botulism, tetanus
Transmission of Disease
Direct: Requires close association between infected and susceptible host
Spread by fomites
Droplet ....transmission of disease (contact)
Transmission via airborne droplets
Transmission by an inanimate reservoir
(food, water, air)
- Arthropods, especially fleas, ticks, and mosquitoes
- -transmit diease by 2 general methods:
- 1-mechanical transmission
- 2-Biological transmission
Arthropod carries pathogen on feet
Pathogen reproduces in vector
- -Are acquired as a result of a hospital stay
- -Affect 5-15% of all hospital patients
Common causes of nosocomial infection. Most common is
Emerging Infectious Diseases
Diseases that are new, increasing in incidence, or showing a potential to increase in the near future.
Who mapped the occurrence of cholera in London?
Collection and analysis of a data
Comparison of a diseased group and a healthy group
Health care workers report specified disease to local, state, and national offices
Nationally notifiable disease
Physicians are required to report occurence
Incidence of a specific notifiable disease
Deaths from notifiable diseases
Number of people affected in relation to the total population in a given time period
Number of deaths from a disease in relation to the population in a given time
What are contributing factors of emerging infectious diseases?
- -Genetic recombination
- *E.coli, avian influenza (H5N1)
- -Evolution of new strains
- -Inappropriate use of antibiotics and pesticides
- *antibiotic-resistant strains
- -Change in weather patterns
Emerging Infectious Diseases
- -Modern transportation
- *West Nile virus
- -Ecological disaster, war, and expanding human settlement
- -Animal control measures
- *lyme disease
- -Public health Failure
The study of where and when diseases occur.
Centers for Disease Control and Prevention
Collects and analyzes epidemiological information in the United States