Chapter 11 Epidemiology

Most sexually transmitted viruses are?

Latent infections

Sometimes, the term virulence is used to express the measure or degree of ________.

pathogenicity

Indirect contact via airborne droplet modes of transmission

sneezing and coughing, airborne enters through respiratory system, droplet through mouth and nose

A disease that is occurring in epidemic proportions in many countries simultaneously, AROUND the world

Pandemic

Never had the disease, but can still spread it

Passive carries

The steps or mechanisms involved in the DEVELOPMENT of a disease

Pathogenesis

The ability to cause disease

Pathogenicity

Number of cases of a disease existing in a given population during a specific time period, ex during year 2009

Period prevalence

Two types of prevalence

Period prevalence and point prevalence

Number of cases of a disease existing in a given population at a particular moment in time, ex. right now.

Point prevalence

Steps in the Pathogenesis of infectious diseases.

1. Enter the body 2. Attach 3. Multiply 4. Spread 5. Evasion of host 6. Damage

An infectious disease than can be transmitted from one person to another

Communicable disease

A communicable disease that is EASILY transmitted from person-to-person. Ex. Ebola

Contagious disease

Why do we need to know modes of transmission?

Decides how much protection we need

What transmission is easiest to control?

Direct transmission

Words containing the prefix "path" or "patho-" pertain to ?

Disease

Who is the father of Epidemiology?

Dr. John Snow

Pathogens that MUST live WITHIN host cells in order to survive and multiply are referred to as ?

Obligate intracellular pathogens

One infectious disease may commonly follow another

Primary Versus Secondary Infections

Sources of microorganism causing infectious diseases are known as?

Reservoirs of infection or reservoirs

Four periods or Phases in the course of an infectious disease. -Patient feels I am coming down with something, before drama begins

Second stage. Prodromal period

Which is more serious, primary or secondary infections?

Secondary

What virulences can cause sickness?

Shigella cells, Salmonella cells

One that occurs only occasionally within the population of a particular geographic area; ex. Tetanus

Sporadic disease

When the infection spreads throughout the body it is said to have become a _______ or generalized infection; ex. miliary tuberculosis caused by mycobacterium tuberculosis

Systemic infections

Best case scenario to break the chain of infection is?

Take away the pathogen, and if you can not take away the pathogen, take away the environment

What do we call antibacterial factors?

bacteriocins

The easiest modes of transmission is?

direct skin-to-skin contact

Four periods or Phases in the course of an infectious disease. -The date between arrival pathogen and onset symptom

first stage. Incubation period time

Most flue can be transmitted during?

incubatory period

A person can be _____ with a pathogen, but no have an ________

infected, infectious disease

Four periods or Phases in the course of an infectious disease. - Experience symptoms of disease

third stage. Period of illness

Transit white recovering

Convalescent carriers

Factors of infect. disease to occur.

-Factors pertaining to the PATHOGEN, HOST, ENVIRONMENT

Factors pertaining to the environment

-Physical factors -climate, season -geographic location - availability of appropriate reservoirs -sanitary and housing conditions -availability of potable water

Factors pertaining to the Host

-health status -nutritional status -hygiene -age -travel -lifestyle -stress, etc

Factors pertaining to the pathogen

-virulence of pathogen (strong/weak) -Mode of enter (air, water) -Number of organisms that can enter body

Completely recovered but have pathogen

Active carriers (completely sick)

Disease is one that has a RAPID ONSET, and is usually followed by a relatively repaid recovery

Acute

What are some nonliving reservoirs?

Air, soil, dust, contaminated water and foods, and fomites

What do we call infections of the pathogen by rabies and lyme?

Arthropod

Most common chronic disease?

Back pain

What bacteria has pathogenicity?

Bad bacteria

Living reservoir- Human

Carrier base Disease

Disease has a SLOW ONSET and lasts a long time

Chronic

What is an example of latent infections?

Cold Sore

One that is always present within the population of a particular geographic area disease never dies out completely; Ex. Common Cold

Endemic disease

Defined as a GREATER than usual number of cases of a disease in a particular region, usually within a short period of time; ex. the legionnaire's disease epidemic of 1976

Epidemic disease

Loosely defined as the study of disease

Epidemiology

Pathogens that are capable of BOTH an INTRACELLULAR AND EXTRACELLULAR existence.

Facultative Intracellular Pathogens

Opposite of obligate is?

Facultative intracellular pathogens

Inanimate (nonliving) objects capable of transmitting pathogens (bedding, towels, eaten and drinking utensils hospital equipment. ONLY health centers

Fomites

Four periods or Phases in the course of an infectious disease. -Patient recovers

Fourth stage. Convalescent period

Number of new cases in specific population in a specific period

Incidence

Four periods or Phases in the course of an infectious disease.

Incubation period time, prodromal period, period of illness, convalescent period

Capable of transmitting during incubation period, spread during initial time

Incubatory carriers

Colonization by a pathogen, the pathogen may or may not go on to cause disease

Infection

A disease caused by a microbe

Infectious disease

What is an example of Pandemic?

Influenza, HIV/AIDS, Tuberculosis, Malaria

Are infectious diseases that of from being symptomatic to asymptomatic and than later go back to being symptomatic.

Latent Infections

Reservoirs are?

Living and nonliving

Once an infectious process is initiated, the disease may REMAIN ______ or it may spread; ex. pimples, boils, abscesses

Localized Infection

Numer of new cases of a during specific time period per a specific population, ex. usually per 1,000/10,000/100,000 (How sick you're going to be)

Morbidity

Ratio of number of people who DIED of a particular disease during a specific time period per a specific population

Mortality

There are symptomatic and asymptomatic diseases.

True

Living reservoirs- Arthropods

Vectors base disease

Plasmodium (which causes malaria) intraerythrocytic pathogens; they live ________.

Within Red blood cells, inside the cell

Diseases from animal sources

Zoonotic disease

Living reservoir- Animals

Zoonotic diseases or zononeses base disease