epi test 1.txt
Card Set Information
epi test 1.txt
Branch of epidemiology that deals with two or more populations at a time, cases are included as risk factors, and the cause of the disease is often known.
Populations in infectious epidemiology
Why is a case a risk factor?
Infection in one person can be transmitted to others.
Uses for infectious epidemiology (5)
Identify causes of new, emerging infections
Study routes of transmission
Surveillance of infectious disease
Identify new interventions
Identify source of outbreaks
Influenza and pneumonia ranking for the leading causes of death in the US.
Infectious/parasitic infections account for what percentage of mortality worldwide.
Respiratory infections account for what percentage of mortality worldwide
Septecemia ranking for leading causes of death in the US.
A disease caused by any of the infectious agents
Transmission of disease, directly or indirectly, from an infected person
Disease transmission through unnatural routes from an infected person.
An infection caused by a parasite
An organism that lives on or in a host organism and gets it's food from or at the expense of the host.
Three major factors of the epidemiologic triangle.
A factor, such as a microorganism, a chemical substance, or a form of radiation- whose presence, excessive presence, or relative absence is essential for the occurrence of disease.
A person or other living animal, including birds and arthropods, that affords subsistence or lodgment to an infectious agent under natural conditions.
The domain in which disease-causing agents exist, survive, or originate.
The ability of an infectious agent to produce an infectous disease in an organism.
Examples of infectious disease agents (6)
The capacity of an agent to enter and multiply in a susceptible host and thus establish an infection.
The severity of disease produced, i.e whether the disease has severe clinical manifestations or is fatal in a large number of cases.
Ability of an infectious agent to produce a toxin.
A toxic substance made by a living organism.
Pathogens that cause disease as a result of their presence or activity within the normal, healthy host.
Example of a primary pathogen
Organisms which cause an infectious disease in a host with depressed resistance.
Examples of opportunistic pathogens
The same organism is present in every case of the disease
It is isolated or grown in pure culture
The disease can be reproduced in animals after infection with pure culture
The identical pathogen is reisolated from the experimental animals.
The use of Koch's postulates in infectious epidemiology
They are one way to prove a disease is infectious.
Host response characteristics
Resistance to infection by an agent
Immunity that the host has developed either from natural infection with an agent or from injection of a vaccine containing an antigen.
Immunity acquired from natural infection
Immunity acquired from vaccination with an antigen
Immunity acquired from antibodies produced by another person or animal.
Examples of passive immunity (2)
Mother to fetus or newborn
Injections containing antibodies
The resistance of an entire community to an infectious agent as a result of the immunity of a large proportion of individuals in that community to the agent.
Percentage of the community that must be vaccinated before herd immunity comes into effect.
Time interval between invasion by an infectious agent and the appearance of the first signs or symptoms of the disease.
Incubation period of influenza
Incubation period of HIV
An infection that does not show obvious clinical signs or symptoms. "inapparent infection"
Time interval between lodgment of an infectious agent in a host and the maximal communicability of the host, precedes active symptoms.
A person or animal that harbors a specific infectious agent without discernible clinical disease and serves as a potential source of infection.
4 types of carriers
Carrier that has been exposed to and harbors a pathogen, are in the beginning stages of disease showing very few symptoms, and can transmit the disease.
Carrier that has been exposed to and harbor a disease causing organism.
Individuals who harbor a pathogen and are still infectious while in recovery
Individuals who have been exposed to and harbor a pathogen but have not had any symptoms of disease
A parasitic nucleic acid, can contain RNA or DNA genome, can be enveloped or nonenveloped, has no cell.
Prokaryotic organism with either gram positive or gram negative cell wall and can be aerobes, anaeorobes, or both.
A eukaryotic organism, can be yeast or mold.
Unicellular, eukaryotic organisms with complex life cycles.
Infectious protein particles that are viral in form and are composed completely of protein with no nucleic acid present.
Large organisms (animals) with complex life cycles.
The first case of a disease to come to the attention of authorities.
Person who has been diagnosed as having a disease, disorder, injury, or condition.
First case of the disease in the population
Those persons who become infected and ill from contact with the primary case
Persons infected by a secondary case
A person who has been exposed but does not have any symptoms yet.
Refers to an infectious disease agent that is habitually present in an environment.
Increase in endemic disease within a given area or group
Health-related state or event in a defined population above the expected over a given time period
Epidemic affecting a large number of people, many countries, continents, or regions.
Highly prevalent and commonly acquired early in life in most all of the children of a given population
A place where infectious agents normally live and muiltiply
Two types of Human Reserviors
Diseases associated with symptomatic human reservoirs
Diseases associated with asymptomatic human reservoirs
Three types of reservoirs
Diseases with animal reservoirs
West Nile Virus
Two main environmental reservoirs
Diseases with water reservoirs
Organisms associated with soil as a reservoir
Direct and esssentially immediate transfer of infectious agents to a receptive portal of entry though which a human or animal infection may take place.
Transmission involving an intermediary source of infection such as a vehicle, droplet nuclei, or vectors.
Site where an infectous agent enters the body.
Portal of Entry
Site where the infectious agent leaves an infected persons body.
Portal of Exit
Result from contact with contaminated vehicles.
Contaminated nonmoving objects.
An inanimate object that carries an infectious disease
Typhoid Fever: Cause and transmisson
Salmonella enteritis: Cause and Transmission
Hepatitis C: Cause and Transmission
Hepatitis C virus (HCV)
Vehicle borne- contaminated needles or blood products
Cholera: Cause and transmission
: Vibrio cholerae
Cryptosporidium parvum: Cause and transmission
Mad Cow Disease (CJD): Cause and transmission
foodborne zoonotic disease
Botulism: cause and transmission
Campylobacter: Cause and transmission
Shigellosis: Cause and transmission
Three Types of Anthrax
Fatality percentage of the three types of anthrax
Most common form of anthrax
Second most common form of anthrax.
Spread of droplet nuclei present in the air.
Whooping cough: cause and transmission
airborne (sneezing and coughing)
Chicken pox: cause and transmission
airborne (sneezing and coughing)
Inhalation anthrax: Cause and transmission
Hantavirus: Cause and transmission
Cutaneous anthrax: cause and transmission
direct contact (zoonotic)
Diseases transmitted by an animate, living insect or animal.
An arthropod, especially fleas and ticks.
Arthropod carries the pathogen on its feet
Pathogen reproduces in vector
Lyme disease: cause and transmission
Vector borne (tick bite)
Malaria: cause and transmission
vector borne ( mosquito bite)
Rabies: cause and transmission
vector borne (animal bite)
Sexually transmitted diseases
Gonorrhea: cause and transmission
Direct contact (sexual)
Mother to fetus causes opthalmia neonatum
Chlamydia: cause and transmission
Mother to newborn causes pneumonia and conjunctivitis
HIV/AIDS: cause and transmission
Vehicle- infected blood products or needles
Direct contact- sexual contact
Four stages of HIV
Asymptomatic/ Stage 2
Symptomatic/ Stage 3
HIV to AIDS/ Stage 4
Stage of HIVwith short flu like illness.
stage 1/ primary
Stage of HIV that lasts an average of 10 years, patient is free of symptoms, very low HIV levels in blood, detectable antibodies in blood.
Stage 2/ Asymptomatic
Stage of HIV where symptoms are mild and there is an emergence of opportunistic infection
Stage 3/ symptomatic
Stage of HIV where the immune system weeakens and illnesses become more severe
Stage 4/ HIV to AIDS
Opportunistic infections with AIDS
Vaccine preventable diseases, their causes and modes of transmission
Diptheria- bacterial- direct contact
Tetanus- clostridiuim tetani- vehicle borne
Pertussis (Whooping cough)- pertussis- direct contact/airborne
Hepatitis A and B- A- HAV, fecal-oral/foodborne
B- HBV, vehicleborne
Chicken Pox- varicella-zoster virus- direct contact
Polio- poliovirus- foodborne
An infection or infectious agent transmissible under natural conditions from vertebrate animals to humans.
An infectious disease that has newly appeared or that has been known for some time but is rapidly increasing in incidence or geographic range.
E. coli O157:H7 (emerging infection)
Virulent E. coli strain
Produces Shiga toxin
Types of Vaccines
The deliberate release of viruses, bacteria, or other germs used to cause illness or death in people, animals, or plants.
Food borne hepatitis
A and E
Blood borne hepatitis
B, C, D