Infection, Infectious Diseases and Epidemiology Flashcards
Acute Disease
Disease in which symptoms develop quickly and runs its course quickly.
Chronic Disease
Disease which usually mild symptoms that develop slowly and last a long time.
Subacute Disease
Disease with time course and symptoms between acute and chronic
Asymptomatic Disease
Disease without symptoms
Latent Disease
Disease that appears a long time after infection
Communicable Disease
Disease transmitted from one host to another
Contagious Disease
Communicable disease that is easily spread
Noncommunicable disease
Disease arising from outside of hosts or disease from opportunistic pathogen
Local Infection
Infection confined to a small region of the body
Systemic Infection
Widespead infection in many systems of the body; often travels through blood or lymph nodes.
Focal Infection
Infection that serves as a source of pathogens for infections at other sites in the body
Primary Infection
Initial infection within a given patient
Secondary Infection
Infection that follow a primary infection; often by opportunistic pathogens.
Mutualism
Organisms work dynamically with each-other +/+
ex.(bacterial flora in gut)
Commencialism
One organism benefits, the other gains nor loses +/ 0
ex.(Staph epidermidis)
Parasitism
One organism benefits, the other suffers +/-
ex.(HIV,Ebola,Chlamydia,Syphilis)
When is normal microbiota established in one’s body?
Within the first two months of life
Resident Microbiota
Mostly commensal, are part of the normal microbiota throughout life
ex.(E.coli in gut, S. Epi on the skin.
Transient Microbiota
Remain in body for short periods of time in the same region as resident microbiota, due to competition from other microorganisms, elimination by the bodies defense cells, and chemical of physical changes in the body.
How do normal microbiota become opportunistic pathogens?
If they are introduced to an unusual site of the body. If broad spectrum antibiotics are used and completely alters the normal state of microbiota causing super infections.
How do normal microbiota become opportunistic pathogens?
If they are introduced to an unusual site of the body. If broad spectrum antibiotics are used and completely alters the normal state of microbiota causing super infections.
Reservoir Infections
Sites where pathogens marinate as a source of infection
Animal reservoir
Zoonoses/ Diseases naturally spread from animal host to humans, Humans are usually a dead-end host to zoonotic pathogens
How does one acquire Zoonoses?
Direct contact with the said animal or its waste, eating animals, and bloodsucking arthropods.
ex.(ticks/Lyme disease)
Why are Zoonoses difficult to eradicate?
One cannot vaccinate EVERY animal on earth.
What viral disease is caused by the inhalation of dried feces and urine in Deer mice?
Hantavirus pulmonary syndrome/ Hantavirus sp.
What bacterial disease is caused by getting bitten by fleas from an infected rodent?
Bubonic Plague/ Yersinia pestis
What fungal disease is caused by direct contact with a domestic animal?
Ringworm/ Microsporum sp.
What protozoan disease are caused by Anopheles mosquitoes carrying infected blood from monkeys?
Malaria/ Plasmodium spp.
What helmithic disease is caused by inhaling larvae ridden dog saliva?
Tapeworm/ Dipylidium Caninum
Human carriers
Asymptomatic individuals can sometimes transmit the sickness and some don’t.
Nonliving reservoirs
Soil, water, and food. Presence of microorgasisms often due to contamination by feces or urine
Contamination
The mere presence of microbes in the body
Infection
When organisms evade the body’s external defenses, multiplies, and becomes established in the body.
What are your three major ports of entry?
Skin, Mucous membranes, Placenta. (also less likely parenteral route (injection))
Name all the routes for invading pathogens
Ear, Conjunctiva of eye, Nose, Mouth, Placenta, Vagina, Penis, Urethra, Anus, Insect bite, Broken skin
How do pathogens invade the skin?
Through openings of the skin or cuts, also by burrowing into/digesting the outer layers of skin.
How does our skin protect us from pathogens?
Our outer layer of dead skin cells acts as a barrier.
Where are mucous membranes located?
They line the body’s cavities that are open to the environment, providing a warm and moist environment hospitable to pathogens.
What is the most common site of entry of a mucous membrane located?
The respiratory tract, through the eyes, nose, or mouth.
Can the gastrointestinal tract also be a source of entry?
Only if the pathogens can survive the acidic pH of the stomach.
How do pathogens affect the Placenta?
Pathogens can cross the placenta and infect the fetus causing spontaneous abortion, birth defects, and premature birth.
ex.(CMV,Rubella,Toxoplasma)
Parenteral Route
Not a true portal of entry, can be circumvented, pathogens are directly deposited into tissues beneath the skin or mucous membranes. (needles)
Adhesion in infection
Process by which microorganisms attach themselves to cells.
Why is adhesion required by microbes?
It is required to successfully establish colonies within the host using specialized structures and attachment proteins.
How do attachment proteins help in adhesion?
Viral/Bacterial “ligands” bind to the host cell’s sugar molecule glycoprotein receptors.
Disease results if…
The invading pathogen alters normal body functions and Disease is also referred to as morbidity
