Terms Relevant To Infectious Disease

Question 1

Acute infection

Answer 1

-develops rapidly, usually febrile and of short duration
-from well to ill in hours or a couple of days
Ex: typical pneumonia due to Strep pneumoniae

Question 2

Subacute infection

Answer 2

-develops more slowly than an acute infection but more rapidly than a chronic infection
-from well to ill in a week or two
Ex: Interstitial pneumonia due to Mycoplasma pneumoniae

Question 3

Chronic infection

Answer 3

-develops slowly, milder and with long-lasting symptoms
-from well to ill in weeks to a month
Ex: Tuberculosis due to Mycobacterium tuberculosis

Question 4

Contagious or communicable diseases

Answer 4

Normally, these diseases are spread from one individual to another
Ex: man to man->common cold (rhinovirus)
Animal to man->tularemia (Francisella tularensis

Question 5

Convalescence

Answer 5

-recovery or the time-period following the illness
-a convalescent individual may still harbor the pathogen and be a carrier
Ex: a source for reinfection (malaria, Plasmodium spp.), or infection (typhoid fever, Salmonella Typhi)

Question 6

Disease or pathology

Answer 6

-a state of impaired or abnormal anatomy or physiology

Ex: tissue destruction, damage to tissue, loss of function, inflammation

Question 7

Endemic disease

Answer 7

-a disease is more-or-less constantly present in a given geographical area
Ex: plague (Western U.S.), malaria (Africa)

Question 8

Epidemic disease

Answer 8

-when the occurrence of a disease in a given area exceeds normally expected levels

Question 9

Exogenous vs endogenous infection

Answer 9

Exogenous infections are caused by agents outside of the body (rabies)

Endogenous infections are caused by agents already in or on the body (urinary tract infections)

Question 10

Frank or strict pathogens

Answer 10

-organisms not known to inhabit humans without causing disease
-in all cases, the ability of bacteria to cause disease is regulated to some degree by the innate and adaptive immune systems
-presence of IgG in the serum (elevated titer) is good proof of pathogenicity.
Ex: rabies virus, Shigella, Salmonella, Vibrio, Neisseria gonorrheae, Plasmodium, Yersinia pestis, Bacillus anthracis, and Francisella tularensis

Question 11

Fulminant infection

Answer 11

-symptoms appear suddenly and intensely; explosive

Question 12

Iatrogenic infection

Answer 12

-due to the activity of a physician or therapy

Ex: an iatrogenic illness is an illness that is caused by a medication or physician

Question 13

Local infection

Answer 13

• infection is confined or localized to a specific site or organ (boil)
• systemic symptoms if present oftentimes involves toxin production

Question 14

Mixed or polymicrobic infections

Answer 14

-infection involving two or more organisms

Question 15

Nosocomial infections

Answer 15

-originating or taking place in a hospital, acquired in a hospital, especially in reference to an infection

Question 16

Opportunistic pathogens

Answer 16

-infection depends chiefly on host factors
-Organism can inhabit humans without causing disease until something impairs innate immune system with pathology/disease following
Ex: Staphylococcus epidermidis, infecting intravenous catheters

Question 17

Pandemic disease

Answer 17

-worldwide epidemic

Question 18

Pathogen

Answer 18

-an organism capable of causing a disease or pathology

Question 19

Pathogenicity

Answer 19

• the ability to cause disease or pathology

- highly pathogenic organisms cause very serious or destructive disease

Question 20

Pathognomonic

Answer 20

-a sign or symptom that is so characteristic of a disease that it can be used to make a diagnosis

Question 21

Pyogenic infection

Answer 21

-pus-forming infection

Question 22

Pyrogenic infection

Answer 22

-fever inducing infection

Question 23

Retrograde infection

Answer 23

• microbial invasion proceeds through a tube or duct against the direction of fluid-flow
• common problem in urinary tract and kidney infections

Question 24

Suppurative infection

Answer 24

-an infection that results in pus formation

Question 25

Systemic infection

Answer 25

-pathology involves many body sites or organs

Ex: malaria, septic shock

Question 26

Virulence

Answer 26

-the ability to produce infection
-highly virulent pathogens need only a few bacteria to successfully overcome immune systems; low virulence pathogens require large numbers of organisms, or special situations
Ex: immunosuppression, trauma, cystic fibrosis (predisposes to Pseudomonas aeruginosa and Staph aureus lung infections

Question 27

Zoonosis or zoonotic diseases

Answer 27

-diseases transmitted to man from infected animals (the reservoir), often via a vector (Lyme disease by a tick bite, Borrelia burgdorferi)