all questions Flashcards
What is a zoonotic disease?
animal disease can be transmitted to human
Nosocomial infections are associated with what are the three events or exposures?
exogenous, endogenous, iatrogenic
What is the difference between Incidence and Prevalence?
incidence: new cases, at a time
prevelence: all cases, during a time
What is sporadic disease?
rare disease
what is Endemic disease
disease constantly present in low numbers,
How does herd immunity work?
everyone is immune to a specific disease, indirect protection
What is the goal of the descriptive epidemiological studies?
identify the first case
What is the goal of the analytical epidemiological studies?
determine the probable cause, mode of transmission, and
methods of prevention
What is the goal of the experimental epidemiological studies?
test hypothesis
What are emerging infectious diseases?
new diseases/ increasing in incidence/ threathen to increase in the future
What is the difference between quarantine and isolation?
quarantine: exposed individuals separated before signs and symptoms
isolation: sick people
What is sepsis?
inflammatory response
What is a focal infection?
local then throughout
What are the similarities between an asymptomatic case versus and asymptomatic carrier?
they both have no signs or symptoms
What are the differences between an asymptomatic case versus and asymptomatic carrier?
case: have disease, no signs/symptoms
carrier: no disease, no signs/symptoms
How does our body attempt to resolve an infection by a non-enveloped virus with spikes?
Nk cells and AB interferons
Based on the most likely immune response, what are the most likely causes of infections with purulent discharge?
pus - by bacteria
Ciprofloxacin blocks nucleic acid synthesis. It has high selective toxicity, why?
target the enzyme topoisomerase
Conjunctivitis caused by Haemophilus influenzae requires treatment with antibiotics for resolution. What structural feature(s) of bacteria would impede a normal immune response so that antibiotics were needed to help?
capsule, biofilm, o-anitgen (gram -)
Hypopions are the result of the influx of leukocytes into corneal tissue in response to an infection. How does this contribute to disease presentation and possible loss of sight?
bystander damage
Staphylococcus aureus has been linked to several types of cutaneous infections.
In the case of boils, which exoenzymes contribute to their formation? Their dissemination? In the case of Scalded Skin Syndrome, the cause is a lysogenized strain of S. aureus. What
does that mean?
exoenzyme: leukocidins, coagulase
dissemination: hyaluronidase
lysogenized: they have phage lysogenic conversion
The fungus that causes “Ringworm” secretes the exoenzyme keratinase. Its action releases by-products which act as _____________ and are recognized by the TLRs on the inflammatory cells causing the cutaneous lesion. Based on that information, what type of immune response is responsible for the cutaneous lesion?
PAMPS - inflammatory response
Malassezia furfur is a member of our microbiome. What contributes to its ability to cause disease?
environment
Necrotizing fasciitis is caused by strains of Streptococcus pyogenes. These strains produce the exoenzyme Streptolysin O. How does this enzyme cause damage
lyse cells
Anthrax, caused by Bacillus anthracis, presents with eschars, skin ulcerations which have a black appearance. These lesions are due to the cooperative action of three toxigenc components that bind together to allow entry into cells and alteration of cellular activities.
PA toxin
What class of antibodies is used as a marker of current infections?
igM
The F peplomer on viruses is associated with what type of cytopathic effect (CPE) in infected cells?
syncitia
What at the two known/proven triggers of autoimmune diseases?
molecule mimicry, sequestered antigens
What happens in the lungs during typical pneumonia which is the underlying cause of a typical cough?
bacteria grow inside aveoli + inflammatory cells
What microbial characteristics are associated with typical pneumonia due to:
Streptococcus pneumoniae? Klebsiella pneumoniae?
strep: pneumolysin: lysis cells
kleb: capsule: jelly-like
What exoenzyme may be produced by respiratory tract pathogens which allows them to evade neutralization?
igA protease
ParvoB19 replicates in erythroid precursor cells. What does that do to a patients hematocrit?
lower RBCs
Prevention of congenital infections is via:
natural passive
Infections by some of the viruses that cross the placental virus may acts as a/an ____________________ interrupting normal development resulting in birth defects.
teratogen
Mycoplasma pneumoniae is a ________________________ which causes cases of walking pneumonia and presents with a non-productive cough. This type of immune response against the organism is due to the absence of peptidoglycan.
cell-wall less
Influenza may be clinically differentiated from a case of the common cold due to the presence of muscle aches and pains associated with Influenza. This difference in the presentation is associated with which of the following?
cold: local
INFLUENZA: systemic
The vaccine used to prevent both Smallpox and Monkeypox infections contains ____________________
genetically related cow-pox
One of the clinical signs used to confirm cases of Smallpox, and exclude Chickenpox, is the presence of___________
SMALL: synchronous
chickenpox: asynchronous (everything)
What is the Innate response which allows resolution of the common cold?
NK and AB interferons
What is needed for confirmation of a urinary tract infection?
significant bacteriuria
What microbial exoenzyme raises the pH of urine resulting in kidney stone formation?
alkaline: urease
Re-infections by some infectious agents (such as gonorrhea) occur because the surface antigens on the pathogen may be altered. What is this process called?
v
antigenic variation
Which two types of microscopy may be used to visualize a pathogen which resists staining (such as Treponema pallidum, Chlamydia trachomatis)?
dark-field, fluorescence
What effect do oncogenic viruses (like HPV) have on the cells they infect?
cause to lose cell devision control
Why are many pathogens successful at ”hiding in” or infect the CNS?
immune priviledge site
How can neonatal infections, which occur during parturition , due to transfer of the mothers own microflora (such as Streptococcus agalactiae), be prevented?
flushing tissue with ANTIBIOTICS
For diseases such as Tetanus and Rabies, both passive immunization (given at the site of the bite or injury) and active immunization may be used as part of the treatment. What is the purpose of each?
passive: neutralize at the site before they be infectious (passive artificial)
active: to make antibodies
What is the source of infection for some cases of neonatal tetanus?
soil
Chlamydia trachomatis is an obligate intracellular pathogen. Describe the life cycle?
intracellular bacteria -> atp
elementary -> replication
In most severe form of polio, what tissue does the virus use to reach the CNS and cause damage to?
motor neuron
What is the difference between botulism due to intoxication and botulism due to infection?
intoxication: consume food contaminated w toxin
infection: bacteria infects body
How does Mycobacterium tuberculosis evade intracellular killing with the phagocyte?
