Introduction Flashcards
what are three examples of disease?
- individual vs population
- viral vs bacterial
- non-notifiable and notifiable
what is hepatitis?
liver inflammation
what is conjunctivitis?
inflammation of the conjunctiva
what are 5 casues for disease/illness?
- bacterial
- viral
- parasitic
- fungal
- non biological
what is vigamox?
- moxifloxacin
- antibiotic against streptococcus
- targets DNA replication
is no effect from an antibiotic enough evidence that it is not a bacterial infection?
no, would need to take a culture and determine exactly what it is
why would a physician give someone a drug without doing a culture first?
to begin treatment and alleviate discomfort
what is viroptic?
- trifluridine
- blocks DNA replication of virus
- is an antiviral
what is mylan-acyclovir?
- acyclovir
- antiviral
- blocks the synthesis of DNA -> is shaped like a nucleic acid
- as effective as trifluridine
how do we know how to treat?
- lab tests
- epidemiological data on commonly reported cases in the area
BC CDC testing
will receive info from physicians regarding their patients: PCR, culturing, ELISA
what determines how efficient a treatment is?
- social resistance
- biological resistance
what is social resistance?
- social determinants
-> abuse of antibiotics, refusal of vaccines
what do we need to consider for biological agents causing disease?
the ecology (how agents react in their environment) and evolution of the host and biological agent
herpes types
- herpes simplex (HSV)
- herpes zoster (HZV)
what is HSV
- herpes simplex
- smaller than HZV
- dsDNA class 1
- can become provirus and incorporate into the nerve cells in the back of the eye
what is HZV?
- herpes zoster
- larger than HSV
- dsDNA class 1
- can become provirus
what is a provirus?
a form of a virus that is integrated into the genetic material of a host cell and by replicating with it can be transmitted from one cell generation to the next without causing lysis.
difference between HSV and HZV?
- size -> HSV is smaller than HZV
is herpes a notifiable disease?
- no, you do not have to report it in canada
- 60-95% of pop is already infection and most ppl immune
is SARS CoV 1 notifiable?
yes
what is seroconversion
antibody production
is SARS CoV 2 notifiable
no, we have a separate database for it
how is SARS CoV 2 different from influenza?
the structure is different but the symptoms are similar
whats presumptive cases?
have not been officially put in the database for reporting if they are notifiable. there is not enough testing data to confirm its what physician thinks
whats confirmed cases
have the correct testing results to confirm it is what physicians think it is. ready to be put into database if notifiable
what is CFR
case fatality rate
(# of deaths / total number of cases)
what kind of vaccine is Astra-zeneca?
recombinant adenovirus with covid 19 protein
what is a bivalent vaccine
original strain plus variants
what is pharyngitis
sore throat / inflammation
what causes TB?
mycobacterium tuberculosis
is TB notifiable
yes
how do we confirm TB?
1) Acid fast staining (AFB) - smear of sputum turns pink (1-2 days)
2) Nucleic acid Amplification Test (NAAT) PCR testing a specific M.tuberculosis gene (2-3 days)
3) Culture if AFB is positive (up to 8 weeks) - Important to determine antibiotic sensitivity
4) Chest X-ray - to see the extent of the infection
why has the number of confirmed cases for TB gone down since 40s?
vaccination and effective antibiotics
where in canada has the highest amount of TB cases?
nunavut - 266 per 100,000
yukon 21 per 100,000
what happens when a presumptive case is confirmed?
secondary contacts become presumptive cases
current TB vaccine?
BCG - live virus vaccine
why don’t we use BCG vaccine anymore in Canada?
disease incidence is low for most of Canada, but northwest territories and nunavut are still immunized
challenges with TB treatment and prevention
- drug resistance - we need new drugs
- vaccine resistance - we need new vaccines
- BCG is efficient in areas with high incidence, not efficient otherwise
what causes herpes?
a virus, dsDNA genome
what causes Sars CoV-2?
a virus, ssRNA
how do we know if a treatment is safe?
- safety testing for drugs and vaccines
- evolving religious and philosophical views
what is the new TB vaccine?
M72
what is a latent infection?
infection that is dormant until active in host cells
why would M72 address the rise is drug resistance for TB?
projected to avert the use of antibiotic treatment for 42m individuals
how many lives is M72 projected to save and prevent TB infection?
8.5m saved and 76m prevented
what is the difference between BCG and M72 for TB?
M72 is not as effective and a live virus vaccine
- BCG is 50% effective for latent TB infections and a ‘subunit’ vaccine for two surface proteins of bacterium
what kind of patients is M72 50% effective for?
latent ones
when was BCG developed
over100 years ago
is TB considered a new disease?
no
what happens as more vaccines are introduced?
the mortality rate decreases
when the was spanish flu?
1918
what did robert koch discover?
the cause of TB as a bacterium in 1882
what are the steps for koch’s postulates?
- Microorganisms are isolated from a diseased or dead animal
- The microorganisms are grown in pure culture
- The microorganisms are identified
- The microorganisms are injected into a healthy laboratory animal
- Disease is reproduced in a laboratory animal
- The microorganisms are isolated from this animal and grown in pure culture
- Microorganisms are identified
what is pathology?
the study of disease
what is etiology?
the study of the cause of the disease
what is normal microbiota?
permanently colonized in host/body
what is transient microbiota?
microorganisms that only temporarily found in the body
what does liebigs law stipulate?
growth is not controlled by the total amount of resources available but by the scarcest resource (limiting factor)
what is a real world example of liebigs law?
plant growth often is not limited by water or sunlight, but rather by nitrogen or phosphate in the soil
what does shelfords law stipulate?
success of an organism relies not only on the availability of nutrients but also that organisms tolerance to the environment. optimal and minimal conditions exist
when was the black death spreading through Europe?
AD 1348
what is an antibiotic?
a substance produced by a microbe that, in small amounts, inhibits another microbe
what is an antimicrobial drug?
a synthetic substance that interferes with the growth of microbes
what are the 5 bacterial sites that are targeted by antibiotics?
- Cell wall (penicillin)
- Protein synthesis (tetracycline)
- Inhibition of nucleic acids (rifampin for RNA, Quinolone for DNA)
- Cell metabolism (sulfonamide)
- Damage to cell membrane (polymixin B)
what does penicillin target?
peptidoglycan
how does penicillin function?
The cyclic oxygen breaks and forms a covalent bond with the enzyme, preventing it from ever being used again.
what are the 4 mechanisms of drug resistance?
- Block drug binding to the target site
- Destruction or inactivation of the drug
- Conformation change of the drug’s target site
- Rapid efflux of the drug from the microbe
who coined the term vaccination?
pasteur
define vaccine
a suspension of organisms or fractions of organisms that induce immunity
What occurs physiologically in response to a vaccine being administered?
A primary immune response which leads to the formation of antibodies and memory cells (IgM and IgG).
