Infectious Disease Epidemiology Flashcards
What is the difference between microparasites and macroparasites?
Microparasites are small and multiply in-host whereas macroparasites are large and multiply out of host
Name some properties of macroparasites
- Age related exposure
- No immunity
- High morbidity, low mortality
- Endemic
- Continual reinfection
What are the two types of transmission routes?
- 1-1 (direct, indirect, droplet)
- no contact (airborne, vehicle, vector borne)
State the equation to work out the DALY
DALY = years lived with disability + years of life lost
How was the plague spread?
Aerosol
What is a vector?
Living organism which transmits infectious disease between humans or animals to humans (WHO)
What is vertical transmission?
Transmission from mother to offspring
Define an epidemic
An increase in incidence of disease
What is the R0 and when does an epidemic occur?
R0 is the basic case reproduction number and an epidemic occurs when it is >1
What is the equation for the R0?
R0 = p x c x D
What is the Re and its formula?
The restrained growth rate
Re = R0 x fraction of ‘s’
What is the Pc?
Percent of population likely to get the disease in a fully susceptible population
What is the formula for effective contact rate?
effective contact rate = p x c
What is the incubation period?
Time between infection and clinical onset of disease
What is the latent period?
Time from infection to infectiousness
In which population are endemic diseases most common?
Animals
What is the CCS equation?
Minimum host population size required for the pathogen to persist
What does an increased infectious period cause?
A slower moving infection
What is a ‘reservoir host’ and a ‘carrier’?
A reservoir host refers to a population or a species and a carrier refers to an individual
What are the 4 aims of intervention?
1) control
2) eliminate
3) eradicate
4) extinct
What are the 2 easy ways to prevent transmission?
- vaccination
- reduction in contact
What are the 2 intervention strategies of intervention?
- tracing + isolation
- culling
Define vectoral capacity
Average number of potentially infective bites that will be delivered by all the vectors feeding upon a host in one day
What is the equation for vectoral capacity?
C = (V/N)(ah)^2 x p^n / -ln(p)
What is the difference between anthroponotic and zoonotic diseases?
Anthrophonotic goes from human to anthropod to human whereas zoonotic goes from animal to anthropod to human
What natural event can affect spread of disease?
Climate change, temperature
What 2 factors can affect BTV transmission?
- temperature
- precipitation
What event offers evidence that climate change can alter disease?
El nino
What is vaccine efficacy?
The % of people who are immunised
Where did SARS-COV-2 originate?
Wuhan, China
How many coronas infect humans?
1/6 of them
