lectures 5-7 Flashcards
what are the 3 classes that emerging infectious diseases can fall under?
- newly emerging
- existing but rapidly increasing in incidence or geographic range
- new epidemics of old pathogens
what factors can be attributed to the emergence of infectious disease?
- deforestation
- urbanisation
- road construction
- climate change
- agricultural development
- habitat fragmentation
- air and water pollution
- hydrological changes (including dam building)
- population movement
- better detection/diagnosis
- drug resistance
what factors can be attributed to the emergence of infectious disease?
- deforestation
- urbanisation
- road construction
- climate change
- agricultural development
- habitat fragmentation
- air and water pollution
- hydrological changes (including dam building)
- population movement
- better detection/diagnosis
- drug resistance
define sequelae
death at a much later stage due to side effects of an infection
what pathogen type are bats a reservoir of?
viruses
how many coronaviruses were found across 1200 bat species?
3204
what animals are the main reservoir for ebola?
bats
what animals have been the reservoir for MERS?
it originated in bats and then crossed over into dromedary camels
what does MERS stand for?
middle east respiratory syndrome
define what is meant by an emerging disease
a disease that has appeared in a population for the first time or that may have existed previously but is rapidly increased in incidence or geographic range
what is meant by a re-emerging disease?
a disease whose incidence has increased in a defined time period and location
what human activity is being attributed to the re-emergence of infectious disease?
- breakdown of public health measures
- poverty and social inequality
- war and famine
- lack of political will
- bioterrorism
what other (non human-caused) factors have been linked to the re-emergence of infectious disease?
- climate and weather
- co-infection
- microbial adaptation and change
define transmission
the mechanism in which a disease is spread
define incubation period
the time between infection and symptom onset
what is a carrier?
a person or animal without apparent disease who harbours a specific infectious agent and is capable of transmitting it to others
define infectivity
the proportion of people exposed to a causative agent who became infected by an infectious disease
what is a reservoir?
the habitat in which an infectious agent normally lives, grows, and multiplies
define zoonoses
an infectious disease that is transmissible from animals to humans
what does the term ‘endemic’ mean?
a disease which is constantly present in a population or geographical area
what does the term ‘epidemic’ mean?
the occurence of more cases of disease than expected in a given area or population over a particular period of time
define what a pandemic is
a worldwide epidemic, affecting a large, widespread population simultaneously
describe the structure and growth of the pathogen which causes lyme disease
- it is coiled and contains a double membrane
- it does microaerophilic growth
what is the transmission of lyme disease like?
- zoonotic reservoirs
- vector-borne transmission
what are the main virulence factors of the Lyme disease pathogen?
- a motile flagella
- exploiting the immune system
- Ospe lipoprotein expression - used for attachment to tick midgut, allowing it to be secreted in tick saliva
what are the cures and treatments for lyme disease?
- no human vaccine
- can be treated with doxycycline if caught early
what are the characteristics of cholera bacteria?
- Gram negative
- facultative anaerobe
- comma shaped rod
- flagellated
what are the 3 classes that infectious diseases can fall under?
- newly emerging
- existing but rapidly increasing in incidence or geographic range
- new epidemics of old pathogens
how is cholera bacteria transmitted?
contaminated water
what are the main virulence factors of cholera?
- cholera enterotoxin
- adherence factors
what is re-emergence of cholera potentially an indicator of?
- linked to increasing size of vulnerable populations living in unsanitary conditions
is cholera re-emergence a consequence of class?
no
is there a cholera vaccine?
yes!
what treatments are used for cholera?
- rehydration therapy
- antibiotic treatment
- zinc treatment
how can cholera be prevented?
safe water and adequate sanitation
what are the characteristics of shigella bacteria?
- Gram negative
- facultative anaerobe
- non-motile
how is shigella bacteria transmitted?
- food
- water
- reduced hygiene
what are the virulence factors associated with shigella?
- invasion of epithelial cells
- shiga toxin
is shigella multidrug resistant?
yes
