Lyme Disease Flashcards
dead end host
a host from which infectious agents are not transmitted to other susceptible hosts
(infected human can’t transmit the disease to other unaffected ticks = level of bacteria circulating in blood = too low)
ecosystem service
the quantifiable services than an ecosystem provides to humans
lyme disease
zoonotic disease vectored by ticks - small mammals are the main reservoir species
what bacteria cause LD
spirochete bacteria
gram-negative
even though there are a number of animals hosts for the pathogen what is the main reservoir
mice
what is the vector for the disease
ticks
what do ticks need to do in their lives
need to malt between different life stages
what must a tick do to become infected
feed on an infected host (not human)
what are LD symptoms
within a few days: skin rash after bite
days/weeks: fatigue, chills, fever, headache, muscle/joint aches (due to inflammation), swollen lymph nodes, Bell’s Palsy
long term neurological problems: problems with concentration, short-term memory loss, severe arthritis/joint pain
what happens once the bacteria enter the BBB
enter the brain - harder to treat as harder to reach
what must happen for human outbreak of LD to occur
human must be bitten by infected ticks = need lots of ticks = need to feed on infected hosts
is LD treatable if so with what
the earlier you catch it the easier it is to treat - treated by antibiotics - not beta-lactam as gram-negative bacteria
what are vertebrate hosts for larval and nymphal ticks
rodents, lizards, birds
what are hosts for adult ticks
deer
how do you get infected by LD
bacteria found in salivary glands of a tick, enter the body at the site of the bite (compounds in ticks saliva = suppress the immune system), bacteria then migrate out of site of the bite
how would you recognize LD
distinctive rash - inflammatory response of the body
who has chronic LD
largely in people who have had LD - treated and no longer test positive = treatment worked but still have symptoms
what are 3 explanations of chronic LD
- hidden infection - (not positive)
- autoimmune response - (triggered by initial infection)
- something else (psychological factors/immune system problems)
what is the problem associated with chronic LD
no evidence: symptoms of chronic LD being caused by bacteria - people convinced of hidden infection = want treatment > long term antibiotics (evolution)
if you increase the awareness of a disease
people are more likely to get tested - as science develops, advanced way of testing = increase in no of cases