CHAPTER 13: CARRIERS, VECTORS, DISEASES contd... Flashcards
Latency
- when the host recovers, microbes may still be present
- in some chronic diseases, after the initial symptoms
-microbe can become active occasionally and person may/may not shed during latent stage
sources and transmission of microbes: 2 types
reservoir and source
Source
individual or object from which an infection is actually acquired
site from which it was transmitted
reservoir
the primary habitat of pathogen in the natural world
- human, animal, soil, water, or plants
this is the site where it resides/multiplies
Living Reservoirs:
- what is a carrier
- types of carriers
a carrier is an individual that has a pathogen and spreads it to others / may or may not experience the disease
- passive carrier
- asymptomatic carrier (3 types)
Passive Carrier
passive: contaminated individual picks up pathogens and transfers to PTs without ever having the disease/being infected
ex) HCPs
Asymptomatic Carrier (3)
- no symptoms, but INFECTED
incubation: spread infec. during incubation period, YES symptoms
convalescent: get better w OUT symptoms
chronic: holds infec. for a long time
chronic carrier
person who continues to shelter and shed infectious agent for long time after recovery
sequelae
long term or permanent damage to tissues or organs as result of infection
Vector
live animal transmits infectious agent from one host to another
- most arthropods (flea, mosquito, ticks)
- some larger like mammals, birds, lower vertebrates
Biological vectors
participate in pathogen life cycle
human and malaria
- such as mosquitoes and ticks may carry pathogens that can multiply within their bodies and be delivered to new hosts, usually by biting
Mechanical vector
not necessary to life cycle of infectious agent, just transport it w OUT being infected
transmit through physical contact
- such as flies can pick up infectious agents on the outside of their bodies and transmit them through physical contact.
Zoonosis
infection indigenous to animals, naturally transmitted to humans
- have to eradicate animal reservoir to eradicate the disease
reservoir vs source
reservoir: habitat
source: how the infection was acquired
Communicable vs Non communicable disease
communicable: infected host can transmit infectious agent to another host and ESTABLISH infec in that host
- highly communic=contagious
noncommunicable: no disease from host to host transmission
- infec in from your OWN microbiome or contact w organism in natural nonliving reservoir
(fungal infection)
