3. Disease reservoir and transmission - PID

Exposure

Exposure

Introduction of a new pathogen into a susceptible population

Transmission

Adoption, establishment, and dissemination in the susceptible population.

transmission

___________ requires a pathogen that can adapt to, and spread between, these hosts.

Reservoir

A habitat or population in which an infectious agent normally lives, grows, and multiplies.

False

(True/False): reservoir individuals are, by definition, not ill.

True

(True/False): reservoir individuals may be ill.

carrier

Asymptomatic individual

reservoir

An individual can be killed by an infectious agent, but still be part of a _______________ if the population maintains the agent.

false

(True/False): Reservoirs are always populations.

False

(True/False): Reservoirs are always habitats (lakes, soils, etc).

Portal of exit

The method the pathogen uses to leave the body of the host

fecundation

Infection at ____________: the virus attaches to spermatozoa or oocyte.

transplacental

Infection in utero through the placenta

transovarial

The passage of a pathogen from the adult female arthropod through the ovaries to the eggs.

Perinatal

Infection at parturition or through colostrum.

Vertical transmission

Infection at fecundation, transplacental infections, transovarial infections, and infection at parturition are all examples of

Direct transmission

Horizontal transmission that spreads directly from the reservoir to a susceptible host.

Indirect transmission

Horizontal transmission that utilizes any sort of intermediary in transmission from reservoir to a susceptible host.

brutal contact

Contact defined by violent damage being done to susceptible host.

mucous membrane contact

Contact that occurs via interaction with sexual organs or saliva

skin contact

Contact that occurs between the dermis of two individuals

direct contact

Skin contact, brutal contact, and mucous membrane contact are all forms of

Droplet spread

Spread of infectious agent via wet, large, short-range aerosols.

airborne spread

Spread of infectious agent via longer range aerosolized particles

waterborne spread

Spread of infectious agent through the gills of aquatic animals.

direct

Waterborne, airborne, and droplet spread are all methods of (DIRECT/INDIRECT) transmission

vehicle

an inanimate object which serves to communicate disease

Fomites

Objects that can be contaminated and transmit disease on a limited scale

vector

An arthropod that carries and transmits pathogens

mechanical vector

An animal that carries a pathogen from one host to another without being infected itself.

Biological vector

An animal that carries a pathogen from one host to another while the pathogen undergoes changes/multiplies within the vector.

biological vector

A mosquito takes a blood meal. It takes in a pathogen that proceeds to replicate within the mosquito. The mosquito takes a blood meal from a new victim. The new victim is infected. The mosquito is a

mechanical vector

A mosquito takes a blood meal. It takes in a pathogen that cannot replicate within the mosquito. The mosquito takes a blood meal from a new victim. The new victim is infected. The mosquito is a

Indirect

Vectors and vehicles are (DIRECT/INDIRECT) modes of transmission.

portal of entry

The method the pathogen uses to enter the body of a susceptible person or animal.

eyes

The most efficient portal of entry is the exposed mucosa of the

susceptible host

Member of a population who is at risk of becoming infected by a disease.