DIGENIA Flashcards
What is a pathogen?
Any organism or substance that produces a disease state.
What does pathogenicity encompass?
The total sum of consequences regarding the presence of a foreign species in the host.
When is a parasite considered pathogenic?
If it causes changes in the anatomy, physiology, or behavior of the host.
What does virulence deal with?
The consequences of the presence of the foreign species on the transmission of the host’s genes.
What is population structure?
A set of quantitative descriptors of a population, including prevalence, density, variance of a frequency distribution, and curve of best fit.
What is prevalence?
The percentage of a single host species at a given time.
What is incidence?
The number of new infections per unit time divided by the number of uninfected hosts at the beginning of the measured time.
What is abundance or density?
The average number of parasites of one species per sample of host individuals of the same species, equal to the arithmetic mean.
What is intensity in the context of parasites?
The number of parasites of one species in an infected host.
What is mean intensity?
The average number of parasites of one species per infected host in a sample.
What does aggregated or over dispersed mean?
A situation in which most of the parasites occur in a relative minority of hosts and most individuals are either uninfected or lightly infected.
What is a parasite community?
The number of different parasite species infecting a single host individual.
What is macroepidemiology?
The study of the effects of large scale factors, such as climate and culture, on the distribution of disease in a population.
What is microepidemiology?
The study of the effects of small scale factors, such as parasite strains and host genetic variation, on the distribution of disease in a population.
What is landscape epidemiology?
An approach of epidemiology that employs all ecological aspects of a nidus.
What is a nidus?
A specific locality of a given disease; result of a unique combination of ecological factors.
