Microbiology Chapter 29 – Epidemiology
Epidemiology; the study of the occurrence, distribution and determinants of health
and disease in a population.
In developed countries infectious diseases cause far fewer death than non-infectious
diseases (heart diseases, cancer)
New diseases are still emerging, effective control of infectious disease remains a
challenge.
29.1 The language of epidemiology
Epidemic; large number of people
Pandemic; widespread
Endemic disease; disease that is constantly present, in low numbers. (pathogen not
very virulent and most individuals are immune)
Incidence; the number of new cases
Prevalence; total number of new and existing disease cases
Reservoirs; sites in which infectious agents remain viable and from which infection of
individuals can occur. (animate or inanimate)
Outbreak; appearance of large number of cases in a short time.
Some infectious disease are cause by pathogens that reproduce in both human and
animals. Zoonosis; disease that infects primarily (hoofdzakelijk) animals but
occasionally (soms) to humans
Carriers (alive reservoirs); subclinical individuals; disease induvial who show no or
mild symptoms have subclinical infections. Individuals may be in the incubation
period.
Virulence; the measure of the relative ability of a pathogen to cause a disease
To cause a disease pathogen must replicate and grow inside a host;
Chronic infections; pathogen lives in balance with its host; both host and pathogen
survive
Acute infections; new pathogens emerge for which species has not developed
resistance. Dramatic disease onset and quick return to health.
Mortality; incidence of death in a population
Morbidity; incidence of disease including fatal and nonfatal diseases (verkoudheid,
kan soms fataal worden) defines public health best
29.2 The host community
Coevolution of a host and its mo/parasite is a common occurrence;
Virulence of the parasite in host-to-host pathogens diminishes
(neemt af) and resistance of the host increases (neemt toe)
Pathogen does not rely on host-to-host transition it may remain
extremely virulent.
Coevolution; development of host resistance, decreases in virulence of
pathogen, new equilibrium.
Epidemiology; the study of the occurrence, distribution and determinants of health
and disease in a population.
In developed countries infectious diseases cause far fewer death than non-infectious
diseases (heart diseases, cancer)
New diseases are still emerging, effective control of infectious disease remains a
challenge.
29.1 The language of epidemiology
Epidemic; large number of people
Pandemic; widespread
Endemic disease; disease that is constantly present, in low numbers. (pathogen not
very virulent and most individuals are immune)
Incidence; the number of new cases
Prevalence; total number of new and existing disease cases
Reservoirs; sites in which infectious agents remain viable and from which infection of
individuals can occur. (animate or inanimate)
Outbreak; appearance of large number of cases in a short time.
Some infectious disease are cause by pathogens that reproduce in both human and
animals. Zoonosis; disease that infects primarily (hoofdzakelijk) animals but
occasionally (soms) to humans
Carriers (alive reservoirs); subclinical individuals; disease induvial who show no or
mild symptoms have subclinical infections. Individuals may be in the incubation
period.
Virulence; the measure of the relative ability of a pathogen to cause a disease
To cause a disease pathogen must replicate and grow inside a host;
Chronic infections; pathogen lives in balance with its host; both host and pathogen
survive
Acute infections; new pathogens emerge for which species has not developed
resistance. Dramatic disease onset and quick return to health.
Mortality; incidence of death in a population
Morbidity; incidence of disease including fatal and nonfatal diseases (verkoudheid,
kan soms fataal worden) defines public health best
29.2 The host community
Coevolution of a host and its mo/parasite is a common occurrence;
Virulence of the parasite in host-to-host pathogens diminishes
(neemt af) and resistance of the host increases (neemt toe)
Pathogen does not rely on host-to-host transition it may remain
extremely virulent.
Coevolution; development of host resistance, decreases in virulence of
pathogen, new equilibrium.
