Lecture 1 Flashcards
Health is?
Health is a spectrum, in which the ends of the spectrum are death and reproduction
What is disease?
a finite abnormality of structure of function with an identifiable pathological basis and recognizable clinical signs
Clinical disease is?
a disease with visible symptoms
Subclinical disease is?
not visible but measurable in some way
Infection is?
invasion and multiplication of microorganisms in body tissues
Inections especially cause local cellular injury due to?
competitive metabolism, toxins, replication, antigen-antibody response
Classification of disease is done by?
Degenerative Anomalous Metabolic Neoplastic Infectious Traumatic
Degenerative disease is?
when the structure is altered by age, use or disuse or biochemical changes
Anomalous disease is?
abnormal structure or function- which can be genetic, a developmental accident or congenital
Metabolic disease is?
due to nutrition, toxins or hormonal activity that alters normal metabolism
Neoplastic disease is?
abnormal growth of cells at the expense of normal tissue structure and function
Infectious disease is?
caused by microorganisms that invade the body and damage normal structure and function
Traumatic disease is?
mechanical injury like a broken bone
Etiology is?
the study of the cause of disease
Etiologic agent?
causative agent of disease but does not equal the cause of disease
Pathogenesis is?
the development of disease, the process by which a pathogen produces disease
Pathogens are?
any disease-producing microorganism or material
Epidemiology is?
the study of patterns of disease that exist under field conditions specifically the frequency, distribution and determinants of health and disease in a population
Koch’s Postulate is?
sick animal–> isolate a pathogen–> infect a healthy animal with this pathogen–>cause the same disease in this animal–>re-isolate the same pathogen
Bacteria are? Different types include?
more like cells, which are capable of replicating outside the host and are mostly responsive ot antimicrobials but can develop a resistance:
- non-pathogenic(don’t cause disease)
- opportunistic(only becomes pathogenic in prime condition)
- pathogenic(cause disease)
Viruses are?
contain some form of nucleic acid(DNA or RNA) and require a host cell to replicate and are not responsive to traditional antimicrobial agents
Prions are?
abnormal form of PrP protein(no DNA/RNA)
they are resistant to proteases, somewhat host specific
Mycotic?
fungal
paratsites are? types include?
intracellular
internal
external
Pathogen examples
bacterium, virus, fungus that cause infection/disease
Virulence includes?
degree of pathogenicity
includes severity
fitness of pathogen
Predisposition with disease?
what predisposes an animal to infectious disease
Fomite transmission is?
Inanimate objects or passive carriers (ones which are alive but the organism doesn’t infect like the human hand)
Vector transmission
invertebrate animal required for agent life cycle and transmission
Horizontal transmission
between animals of the same generation, infectious and contagious
Vertical transmission
from mother to offspring
Contagious means?
capable of being transmitted from animal to animal
Determinants of disease include?
Host factors age genetics physioologic state production level nutritional status agent factors environment factors
Immune status is dependent on?
nature of agent, challenge and environment
Age as a determinant of disease
as one ages there is a physiologic effect which causes chages in cell or organ function which are inevitable
Physiological changes associated with age are associated with?
changes in production level, immune status and physiologic state
Physiologic state example
pregnant
lactating
Agent factors as determinants of disease
virulence determinants
pathogen challenge
Environmental factors affect?
pathogen load and host response
Necessary cause is?
without this factor, the disease cannot occur but the presence of a disease agent may not be sufficient to cause disease
Sufficient cause?
factors working together to produce disease, alone one factor may not be sufficient but in various combinations, disease occurs
Carrier state
no clinical disease but potential to transmit an infectious agent-may reamin asymptomatic, incubating the disease or convalescing from the disease
Morbidity
the amount of disease
Mortality
the number of deaths as a statistic
Case fatality
rate- proportion of animals with a specific disease that die from it
Prevalence of disease
at a point in time, the number of animals that are diseased/number of animals in the population
incedence of disease
number of new cases of disease in a specified time period or risk period/by number at risk. Implies at least observations or measurements
