Characteristics of disease
Disease?
any condition in which normal structures or functions of the body are damaged/impaired
Signs of disease are?
objective and quantifiable and can be directly observed by a clinician
Communicable disease?
Disease capable of being spread from person to person by direct/indirect mechanisms
Occurs in an acute disease after initial exposure of pathogen into host
Incubation Period
Pathogenicity vs virulence
Pathogenicity- ability of microbial agent to cause disease
Virulence- degree to which organism is pathogenic to host
Pyrogen? How does it affect the individual?
raises body temp to kill pathogen, makes the individual feel sick
Symptoms can be experienced by the patient but cannot?
cannot be clinically confirmed or objectively measured
Diseases that are acquired in a hospital setting?
Nosocomial diseases
Pathogen continues to multiply and the host begins to experience signs/symptoms of illness
Prodromal
# of pathogenic cells, virions, or amount of toxin required to kill 50% of infected animals
Median Lethal Dose
What are infections?
Successful colonization of host by microorganisms
Syndromes have?
A specific group of signs and symptoms characteristic of a particular disease
Diseases that occur after a procedure involving wound treatments?
Iatrogenic
Period of illness?
Signs and symptoms are most obvious and severe
# of pathogenic cells or virions required to cause active infection in 50% of inoculated animals
Median Infectious Dose
infectious disease that is NOT spread from one person
What does is mean to be asymptomatic?
signs and symptoms are not present
Diseases that are directly transmitted from animals to humans?
Zoonotic disease
Period of decline?
signs and symptoms of illness decline because number of pathogen particles begin to decrease
Primary vs Opportunistic pathogens
Primary-cause disease in host regardless of its resident microbiota or immune system
Opportunistic-can ONLY cause disease in situations that compromise host defenses
Noninfectious diseases?
not caused by pathogens, Genetics, Environment, Immune dysfunction
Nomenclature?
Naming system based on signs and symptoms or location of disease
Acute vs Chronic vs Latent diseases?
Acute- short, rapid onset of disease conditions (hours, days, weeks)
Chronic- pathologic changes over a much longer time (months, years, lifetime)
Latent- pathogen goes dormant for extended periods with no active replication
Period of Convalescence
Patient generally returns to normal functions
What are the stages of pathogenesis?
Exposure-(contact)
Adhesion(colonization)
Invasion (disseminates through local tissues or body and reproduce)
Infection(successful multiplication)