carriers

organisms (usually  refers to humans) that parbor pathogens and transmit them to others

contact transmission

the spread of disease by direct or indirect contact or via droplets

direct contract  transmission

a method of spreading infection from one host to another through some kind of close association between the hosts

etiology

the study of the cause of a disease

incidence

the fraction of the population that contracts a disease during a particular period of time

pathogen 

a disease causing organism

prevalence

the fraction of a popu;lation having a specific disease at a given time

sepsis

the presence of a  toxin or pathogenic organism in blood and tissue

subacute

disease-a disease with symptoms

toxemia

the presence of toxins in the blood

adaptive immunity

the ability, obtained during the life of the individual, to produce specific antibodies and T cells 

exotoxin

a protein released from living, mostly gram-positive bacterial cells

antitoxin

a specific antibody produced by the body in response to a bacterial exotoxin or its toxoid

leukocidins

substances produced by some bacteria that can destory neutrophils and macrophages

parental  route

a portal of entry for pathogens by deposition directly into tissues beneath the skin and mucous membranes

receptor

an attachment for a pathogen on a host cell

septic shock

a sudden drop in blood pressure induced by bacterial toxins

pathogenicity

the ability of a microorganism to cause diesea by overcoming the  defences of a host

toxoid

an inactivated toxin

virulence

the degree of pathogenicity of a microorganism