Ch. 36 - Epidemiology

• john snow


  the first epidemiologist; studied cholera in london
• CDC


  located in atlanta, functions to develop and apply disease control and prevention and promote health education
• sporadic disease


  occurs occasionally and at irregular intervals
• endemic disease


  maintains a relatively steady low-level frequency at a moderate interval
• hyperendemic disease


  gradual increase in occurrence frequency above endemic level but not epidemic level
• public health surveillance


  review of death certificates, investigation into epidemics, and investigation into actual cases to identify and prevent issues
• remote sensing


  gathering of digital images of earth's surface from satellites and transforming data into maps
• GIS


  data management system that organizes and displays digital map data from remote sensing
• disease frequency


  measured by morbidity rate, prevalence rate, and mortality rate
• morbidity rate


  # of new cases during a specific time / # of individuals in a population
• mortality rate


  # of deaths due to given disease / size of total population with disease
• common source epidemic


  a single common contaminated source such as food, high amount of individuals infected but lasts a short time
• propagated epidemic


  one infected individual into a susceptible group, infection propagated to others; follows a longer bell curve
• herd immunity


  resistance of a population to infection and spread because of the immunity of a large percentage of the population; levels can be altered by introduction of a new susceptible individuals or antigenic changes in the pathogen
• reasons for increases in emerging and reemerging infections


  population growth, international travel, habitat disruption, microbial evolution, and inadequate public infrastructure
• nosocomial infections


  hospital infections; can be caused by an endogenous (acquired or brought in) or exogenous pathogen, or autogenous infection
• control of epidemics


  reduce or eliminate source of reservoir of infection, break connection between source and susceptible individual, and reduce number of susceptible individuals
• vaccines


  attempt to induce antibodies and activate T cells to protect host from future infection
• adjuvants


  mixed with antigens in vaccines to prolong the antigen interaction with immune cells and stimulate a response
• subunit vaccines


  use of purified molecules from microbes to avoid the risks of normal whole-cell vaccines; capsular polysaccharides, recombinant surface antigens, and inactivated exotoxins
• recombinant-vector vaccines


  pathogen genes that encode antigens are inserted into nonvirulent bacteria/viruses which serve as vectors and express the gene
• DNA vaccines


  DNA is directly introduced into host cell via air pressure or gene gun, then taken into nucleus and pathogen's DNA fragment is expressed