(agglutination-1)

• Epidemiology


  Studying the spread of infections
• Incidence


  Number of new cases over time
• Prevalence


  Total number of cases over time
• Acute disease


  • Incidence and prevalence are similar
• Chronic/latent diseases


  • Incidence and prevalence are different
• Endemic


  Steady incidence rate for a common disease
• Pandemic


  Epidemic on multiple continents at the same time
• Epidemiologic studies


  1. Descriptive: where is disease happening?

  2. Analytical: is there a pattern?

  3. Experimental: what happens if?
• Identifying the source of an illness can help contain an outbreak
• Epidemiologic studies


  • John Snow + 1854 Broad ST cholera epidemic
  • Typhoid Mary
  • Smallpox
• Agglutination for diagnostic testing


  • Antibody recognizes antigen in 3D, native configuration
  • Antibody is made in response to infection, persists in serum
  • Most pathogen antigens are proteins, which are not particulate by themselves
• Making non-particulate antigen into a particle

  1. Latex/carbon beads are coated with antigen to become particulate

  2. Positive serum from patient= agglutination is positive
• Agglutination tests


  • Non-treponemal syphilis test= RPR card
  • Monospot latex agglutination = EBV
• Latex beads are more stable than RBCs and have fewer cross-reactive antigens
• EBV


  1. cell proliferation + heterophile antibody production