Infectious diseases

Anmerkungen:

• 1. caused by infectious agents (generate spontaneous/from air)

1. Definition
   1. Infectious disease

      Anmerkungen:

      • -disease caused by infectious agents(bacterium, virus, protozoan, fungus) -can be passed to other host
   2. Infection

      Anmerkungen:

      • -occurs when the infectious agent enter the body and start reproduction -may or may not lead disease
      1. Pathogen

         Anmerkungen:

         • -a type of infectious agent can cause disease
      2. Host

         Anmerkungen:

         • -an organism infected by another organism
      3. Virulence

         Anmerkungen:

         • the relative ability of an agent can cause rapid and severe disease in a host
   3. Prevalence

      Anmerkungen:

      • -number of cases at a given time -expressed as a percent at a given time =product of incidence x duration of disease(long duration:hepatitis B)
   4. Contamination

      Anmerkungen:

      • The presence of an infectious agent on different kinds of material/substances(e.g. water, a body surface, clothes)
   5. Disease

      Anmerkungen:

      • -a pathological condition -characterized by signs and symptoms
   6. Immunogenicity

      Anmerkungen:

      • The ability of an organism to produce immune response after an infection: -providing protection against a similar or the same organism(e.g. infectious agents)
   7. Vector of infection

      Anmerkungen:

      • an insect or any living carriers:transport an infectious agent from an infected individual/its wastes to other susceptible individuals/food/surroundings.
   8. Reservoir

      Anmerkungen:

      • any person,animal, arthropod, plant, soil or substance or combination of these:allow an infectious agent to live and multiplies. -an infectious agent are transmittable to other susceptible(natural habitat)
   9. Imapparent infection

      Anmerkungen:

      • -no detectable clinical symptoms -can be documented by :    1.isolation of a pathogen,     2. detection of it component(DNA)    3. produce a specific immune response in                 person(asymptomatic)
   10. Incidence

       Anmerkungen:

       • 1.number of new cases in a given time period 2.expressed as percent infected per year/number per person time of observation
   11. Special terms
       1. Nosocomial

          Anmerkungen:

          • 1. an infection originating in a patient while in a hospital 2. not related to the patient's primary condition-e.g. infection of surgical wound, hepatitis B, urinary tract infection
          1. Opportunistic infections

             Anmerkungen:

             • infection by organisms -take opportunity provided by a defect in host defense -organism infect the host and cause disease. 
       2. Eradication

          Anmerkungen:

          • -aims to termination of all transmission of infection(extermination of the infectious agent) -absolute process(an all or non phenomenon)
          1. Elimination

             Anmerkungen:

             • It is used to describe eradication of a disease(e.g. measles/polio) from a large geographic  region.
       3. Reproductive rate

          Anmerkungen:

          • It describes the potential for an infectious disease to spread. Influential factors: 1.probability of transmission 2.frequency of population contact 3.virulence of the organism 4.population immune proportion 5.duration of infection
2. Causes
   1. Genetic
   2. Biological
   3. Physical
   4. Environment
   5. Chemical
3. Early history

   Anmerkungen:

   • 1.Smallpox-trigger epidemic in ancient Greece and Egypt 2.Plague-coinfect with measles and smallpox  3.Syphilis- spreadly rapidly through europe in 1490s and cause high mortality
4. Koch's Postulates(a particular agent can cause a specific disease)

   Anmerkungen:

   • 1. specific agent must be associated with every case of the disease. 2. the agent can be isolated from a diseased host and grown in culture 3. the culture-grown agent is introduced into a healthy species must cause the same disease 4.the same agent must be again isolated from the infected host
5. Caused by infectious disease agents

   Anmerkungen:

   • 1.microbes/microorganisms -bacteria -viruses -protozoa -fungi -Helminths(animals)
   1. MOA for induceing disease

      Anmerkungen:

      • 1.production of poisons(enzymes or toxins) 2.direct invasion and destruction 3.trigger immune responsed
6. Phases
   1. Incubation period

      Anmerkungen:

      • Time between infection and apparent of symptoms
      1. Prodromal period

         Anmerkungen:

         • mild,non specific symptoms that signal onset of some disease
         1. Clinical phase

            Anmerkungen:

            • a person experiences typical signs and symptoms
            1. Decline phase

               Anmerkungen:

               • subsidence of symptoms
               1. Recovery phase

                  Anmerkungen:

                  • symptoms have disappeared -tissue heal -body remains strength
7. Classifications
   1. By duration

      Anmerkungen:

      • 1. Acute 2.Chronic 3.Latent -characterized by periods of no symptoms between outbreaks of illness
   2. By location

      Anmerkungen:

      • 1. Local- confined to a specific area of body 2. Systemic- infects most of the body with pathogens distributed widely in tissues
   3. By Timing

      Anmerkungen:

      • 1. Primary:initial infection in a healthy person 2. Secondary:infection that occurs in a person weakened by a primary infection
   4. Clinical

      Anmerkungen:

      • 1. Diarrheal diseases 2. Respiratory diseases 3. Central nervous system infection 4. Cardiovascular infection 5.Sepsis
   5. Microbiological

      Anmerkungen:

      • 1. Bacterial 2. Viral 3. Fungal 4. Parasitic 5. Prion
   6. Transmission

      Anmerkungen:

      • 1. Contact(direct/indirect) 2. Food/water borne 3. Airborne 4. Vecter borne 5. Perinatal:occurs during pregnancy
   7. Reservoir

      Anmerkungen:

      • 1. Human:HIV, HBV 2. Animals: Rabies 3. Soil 4. Water:Pseudomonas aeruginosa
8. The severe level
   1. Endemic

      Anmerkungen:

      • The constant of a disease or infectious agent within a given geographic area
   2. Pandemic

      Anmerkungen:

      • an worldwide epidemic affect high proportion of global population
   3. Epidemic

      Anmerkungen:

      • The occurrence of a disease/illnesses excess of what may be expected on the basis of past experience for a given population
9. Transmission

   Anmerkungen:

   • 1.air 2.contaminated food/water 3. body fluids 4.Direct contact 5.animal vectors
   1. Reducing spreading

      Anmerkungen:

      • 1.Vaccines 2.Antimicrobial drugs 3.Good personal hygiene 4.Protection against vectors 5.Quarantine