Terms in this set (23)

  • What are the two tick born diseases?
    Rocky Mountain Spotted Fever & Lyme Disease
  • What are the symptoms of Rocky Mountain Spotted Fever?
    • Distinguished by initial rash of faint pink spots - Appears first on palms, wrists ankles and soles of feet • Rash eventually spreads to other parts of the body - Spots become raised bumps and are hemorrhagic
  • What can occur with Rocky Mountain Spotted Fever when body systems are involved?
    Shock or death can occur when certain body systems become involved - Especially the heart and kidney
  • What is the characteristic of the rash for Rocky Mountain Spotted Fever?
    Non Itchy rash
  • What is the pathogen of Rocky Mountain Spotted Fever?
    Rickettsia rickettsii Obligate, intracellular bacterium - Requires host organism for survival
  • What is the Pathogenesis for Rocky Mountain Spotted Fever?
    • Disease acquired from bite of a tick infected with R. rickettsii • Bacteria are released into blood and taken up by cells lining vessels (Endothelia Cells) • Bacteria enter cells through endocytosis - After endocytosis, cell leaves protective phagosome • Bacterial endotoxin released in bloodstream can cause disseminated intravascular coagulation - This is recognized by shock and generalized bleeding KNOW THIS PATHWAY!!! ENDOTHELIA CELLS, ENDOCYTOSIS, and ENDOTOXIN
  • What is the Epidemiology for Rocky Mountain Spotted Fever?
    • Zoonotic disease - Spread from animals to humans • Occurs in areas in the US, Canada and Mexico - Highest incidence in US is in south Atlantic and south/central US • Maintained in several species in nature - Primarily in ticks and certain mammals • Main vectors include wood tick, Dermacentor andersoni and the dog tick, Dermacentor variabilis - Tick vectors remain infected for life
  • What does the endotoxin released by Rickettsia rickettsii cause?
    Intravascular coagulation which is a deadly complication Bleeding from all openings and can go into Hypovolemic shock
  • What is Hypovolemic shock?
    Shock caused by severe blood or fluid loss
  • How is Rocky Mountain Spotted Fever prevented?
    • No vaccine currently available • Prevention should be directed towards: - Avoiding tick infested areas - Use protective clothing - Use tick repellents containing DEET - Carefully inspecting body (Especially dark, moist areas) - Removing attached ticks carefully (Avoid crushing and contaminating bite area)
  • How is Rocky Mountain Spotted Fever treated?
    Blood transfusion, steroids, and drugs
  • What is the treatment for Rocky Mountain Spotted Fever?
    • Antibiotics are highly effective in treatment if given early - Doxycycline and chloramphenicol used most often • Without treatment overall mortality reaches approximately 20% • With early diagnosis and treatment, mortality rates drop to less than 5% Sooner treated the better
  • What are the stages of infectious diseases?
    Be able to label on a chart Incubation Period - Organism is replication
  • When was Lyme Disease discovered?
    Disease recognized in mid 1970's in Lyme, Connecticut • First identified by Dr. Willy Burgdorfer
  • What is the pathogen of Lyme Disease?
    • Borrelia burgdorferi • Large microaerophilic spirochete
  • What happens during the first stage of Lyme Disease?
    Migrans, Influenze signs, and Bulls Eye Rash • Characterized by erythema migrans (skin rash) and enlargement of lymph nodes • Rash begins as small red spot at the site of a tick bite and slowly enlarges • Other symptoms influenza like and include malaise, chills, fever, headache, stiff neck, joint and muscle pain and backache
  • What happens during the second stage of Lyme Disease?
    Begin 2 to 8 weeks post rash Involve heart and nervous system - Electrical conduction to heart is impaired - Nervous system involvement leads to paralysis of facial muscles and impaired concentration and emotional instability
  • What happens during the third stage of Lyme Disease?
    Characterized by arthritis - Usually of the large joints such as the knee Symptoms develop in 60% of untreated cases - Begin within 6 months after rash - Slowly disappear over years Chronic nervous system impairment may occur
  • How are the stages treated?
    Stages 1 and 2 can be treated with antibiotics but not third stage
  • What is the pathogenesis of Lyme Disease?
    Bacteria introduced into skin through bite of infected tick • Once in skin, bacteria migrate outward in radial fashion • Causes inflammatory reaction in the skin (Migration and inflammation produces an expanding rash) Host immunity is initially suppressed • Allows for continued multiplication of bacteria Bacteria enter bloodstream and circulate to other parts of the body • Bacteria do not cross the placenta
  • What is the Epidemiology for Lyme Disease?
    • Disease is zoonotic • Wide spread in US • Several tick species implicated as vectors - Most important is black-legged tick, Ixodes scapularis
  • How is Lyme Disease prevented?
    - No vaccine currently available - Prevention should be directed towards: • Avoiding tick infested areas • Use protective clothing • Use tick repellents containing DEET • Carefully inspecting body - Especially dark, moist areas • Removing attached ticks carefully - Avoid crushing and contaminating bite area
  • How is Lyme Disease treated?
    - Antibiotics relatively effective in early stage disease - Less effective in late disease - Presumably because bacteria are not actively multiplying