Microbiology Unit 3

  1. Epstein-Barr virus
    • a herpesvirus that causes infectious mononucleosis
    • sx: swollen lymph nodes, sore throat, extreme fatigue, enlarged spleen, inflamed lymphatic tissue, enlarged liver, and damage to liver cells
    • Dx: CBC, Monospot (antibody)
  2. Epstein-Barr virus continue
    • strep throat is often a secondary infection in mono
    • tx: rest
    • chronic fatigue syndrome - exact cause is not known, many patients have EBV antibodies which may be linked to EBV
    • sx: extreme fatigue, memory loss, joint-pain, and flu-like symptoms
  3. EBV Association
    • Burkitt Lymphoma and B-Cell lymphomas in imuunocompromomised
    • nasopharyngeal carcinoma
    • Hodgkin's Disease
    • MS
  4. Cytomegalovirus (CMV)
    • a herpes, very common infection, flu-like symptoms so it often goes undiagnosed
    • usually infects older children and adults
    • more severe disease in AIDS and immunocompromised
    • transmission: virus sheds in body fluids over many months -- saliva, blood, urine, and breast milk and semen
  5. CMV continue
    • largest quantity of virus are in the urin
    • virus can stay in the urine up to a year
    • if pregnant during active CMV, can cause sever brain damage, hearing loss, liver damage, impaired vision
    • TORCH Panel
  6. Viral diseases that causes hemorrhagic fevers
    • aka arboviruses because they are arthropodborne
    • yellow fever - extreme jaundice
    • dengue fever - bone breaking
  7. Viral gastroenteritis
    • sx vary, most include diarrhea, nausea, vomiting, low-grade fever, cramps, headache, and malaise
    • causes: rotavirus, noroviruses (aka norwalk), coxsackie A and B, and echoviruses
  8. Rotavirus
    • major cause of viral gastroenteritis
    • very watery, sewery smell
    • cases occur during winter months
    • high infant mortality rate in underdeveloped world for children less than 5 years old
    • transmission: fecal-oral route, replicates in the intestinal epitheliel cells, impairs intestinal absorption
    • causes sever dehydration and death if not treated
    • dx: rapid tube test from stool speciman
    • tx: restore loss fluid and electrolytes
    • prevention: rotarix
  9. Viral diseases of nervous system
    • rabies
    • polio
    • arboviruses
  10. Rabies
    • transmitted by animal bite of infected animal
    • virus migrates from the bite to the nerves and spreads to the spinal cord and then brain
    • sx: uncoordinated movement, paralysis, difficulty swallowing, hypersensitive nerve ending in skin, brain degeneration and death
    • once rabies occur: no cure except for a couple of cases
    • dx: examine brain tissue of animals for negri bodies
    • new fluorescent antibody technique to look for rabies antibodies in brain tissue
  11. Rabies prevention
    • rabies vaccine is available for vets or anyone working with animals
    • gives immunity to rabies
    • if bitten by infected animal, 1 dose of rabies immune globulin
    • give 5 IM injections over 28 days
  12. Poliovirus
    • infantile paralysis
    • poliomyelities
    • transmission: fecal-oral route
    • naked virus
    • associated with swimming pools
    • when ingested, causes nausea, diarrhea, cramps
    • can spread through the body to meninges and cause meningities -> paralysis or arms, legs and trunk
    • severe cases include paralysis of tongue, neck, diaphragm and difficulty breathing
  13. Poliovirus prevention
    vaccine available
  14. Posptpolio Syndrome (PPS)
    • people who had polio decades ago experience re-emergence of symptoms
    • muscle weakness/atrophy
    • general fatigue/exhaustion
    • muscle/joint pain
    • breathing/swallowing difficulty
    • 25-50% survivors are affected
  15. Arborvirus
    • arthropod born virus - over 350 strains
    • causes arboviral encephalitis - acute inflammation of the brain
    • transmission: arthropod bite transmits to humans and animals
    • virus travels to neurons and CNS
  16. Arbovirus disease continue
    • sx: headache, fever, confusion, weakness, convulsions
    • can destroy nerve cells, permanent brain damage and death
    • in US, strains are: St Louis encelphalitis, La Cross encephalitis, Eastern Equine encphalitis, and Western equine encephalitis
  17. West Nile Virus
    • is an arbovirus
    • an emerging disease from Egypt
    • birds and horses are hosts
    • severe and often fatal
    • usually not severe in humans
    • causes flu-like symptoms or can be asymptomatic
    • about 1/150 cases complicate as the virus enter the CNS
Card Set
Microbiology Unit 3
Viral infection of the blood, lymphatic, gastrointestinal and nervous system