Lecture 22 Flashcards
What disease does herpes simplex type 1 virus 1 cause?
Cold Sores
What disease does herpes simplex type 2 virus cause?
GenItial herpes
What disease does varicella zoster virus cause?
Chicken pox and shingles
What disease does Epstein-Barr Virus cause?
Glandular fever
What disease does cytomegalovirus cause?
Minor illness
What disease does human herpes virus 6 cause?
Roseola infantum
What disease does human herpes virus 7 cause
minor illness
What disease does human herpes virus 8 cause?
Kaposi’s Sarcoma
What are the common features of herpes virus infections?
Uusally cause a minor illness
Have persistent latent infection with intermittent shedding
Is a lytic virus
Persistent infection of nerve cells, skin and lymphocytes
What is tegument?
Gloop inside the envelope of the virus
What is the structure of herpes viruses?
Enveloped virus with a nucleocapsid, envelope contains 80 viral proteins
How are herpes viruses diagnosed?
Syndrome, immunofluorescence, culture, serology, PCR
How are herpes simplex 1 and 2 treated?
Acyclovir or related drugs
What are the features of herpes simplex type 1 virus?
Infection occurs via contaminated saliva
Replication of the virus occurs in the skin and oral mambranes
Latent infection occurs in trigeminal ganglion
Reactivation of the virus causes cold sores
What causes neonatal herpes and what is its frequency?
1:5000 births
Timing is important as a recurrent shedding of the virus must occur during birth but there must be no antibodies yet present in the mother which could be transferred to the child
The young immune system of the child results in the virus being spread throughout the entire body
How can herpes simplex virus 1 cause encephalitis or meningitis?
Instead of spreading down the axon, the herpes virus does the other way travelling towards the brain
What are the features of varicella zoster virus?
Infection occurs through saliva or skin or coughing
Replication occurs in skin and mucous membranes
Latent infection occurs in the dorsal root ganglion
Reactivation causes shingles restricted to the dermatome of the latently infected neuron
What are the features of the epstein-Barr virus?
Infection occurs via infected saliva (“Kissing Disease”)
Infection occurs in B lymphocytes in tonsils, allowing spread to other lymph nodes
Cytotoxic T lymphocytes attack the infected B lymphocytes causing illness
What is glandular fever?
acute Epstein-Barr Virus infection
about 30 days is required as an incubation phase as the T lymphocytes must first recognise and mount an immune response
Sore throats, swollen tonsils and enlarged, tender lymph nodes occur
Typically lethargy and anorexia occur
What is the effect of EBV infection on B lymphocytes?
They become continually activated, constantly secreting virus and antibodies
Inadequate killing of these cells can cause B cell lymphoma
How is EBV infection diagnosed?
Test for presence of antibodies (sheep red blood cells can be used here as the antibody against EBV also reacts against them)
Specific EBV antibodies can be tested
EBV DNA can be detected
Detection of abnormal activated cytotoxic T cells
