Ch. 16 - Blood Viral Infections Flashcards
Infectious Mononucleosis
EBV
Target epithelial cells in oropharynx –> spread to nearby B cells in lymph nodes
Symptoms: sore throat, swollen lymph nodes, malaise
Many kids do not show symptoms
Spread via saliva –> kissing disease!
First human virus associated with cancer - Burkitt’s Lymphoma (cancer of the oropharynx)
Complications: heart defects, facial paralysis, rupture of spleen, jaundice
Diagnosis of Infectious Mononucleosis
Elevated lymphocyte count (lymphocytosis)
Monospot test - Heterphile Antibody Test
- after onset of EBV, develop heteroantibodies
1. Blood from pt.
2. Separate serum and RBC
3. Serum mixed with Guinea pig extract –> rxn removes any closely related Ab
4. Add horse erythrocytes
+EBV: EBV Ab in serum, erythrocytes will agglutinate
-EBV: no EBV Ab in serum, no agglutination
Cytomegalovirus (CMV)
Herpes virus - largest member of Herpes family
Cytomegalic inclusion disease –> common cause of congenital abnormalities
Asymptomatic or mono-like symptoms in adults (fever, malaise, swollen lymph nodes)
In infants/fetus: sever congenital abnormalities –> BLINDNESS
Hepatitis B (HBV)
Virions antigens:
HBsAg - envelope surface antigen; used in vaccine, but genetically engineered via yeast cells
HBcAg - surround nucleocapsid
HBeAg - viral protein secreted by infected cells; best indicator of transmissibility
DNA genome: only DNA genome in hepatitis virus; partially ds DNA (gap in one of the two strands)
Transmission: contact with contaminated bodily fluids
Incubation: 1-6 mo. (Long)
Virus infects the liver –> primary symptom jaundice
Causes: cirrhosis and liver cancer ( Hepatocellular carcinoma = HCC)
Carrier rate = 5%
Treatment: interferon for chronic infections; HBV immunoglobulins for needle stick exposure
Hepatitis C (HBC)
Post-transfusion hepatitis - injection drug users (not common to transmit sexually)
Most common chronic blood borne infection in US - high carrier rate (80-90%); primary reason for liver transplants in US
Symptoms: mild, subclinical
Causes: cirrhosis, Hepatocellular carcinoma (HCC)
No vaccine - recent development of pill
Treatment: Interferon and Ribavirin
Ribavirin - nucleoside (base) analog; inhibit transcription of DNA/RNA
–>inhibit synthesis of viral nucleic acid
Hepatitis D (HDV)
Caused by 2 viruses (co-infection): HBV and HDV
HDV = protein fragment (delta antigen) and segment of RNA
Co-infection: only cause liver damage if HBV present –> chronic/more advanced hepatitis
HIV/AIDS
(+) ss RNA
Retroviridae
Envelope
Icosahedral
Enzymes: reverse transcriptase, integrase, protease
Surface antigens: gp120 ( attach to CD4 on T cells) - attachment protein; go 41 fusion protein (help virus fuse with T cell membrane)
Reverse transcriptase - make mistakes –> change in surface proteins; hard to develop immunity
AIDS: CD4 count 2 Reverse transcriptase inhibitors
