Ch. 16 - Blood Viral Infections Flashcards Preview

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Flashcards in Ch. 16 - Blood Viral Infections Deck (7):
1

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

2

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

3

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

4

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

4

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


5

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

6

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