Retroviruses (Know this well)

Questions

1. Describe the general properties of retroviruses

2. What are the most common retroviruses, include the diseases they cause?

3. How would you diagnose retroviruses?

4. How would you prevent retroviruses?

5. How would you treat retroviruses?

• The general properties of retroviruses include: 10-120nm in size, ss +ve polarity, reverse transcriptase present, helical in structure, enveloped.
  
• In man, there are different viruses including: HTLV-1, HTLV-2, HIV 1, HIV 2.
• The 1^st one is associated with adult T cell leukaemia/lymphoma. It is transmitted by blood transfusions, sexual contact, IVDU and also breast feeding.
  
• HTLV -2 causes lymphoproliferative diseases. HIV 1 & 2 causes AIDS. The transmission in this case is: unprotected sex, IVDU, mother ≫ offspring, blood and blood products.
  
• Diagnosis can be done serologically, ELISA, fluorescent antibody test, detection of viral nucleic acid in the blood and other body fluids, and also monitoring of CD4+ levels due to progression of disease.
  
• You can prevent by screening all blood and blood products, education of high risk groups.
  
• Treatment for retroviruses is HAART (highly active antiretroviral therapy). This includes a cocktail of antivirals including: nucleoside analogues of reverse transcriptase inhibitors, protease inhibitors, and integrase inhibitors (does not let viral RNA to be integrated into DNA of T cells). Vaccine is under development. Antiviral therapy is expensive, and offers hope to people who can afford it.

Category: Microbiology Notes