16.HHV6_Flashcards

Question 1

What is HHV-6, and what cells does it target?

Answer 1

HHV-6 is a T-lymphotropic virus targeting CD4+ T cells, B cells, megakaryocytes, glial cells, and fibroblasts.

Question 2

What are the key characteristics of HHV-6?

Answer 2

1. Genetically resembles CMV.
2. Antigenically unrelated to other herpesviruses except for cross-reactivity with HHV-7.
3. Isolated from patients with lymphoproliferative disease.

Question 3

What are the two subtypes of HHV-6, and how do they differ?

Answer 3

1. HHV-6A: Neurovirulent and associated with neuroinflammatory diseases like multiple sclerosis.
2. HHV-6B: Common in childhood, causing diseases like Roseola Infantum (6th disease) and Exanthema Subitum.

Question 4

How is HHV-6 transmitted?

Answer 4

HHV-6 is transmitted via oral secretions (saliva), infecting the oropharynx.

Question 5

What diseases are caused by HHV-6B?

Answer 5

1. Roseola Infantum (6th disease): High fever followed by a rash.
2. Exanthema Subitum: Common skin rash and fever in young children.

Question 6

What is the primary site of latency for HHV-6?

Answer 6

HHV-6 targets T-lymphocytes and establishes latency there.

Question 7

What happens to HHV-6 infection in transplant patients?

Answer 7

Infection persists for life, and reactivation is common in transplant patients.

Question 8

How is HHV-6 diagnosed?

Answer 8

1. Examination of tonsils.
2. Western blot (WB) with a 100% detection rate.

Question 9

What treatments and vaccines are available for HHV-6?

Answer 9

1. No specific antiviral therapy is available.
2. No vaccine exists for HHV-6.