HTLV 1 & 2

What are these things?

HTLV 1 & 2

• T-cell Leukaemia/Lymphotropic Viruses.

• Occur in both Old World primates and Humans.

• The primate varieties are called Simian T-cell Leukemia/Lymphotropic Viruses. (STLV)

• The human varieties are HTLV.

HTLV 1 & 2

• STLV. Occurs as type 1 & 2.

• STLV 1 is confined to Africa and Asia in about 19 species of primates.

• Distribution of STLV 2 is virtually unknown.

HTLV 1 & 2

• Transmission of these agents, primate and human.– Sexual contact (type 2 may be poorly

transmitted sexually)– Breast feeding – Blood transfusions (humans)– I.V drug use with needle sharing (humans)

HTLV 1 & 2

• Interesting distribution pattern

• Type 1. Worldwide. 15-20 million people infected.

• Local regions of high prevalence– S. Japan– Caribbean– Tropical Africa

HTLV 1 & 2

• Type 2 distribution• Originally thought to be New World and brought

in by human migrations 10-20k years ago.• However also found in the oldest human ethnic

group… Pygmy group from central Africa.• Very high rates of infection in IV drug users.

HTLV 1 & 2

HTLV 1 & 2

• HTLV 1 &2 are classified in the family Retroviridae.

• Single stranded RNA viruses.

• Reverse transcriptase.

• Integrates into the host genome, lifelong infection, evades the immune system of the host.

HTLV 1 & 2

• HTLV 1. adult T-cell Leukaemia/lymphoma, and a rare myelopathy also known as tropical spastic parapariesis. Infective dermatitis of children and also uveitis. Lots of speculation in terms of other diseases.

• HTLV 2. Myelopathy?, no leukaemia/lymphoma no other convincing disease associations but lots of speculation.