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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.
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