Transcript HTLV 1 & 2 - London Health Sciences Centre

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 Tcell 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.