Other Retroviruses That May Cause Human Illness: Facts
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Other Retroviruses That May Cause Human Illness: Facts (PDF)
Retroviruses are a family of viruses that are grouped together based on how
they are structured and how they replicate within a host. Besides human immunodeficiency
virus (HIV), the virus that causes AIDS, there a two other retroviruses that
can cause human illness. One is called human T-lymphotropic virus type 1 (HTLV-1)
and the other is called human T-lymphotropic virus type 2 (HTLV-II). Both of
these viruses are transmitted between people through sexual contact, infected
blood or tissue exposure, or during pregnancy or childbirth from an infected
mother to her child.
Human T-lymphotropic Viruses Types 1 and 2 Facts
Human T-lymphotropic virus type 1 (HTLV-I) causes adult T-cell leukemia in about 2.5% of those persons infected with the virus. The time between acquiring the infection with HTLV-1 and developing disease is thought to be 30-50 years. HTLV-1 also can cause a neurological disease called HTLV-1-associated myelopathy/tropical spastic paraparesis in about 5% of those infected. This is an illness that affects the spinal cord and white matter of the central nervous system. Manifestations include difficulty walking and weakness and stiffness of the lower extremities more than the upper extremities. Bowel and bladder control may be lost. A number of other disorders have been associated with HTLV-1 including inflammation of the joints or eyes. HTLV-I is endemic in Japan, the Caribbean, New Guinea and parts of Central Africa. Prevalence is highest in southwest Japan. It is not common in the United States.
Human T-lymphotropic virus type 2 (HTLV-II) may cause neurodegenerative disease such as myelopathy, and it may be associated with hematological malignancies but the association between the virus and these diseases is weak. The virus is endemic in Native Americans in South, Central, and North America.
Enzyme immunoassay screening of serum, with confirmation by type specific
western blot, immunofluorescent assay or polymerase chain reaction can
be used to determine carrier status and help in confirmation of either
HTLV-I or HTLV-II disease. Specific pathological conditions must be present
for disease diagnosis.
For more information, contact:
Infectious Disease Epidemiology, Prevention and Control Division
STD, HIV and TB Section
Minnesota Department of Health
625 Robert Street North
PO Box 64975
St. Paul, MN 55164-0975
Minnesota AIDS Project AIDSLine
612-373-2465 TTY (Metro)
1-888-820-2437 TTY (State)
CDC National STD and AIDS Hotlines
1-800-227-8922 or 1-800-CDC-INFO
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