Definition

Human T cell lymphotropic virus (HTLV) infects a type of white blood cell called a T-cell or T-lymphocyte. White blood cells help fight infection.

Causes

HTLV infection is caused by a specific virus.

Risk Factors

There are two types of HTLV: HTLV-I and HTLV-II.

Factors that increase your chances of getting HTLV-I include:

• Living in an area where the virus is common, such as Southern Japan, Caribbean countries, parts of Africa and South America, the Middle East, and Melanesia
• Being breastfed by an infected mother
• Receiving a blood transfusion or transplant in the United States before 1988
• Having unprotected sex with someone who is infected with the virus, who is an injection drug user, or who is from an area where the virus is common
• Injection drug use

People of American Indian or African Pygmy descent are at greater risk for HTLV-II.

Factors that increase your chances of getting HTLV-II include:

• Being breastfed by an infected mother
• Receiving a blood transfusion in the United States before 1988
• Having unprotected sex with someone who is infected with the virus or who is an injection drug user
• Injection drug use

Symptoms

More than 95% of people with HTLV do not have symptoms. However, having the virus puts you at higher risk of developing certain conditions.

• If you are infected with the HTLV-I virus, it is possible that you may also develop
  • Adult T-cell leukemia (ATL). This disease involves cancer of a specific group of blood cells.
  • Opportunistic infections, including Strongyloides stercoralis hyperinfection
  • Inflammation of the eyes, joints, muscles, lungs, or skin (rare)

If you are infected with HTLV-I or HTLV-II, you may also develop a disorder of the nervous system known as HTLV associated myelopathy/tropical spastic paraparesis (HAM/TSP). It can cause weakness, numbness and stiffness in the legs, and difficulty walking.

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done.

HTLV infection can only be diagnosed with a specific blood test. The presence of HTLV antibodies is a sign of infection with the virus.

Treatment

There is no treatment that can remove the virus from the body. Treatment is aimed at managing HTLV-associated diseases and reducing their symptoms.

To prevent spreading HTLV to others:

• Do not donate plasma, bone marrow, organs, semen, or breast milk.
• Do not breastfeed your baby.
• Avoid unprotected sex.
• Avoid sharing needles or syringes.

Prevention

To help reduce your chance of getting the virus:

• Avoid unprotected sex. If your partner has the virus, discuss ways to prevent the spread of the virus with your doctor.
• Avoid sharing needles or syringes.

National Institute of Allergy and Infectious Diseases http://www.niaid.nih.gov

Public Health Agency of Canada http://www.phac-aspc.gc.ca

Human T-Lymphotropic Virus (HTLV). New York State Office of Alcoholism and Substance Abuse Services website. Available at:
http://www.oasas.ny.gov/AdMed/FYI/HTLV-FYI.cfm
Accessed January 16, 2015.

Tropical spastic paraparesis. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated July 9, 2010. Accessed January 16, 2015.

What is HTLV-II? The National Centre for Human Retrovirology website. Available at:
http://www.htlv1.eu/htlv_two.html
Accessed January 16, 2015.