Human T-lymphotropic virus 1 (HTLV-1)
Key facts
- Human T-cell lymphotropic virus type 1 (HTLV-1) is a virus that infects your T-cells, which are a type of white blood cell.
- Most people with HTLV-1 have no symptoms.
- Some people may develop a type of blood cancer or serious spinal cord issues.
- Once you have HTLV-1 you have it for life.
- HTLV-1 is spread through infected bodily fluids such as blood, breast milk and semen.
What is human T-cell lymphotropic virus type 1 (HTLV-1)?
Human T-cell lymphotropic virus type 1 (HTLV-1) is a virus that infects T-cells. T-cells are a type of white blood cell and are part of your immune system.
Most people with the virus don't have symptoms. Infection may lead to serious illness.
There is no cure or vaccine for HTLV-1. Taking careful steps can help reduce the risk of spreading it.
HTLV-1 in Australia
HTLV-1 virus is found in many countries, including Australia.
In Australia, it affects Aboriginal and/or Torres Strait Islander people more than others. In some communities in central Australia, up to 1 in every 2 adults have the virus.
What are the symptoms of HTLV-1?
Most people with HTLV-1 don't have symptoms. It can take 10 to 40 years for symptoms to appear. This time is called the incubation period.
Health conditions related to HTLV-1
There are serious health conditions that are caused by or related to HTLV-1. These conditions may have symptoms that suggest you have the virus.
HTLV-1 is related to serious health conditions, such as:
- adult T-cell leukemia/lymphoma (ATLL) — a type of cancer that affects your blood and lymph nodes. This may lead to swollen lymph nodes (glands), an enlarged liver or spleen and high calcium levels in your blood.
- HTLV-1-associated myelopathy (HAM/TSP) — a condition that affects your nervous system. This may lead to leg weakness, muscle stiffness, lower back pain and bladder or bowel issues.
People with HTLV‐1 infection may also experience more severe infections such as uveitis (inflammation in the eye).
What causes HTLV-1?
HTLV-1 is mainly spread through direct contact with body fluids, such as blood, breast milk and semen. You can get HTLV-1 from an infected person by:
- having unprotected sex
- sharing needles
- breastfeeding
- contact with infected blood
You cannot catch HTLV-1 from:
- shaking hands
- hugging
- kissing
- sharing a glass
- coughing
When should I see my doctor?
You should see your doctor if you notice any symptoms that may be related to HTLV-1, especially if you live in an area where the virus is common.
It's also important to see your doctor if you have HTLV-1 and are planning a pregnancy, especially if you live with someone who has the virus. Your doctor can advise you on ways to reduce the risk of spreading the virus to your baby.
CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.
How is HTLV-1 diagnosed?
HTLV-1 is diagnosed with a blood test that detects antibodies to the virus.
Australian blood donor centres screen blood for HTLV-1 infection.
FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.
How is HTLV-1 treated?
There is no treatment for HTLV-1.
Treatment is available for some of the complications of HTLV-1.
Living with HTLV-1
Living with HTLV-1 means managing your risk of developing related health issues. It involves taking steps to protect your health and prevent spreading the virus to others. This includes practicing safe sex and not donating blood or organs.
If you are pregnant, speak with your maternity care provider about if its safe for you to breastfeed.
It's important to monitor your health and have regular check-ups with a healthcare provider.
ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.
HTLV-1 complications
There are several complications of having the HTLV-1 virus. For people with HTLV-1, some infections such as roundworm and scabies can become more severe.
There are 2 main conditions linked to the virus:
- ATLL — a type of blood cancer
- HAM/TSP — a spinal cord disease that causes muscle weakness
Other conditions associated with HTLV-1 are:
- inflammation of the eye — HTLV-1 uveitis
- skin conditions — such as seborrheic dermatitis
- lung problems — such as bronchiectasis, bronchitis and bronchiolitis
- autoimmune disorders — such as Sjögren's syndrome and rheumatoid arthritis
- fibromyalgia — a condition that causes pain and muscle stiffness
- ulcerative colitis — a type of bowel disease
Can HTLV-1 be prevented?
You can reduce the risk of catching or spreading the HTLV-1 virus by:
- practising safe sex, such as using a condom
- not sharing needles
- not donating blood if you have the virus
- bottle feeding your baby, or freeze-thawing breast milk
Once you have HTLV-1, you can pass it on to other people for the rest of your life.
If you are planning a pregnancy or want to feed your baby breastmilk, talk to a midwife, nurse or doctor who has experience with HTLV-1 infection.
There is no vaccine against HTLV-1.
Resources and support
The Government of South Australia has information on:
You can read more about blood cancer on the Leukaemia Foundation website.
You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to talk with 24 hours a day, 7 days a week.
Looking for information for Aboriginal and/or Torres Strait Islander people?
- Australian Indigenous HealthInfoNet has HTLV-1 resources relevant for Aboriginal and/or Torres Strait Islander communities.
- Find an Aboriginal Community Controlled Health Organisation (ACCHO) or Affiliate near you.
Learn more here about the development and quality assurance of healthdirect content.
Last reviewed: October 2024
