HTLV-I Testing and Symptoms Timeline


I am confused concerning timelines. I understand that standard practice is HIV testing at 3 and 6 months and that possible no symptoms may be experienced (after possible ARS) for many years. I am howver confused on HTLV-1 as I read at this site there are no symptoms for years yet other sources say that HTLV-1 can lead to leukemia and fulminant disease causing death in months. If a person has HTLV-1, how soon would symptoms begin? Are elevated liver enzymes possible early indication of disease? Thank you.


Thank you for your question. The following is a GENERAL review comparing when tests will detect infection with Human T-Lymphotropic Virus Type 1 (HTLV-I) infection, and when symptoms from this virus generally appear. HTLV-I is a different virus than HIV, and HTLV-I does not cause AIDS. You will also note that the testing times associated with this virus, and the times when symptoms arise, are different from those of HIV.


Antibody testing and PCR tests = These are different tests than HIV antibody tests and HIV PCR tests. Antibodies against HTLV-I are often produced by 40 days after infection, with a range most commonly between 20 days to 90 days. Some people may take longer than this to show positive. For example, some people may take up to 6 months to show positive, and one study even suggests that it in some people, it may take years for detectable antibodies to develop. Therefore, if a person is showing symptoms possibly due to HTLV-I (see below), but they test antibody negative, then special tests can be done (most often PCR tests) to make a diagnosis of HTLV-I. Because of the difficulties in doing PCR tests (high cost, very time consuming, occasional false-positive results, etc.), PCR tests are not recommended for routine screening of HTLV-I. But PCR tests can be used in persons who are suspected of having an HTLV-I associated illness, but test antibody negative.


In some people, HTLV-I causes "HTLV-I Associated Myelopathy/Tropical Spastic Paraparesis" (HAM/TSP), a neurological disorder. In other people, HTLV-I causes "Adult T-Cell Leukemia" (ATL), a cancer of the immune system. Occasionally dermatitis, joint disorders and various other problems have been associated with HTLV-I as well, but HAM/TSP and ATL are the most common HTLV-I related disorders. Luckily, most people do not get these diseases, and most do not show any symptoms of infection.
HAM/TSP = Symptoms of this neurological disorder generally appear 3 to 5 years after infection. Symptoms can include limb weakness, inability to control your bladder (incontinence), impotence, lower back pain, a tingling pins and needles sensation, and other neurological symptoms. It is estimated that less than 1% of people with HTLV-I will develop this disorder.

ATL = Symptoms of this form of leukemia most often appear 20-30 years after infection with the HTLV-I virus. It has been estimated that up to 5% of people with HTLV-I will get leukemia. Symptoms of ATL include swollen glands, an enlarged liver, abnormal liver function tests, an enlarged spleen, skin lesions, bone lesions, and sometimes an increased level of calcium in the blood. Because leukemia damages the immune system, opportunistic diseases may be seen as well. Once ATL has been diagnosed, the life expectancy is often less than a year (although some people may live longer). So although ATL may not begin until literally decades after infection, this form of leukemia can kill a person within months after the symptoms begin.

In summary:

You will note that most people who have HTLV-I do not show any symptoms at all. And even when symptoms of HAM/TSP and ATL are seen, they are similar to the symptoms of many other illnesses. Therefore having these symptoms alone does not indicate infection with the HTLV-I virus. HTLV-I (and the illnesses associated with this virus) can only be diagnosed by a doctor through various laboratory tests.

If you have any further questions, please feel free to call the Centers for Disease Control at 1.800.232.4636 (Nationwide).