What is HTLV-1, a little-known virus that reaches more than 800,000 Brazilians | Science and health

The diagnosis came only a year later, when her first child was one year old: Erika was suffering from tropical spastic paraparesis which, over time, paralyzed and invalidated some people.

This is a little known disease, caused by a little-known virus, the human T-cell lymphotropic virus (HTLV-1), of which Brazil is one of the world champions in absolute numbers, with at least 800,000 infected – up to 2.5 million depending on the source. In the world, it is estimated that between 10 and 15 million people.

He is the first of this group to be discovered in 1980 – the same as his most popular cousin, HIV, who causes AIDS.

"It integrates with our DNA and can be transmitted," says Jorge Cbadeb, physician at the HTLV outpatient clinic and professor at the Institute of Tropical Medicine at the University of São Paulo ( USP).

SYMPTOMS AND CONSEQUENCES

The virus usually rests, integrated with the DNA of its carriers. But in 5 to 10% of those infected, it can cause two diseases: HTLV-1-badociated myelopathy or tropical spastic paraparesis (HAM / TSP), and adult T-cell leukemia / lymphoma (ATLL), a type of very aggressive blood cancer that causes the death of the patient within two years.

"Over time, the patient may be unable to walk," says Adele Caterino de Araujo, research scientist at the Immunology Center of the Adolfo Lutz Institute.

"Over time, symptoms such as lower back pain, fatigue, urinary and badual dysfunction (erectile dysfunction, loss of libido), cramps, intestinal constipation, myalgia (muscle pain), and uveitis (inflammation in the eyes), dermatitis and emotional, such as anxiety and depression ".

Erika knows what Adele is talking about.

"I had an incontinence phase and barely left the house, when I took a medicine it helped me, but it made me groggy," he says.

"I then started treatment with pulse therapy [terapia baseada em doses elevadas de corticoides por via endovenosa, durante um curto período de tempo] I did it three times a month, coming back from the hospital, we do not know what is worse, than this either the uncontrollable pain caused by HTLV or the reaction to the drug. "

" In addition to weakness, urinary incontinence and pain, the emotional side becomes extremely fragile, very crying, very sad, very angry, "reports Erika. I fought with my father because he and his mother had taken drugs and contracted AIDS (she died 24 years ago). After all, he was co-author of this crime, since it's from them that I should have taken the HTLV-1, and I was afraid of losing my husband, who would anyway have a craze for them. wheel chairs? "In general, people irritated me deeply, I was angry and arrogant."

According to Adele, HTLV-1 acts to preferentially infect CD4 + T cells (major cells of the immune system) and can remain inserted in their DNA in the form of provirus (the latent state of the retrovirus RNA after its appearance) incorporated into the DNA of the host cell).

"It needs to a cell-to-cell contact to spread, so that transmission by free particles in the blood is virtually non-existent or ineffective, "he explains." Since the proviral load of HTLV-1 is low, the proliferation of infected cells is what promotes the spread of the virus in the body. "

Symptoms that take time to manifest

Which may take time to occur.The estimated average time between infection at HTLV-1 and the development of the disease is long and is generally around the fourth decade of life. The infected individual can remain as an asymptomatic carrier only.

"It has been reported that about 5% of infected people develop diseases, but these data seem to be underestimated because more than 20% of patients in Brazil develop a condition badociated with them", explains Adele.

Despite these numbers and the problems that this causes to people who develop diseases, HTLV-1 is the subject of little attention in Brazil and even in the world. Doctors and researchers who work with him complain about the lack of structure and the lack of specific actions against the virus. There is no national program to try to control or eradicate it.

"There is no cure for the diseases it causes, but insufficient attention has been given to these diseases and they are not even listed in the list of diseases neglected by the World Organization of health, "explains Adele.

The fact that the vast majority of patients are asymptomatic is one of the possible reasons why HTLV-1 does not receive proper attention. In terms of evolution, it is an old virus, it is well adapted and most people do not develop the most serious complications because the patient's immune system controls it.

In most cases, carriers do not notice or know that they are infected.

"They have trouble climbing stairs, a pain, but who's going to see the doctor because of that?" Asks Cbadeb. "When someone does x-rays, CT scans, MRIs, and usually the results are normal, sometimes the person spends seven or even ten years discovering the cause of these symptoms."

Ignorance of care too

The lack of knowledge of health professionals about HTLV-1 is another problem that contributes to the long interval between the onset of symptoms of diagnosis. For example, Cbadeb reports the case of a patient from inside São Paulo, who consulted 29 doctors until she found one who was living in the HTLV outpatient clinic from Emílio Ribas hospital and knew the virus well.

"He asked for a serology [exame de laboratório realizado para comprovar a presença de anticorpos no sangue] that costs about 3 reais and that was positive," he says. "But if you do not think and do not ask for the exam, you can not identify the infection caused by it."

In order to inform and mobilize society and the public authorities about the importance of infection caused by the first described human retrovirus, the International Association of Retrovirology (IRVA) has instituted on November 10 HTLV World Day.

Also, in May of this year, doctors, researchers and patient representatives from around the world sent an open letter to the WHO asking for the creation of strategies for the eradication of the virus, including more tests and health professionals and the general public.

This is not impossible or difficult to achieve because the forms of virus transmission are well known. There are three types: parenteral (through blood transfusion and sharing contaminated needles and syringes when using licit and illicit injection drugs), badual (during bad without condoms) and vertical (through badfeeding). prolonged, during pregnancy and at the time of delivery).

"At the present time, the first channel of diffusion has decreased considerably in Brazil, since it has become mandatory for HTLV serology in all blood banks in the country since 1993," reports Adele. .

The importance of campaigns

An example of an effective strategy to combat the transmission of the virus comes from the city of Nagasaki, Japan: steps have been taken to test pregnant women and guide mothers HTLV -1 not to badfeed. their children, or to do it for shorter periods – no more than six months. With this, it was possible to reduce the prevalence of the disease from 20.3% to 2.5% in 20 years.

According to Marina Lobato Martins, head of scientific and technical development of the Hematology and Hemotherapy Center of Minas Gerais (Hemominas), linked to the Minas Gerais State Health Secretariat, Brazil must take steps so that the number of HTLV-1 does not continue to grow.

"Any uncontrolled communicable disease can increase over time because infected people will continue to spread the virus to others," he warns.

According to her, this is especially true for badually transmitted infections. "It is necessary for HTLV to participate in public campaigns for the control of communicable infections in this way, provide diagnostic tests to the population and create reference centers for the evaluation and orientation of the carrier of the virus as well as for the treatment of the sick, "recommends.

Despite the problems she faces, Erika is optimistic. "It's not easy, but we're progressing progressively," he says.