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Silent, unknown and neglected, the HTLV requires massive investment in research, said Dr. Bernardo Galvão Filho

Despite greatly impacting public health, the HTLV remains neglected to the point of even being part of the WHOs list of neglected diseases. The disease is neglected even regarding notification


According to researches, the virus may reach 1% of the population. However, these numbers should be underestimated, because they lack broad surveys and in many regions of the world the infection was never investigated

It is estimated that, worldwide, between five and ten million people are infected by the Human T-cell Lymphotropic Virus (HTLV) and Brazil is probably the champion in absolute numbers. According to mathematical projections, the country has 2.5 million people infected by the virus. Most people are asymptomatic carriers, and only 10% develop diseases. The significant increase in Sexually Transmitted Diseases (STDs) causes HTLV to follow this trend.

Professor Dr. Bernardo Galvão Filho, who implanted the HTLV-1 Multidisciplinary Integrative Center at the Bahia School of Medicine and Public Health (EBMSP), in 2001, explains that despite the evidences of serious harms to human health, the HTLV is still unknown in Brail due to extreme government neglect. The Ministry of Health does not include it in the diseases agenda and, consequently, there are no public policies that establish prevention measures and a treatment protocol for patients in Brazil. The research notices do not include HTLV. Therefore, the infection caused by it can be considered the most neglected among those neglected, he criticizes.

Almost 40 years have passed and researches on the virus remain stagnant and no country has been able to develop an antiretroviral drug able to combat it. To Dr. Galvão, who is also coordinator at the HTLV Multidisciplinary Integrative Center at the EBMSP, Brazil is far behind in the fight against the virus, that despite affecting more people than the HIV and hepatitis C, is given little attention.  Researches on the HTLV-a, the first human retrovirus identified, was ground for the hypothesis that AIDS was caused by a human retrovirus, facilitating the identification of the HIV-1. Despite this fact, it is regrettable that the infection it causes has been neglected, even though it causes very severe diseases. To the moment there are no international clinical guidelines or financial support to develop drugs or clinical trials, he says.

Strategies to eradicate HTLV-1

To Dr. Galvão, the first measure to be takes would be incorporating the HTLV to agendas of the World Health Organization (WHO) and the Ministry of Health, indicating the severity of this public health problem. Besides this, effective prevention measures should be implemented, such as: obligatory screening for blood donations, already held in Brazil; universal incorporation of HTLV screening in prenatal exams; suspension of breastfeeding for seropositive mothers and provision of the milk formula; screening of transplant organ donors; use of condoms in sexual intercourses.

He is emphatic while observing that a chronic infection, that among its transmission routes includes sexual intercourse, cannot have an easy control. He acknowledges the lack of structure to deploy a range of effective care line and that prevention actions are scarce. However, if preventive measures are implemented, it will be possible to considerably reduce transmission and control this serious and dangerous public health problem. But for this, it will be of utmost importance to implement a care line, as well as fund research, which will contribute to alleviate the biopsychosocial suffering of thousands of individuals living with HTLV, he says.

North and Northeast are the most endemic regions

Previous studies involving blood donors have showed that the North and Northeast regions account for most people with HTLV. High prevalence was observed in Salvador – Bahia, São Luís – MA and Belem – PA. According to Dr. Galvão, in Salvador and São Luís, probably these rates result from the arrival of Africans during slave marketing, in a post-Colombian introduction of HTLV-1 in Brazil. While in Belém, we could hypothesize that the introduction occurred during pre-Colombian settlements by Asian population that compose the current indigenous population. We should also consider that populations in the North and Northeast are socioeconomically less favored and that HTLV-1 infection takes place more frequently in individuals with lower income and schooling, he admits.

Bahia is the state with the largest number of infections: the rate reaches 1.8%, while in other cities it is estimated to be less than 1%. According to data from the Bahia state Health Secretariat (Sesab), in 2015, the percentage reached 77%, where women were the greatest victims. The main route of infection is breastfeeding, and infection occurs in up to 30% of the cases. Social vulnerability is considered as one of the factors. In 2003, researchers at Fiocruz Bahia in cooperation with the Bahia Federal University Collective Health Institute (ISC), conducted a population-based study, which pointed out that Salvador had around 40 thousand people living with the HTLV-1. In cooperation with the Bahia Central Public Health Laboratory (LACEN-BA), another survey conducted by the IGM pointed that Bahia has 130 thousand infected people. Most recently, in 2017, a study showed evidences that the main transmission route in Salvador is intercourse, nonetheless, there are also evidences that vertical transmission, from mother to child, has an important role in transmission.




Only a few states keep recurrent researches about the virus, mostly with partnerships or funded by the private sector. Minas Gerais Federal University, for example, is part of the Interdisciplinary Research Group on HTLV, composed by Hemominas Foundation, Fiocruz/René Rachou, Eduardo de Menezes Hospital, Fhemig and Sarah Rehabilitation Hospitals Network. The universitys studies resulted in a patent of a diagnostic test, funded by the Unified Health System (SUS), that is being licensed for a Minas Gerais-based company.

In 2015, the Ministry of Health, based on clinical evidences of better prognosis among patients that used zidovudine to treat leukemia/Lymphoma associated to HTVL-1, incorporated within the SUS this antiretroviral drug to treat this disease that has high mortality, reminds Dr. Galvão.

The Ministry of Health is preparing a national study to discover the prevalence of HTLV-1 in pregnant women in Brazil. The result should serve as basis to define future actions to combat the transmission of the virus from mother to child. The study is expected to be completed this year. In addition, the Ministry is also working on updating the Protocol of HTLV-1. The document should serve as a guide to train health professionals.

Health professionals ignorance and awareness about the virus

Lack of knowledge among part of health professionals contributes to the wide gap between the onset of symptoms and diagnosis. If health professionals are unaware of the HTLV, the transmission routes and the diseases related to this virus, they not request relevant serological tests, e.g., in prenatal care and in the differential diagnosis”, reminds Dr. Galvão while adding that asymptomatic individuals have no need to seek health services to perform the HTLV testing, however, the inclusion of tests for virus detection in blood banks and in prenatal tests have identified a large number of asymptomatic carriers. One in 20 infected persons may develop leukemia and neurodegenerative disease.

Even though it was discovered before HIV, the severity of the infection and the speed of its spread caused the focus to be diverted from HTLV. Although they are related and have similar transmission routes, there are important differences between HIV and HTLV. HIV causes a pandemic, i.e. it is present almost everywhere in the world, reaching both developed and developing countries. While the HTLV, with the exception of Japan, is present mainly in developing regions such as Africa, Central and South America and in indigenous Australians, reaching economically disadvantaged populations without ability to organize and press governments to establish counter program against this serious and severe health problem.

Dr. Galvão adds that due to the severity of endemic/epidemic in the State of Bahia and thanks to the mobilization of the civil society, represented mainly by the Association of C of HTLV (HTLVIDA), governmental measures were implemented, as mandatory screening in prenatal care and the establishment of a line of care for people living with HTLV.

There is no cure for HTLV and all treatments are palliative. And although it belongs to the family of the HIV, the drugs used in the treatment have no effect against HTLV. The virus can remain incubated in the body for up to 30 years before the first symptoms appear. The HTLV-1 focuses on sub-Saharan Africa, in Latin America, the Caribbean, and in countries like Japan, China and Australia. On the other hand, the HTLV-2, infects about 200 thousand people in Brazil, with a higher prevalence in groups such as indigenous peoples and injectable drug users.

The world day of HTLV, November 10, was established by the International Retrovirology Association to give the virus more visibility.…