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Blocking HTLV-1/2 silent transmission in Brazil: Current public health policies and proposal for additional strategies

Blocking HTLV-1/2 silent transmission in Brazil: Current public health policies and proposal for additional strategies

  • Carolina Rosadas, 
  • Maria Luiza B. Menezes, 
  • Bernardo Galvão-Castro, 
  • Tatiane Assone, 
  • Angélica E. Miranda, 
  • Mayra G. Aragón, 
  • Adele Caterino-de-Araujo, 
  • Graham P. Taylor, 
  • Ricardo Ishak


Human T-cell lymphotropic viruses 1 and 2 (HTLV-1/2) are relatively common in Brazil but remain silent and neglected infections. HTLV-1 is associated with a range of diseases with high morbidity and mortality. There is no curative treatment for this lifelong infection, so measures to prevent transmission are essential. This narrative review discusses HTLV-1/2 transmission routes and measures to prevent its continuous dissemination. The public health policies that are currently implemented in Brazil to avoid HTLV-1/2 transmission are addressed, and further strategies are proposed.


Human T-cell lymphotropic virus 1 and 2 (HTLV-1/2) are retroviruses that cause persistent infection, mainly in T-cell lymphocytes. HTLV-1 is associated with high morbidity and mortality clinical conditions, while HTLV-2 is rarely associated with disease. Transmission occurs through sexual relations, transfusion/transplantation of blood/organs infected with the virus, and from mother to child, mainly by breastfeeding. Although it has a worldwide distribution, except for Japan, low- and middle-income countries and predominantly ethnic minority population groups in high-income nations are the most affected. It has been estimated that 800,000 to 2.5 million people are living with HTLV-1 (PLHTLV) in Brazil [1,2].

A large proportion of infected persons will remain asymptomatic throughout their entire life, but many PLHTLV will develop one or more of a range of diseases. HTLV-1–associated myelopathy (HAM) is a debilitating condition that results from an inflammatory response mainly within the spinal cord, but with increasing evidence of widespread brain inflammation. HAM greatly impacts patient’s autonomy and quality of life, and, during follow-up, about 50% become wheelchair dependent [36]. In Brazil, the risk of HAM and other neurological diseases is reported to be higher than usual at 5% [79]. In addition to the high morbidity, HAM was also identified as a significant predictor of increased mortality in PLHTLV from Brazil (hazard ratio (HR) 5.03, 95% CI 1.96 to 12.91) [10]. Adult T-cell leukaemia (ATL) is an aggressive neoplasm caused by HTLV-1 with a median survival of 8 months and affects about 4% of carriers [11]. In Brazil, ATL is probably underdiagnosed [12]. Other inflammatory diseases, including uveitis, keratoconjunctivitis, infective dermatitis, arthritis, and a range of pulmonary pathologies may also occur as a consequence of HTLV-1 infection. Moreover, the impact of HTLV-1 on several coinfections, including Strongyloides stercoralis and Mycobacterium tuberculosis is recognised [13,14]. Indeed, HTLV-1 infection is associated with an increased risk of all-cause mortality (adj MR 1.57) not explained by the two well-characterised HTLV-1–associated diseases, ATL and HAM [13].

Asymptomatic and subclinical HTLV-1/2 infections facilitate the maintenance and spread of HTLV-1/2 within communities. The long incubation period in many cases of HTLV-1–associated diseases, which usually occur in late adulthood, and the underdiagnosis of infection increase the risk of HTLV-1/2 silent transmission. There is no vaccine or curative treatment for HTLV-1/2. Available antiretroviral therapy has no beneficial effect on established HTLV-1/2 infection, and it is not medically indicated [15]. Therapeutic intervention, however, should focus on the management of clinical diseases associated with the infection and to improve patients’ autonomy and quality of life [1520]. A multidisciplinary approach towards PLHTLV care is recommended to optimise care and outcomes [21].

HTLV-1/2 are neglected infections, but prevention of transmission is an attainable goal. HTLV-1/2 are cell-associated viruses with provirus present in the blood, semen, vaginal fluid, and maternal milk, and every effort should be directed to eliminate transmission related to these fluids. Following a public call for action to eradicate the virus [22,23], the World Health Organization (WHO) conducted a global consultation on HTLV-1, aiming to review existing data to better understand the public health implications of HTLV-1 and its associated diseases. Public health measures currently implemented in different countries were presented, and the report identified that Japan alone has an overall national programme for HTLV-1 infection [24]. There is limited information about the policies available in Brazil, one of the countries most affected by both HTLV-1 and HTLV-2. Although there is no formal Brazilian HTLV-1/2 national programme yet, there are several policies dating back as far as 1993, and, Bahia, the state with the highest prevalence of HTLV-1 infection in the country, established a protocol for the integrated care of PLHTLV at the end of 2020 [25]. Here, we discuss the public health policies that are already implemented in Brazil and propose further strategies to detect and prevent HTLV-1/2 spread in the country.


In addition to the policy documents known to the authors, the public website of the Brazilian Ministry of Health (MoH) was interrogated for relevant policies using the search term “HTLV” in each of their clinical guidelines and therapeutic protocols. Each policy was then examined to confirm the applicability to HTLV infection. All relevant policies were then included in the narrative following additional strategies discussed by the authors and recommendations agreed.

Policies that are implemented in Brazil that may impact HTLV-1/2 transmission

HTLV-1/2 as a sexually transmitted infection (STI).

HTLV-1/2 infected cells are present in seminal and vaginal fluid and are transmitted by unprotected sexual intercourse [2629]. High HTLV-1 DNA copy number (also known as proviral load, PVL) in circulating peripheral blood mononuclear cells (PBMCs) is a known risk factor for sexual transmission, and the efficiency of HTLV-1 transmission is higher from male to female than from female to male [26]. Some authors hypothesise that penile ulcers and lesions on vaginal mucosa, which may occur as a result of other sexually transmitted infections (STIs), may facilitate HTLV-1 sexual transmission. In fact, cervicitis increases HTLV-1 shedding, and the prevalence of HTLV-1 infection is higher in patients with STI, such as syphilis, chlamydia, and human papilloma virus [30,31].

Effective prevention of HTLV-1/2 sexual transmission is primarily linked to the use of barrier methods during sexual activity. However, public policies to prevent this route of infection should not rely solely on safer sex, but rather on an integrated strategy, requiring biomedical, behavioural, and structural interventions, as for other STI [32]. Perversely, strategies developed to prevent HIV transmission may result in increased exposure to HTLV if reliance on, for example, HIV-specific pre-exposure prophylaxis (PreP) displaces broader STI reduction approaches, unless antiretrovirals that inhibit both viruses (particularly integrase inhibitors) are used.

Screening for HTLV-1 is compulsory for both donors and recipients for assisted reproduction. HTLV-1 infection is considered an exclusion criterion for reproductive gamete donors since 2011 [33]. It is important to stress that HTLV-1 infection should not be an obstacle for HTLV-1 discordant couples wishing to procreate. Medical advice should be sought, and couples should be tested for other STI. If the woman is infected by HTLV-1, assisted reproduction (domestic insemination) should be offered. If the man is infected, sperm washing followed by artificial insemination could be considered based on biological principle. This process, current in use for HIV discordant couples, should be highly effective in preventing HTLV-1 transmission by separating the sperm from the seminal fluid and cells. This is recommended by the American Society for Reproductive Medicine [34]. However, the European Society of Human Reproduction and Embryology (ESHRE) concluded that there is not enough evidence to recommend the routine use of advanced processing of semen from HTLV-1/2 seropositive patients [35]. In the absence of sperm washing, the use of barrier contraception except following ovulation with support and education for the couple to identify the fertile period could be considered as a risk reduction strategy. It is worth noting that published transmission data are focused on discordant couples where HTLV transmission has not occurred despite prior unprotected sexual intercourse and that the risk of transmission in new relationships may be considerably higher. A case of HAM following a single sexual exposure to HTLV-1 has been reported [36].

HTLV-1 is already included in the Clinical Protocol and Therapeutic Guidelines for Sexually Transmitted Infections (PCDT IST) published by the Brazilian MoH [32]. Information about HTLV-1 is also available on the website of the Department of Chronic Diseases and Sexually Transmitted Infections of MoH. Additional strategies aiming to prevent HTLV-1/2 sexual transmission should include the following:

  1. screening the sexual contacts of PLHTLV;
  2. counselling of PLHTLV to assure that they are aware of the chronic aspect of HTLV-1 infection, its transmission routes, and how to prevent new infections;
  3. HTLV-1 screening in people with other STI; and
  4. increasing awareness about HTLV-1 in the general population, among healthcare workers and ensuring that HTLV-1/2 is included in STI awareness campaigns.

HTLV-1/2 as a blood-borne infection.

HTLV-1/2 screening of blood donors was implemented in Brazil in 1993 and constitutes a key measure to control parenteral transmission of these viruses [37]. Donors and recipients of organs, tissues, cells, or body parts are also screened since 2009 [38]. HTLV-1/2 infection is a definitive exclusion criterion. ATL and HAM has been described in patients infected peri-transplantation. The risk of HTLV-1 infection following solid organ transplantation is 100%, and the risk of HAM following HTLV-1 infection acquired by this route is high (40%) and occurs after a relatively short interval (3.8 years) [3941]. The risk acceptance of HTLV-1 infection as a consequence of solid organ transplantation was investigated in Canada and confirmed that patients would not be willing to forego HTLV-1 screening of solid organs donors [42].

The current Brazilian policies to prevent HTLV-1/2 parenteral transmission are important but still need improvement. A crucial point is to include complementary tests (confirmatory and discriminatory for HTLV-1 and HTLV-2) for those persons with seroreactive tests in the screening assay. Positive ELISA tests should be followed by western blot (WB) and/or PCR to avoid false-positive results and the uncertainty and discomfort that unconfirmed reactivity generates for the donors. Assays for confirmatory testing for HTLV-1/2 were made available to the public health system in 2016 but are limited to those persons who need laboratory confirmation of ATL [43]. The inclusion of line immunoassay (LIA) is recommended based on its superior performance compared to WB [4446]. A screening test is insufficient to diagnose HTLV-1/2 infection, and confirmation is necessary for those who are willing to donate their blood and organs. Blood and organ donation is, above all, an act of kindness and selflessness. It is not unusual to come across individuals who have been informed of a reactive HTLV-1/2 ELISA test with no further testing, who are subsequently shown to be uninfected, sometimes years after being informed of the screening test result. The impact of a false-positive HTLV-1/2 diagnosis is profound, influencing key life decisions and should not be underestimated. Using the methodology previously described [47] and considering (1) 3.3 million of blood donors; (2) specificity of screening test [48]; and (3) prevalence of HTLV-1 infection in blood donors [2], we have estimated that HTLV-1/2 screening would result in 8,580 to 256,080 false-positive results annually. The lack of national reference centres for counselling and follow-up of PLHTLV or those with seroreactivity in screening test adds uncertainty for those newly diagnosed individuals.

Needle sharing among people who inject recreational drugs is another important route of HTLV-1/2 parenteral dissemination. High prevalence rates of HTLV-1/2 among this specific population have been frequently reported [2,4951]. A comprehensive strategy focusing on this vulnerable population is of utmost importance. These are already undergoing as part of HIV-1 and other STI prevention programmes and comprise a range of activities including more simple strategies such as offering harm reduction initiatives, provision of sterile needles for people who inject drugs, and enabling the safe disposal of needles and syringes up to more complex interventions. Complex interventions comprise behavioural and structural changes aiming to reduce stigma, inequalities, and any barrier that may prevent access to universal health. HTLV-1/2 transmission by skin scarification and self-flagellation has been reported in indigenous people and during religious ceremonies [5254].

HTLV-1/2 mother-to-child transmission.

HTLV-1/2 is transmitted from mother to child, mainly by breastfeeding. Residual transmission may occur in about 2.5% of those children that are exclusively fed by milk formula substitutes, indicating that transmission may occur during pregnancy or delivery [55]. In Brazil, in urban areas, mother-to-child transmission rate was reported to be 14.1% [56], with an estimated number of new infections reaching at least 16,500 new cases annually [57]. Low-income pregnant women with (i) high HTLV-1 PVL in blood and milk; (ii) breastfeeding for longer periods; (iii) HLA concordance between mother and child; (iv) Strongyloides sp. coinfection; and (v) patients with HAM have a higher risk of transmitting HTLV-1 to their children [55]. Vertical transmission of HTLV-1 is not only implicated with higher risk of adverse clinical outcome associated with HTLV-1 infection but also with maternal feelings of guilt [58,59]. Among highly vulnerable indigenous communities in the Amazon region of Brazil, mother-to-child transmission of HTLV-2 is common and reaches as high as 30% [54,60]. There are no clear consequences of the perpetuation of this virus among semi-closed and isolated communities nor policies towards the elimination of HTLV-2 among these population groups.

The Brazilian MoH recommends the interruption of breastfeeding, using pharmaceutical intervention of mothers to suppress lactation (Cabergolin), and provision of milk formula substitutes for those babies born of HTLV-1/2 seropositive women [32,61]. The first step should be to identify those pregnant women that are infected with HTLV-1/2. A national antenatal screening programme is of utmost importance and should be a priority in the country. Some Brazilian States, including Bahia, Minas Gerais, and Mato Grosso do Sul, have implemented HTLV-1/2 policies for antenatal screening, but the measure should be expanded and implemented nationally, as in Japan. In fact, Japan first implemented regional antenatal screening combined with other policies to avoid mother-to-child transmission in the late 1980s [62,63]. The national screening programme, established in 2010, is one of the main pillars to achieve their aim to eliminate HTLV-1/2 infection in Japan. It is worth mentioning that short-term breastfeeding and use of freeze and thaw maternal milk were reported to reduce the risk of transmission but not as effectively as the avoidance of breastfeeding. Although all the measures were initially recommended in Japan, this was revised in 2016 to recommend exclusive milk formula substitutes feeding for the babies of all mothers who are positive for HTLV-1 [63]. In situations where exclusive formula feeding is not acceptable, feasible, affordable, sustainable, and safe (AFASS), alternative methods to reduce the risk of transmission may still be considered. Limiting the duration of breastfeeding is not always practical or achieved, and, therefore, in such settings, innovative alternatives are needed.

A graphic summary for the proposed clinical management of HTLV-1/2 infection in pregnant women and prevention of mother-to-child transmission is shown in Fig 1. Antenatal screening is strongly recommended at the first trimester, which would allow proper confirmatory testing and counselling for those seropositive mothers prior to delivery. The diagnostic algorithm should be similar as to the general population, using an ELISA or CMIA as screening test, followed by confirmation using PCR, WB, or LIA [64]. Pregnancy does not adversely affect HTLV-1 diagnosis[65]. Counselling and detailed clinical evaluation should be offered to identify signs or symptoms of any HTLV-1/2–associated diseases, and it is important to reinforce the information about the risk of HTLV-1/2 transmission and importance of avoidance of breastfeeding. Stigma and prejudice may impair the adherence of new mothers to the recommendations [66,67]. A recent study commissioned by WHO identified that women infected by HTLV express concerns about social perceptions of not breastfeeding, as well as the artificial alternatives of breast milk[59,66]. Mothers commonly indicate that they are afraid of not bonding to the child if they do not breastfeed [59]. Misconceptions must be fully discussed during counselling. In addition, the limited knowledge of healthcare professionals about HTLV-1/2 should be addressed in order to avoid misleading recommendations [68].

Fig 1. Flowchart proposal for management of HTLV-1/2 infection in pregnant women and prevention of mother-to-child transmission.

CMIA, chemiluminescence assay; HTLV-1/2, human T-cell lymphotropic virus 1 and 2; LIA, line immunoassay; WB, western blot.

HTLV-1/2 testing should be offered for relatives, including sexual partners and children of previous pregnancies. Antiretroviral drugs do not decrease HTLV-1/2 PVL in established infection and are not currently recommended for the prevention of mother-to-child transmission, although this has been offered in very high–risk cases of mothers with ATL in pregnancy [69]. Although some argue that cesarean section should be recommended to pregnant women with HTLV-1/2 infection [70], there is no consensus about the impact of the procedure in reducing the risk of HTLV-1/2 mother-to-child transmission. However, avoiding contact between maternal blood and the neonate during delivery was linked to the reduction of HTLV-1 transmission among exclusive formula-feed children in Japan [71]. In Brazil, when a woman living with HTLV-1/2 is submitted to cesarean section, immediate clamping of the umbilical cord is recommended [72].

Postnatal care should include early cessation of breastfeeding. Milk formula substitutes should be offered for women living with HTLV-1/2, which is already available in some Brazilian states, including Bahia and São Paulo. Screening of infants is necessary to rule out mother-to-child transmission of HTLV-1/2, and the aforementioned diagnostic algorithm can be used if the child is older than 18 months. If the child is tested earlier, maternal antibodies may be detected by serological assays. Seroconversion has been shown in long-term follow-up studies with incident infection in breastfed babies as late as 3 years of age [73,74]. No seroconversions were reported in a longitudinal study of breastfed children from age 2 to 12 years old [75]. Multidisciplinary lifelong follow-up is needed for PLHTLV. Specialised centres play an important role advising mothers-to-be who live with HTLV-1/2 infection. Studies showed that they are vital as the women tend to trust their advice even when faced with contradictory views from other health staff [66,68,76].

The Brazilian MoH has implemented one of the most successful antenatal programmes to prevent other STI, including HIV-1 and in three Brazilian cities (São Paulo, Curitiba e Umuarama), the elimination of vertical transmission of HIV-1 has been highly successful. The network and knowledge are already established in the country, and the prevention of HTLV-1/2 transmission should be considered as an extension of a successful existing programme. Recently, HTLV-1/2 infection has been addressed in the Clinical Protocol and Therapeutic Guidelines for Prevention of Vertical Transmission of HIV, Syphilis, and Viral Hepatitis, published by the Brazilian MoH [61].

A neglected virus affecting a neglected population needs an integrated strategy to prevent its spread

Brazil has the highest number of PLHTLV in the world. However, within the country, HTLV-1/2 infection is not equally distributed [2]. Compulsory notification of HTLV-1/2 infection would facilitate the identification of the real situation of these viruses in Brazil. Very few countries maintain the registry of PLHTLV such as Japan and the United Kingdom [63,77,78].

Available data on HTLV-1 infection show that black/mixed ethnicities, with low income and education level, are those more frequently infected [2]. Women are mostly affected, are more susceptible to sexual transmission, and have greater risk of HAM [22,79]. In addition, they carry the burden of transmitting the virus to their children. Women who are victims of domestic and/or sexual violence have 9 times more risk of being infected by HTLV-1/2 in Brazil [80], which reinforces the observation that this neglected virus will predominantly affect vulnerable individuals. Other vulnerable population groups that are considered high risk for acquiring infection were already identified and include men who have sex with other men (MSM), commercial sex workers, and people who inject drugs. High prevalence of HTLV-1/2 infection is well documented in Brazilian indigenous populations [81,82]. Due to its complexity, HTLV-1/2 prevention needs a combined approach. Structural interventions, targeting sociocultural factors that will impact the vulnerability of individuals and specific social groups, are necessary.

Perspective of actions

Table 1 shows the public health policies that are currently available in Brazil and the additional proposed strategies that aim to reduce HTLV-1/2 transmission. Recently, the Brazilian MoH commissioned the construction of a specific Clinical Protocol and Therapeutic Guidelines dedicated for HTLV-1/2 by a technical advisory committee, including patient representatives. This document, which is already considered a milestone in public health policies to prevent HTLV-1/2 in the country, is presently under scrutiny by the technical staff of the MoH. In Brazil, as in other parts of the world, HTLV-1/2 infection has been considered “neglected,” “silent,” or “invisible,” despite up to 10 million of PLHTLV who are mostly still unaware of their condition. A definitive step to start fighting against this deplorable situation would be to increase HTLV-1/2 awareness and to allow PLHTLV to have access to the existing public health services. Several infectious diseases have similar incidence and prevalence to HTLV-1/2, and those patients, unlike PLHTLV, have their right to receive proper diagnosis, treatment, and well-recognised support. Curiously, in Brazil, the number of HTLV-1 infected pregnant women is double that of HIV-1 (16,548 versus 8,699, respectively, in 2018) [57]; furthermore, screening for rare diseases among neonates is routine, aiming to improve the early clinical management of these patients, increase their survival, and improve their quality of life. These achievements that conquered other diseases are similar to what is needed for those infected by HTLV-1/2 and is granted by the Brazilian Constitution.

Table 1. Current public health policies towards HTLV-1/2 in Brazil and additional proposed interventions.

Since the 1980s, there are several relevant landmarks in the country to provide information to the general laymen, to PLHTLV, or to healthcare workers. These include, but are not limited to, the publication of the Guideline for Clinical Management of HTLV-1 Infection (published in 2004 and revised in 2013), the establishment of 23rd March as the HTLV National Awareness Day, participation of representatives of MoH in scientific events that occurs every 2 years in the country, distribution of HTLV-1/2 diagnostic algorithm to primary healthcare units, and publication of a commissioned review about HTLV-1/2 infection prepared by technical advisory group. However, there is still a need for more aggressive campaigns to raise awareness of the virus. There is no compulsory notification for the HTLV-1–associated diseases, and the absence of reliable numbers posed difficulties to implement public health policies to eliminate HTLV-1/2. A national registry for pregnant women infected by HTLV-1/2 is under development. There are an estimated 2,500,000 PLHTLV in Brazil, including men, women, children, living in urban, nonurban, and specific vulnerable population groups such as pregnant women, MSM, male and female sex workers, people who inject recreational drugs, quilombolas (slave escapees), and indigenous communities. The Brazilian MoH granted research funding to better understand the prevalence and distribution of these viruses in the country. A national prevalence study on pregnant women is planned but was delayed due to the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic. The MoH also published recently an epidemiological bulletin about HTLV-1/2 prevalence and distribution in Brazil [2].

Brazil is a large country with a well-established healthcare system that is able to assist patients, to provide antenatal care to pregnant women, has an integrative conglomerate of centres for blood donors, and the ability to provide synchronous mass administration of vaccines. The inclusion of the proposed strategies to prevent HTLV-1/2 in this network requires just a discrete financial and administrative adaptation but is crucial to the benefit of the general population and to the Brazilian citizen living with HTLV-1/2.

Key learning points

  • Human T-cell lymphotropic virus (HTLV) is associated with high morbidity and mortality diseases, and there is no curative treatment available for this infection.
  • HTLV is an important health problem in Brazil, and the country has implemented several HTLV public health policies, dating back to 1993, and is continuously advancing in establishing measures to control the virus.
  • Public health policies include universal screening of organs, tissues, and reproductive gametes recipients and donors and blood donors; recommendations on avoidance of breastfeeding for seropositive mothers; and a national programme for sexually transmitted infection (STI) with HTLV as a priority.
  • HTLV is a neglected virus, causing neglected diseases affecting vulnerable populations; thus, an integral approach to prevent its transmission is needed.
  • Proposed public health policies comprise universal antenatal screening, inclusion of confirmatory testing for those reactive in screening assays, compulsory notification, establishment of multidisciplinary reference centres, offer of testing to high-risk population, and public education to increase awareness.

Top five papers

  1. WHO. Human T-lymphotropic virus type 1: technical report. [Internet]. 2021. Available from:
  2. Gessain A, Cassar O. Epidemiological Aspects and World Distribution of HTLV-1 Infection. Front Microbiol. 2012;3:388. 10.3389/fmicb.2012.00388
  3. Martin F, Tagaya Y, Gallo R. Time to eradicate HTLV-1: an open letter to WHO. Lancet. 2018;391:1893–4. 10.1016/S0140-6736(18)30974-7
  4. Hino S. Establishment of the milk-borne transmission as a key factor for the peculiar endemicity of human T-lymphotropic virus type 1 (HTLV-1): the ATL Prevention Program Nagasaki. Proc Jpn Acad Ser B Phys Biol Sci. 2011;87:152–66. Available from:
  5. Puccioni-Sohler M, Grassi MFR, Galvão-Castro B, Caterino A, Proietti AB, Vicente ACP, et al. Increasing awareness of human T-lymphotropic virus type-1 infection: a serious, invisible, and neglected health problem in Brazil. Rev Soc Bras Med Trop. 2019;52:e20190343. 10.1590/0037-8682-0343-2019


  1. 1. Gessain A, Cassar O. Epidemiological Aspects and World Distribution of HTLV-1 Infection. Front Microbiol. 2012;3:388. pmid:23162541
  2. 2. CGIST/DDCI/SVS C-G de V das IST, Rosadas C, Espinosa Miranda A, Utscg Gonçalves D, Caterino-de-Araujo A, Assone T, et al. Prevalência da Infecção por HTLV-1/2 no Brasil. Bol Epidemiológico. 2020;51. Available:
  3. 3. Rosadas C, Assone T, Yamashita M, Adonis A, Puccioni-Sohler M, Santos M, et al. Health state utility values in people living with htlv-1 and in patients with ham/tsp: The impact of a neglected disease on the quality of life. PLoS Negl Trop Dis. 2020;14. pmid:33064742
  4. 4. Andrade R, Tanajura D, Santana D, dos Santos D, Carvalho EM. Association between urinary symptoms and quality of life in HTLV-1 infected subjects without myelopathy. Int Braz J Urol. 2013;39:861–6. pmid:24456778
  5. 5. Gascón MRP, Capitão CG, Casseb J, Nogueira-Martins MCF, Smid J, Oliveira ACP. de. Prevalence of anxiety, depression and quality of life in HTLV-1 infected patients. Braz J Infect Dis. 15: 578–82. Available. pmid:22218518
  6. 6. Galvão-Castro AV, Boa-Sorte N, Kruschewsky RA, Grassi MFR, Galvão-Castro B. Impact of depression on quality of life in people living with human T cell lymphotropic virus type 1 (HTLV-1) in Salvador. Brazil Qual Life Res. 2012;21:1545–50. pmid:22109110
  7. 7. Tanajura D, Castro N, Oliveira P, Neto A, Muniz A, Carvalho NB, et al. Neurological Manifestations in Human T-Cell Lymphotropic Virus Type 1 (HTLV-1)-Infected Individuals Without HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis: A Longitudinal Cohort Study. Clin Infect Dis. 2015;61:49–56. pmid:25820277
  8. 8. Araujo AQC, Wedemann D. HTLV-1 Associated Neurological Complex. What is Hidden below the Water? AIDS Rev. 2019;21:211–7. pmid:31834313
  9. 9. Haziot ME, Gascon MR, Assone T, Fonseca LAM, Luiz O, do C, et al. Detection of clinical and neurological signs in apparently asymptomatic HTLV-1 infected carriers: Association with high proviral load. PLoS Negl Trop Dis. 2019;13:e0006967. pmid:31042700
  10. 10. Marcusso RMN, Van Weyenbergh J, de Moura JVL, Dahy FE, de Moura Brasil Matos A, Haziot MEJ, et al. Dichotomy in Fatal Outcomes in a Large Cohort of People Living with HTLV-1 in São Paulo, Brazil. Pathog (Basel, Switzerland). Pathogens; 2019;9. pmid:31888093
  11. 11. Iwanaga M, Watanabe T, Yamaguchi K. Adult T-cell leukemia: a review of epidemiological evidence. Front Microbiol. Frontiers Media SA; 2012;3: 322. pmid:22973265
  12. 12. Rosadas C, Puccioni-Sohler M, Oliveira ACP, Casseb J, Sousa M, Taylor GP. Adult T-cell leukaemia/lymphoma in Brazil: A rare disease or rarely diagnosed? Br J Haematol Br J Haematol. 2020;188:e46–9. pmid:31743423
  13. 13. Schierhout G, McGregor S, Gessain A, Einsiedel L, Martinello M, Kaldor J. Association between HTLV-1 infection and adverse health outcomes: a systematic review and meta-analysis of epidemiological studies. Lancet Infect Dis Elsevier; 2019;0. pmid:31648940
  14. 14. Rathsam-Pinheiro RH, Boa-Sorte N, Grassi MFR, Copello ÚC, Rios KTSG, Araújo T, et al. Revisiting Keratoconjunctivitis sicca associated with Human T-Cell Lymphotropic Virus Type 1: prevalence, clinical aspects and proviral load. Braz J Infect Dis. 2019;23:95–101. pmid:31059675
  15. 15. Araujo A, Bangham CRM, Casseb J, Gotuzzo E, Jacobson S, Martin F, et al. Management of HAM/TSP. Neurol Clin Pract. Wolters Kluwer Health, Inc on behalf of the American Academy of Neurology; 2020; 10.1212/CPJ.0000000000000832. pmid:33968472
  16. 16. Andrade RCP, Neto JA, Andrade L, Oliveira TS, Santos DN, Oliveira CJV, et al. Effects of Physiotherapy in the Treatment of Neurogenic Bladder in Patients Infected With Human T-Lymphotropic Virus 1. Urology. 2016;89:33–9. pmid:26724409
  17. 17. Cook L, Haddow J, Olavarria E, Ayto R, Wilkins A, Drysdale S, et al. Managing Human T-Lymphotropic virus (HTLV) associated adult T-cell Leukaemia/Lymphoma in pregnancy and prevention of transmission to the neonate: The UK Experience. 35th Annual meeting of the European Society for paediatric infectious diseases (ESPID). Madrid; 2017. pp. 927 (ESP17–0561). Available: abstracts.pdf
  18. 18. Borges J, Baptista AF, Santana N, Souza I, Kruschewsky RA, Galvão-Castro B, et al. Pilates exercises improve low back pain and quality of life in patients with HTLV-1 virus: A randomized crossover clinical trial. J Bodyw Mov Ther. 2014;18:68–74. pmid:24411152
  19. 19. Bottini DAMC, De Assis PV, Salgado PR, Domingos JA, Christofoletti G, Pegorare ABG de S. Treinamento do assoalho pélvico com ou sem eletroterapia no tratamento dos sintomas da hiperatividade do detrusor em mulheres com esclerose múltipla e mielopatia associada ao HTLV-I (HAM/TSP): um ensaio clí-nico randomizado. Fisioter Bras. 2019;20: 500–508.
  20. 20. Klautau AV, da Silva Pinto D, Santana BB, Freitas Queiroz MA, Rangel da Silva ANM, Vieira Cayres-Vallinoto IM, et al. Pilates exercise improves the clinical and immunological profiles of patients with human T-cell lymphotropic virus 1 associated myelopathy: A pilot study. J Bodyw Mov Ther. 2020;24: 1–8. pmid:32825975
  21. 21. Galvão-Castro B, Rios Grassi MF, Nunes A, Galvão-Barroso AK, Galvão-Castro AV, Lírio M, et al. Challenges in establishing telehealth care during the COVID-19 pandemic in a neglected HTLV-1-infected population in northeastern Brazil. Ramos AN, editor. PLoS Negl Trop Dis. 2020;14: e0008922. pmid:33382699
  22. 22. Martin F, Tagaya Y, Gallo R. Time to eradicate HTLV-1: an open letter to WHO. Lancet. 2018;391:1893–4. pmid:29781438
  23. 23. Puccioni-Sohler M, Grassi MFR, Galvão-Castro B, Caterino A, Proietti AB, de FC VACP, et al. Increasing awareness of human T-lymphotropic virus type-1 infection: a serious, invisible, and neglected health problem in Brazil. Rev Soc Bras Med Trop. 2019;52:e20190343. pmid:31618310
  24. 24. WHO. Human T-lymphotropic virus type 1: technical report. [Internet]. 2021. Available:
  25. 25. SESAB Secretaria do Estado da Bahia. PORTARIA No 460, de 19 de novembro de 2020 [Internet]. 2020. Available:
  26. 26. Paiva A, Casseb J. Sexual transmission of human T-cell lymphotropic virus type 1. Rev Soc Bras Med Trop. 2014;47: 265–74. Available. pmid:25075475
  27. 27. Belec L, Georges AJ, Hallouin M-C, Mohamed AS, Morand-Joubert L. Georges-CourbotM-C. Human T-Lymphotropic Virus Type I Excretion and Specific Antibody Response in Paired Saliva and Cervicovaginal Secretions AIDS Res Hum Retroviruses. 1996;12:157–67. pmid:8834466
  28. 28. Firmino A de A, Martins ALL, Gois LL, Paixão TS, Batista E da S, Galvão-Castro B, et al. Evaluation of the cervicovaginal environment in asymptomatic Human T-cell lymphotropic virus type 1 infected women. Braz J Infect Dis. 2019;23: 27–33. pmid:30849331
  29. 29. Nakano S, Ando Y, Ichijo M, Moriyama I, Saito S, Sugamura K, et al. Search for possible routes of vertical and horizontal transmission of adult T-cell leukemia virus. Gan. 1984;75: 1044–5. Available. pmid:6098502
  30. 30. Murphy EL, Figueroa JP, Gibbs WN, Brathwaite A, Holding-Cobham M, Waters D, et al. Sexual Transmission of Human T-Lymphotropic Virus Type I (HTLV-I). Ann Intern Med. American College of Physicians; 1989;111: 555. pmid:2789009
  31. 31. Boulos R, Ruff AJ, Nahmias A, Holt E, Harrison L, Magder L, et al. Herpes Simplex Virus Type 2 Infection, Syphilis, and Hepatitis B Virus Infection in Haitian Women with Human Immunodeficiency Virus Type 1 and Human T Lymphotropic Virus Type I Infections. J Infect Dis. 1992;166:418–20. pmid:1321862
  32. 32. Ministério da Saúde do Brasil. Protocolo Clínico e Diretrizes Terapêuticas para atenção integral às pessoas com infeções sexualmente transmissíveis (IST) [Internet]. 2020. Available: file:///C:/Users/User/Downloads/pcdt_ist_final_revisado_020420 (2).pdf
  33. 33. ANVISA. RDC n 23, 27 de maio de 2011 [Internet]. 2011. Available: file:///C:/Users/User/Downloads/resoluo rdc n 23 2011—banco de células e tecidos germinativos bctg republicada (1).pdf
  34. 34. Penzias A, Azziz R, Bendikson K, Falcone T, Hansen K, Hill M, et al. Recommendations for reducing the risk of viral transmission during fertility treatment with the use of autologous gametes: a committee opinion. Fertil Steril. 2020;114:1158–64. pmid:33280723
  35. 35. ESHRE Viral infection Guideline Group. Medically assisted reproduction in patients with a viral infection/disease [Internet]. 2021. Available:
  36. 36. Caswell RJ, Nall P, Boothby M, Taylor GP. Rapid onset and progression of myelopathy following an STI: a case for screening? Sex Transm Infect Sex Transm Infect. 2019;95:244–5. pmid:30824578
  37. 37. Ministério da Saúde do Brasil. Portaria 1376 de 19/11/1993—Ministério da Saúde. 1993.
  38. 38. Ministério da Saúde do Brasil. PORTARIA No. 2600, DE 21 DE OUTUBRO DE 2009 [Internet]. 2009. Available:
  39. 39. Ichikawa T, Taura N, Miyaaki H, Matsuzaki T, Ohtani M, Eguchi S, et al. Human T-cell leukemia virus type 1 infection worsens prognosis of hepatitis C virus-related living donor liver transplantation. Transpl Int Transpl Int. 2012;25:433–8. pmid:22417010
  40. 40. Yamauchi J, Yamano Y, Yuzawa K. Risk of Human T-Cell Leukemia Virus Type 1 Infection in Kidney Transplantation. N Engl J Med. 2019;380:296–8. pmid:30650320
  41. 41. Taylor GP. Human T-lymphotropic virus type 1 infection and solid organ transplantation. Rev Med Virol. 2018;28. pmid:29380451
  42. 42. Patriquin G, Hatchette JE, Hatchette TF. Risk acceptance of human T-lymphotropic virus infection in solid organ transplantation-A survey of Atlantic Canadian ambulatory patients. Transpl Infect Dis. 2018;20:e12958. pmid:29959880
  43. 43. Ministério da Saúde do Brasil. Portaria número 23, de 31 de maio de 2016 [Internet]. 2016. Available:
  44. 44. Campos KR, Santos FLN, da Silva Brito V, Gonçalves NLS, Araujo THA, Galvão-Castro B, et al. Line Immunoassay for Confirmation and Discrimination of Human T-Cell Lymphotropic Virus Infections in Inconclusive Western Blot Serum Samples from Brazil. Tang Y-W, editor. J Clin Microbiol. 2019;58. pmid:31597749
  45. 45. Umeki K, Umekita K, Hashikura Y, Yamamoto I, Kubo K, Nagatomo Y, et al. Evaluation of Line Immunoassay to Detect HTLV-1 Infection in an Endemic Area, Southwestern Japan; Comparison with Polymerase Chain Reaction and Western Blot. Clin Lab Clin Lab. 2017;63:227–33. pmid:28182361
  46. 46. Okuma K, Kuramitsu M, Niwa T, Taniguchi T, Masaki Y, Ueda G, et al. Establishment of a novel diagnostic test algorithm for human T-cell leukemia virus type 1 infection with line immunoassay replacement of western blotting: a collaborative study for performance evaluation of diagnostic assays in Japan. Retrovirology. 2020;17:26. pmid:32831150
  47. 47. Rosadas C, Caterino-de-Araujo A, Taylor GP. Specificity of HTLV screening tests and its impact on health care program costs: The perspective of antenatal screening in Brazil. Rev Soc Bras Med Trop. 2021;54. pmid:33681940
  48. 48. da Silva Brito V, Santos FLN, Gonçalves NLS, Araujo THA, Nascimento DSV, Pereira FM, et al. Performance of Commercially Available Serological Screening Tests for Human T-Cell Lymphotropic Virus Infection in Brazil. Tang Y-W, editor. J Clin Microbiol. 2018;56. pmid:30232131
  49. 49. Oliveira-Filho AB, Araújo APS, Souza APC, Gomes CM, Silva-Oliveira GC, Martins LC, et al. Human T-lymphotropic virus 1 and 2 among people who used illicit drugs in the state of Pará, northern Brazil. Sci Rep. 2019;9:14750. pmid:31611600
  50. 50. Caterino-de-Araujo A, Sacchi CT, Gonçalves MG, Campos KR, Magri MC, Alencar WK, et al. Short Communication: Current Prevalence and Risk Factors Associated with Human T Lymphotropic Virus Type 1 and Human T Lymphotropic Virus Type 2 Infections Among HIV/AIDS Patients in São Paulo. Brazil AIDS Res Hum Retroviruses. 2015;31:543–9. pmid:25464979
  51. 51. Magri MC, Brigido LF de M, Morimoto HK, Caterino-de-Araujo A.. Human T cell lymphotropic virus type 2a strains among HIV type 1-coinfected patients from Brazil have originated mostly from Brazilian Amerindians. AIDS Res Hum Retrovir. 2013;29:1010–8. pmid:23484539
  52. 52. Einsiedel L, Woodman RJ, Flynn M, Wilson K, Cassar O, Gessain A. Human T-Lymphotropic Virus type 1 infection in an Indigenous Australian population: epidemiological insights from a hospital-based cohort study. BMC Public Health BMC Public Health; 2016;16: 787. pmid:27526923
  53. 53. Tang AR, Taylor GP, Dhasmana D. Self-Flagellation as Possible Route of Human T-Cell Lymphotropic Virus Type-1 Transmission. Emerg Infect Dis. 2019;25:811–3. pmid:30882326
  54. 54. Ishak R, Harrington WJ, Azevedo VN, Eiraku N, Ishak MO, Guerreiro JF, et al. Identification of human T cell lymphotropic virus type IIa infection in the Kayapo, an indigenous population of Brazil. AIDS Res Hum Retroviruses AIDS Res Hum Retroviruses. 1995;11:813–21. pmid:7546908
  55. 55. Rosadas C, Taylor GP. Mother-to-child HTLV-1 transmission: Unmet research needs. Front Microbiol. 2019;10. pmid:31134031
  56. 56. Paiva AM, Assone T, Haziot MEJ, Smid J, Fonseca LAM, Luiz O do C, et al. Risk factors associated with HTLV-1 vertical transmission in Brazil: longer breastfeeding, higher maternal proviral load and previous HTLV-1-infected offspring. Sci Rep. Nat Publ Group; 2018;8: 7742. pmid:29773807
  57. 57. Rosadas C, Malik B, Taylor GP, Puccioni-Sohler M. Estimation of HTLV-1 vertical transmission cases in Brazil per annum. Althouse B, editor. PLoS Negl Trop Dis. Public Library of Science; 2018;12: e0006913. pmid:30418973
  58. 58. Alvarenga A, Zihlmann K. Reproductive Decisions among People Living with Human T-cell Lymphotropic Virus Type 1 (HTLV-1). J Infect Dis Ther. 2013;01.
  59. 59. Zihlmann KF, Mazzaia MC, de Alvarenga AT. Sentidos da interrupção da amamentação devido infeção pelo vírus linfotrópico de células T humanas do tipo 1 (HTLV-1). Acta Paul Enferm. 2017;30:80–6.
  60. 60. Ishak R, Vallinoto ACR, Azevedo VN, Lewis M, Hall WW, Ishak MOG. Molecular evidence of mother-to-child transmission of HTLV-IIc in the Kararao Village (Kayapo) in the Amazon Region of Brazil Evidência molecular da transmissão do HTLV-IIc de mãe para filho, na aldeia Kararao (Kayapó), na região amazônica brasileira. 2001;34:519–25.
  61. 61. Ministério da Saúde do Brasil M. Protocolo Clínico e Diretrizes Terapêuticas para Prevenção da Transmissão Vertical de HIV, Sífilis e Hepatites Virais [Internet]. 2019. Available:
  62. 62. Hino S. Establishment of the milk-borne transmission as a key factor for the peculiar endemicity of human T-lymphotropic virus type 1 (HTLV-1): the ATL Prevention Program Nagasaki. Proc Jpn Acad Ser B Phys Biol Sci. 2011;87: 152–66. Available: pmid:21558754
  63. 63. Nishijima T, Shimada S, Noda H, Miyake K. Towards the elimination of HTLV-1 infection in Japan. Lancet Infect Dis Elsevier. 2019;19:15–6. pmid:30587282
  64. 64. Caterino-de-Araujo A, Barbosa-Stancioli EF, Alonso Neto JB, Aragón MG, Galvão-Castro B, Ishak R, et al. Laboratory diagnosis of human T-lymphotropic virus in Brazil: assays, flowcharts, challenges, and perspectives. Rev Soc Bras Med Trop. 2021;54. pmid:34105630
  65. 65. Rosadas C, Tosswill JH, Tedder R, Taylor GP. Pregnancy does not adversely impact diagnostic tests for HTLV-1/2 infection. PLoS Negl Trop Dis. 2019;13. pmid:31134031
  66. 66. Carroll C, Booth A, Campbell F, Relton C. Qualitative evidence synthesis of values and preferences to inform infant feeding in the context of non-HIV transmission risk. PLoS ONE. 2020;15:e0242669. pmid:33259512
  67. 67. Garcia IF da S, Hennington ÉA.. HTLV: uma infecção estigmatizante? Cad Saude Publica. 2019;35. pmid:31721899
  68. 68. Zihlmann KF, de Alvarenga AT, Casseb J. Living Invisible: HTLV-1-Infected Persons and the Lack of Care in Public Health. Kashanchi F, editor. PLoS Negl Trop Dis. 2012;6: e1705. pmid:22720112
  69. 69. Motedayen Aval L, Boullier M, Lyall H, Collins GP, Ayto R, Kelly DF, et al. Adult T cell leukaemia/lymphoma (ATL) in pregnancy: A UK case series. eJHaem. 2021;2:134–8.
  70. 70. Bittencourt AL, Sabino EC, Costa MC, Pedroso C, Moreira L. No evidence of vertical transmission of HTLV-I in bottle-fed children. Rev Inst Med Trop Sao Paulo. 2002;44:63–5. pmid:12048541
  71. 71. Kashiwagi K, Furusyo N, Nakashima H, Kubo N, Kinukawa N, Kashiwagi S, et al. A decrease in mother-to-child transmission of human T lymphotropic virus type I (HTLV-I) in Okinawa. Japan Am J Trop Med Hyg. 2004;70:158–63. pmid:14993627
  72. 72. Ministério da Saúde do Brasil. PORTARIA No 306, DE 28 DE MARÇO DE 2016 [Internet]. 2016. Available:
  73. 73. Kusuhara K, Sonoda S, Kazuo T, Tokugawa K, Fukushige J, Ueda K. Mother-to-child transmission of Human T-cell leukemia virus type I (HTLV-1): A fifteen-year follow-up study in Okinawa. Japan Int J Cancer. 1987;40:755–7. pmid:2891625
  74. 74. Nyambi PN, Ville Y, Louwagie J, Bedjabaga I, Glowaczower E, Peeters M, et al. Mother-to-Child Transmission of Human T-cell Lymphotropic Virus Types I and II (HTLV-1 / 11) in Gabon: A Prospective Follow-up of 4 Years. J Acquir Immune Defic Syndr Hum Retrovirol 1996;12: 187–192. Available: pmid:8680891
  75. 75. Ando Y, Matsumoto Y, Nakano S, Saito K, Kakimoto K, Tanigawa T, et al. Long-term Follow up Study of Vertical HTLV-I Infection in Children Breast-fed by Seropositive Mothers. J Infect WB Saunders. 2003;46:177–9. pmid:12643867
  76. 76. Oni T, Djossou F, Joubert M, Heraud J-MM. Awareness of mother-to-child transmission of human T-cell lymphotropic virus (HTLV) type I through breastfeeding in a small group of HTLV-positive women in Maripasoula and Papaïchton, French Guiana. Trans R Soc Trop Med Hyg. No longer published by Elsevier; 2006;100: 715–718. pmid:16481017
  77. 77. Coler-Reilly ALG, Yagishita N, Suzuki H, Sato T, Araya N, Inoue E, et al. Nation-wide epidemiological study of Japanese patients with rare viral myelopathy using novel registration system (HAM-net). Orphanet J Rare Dis Orphanet J Rare Dis; 2016;11: 69. pmid:27225443
  78. 78. Ireland G, Croxford S, Tosswill J, Raghu R, Davison K, Hewitt P, et al. Human T-lymphotropic viruses (HTLV) in England and Wales, 2004 to 2013: testing and diagnoses. Euro Surveill. 2017;22. pmid:28598325
  79. 79. Lopes Martins AL, Rios Grassi MF, de Aquino FA, Lacerda Araujo JP, Paixao TS, Galvão-Castro B, et al. Human T-Lymphotropic Virus-1-Associated Myelopathy/Tropical Spastic Paraparesis Is Associated With Sexual Dysfunction in Infected Women of Reproductive Age. Sex Med Elsevier. 2018;6:324–31. pmid:30181035
  80. 80. Vargas L, Bastos F, Guimarães A, Amaral S, Fausto T, Arriaga M, et al. Seroprevalence and factors associated with Human Immunodeficiency virus, Human T lymphotropic virus and Hepatitis B/C infections in parturient women of Salvador–Bahia. Brazil Brazilian J Infect Dis. 2020;24:279–87. pmid:32464116
  81. 81. Paiva A, Casseb J. Origin and prevalence of human T-lymphotropic virus type 1 (HTLV-1) and type 2 (HTLV-2) among indigenous populations in the Americas. Rev Inst Med Trop Sao Paulo. Instituto De Medicina Tropical De Sao Paulo. 2015;57:1–13. pmid:25651320
  82. 82. Machado LFA, Fonseca RR de S, Queiroz MAF, Oliveira-Filho AB, Cayres-Vallinoto IMV, Vallinoto ACR, et al. The Epidemiological Impact of STIs among General and Vulnerable Populations of the Amazon Region of Brazil: 30 years of Surveillance. Viruses 2021;13: 855. pmid:34067165