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A silent spread of human T cell lymphotropic virus type 1 (HTLV-1) has been occurring for thousands of years, with a high prevalence in some regions due to the sexual and vertical transmission and formation of family clusters. The time from HTLV-1 infection until the onset of virus-associated diseases is extremely long, approximately one to three decades. In this study, we evaluated intrafamilial HTLV-1 transmission and associated diseases in 1,204 individuals enrolled and followed up by the GIPH cohort between 1997 and 2017. The family groups ( n  = 43) were composed of 279 individuals who were tested for HTLV-1/human T cell lymphotropic virus type 2 (HTLV-2) and were classified as two groups according to the index case: blood donor (blood donors referred to the GIPH cohort) and nondonor (individuals referred to the GIPH cohort by other health services). The observed rates of HTLV-1 transmission and associated diseases among the relatives were high. Of 236 family members and sexual partners tested for HTLV, 104 (44.1%) were confirmed as having HTLV infection, with 36.7% of relatives whose index case was blood donors and 56.9% of relatives with nondonor index cases. At least one case of HTLV-1-associated myelopathy was observed in 42.9% of the families with intrafamilial transmission of HTLV-1. Brazil is an endemic area for HTLV-1/2 and has implemented mandatory universal screening of blood donors for HTLV-1/2 since 1993. However, the lack of public health services offer diagnosis for HTLV to the general population and pregnant women in the country makes it difficult to identify infected people, and contributes to the silent spread of the virus.

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., Competing Interests: The authors have declared that no competing interests exist.

Human T-lymphotropic virus 1 and 2 (HTLV-1/2) belong to the delta group of retroviruses which may cause a life-long infection in humans, HTLV-1 leading to adult T-cell leukemia/lymphoma and other diseases. Different transmission modes have been described, such as breastfeeding, and, as for other blood-borne pathogens, unsafe sexual activity, intravenous drug usage, and blood transfusion and transplantation. The present systematic review was conducted to identify all peer-reviewed studies concerning the work-related infection by HTLV-1/2. A literature search was conducted from January to May 2021, according to the PRISMA methodology, selecting 29 studies: seven related to health care workers (HCWs), five to non-HCWs, and 17 to sex workers (SWs). The findings showed no clear evidence as to the possibility of HTLV-1/2 occupational transmission in HCWs, according to the limited number and quality of the papers. Moreover, non-HCWs showed a higher prevalence in jobs consistent with a lower socioeconomic status or that could represent a familial cluster, and an increased risk of zoonotic transmission from STLV-1-infected non-human primates has been observed in African hunters. Finally, a general increase of HTLV-1 infection was observed in SWs, whereas only one paper described an increased prevalence for HTLV-2, supporting the urgent need for prevention and control measures, including screening, diagnosis, and treatment of HTLV-1/2, to be offered routinely as part of a comprehensive approach to decrease the impact of sexually transmitted diseases in SWs.

HTLV-1/2 are transmitted sexually, by whole cell blood products and from mother-to-child (MTC), mainly through breastfeeding. HTLV-1/2 prevalence in pregnant women is high in Rio de Janeiro, however there were no local studies addressing the rate of adverse pregnancy outcomes (APO) and MTC transmission. The aim was to study sociodemographic characteristics which may be associated to HTLV-1/2 infection and describe pregnancy outcomes and MTC transmission in HTLV-1/2-positive women. The cross-sectional study screened 1,628 pregnant women in of Rio de Janeiro (2012-2014) and found 12 asymptomatic carrier mothers (prevalence = 0.74%). Pregnancy outcome information was retrieved from medical records. Sociodemographic characteristics were similar between the positive and negative groups except for maternal age, which was higher in carrier mothers. The incidence of adverse pregnancy outcomes was similar in infected and non-infected patients (p = 0.33), however there was a high rate of premature rupture of membranes (PROM) amid infected mothers (3/12). Multilevel logistic regression found that for each additional year of age, the chance of being HTLV-1/2-positive increased 11% and that having another sexually transmitted infection (STI) increased 9 times the chance of being infected. Carrier mothers had more antenatal visits (OR = 5.26). Among the children of HTLV-1/2-positive mothers there was one fetal death, one infant death and one loss of follow-up. After two years of follow-up there was one case of MTC transmission (1/9). The mother reported breastfeeding for one month only. Knowledge about factors associated to HTLV-1/2 infection, its impact on pregnancy outcomes and the MTC transmission rate is important to guide public health policies on antenatal screening and management., Competing Interests: The authors have declared that no competing interests exist.

Independent epidemiology for respective human T-cell lymphotropic virus (HTLV) types 1 and 2 is little known in blood donors in Brazil, where screening for HTLV-1/2 is mandatory at blood banks, but no testing to confirm/differentiate these viruses. Therefore, this study aims to assess the prevalence of HTLV-1 and -2 in a first-time blood donor population in Northeastern Brazil and to carry out molecular characterization of respective isolates. A cross-sectional study was conducted at the State Blood Bank in Piauí. Samples were screened for anti-HTLV-1/2 by enzyme immunoassay, and reactive samples were confirmed using a line immunoassay and polymerase chain reaction (PCR). Of 37 306 blood donors, 47 were anti-HTLV-1/2 reactive by enzyme immunoassay. After confirmed by line immunoassay, 22 were positive for HTLV-1 (0.59 per 1000; 95% CI: 0.38-0.87), 14 were positive for HTLV-2 (0.37 per 1000; 95% CI: 0.21-0.61), 1 was indeterminate, and the remaining donors were negative. The HTLV-1 infection was also confirmed by PCR in all anti-HTLV-1-positive samples, and sequencing classified these isolates as belonging to the Transcontinental (A) subgroup of the Cosmopolitan (1a) subtype. Of 14 anti-HTLV-2-positive samples, 11 were also PCR positive, which belonged to subtype a (HTLV-2a/c). In addition, 38 family members of 5 HTLV-1- and 3 HTLV-2-infected donors were analyzed. Familial transmission of HTLV-1 and -2 was evidenced in 3 families. In conclusion, in Northeastern Brazil, where HTLV-1 and -2 are endemic, counseling blood donor candidates and their families might play a key role in limiting the spread of these viruses., (© 2018 Wiley Periodicals, Inc.)

Many countries currently perform antibody screening for HTLV-1 infection in blood donors, and this intervention is likely cost-effective in preventing HTLV-1 related diseases in high prevalence countries. However, a number of high-income countries with low prevalence of HTLV-1 infection also perform universal HTLV-1 screening and debate has arisen regarding the cost-effectiveness of these strategies. Filter-based leukoreduction is likely to substantially reduce HTLV-1 transmission by removing infected lymphocytes, but actual laboratory data on its efficacy is currently lacking. Similarly, cost-effectiveness research on HTLV-1 prevention strategies is limited by poor data on prevalence, transmission efficacy and the cost of treating HTLV1 diseases., Competing Interests: of interest The author declares that he has no competing interest., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Human T-cell leukemia viruses (HTLV-1 and HTLV-2) are associated with a variety of human diseases, including some severe ones. Transfusion transmission of HTLV through cellular blood components is undeniable. HTLV screening of blood donations became mandatory in different countries to improve the safety of blood supplies. In Japan and Europe, most HTLV-infected donors are HTLV-1 positive, whereas in the United States a higher prevalence of HTLV-2 is reported. Many industrialized countries have also introduced universal leukoreduction of blood components, and pathogen inactivation technologies might be another effective preventive strategy, especially if and when generalized to all blood cellular products. Considering all measures available to minimize HTLV blood transmission, the question is what would be the most suitable and cost-effective strategy to ensure a high level of blood safety regarding these viruses, considering that there is no solution that can be deemed optimal for all countries., (© 2015 AABB.)

Objectives: The objective of this study was to estimate the prevalence of human T cell lymphotropic virus (HTLV)-1/2, HIV-1, hepatitis B virus (HBV), Trypanosoma cruzi, Treponema pallidum and Toxoplasma gondii infections and to identify the subtypes/subgroups of HTLV-1/2 among pregnant women (PW) from non-endemic provinces of Argentina., Methods: Methods A total of 2403 samples were screened for HTLV-1/2 and confirmed by western blot and PCR. The long terminal repeat (LTR) of HTLV-1 and HTLV-2 were amplified. Phylogenetic analysis was performed by Neighbour Joining by using molecular evolutionary genetics analysis (MEGA) 4.0., Results: Among a total of 2403 PW studied, 6 (0.25%) tested positive for HTLV-1/2 (3 HTLV-1 (0.12%) and 3 HTLV-2 (0.12%)). The total prevalence when distributed by province was 0.3% (3/804) for Buenos Aires (BA), 0.4% (1/241) for BA surroundings, 0.1% (1/707) for Neuquen and 1.0% (1/95) for Ushuaia. In San Juan, no PW were HTLV-1/2 positive. The prevalence was similar when compared with rates among blood donors of the same areas and years. The phylogenetic analysis classified one sequence as HTLV-1 aA and one as HTLV-2b. The prevalence of HIV-1, HBV, T cruzi, T pallidum and T gondii was 0.6%, 0.2%, 1.4%, 1.2% and 20.9%, respectively. One case of HTLV-1/HIV-1 and one of HTLV-2/HIV-1 co-infection were detected., Conclusions: HTLV-1/2, which have been associated with different diseases, are circulating among PW of Argentina, even in non-endemic areas. Therefore, testing should be recommended in women who have risk factors for these infections given that the majority of HTLV-1/2 mother to child transmission can be prevented by the avoidance of breast feeding.

Background: In the United States, blood products are tested for infectious diseases including human T-lymphotropic virus (HTLV)-I/II. Positive results of maternal blood samples at the time of cord blood (CB) donation must be reported to mother and physician. Tests for HTLV have a high false-positive rate. This is problematic because there is no prenatal testing of the mother., Study Design and Methods: This study involves 119,769 maternal blood samples at time of CB donation and evaluates positive results for HTLV in screening tests, supplemental immunoassays, and nucleic acid tests (NATs). Infectious disease markers (IDMs) and maternal health histories of HTLV-positive and -negative mothers were compared., Results: Of 119,769 mothers donating CB, 545 tested positive with the screening test, 33 were positive with the supplemental tests, and two were positive with NAT. When indeterminate results were excluded from the supplemental test only six were positive. Eight of 34 mothers with positive or indeterminate supplemental test results had received intravenous immunoglobulin. There were no significant differences between HTLV-positive and -negative mothers with regard to the incidence of other IDMs., Conclusions: Testing maternal blood for HTLV is problematic for CB banks, obstetricians, and mothers because of the high false-positive rate. CB banks need rapid turnaround time and supplemental testing. If results on the latter are positive the obstetrician should be notified, educated, do follow-up testing, and counseling. Indeterminate results on supplemental tests are most likely false positives. We recommend that mothers with positive or indeterminate supplemental test results have follow-up NAT., (© 2012 American Association of Blood Banks.)

This article reviews risks of illness or exposures to breastfed infants. Galactosemia in an infant is a contraindication to breastfeeding. There are no medical conditions in the mother that are contraindications, although diagnostic procedures, treatment, or illness can interfere. Restrictive diets or malnutrition are not contraindications but are opportunities to provide nutritional counseling. Environmental toxic exposures within the United States are uncommon; breastfeeding is not usually contraindicated. In any concerning situation, an assessment and discussion of risks and benefits for the mother-infant dyad (breastfed or formula fed) is indicated. Coordinated medical care and lactation assistance can facilitate successful breastfeeding., (Copyright © 2013 Elsevier Inc. All rights reserved.)

This study aimed to describe the epidemiological, immunological and molecular features of infection by the human T-lymphotropic virus-1/2 (HTLV-1/2) in individuals with HIV-1 in an urban area of Piaui State, Brazil. Exclusion criteria included patients under 18 years of age, pregnant women or Amerindians. Of 805 individuals analyzed by the serological method (ELISA) for the detection of anti-HTLV-1/2, 18 (2.24%) were positive, but only 13 (1.61%) were confirmed by PCR. The RFLP analysis revealed that nine (1.12%) of these subjects were positive for HTLV-1 and four (0.5%) for HTLV-2. The mean age of these co-infected individuals was 50.9±9.1 years, and a significant association was found with age (above 40 years: p = 0.002), minor surgeries (p = 0.004) and blood transfusion (p = 0.031). Quantification of the T CD4+/CD8+ lymphocytes and the HIV-1 viral load showed no significant association of T CD8 + lymphocyte levels with co-infection in the patients with HIV-1/HTLV-1. The sequencing of the LTR region and phylogenetic analysis indicated that the nine HTLV-1 strains belong to the Transcontinental subgroup of the Cosmopolitan group (1a), with a 83% (neighbor-joining) bootstrap value. The HTLV-2 strains were identified as subtype HTLV-2c, supported by a bootstrap value of 79%. Further studies in other population subgroups, such as blood donors and drug users, will be necessary to clarify the dissemination of HTLV-1/2 in Piau and elucidate the developmental profile of the virus in the region.

Background: Human T cell lymphotropic virus type 1 and 2 (HTLV-1/2) causes serious diseases and is endemic in many parts of the world. It is transmitted from mother to child in 15-25% of the cases, primarily through breastfeeding. Proviral load and duration of breastfeeding are thought to play a role in transmission. This study aimed to detect HTLV-seropositive mothers through testing of neonates, to evaluate maternal HTLV proviral load and to measure the rates of transmission blocking when interruption of breastfeeding was implemented., Methods: Neonates were screened for HTLV-1/2 IgG by enzyme immunoassay using the neonatal screening program of Minas Gerais State, Brazil. Breastfeeding interruption was recommended to those whose mothers were confirmed HTLV-positive. Children were tested by polymerase chain reaction at birth and at 12 months of age., Results: Of 55,293 neonates tested, 42 (0.076%) were positive for HTLV-1 or HTLV-2 IgG. All 42 were polymerase chain reaction-negative at birth and 1 of 37 (2.7%) became antibody-positive after 12 months. His mother had delivered him vaginally and was informed of the positive HTLV-1 polymerase chain reaction after 7 days of breastfeeding. The mother's proviral load was 271 copies/10,000 cells, whereas the average is 109.2 copies/10,000 cells (95% confidence interval: 70.56-147.83)., Conclusions: Maternal HTLV-1 proviral load and the route of delivery may have played a role in the transmission observed. Avoidance of breastfeeding was an effective measure to reduce HTLV transmission. In endemic countries, routine prenatal or neonatal screening combined with formula feeding for mothers confirmed HTLV-positive may be an important strategy to prevent future development of illnesses related to HTLV.

Background: The human T-lymphotropic virus I (HTLV-I) causes spastic para-paresis and adult T-cell leukemia/lymphoma. It can be sexually transmitted and is highly prevalent in Central and South America., Aim: To study HTLV-I/IIprevalence in serum samples obtained from two Sexually Transmitted Diseases (STD) clinics., Material and Methods: Two hundred serum samples were randomly chosen from two reference STD centers of Santiago. The presence of specific HTLV I/II antibodies was detected by indirect immunofluorescence., Results: The analyzed samples came from participants aged 14 to 70 years. Forty nine percent were women and 76% were heterosexual. Only one of the 200 samples was positive (0.5%) and it came from a 70 year-old woman, housewife, with a stable single partner, a history of recurrent genital ulcers, VDRL (-) and positive serology for herpes simplex virus., Conclusions: The prevalence of HTLV-I found in this group is similar to that demonstrated in other populations in Chile, except for aboriginal populations, and similar to international STD studies. Our data is consistent with the low transmissibility by sexual contact.

In France, the screening for human T-cell leukemia/ lymphoma virus type 1 and 2 (HTLV-1 and HTLV-2) during the donation of human milk has been carried out from 1992 with the application of the circular DGS 24 November 1992. The screening for antibodies against these viruses is regulated and done systematically during every donation of milk. Breast feeding being the main mode of transmission of the HTLV-1, the last ministerial decree of 25 August 2010 has made the screening test compulsory for the anonymous donation and for the personalized donation (of a mother for her own child) from all women including those affected by the infection. The milk delivered by milk banks is pasteurized (62.5 °C for 30 minutes) before freezing at -18 °C, which inactivates the pathogens. This double means of prevention of the transmission of the HTLV-1 paradoxically seems disproportionate in the absence of any precautionary measure in the case of direct breast-feeding and the use of mother's raw milk. Indeed, in most neonatal intensive care units in maternity hospitals, unpasteurized milk is administered to the neonates without any systematic preliminary testing of the serological HTLV-1 status of the mother. An increased sensitization of the community of the obstetricians, midwives and neonatologists by the Association of the Milk Banks of France (ADLF) and the Société de pathologie exotique could address the issue of screening for HTLV-1 in "donated" milk and breast-feeding.

Objective: To evaluate the geographic distribution of human T-lymphotropic virus types 1 and 2 (HTLV-1/2) in the State of Minas Gerais, Brazil, in puerperal women whose newborns were tested for HTLV-1/2 during neonatal screening, and to overlap seropositivity with social and economic status determinants., Methods: During September-November 2007, the dry-blood samples taken from newborns on filter paper for routine screening were also tested for maternal IgG anti-HTLV-1/2 antibodies. For reactive samples, the mothers of the newborns had blood drawn to test for these viruses., Results: The study analyzed 55,293 specimens taken from newborns. Of these, 52 (9.4 per 10,000) were reactive and 42 mothers (7.6 per 10,000) were confirmed with HTLV-1/2 infection. HTLV-1/2 geographic distribution was heterogeneous, with a tendency to be higher in the North and North-East parts of Minas Gerais. The highest rates of seropositivity were observed in Vale do Mucuri (55.9 per 10,000) and in Jequitinhonha (16.0 per 10,000), overlapping with the State's worst social and economic indicators., Conclusions: To our knowledge this was the first time that neonatal screening for HTLV-1/2 was performed in Brazil. This model could be used in other areas with high HTLV-1/2 prevalence rates. The detection of carrier mothers can enable intervention measures, such as providing infant formula to newborns, to be implemented expeditiously to reduce vertical transmission.

The objective of this study was to perform lookback study in recipients of blood components from human T-lymphotropic virus (HTLV) seropositive donors. HTLV-1/2 may be transmitted by blood transfusion. Brazil is an endemic area for the virus and its screening in blood donors is mandatory since 1993. Hemominas Foundation (HF) is the public transfusion centre in Minas Gerais, Brazil. Data on HTLV-1/2 seropositive donors and recipients from 1993 to 2004 were obtained at HF and 24 contracting hospitals. From 1993 to 2004, HTLV-1/2 enzyme immunoassay (EIA) was performed in 918 678 donations of approximately 422 600 blood donor candidates. Of these, 456 donors (0.1%) were reactive and confirmed by Western blot (WB): 449 HTLV-1 and 7 HTLV-2. Sixty-six (14.5%) were repeat donors and had 194 blood cellular components produced from their previous donations. Of the distributed components, 119/146 (81.5%) had the recipient traced, with a total of 114 individuals. Of these, only 13 recipients were tested: six (46%) were HTLV-1 positive (four recipients of red cell units, two of platelets) and seven (54%) were negative (six of red cell units and one of platelets). Eleven did not respond and 62/114 (54.0%) were deceased. Another 28/114 (25.0%) could not be located. All six seropositive HTLV-1 recipients identified had no symptoms suggestive of HTLV-1-associated diseases. Acellular components, when used alone, were not associated with HTLV seropositivity. HTLV-1 transmission by cellular blood components occurred before screening for the virus was introduced. Haemovigilance was difficult to perform due to unavailability of computer systems before 1999 and to inadequate medical records at hospitals.

Introduction: To estimate the seroprevalence of infection by Trypanosoma cruzi and human T lymphotropic virus (HTLV) in pregnant Latin American women., Methods: Serological survey carried out in pregnant Latin American women attending the antenatal care clinic of a Spanish hospital from January 2006 to June 2007., Results: Of the 229 women enrolled, 4 had antibodies against T. cruzi (1.75%; 95% confidence interval [95% CI], 0.68-4.4); 2 of these women came from Bolivia (13.33%; 95% CI, 3.73-37.88) and the other 2 from Paraguay (11.76%; 95% CI, 3.29-34.33). None of the women had anti-HTLV-1 antibodies (95% CI, 0-1.6), and 2 had HTLV-2 antibodies (0.87; 95% CI, 0.24-3.12)., Conclusions: A notable percentage of pregnant immigrant women from Latin American had T. cruzi infection. The seroprevalence of HTLV infection is low.

Sexually transmitted infections during pregnancy pose a major risk to the fetus due to vertical transmission. The study's objective was to determine the prevalence of HIV, syphilis, hepatitis B and C, and HTLV-I/II infection among low-income postpartum and pregnant women treated in Greater Metropolitan Vitória, Espírito Santo State, Brazil, and the risk factors associated with these infections. A cross-sectional study was conducted from February to October 1999 assessing postpartum and pregnant women from the maternity ward of the Vitória Mercy Hospital and the Carapina Outpatient Referral Unit in the Municipality of Serra, respectively. Patients were systematically interviewed and had blood samples drawn for serological tests (HIV 1&2, VDRL, HbsAg, anti-HCV, and HTLV-I/II). A total of 534 patients (332 postpartum and 202 pregnant women) were assessed. Seroprevalence rates for the target infections in postpartum and pregnant women and the overall sample were as follows, respectively: HIV 0.9%, 0%, and 0.6%; syphilis 2.1%, 3.6%, and 2.7%; HBV 1.2%, 1%, and 1.1%; HCV 1.8%, 0.6%, and 1.4%; and HTLV-I/II 1.7%, 0.6%, and 1.3%. Factors associated with the various infections are presented and analyzed in light of other research findings from the literature.

Background: To prevent the blood transmission of human T-cell lymphotropic virus (HTLV), different countries have introduced anti-HTLV blood screening. Furthermore, leucoreduction of blood components has been implemented to preclude the transmission of infectious agents present in white blood cells., Study Design and Methods: To evaluate the current European strategies adopted to ensure the blood safety for HTLV, a European investigation spanning a period from 2003 to 2008 was carried out., Results: In 2003, of the 23 included countries, 11 performed anti-HTLV screening, four of which (Scandinavian countries) only did it on first-time donors. Norway and Finland stopped it in 2007 and 2008, respectively. Two groups may be defined according to increasing prevalence rates per 10 000 donations in first-time donors: Scandinavia and Ireland (0 to 0.17), France, the Netherlands and UK (0.45 to 0.48); Romania was clearly apart from all other participating countries (5.33). HTLV-positive donors (88.6%) either come from endemic areas (82.3%) or declare to have a sexual partner coming from endemic areas (6.3%). Of the 283 HTLV-positive donations that could be characterized, 6.6% were HTLV-II. Fourteen of 22 countries currently use systematic leucoreduction, at least in cellular blood components. Six countries perform both universal anti-HTLV screening and blood cell leucoreduction., Conclusion: The implementation of leucoreduction did not modify the blood HTLVscreening policy, except for Norway and Finland. Several screening strategies in low endemic countries performing leucoreduction were discussed. However, the withdrawal of anti-HTLV screening should be decided after assessing the remaining HTLV transfusion risk.

Human T-cell lymphotropic virus type 1 (HTLV-1) is transmitted through a viral synapse and enters target cells via interaction with the glucose transporter GLUT1. Here, we show that Neuropilin-1 (NRP1), the receptor for semaphorin-3A and VEGF-A165 and a member of the immune synapse, is also a physical and functional partner of HTLV-1 envelope (Env) proteins. HTLV-1 Env and NRP1 complexes are formed in cotransfected cells, and endogenous NRP1 contributes to the binding of HTLV-1 Env to target cells. NRP1 overexpression increases HTLV-1 Env-dependent syncytium formation. Moreover, overexpression of NRP1 increases both HTLV-1 and HTLV-2 Env-dependent infection, whereas down-regulation of endogenous NRP1 has the opposite effect. Finally, overexpressed GLUT1, NRP1, and Env form ternary complexes in transfected cells, and endogenous NRP1 and GLUT1 colocalize in membrane junctions formed between uninfected and HTLV-1-infected T cells. These data show that NRP1 is involved in HTLV-1 and HTLV-2 entry, suggesting that the HTLV receptor has a multicomponent nature.

Background: This study reports on the efficacy of an investigational human T-lymphotropic virus (HTLV)-I and -II lookback program in the context of differing confirmatory testing algorithms., Study Design and Methods: The results of testing approximately 35 million donations for anti-HTLV-I and -II were evaluated for two recent periods reflecting the use of two different confirmatory algorithms. The number of seroconverting donors was established for the entire period, and the results of lookback on their prior donations were investigated., Results: The dual enzyme immunoassay (EIA) strategy was used throughout both study periods and resulted in a 57 to 76 percent reduction in the number of samples requiring confirmatory testing. From May 2000 to February 2002, a total of 9138 samples were repeatedly reactive by the primary screening test; of the concordant EIA-reactive samples, 461 (12%) were confirmed by Western blot, whereas 3083 (79%) were indeterminate. From March 2002 to December 2004, a total of 21,291 samples were repeatedly reactive; of the concordant EIA-reactive samples, 1099 (22%) were confirmed by the State of California's reference laboratory and only 273 (5%) were equivocal. Overall, 38 or 1 in 921,000 donations were from a seroconverting donor with 32 prior donations within the lookback period. Of those 32, components from only 11 were transfused to recipients who survived; of these, 4 were tested and all were nonreactive for HTLV-I and -II antibodies., Conclusion: Use of creative algorithms can increase the efficacy of anti-HTLV-I and -II confirmatory testing and reduce the number of indeterminate results. Currently, lookback for HTLV-I and -II has a very low yield, and its public health benefit is questionable.

Health care workers, mainly in emergency and forensic services, are at risk of exposure to bloodborne pathogens. Human T-cell lymphotropic virus type I and type II (HTLV-I and HTLV-II) are cosmopolitan human delta retroviruses causing endemic infection in Japan, the Caribbean basin, South America, and sub-Saharan Africa, and in clusters among intravenous drug users in Europe and the United States. The seroprevalence of HTLV-I and HTLV-II among Brazilian blood donors ranges from 0.08% to 1.35%. HTLV-I transmission to a Japanese researcher has already been reported. We describe the transmission of HTLV-II infection to a Brazilian laboratory worker caused by a needlestick injury when she was recapping a syringe after collecting material for arterial blood gas analysis. To our knowledge, this is the first report of an occupational transmission of HTLV-II to a health care worker.

Human T-cell lymphotropic virus type 2 (HTLV-2) is endemic in injection drug users (IDU), and native American populations in the Americas. Transmission is associated with high-risk injection and sexual practices. A cohort of 2561 IDU in King County, Washington completed 2 study visits over 1 y. HTLV-2 infection was detected in 190 (7.4%) of 2561 IDU, and 13 (7.8 cases per 1000 person-y) incident infections occurred during the study. Prevalent infection was associated with female gender, non-white race, longer duration as IDU, having a tattoo, combined injection of heroin and cocaine, and with serologic evidence of hepatitis B and C infection. Seroconversion was more common in women, and was associated with African American race, heterosexual identity and longer duration as IDU. In conclusion, increased risk of HTLV-2 infection was associated with non-white race, and injection drug of choice, suggesting injection networks may play an important role in transmission of HTLV-2. The high correlation of HTLV-2 infection with HCV infection suggests the major route of transmission in IDU is via injection practices. Additional studies are needed to examine the clinical manifestations of HTLV-2 infection, as well as the clinical and virological manifestations of HTLV-2/HCV coinfection.

Human T-cell lymphotropic virus (HTLV) type II has spread among intravenous drug users (IDUs), many of whom are coinfected with HIV-1. We have investigated the rate of HTLV-II infection in 3574 Italian IDUs screened for HIV-1, HTLV-I, and HTLV-II from 1986 to the present. HTLV-II proviral load was determined by a real-time polymerase chain reaction specifically designed for tax amplification. The frequency of HTLV-II infection was 6.7% among HIV-1-positive subjects and 1.1% among HIV-1-negative subjects (P < 0.0001). For examination of AIDS progression, a group of 437 HIV-1-monoinfected subjects and another group of 96 HIV-1/HTLV-II-coinfected subjects were monitored. Enrollees were matched at entry by CD4 cell counts and followed for an average of 13 years. HIV-1/HTLV-II coinfection was associated with older age (P < 0.0001) and higher CD4 (P < 0.0001) and CD8 (P < 0.001) cell counts compared with monoinfected IDUs. The number of long-term nonprogressors for AIDS was significantly higher (P < 0.0001) among coinfected patients (13 [13.5%] of 96 patients) than HIV monoinfected patients (5 [1.1%] of 437 patients), showing that HTLV-II exerts a protective role. An increased incidence of liver disease and hepatitis C virus positivity among coinfected IDUs was observed. Five coinfected subjects undergoing antiretroviral therapy showed a significant (P < 0.05) increase in HTLV-II proviral load concomitant to a decrease in HIV-1 viremia, suggesting that the treatment is ineffective against HTLV-II infection.

The first description of the human T-lymphotropic virus type 1 (HTLV-1) was made in 1980, followed closely by the discovery of HTLV-2, in 1982. Since then, the main characteristics of these viruses, commonly referred to as HTLV-1/2, have been thoroughly studied. Central and South America and the Caribbean are areas of high prevalence of HTLV-1 and HTVL-2 and have clusters of infected people. The major modes of transmission have been through sexual contact, blood, and mother to child via breast-feeding. HTLV-1 is associated with adult T-cell leukemia/lymphoma (ATL), HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and HTLV-associated uveitis as well as infectious dermatitis of children. More clarification is needed in the possible role of HTLV in rheumatologic, psychiatric, and infectious diseases. Since cures for ATL and HAM/TSP are lacking and no vaccine is available to prevent HTLV-1 and HTLV-2 transmission, these illnesses impose enormous social and financial costs on infected individuals, their families, and health care systems. For this reason, public health interventions aimed at counseling and educating high-risk individuals and populations are of vital importance. In the Americas this is especially important in the areas of high prevalence.

Background: An ongoing issue in transfusion medicine is whether newly identified or emerging pathogens can be transmitted by transfusion. One method to study this question is through the use of a contemporary linked donor-recipient repository., Study Design and Methods: The Retrovirus Epidemiology Donor Study Allogeneic Donor and Recipient (RADAR) repository was established between 2000 and 2003 by seven blood centers and eight collaborating hospitals. Specimens from consented donors were collected, components from their donations were routed to participating hospitals, and recipients of these units gave enrollment and follow-up specimens for long-term storage. The repository was designed to show that zero transmissions to enrolled recipients would indicate with 95 percent confidence that the transfusion transmission rate of an agent with prevalence of 0.05 to 1 percent was lower than 25 percent., Results: The repository contains pre- and posttransfusion specimens from 3,575 cardiac, vascular, and orthopedic surgery patients, linked to 13,201 donation specimens. The mean number of RADAR donation exposures per recipient is 3.85. The distribution of components transfused is 77 percent red cells, 13 percent whole blood-derived platelet concentrates, and 10 percent fresh frozen plasma. A supplementary unlinked donation repository containing 99,906 specimens from 84,339 donors was also established and can be used to evaluate the prevalence of an agent and validate assay(s) performance before accessing the donor-recipient-linked repository. Recipient testing conducted during the establishment of RADAR revealed no transmissions of human immunodeficiency virus, hepatitis C virus, or human T-lymphotropic virus., Conclusions: RADAR is a contemporary donor-recipient repository that can be accessed to study the transfusion transmissibility of emerging agents.

Human T cell lymphotropic virus type 2 (HTLV-2) has been shown to be endemic in Brazilian Indians and among intravenous drug users in urban areas, but transmission of this infection seems to be infrequent in the general population living in urban areas in Brazil. Six persons in three generations of a Brazilian family were evaluated to assess HTLV-2 transmission and its molecular features in the positive cases. The index was detected during screening (HTLV EIA) of donated blood in Fundação Hemominas, Belo Horizonte, Brazil. Confirmatory serological test and viral typing were performed by Western blotting and polymerase chain reaction. The family consisted of husband, wife (index case), three daughters, and the mother of the index case. The husband and one daughter were found positive, thus pointing to horizontal and vertical transmission. The husband was a truck driver, who reported casual sex during frequent traveling. The positive daughter was breast-fed for 3 months, as opposed to the remaining two (seronegative), who breast-fed for 1 month. The index case's mother was negative. To identify HTLV-2 subtype(s), phylogenetic analysis of the noncoding long terminal repeat region and part of the env and tax coding regions was performed. These new isolates from Belo Horizonte are related to subtype IIa but present a molecular variant with extended tax, previously reported in subtype IIc. Analyzing both LTR and env regions, the family's sequences clustered with isolates of Brazilian intravenous drug users and transfusion transmitted virus.

Background: Cross-sectional studies support sexual transmission of human T lymphotropic virus (HTLV)-I/II; however, prospective incidence data, particularly for HTLV-II, are limited., Methods: A cohort of 85 HTLV-positive (30 with HTLV-I and 55 with HTLV-II) blood donors and their stable (>or=6 months) heterosexual sex partners were followed biannually over the course of a 10-year period., Results: Four of 85 initially seronegative sex partners of HTLV-I and -II carriers seroconverted, for an incidence rate (IR) of 0.6 transmissions/100 person-years (py) (95% confidence interval [CI], 0.2-1.6). This includes 2 HTLV-I transmissions/219 py (IR, 0.9 transmissions/100 py [95% CI, 0.1-3.3]) and 2 HTLV-II transmissions/411 py (IR, 0.5 transmissions/100 py [95% CI, 0.06-1.8]), with no significant difference by HTLV type. There were 2 male-to-female (IR, 1.2 transmissions/100 py [95% CI, 0.1-4.3]) and 2 female-to-male (IR, 0.4 transmissions/100 py [95% CI, 0.05-1.6) transmissions. HTLV-I or -II proviral load was 2 log10 lower in newly infected partners than in index positive partners who transmitted HTLV (P=.007)., Conclusions: The incidence of sexual transmission of HTLV-II may be similar to that of HTLV-I, and female-to-male transmission may play a more important role than previously thought. HTLV-I and -II proviral load may be lower in sexually acquired infection, because of a small infectious dose.

Human T-cell lymphotropic virus (HTLV) is a retrovirus transmitted through breastfeeding, sexual contact, blood transfusion and injecting drug use. HTLV is endemic in the Caribbean and parts of Africa, Japan and South America, with isolated foci in other areas. Infection is life-long. Less than 5% of those infected progress to one of the HTLV-related diseases, but these are debilitating and often fatal. Laboratory reports of new HTLV diagnoses are followed up through clinicians to establish information such as probable country of infection, country of birth, clinical details and reason for test. Clinician reports are also received for HTLV-infected blood donors identified by the National Blood Service. Seventy-seven individuals newly diagnosed with HTLV infection in 2002 were reported to the Communicable Disease Surveillance Centre (CDSC) by June 2003. Thirty-three (43%) were male, and 44 (57%) female, with median ages at diagnosis of 58.5 and 50.1 years respectively. Seventy-three (95%) individuals were HTLV-I positive and three HTLV-II positive, with one remaining untyped. For 52 of the 77 infections, clinician reports were received. Where ethnicity was reported (48), 30 (63%) were Black Caribbean, 12 (25%) White, and the remainder (6) of other ethnicities. Probable route of infection was reported for 31 individuals: nine (29%) were probably infected heterosexually, seven (23%) through mother-to-child transmission, 12 (40%) through either route, two through blood transfusion, and one through injecting drug use (HTLV-II positive). Where probable country of infection was reported (31), 14 (45%) were probably infected in the UK, 13 (42%) in the Caribbean, and four elsewhere. Where reported (50), reason for test was: symptoms for 19 (38%) individuals, blood donation for 21 (42%), and the remainder for other reasons. Numbers of new HTLV diagnoses were relatively high in 2002, and the characteristics of patients and clinical presentations differed from previous years, mainly due to the introduction of blood donor testing for anti-HTLV. Beyond 2004, the number of HTLV-infected individuals detected through blood donation is expected to decline. While numbers of individuals affected are small compared to many other diseases, the infection is chronic and untreatable, and it is important that adequate standards of diagnosis, prevention, care and support are provided, and surveillance maintained.

Human T-lymphotropic virus type II (HTLV-II) is a human retrovirus which is endemic in Amerindian and pygmy tribes. Molecular subtypes show geographic segregation consistent with an ancient origin of this virus within humans in Africa or South America. More recently, injection drug users in the United States and Europe have become infected with HTLV-II, and secondary sexual transmission has introduced the virus at low levels into the general population and blood donors. HTLV-II has been linked with a spastic paraparesis called HTLV-associated myelopathy / tropical spastic paraparesis (HAM/TSP), and perhaps with other neurological syndromes. It is also associated with an increased incidence of pneumonia and bronchitis, inflammatory conditions such as arthritis, and perhaps with increased mortality. Except for a few cases of cutaneous lymphoma in patients coinfected with HIV, there is no evidence that HTLV-II causes lymphoproliferative disease. HTLV-II and HIV coinfection has not been proven to alter the course of HIV disease, but such patients may have altered levels of CD4+ and CD8+ lymphocytes, and antiretroviral therapy may paradoxically increase HTLV-II proviral load.

Human T cell lymphotropic virus (HTLV) I/II is a retrovirus that is usually transmitted through transfusion of cellular blood products, sexual contact, and vertically from mother to child through breastfeeding. Policies to screen donated blood for this virus have varied from country to country, based on seroepidemiological data. Before 1991, no such data existed on HTLV-I/II among the Saudi population. Since then, several reports have documented a low seroprevalence rate among Saudi blood donors (0-0.026%). We did a retrospective review of all blood donated at King Fahad National Guard Hospital over the preceding 3 years to assess the seroprevalence of HTLV-I/II. After retesting positive and borderline samples, we were able to detect 1 positive and 38 borderline samples. As well, we reviewed the Saudi literature to identify the national seroprevalence of the disease and propose a cost-effective approach for screening donated blood in Saudi Arabia for HTLV-I/II.

Up to December 2002, a total of 56, 566 and 109 cases of human T-lymphotropic virus type 1 (HTLV-I), HTLV-II and human immunodeficiency virus type 2 (HIV-2) infection, respectively, were identified in Spain. Most HTLV-I- and HIV-2-infected subjects were immigrants from endemic areas or Spaniards who had traveled to, or had sexual contacts with natives from, these areas. In contrast, HTLV-II infection was mainly limited to Spanish intravenous drug users (IDU) who were frequently coinfected with HIV-1. Among HTLV-I-infected patients, 12 developed subacute myelopathy and 4 adult T-cell leukemia. As for the HIV-2-positive subjects, only 20 (18.3%) developed AIDS. There was no evidence of an increase in the incidence of HIV-2 and HTLV-I infections over time. In contrast, HTLV-II infection has spread in recent years among the HIV-1-positive IDU population in prisons, with a rate of 18% in some regions of Spain. Nevertheless, the prevalence of HTLV-II infection in HIV-1-positive IDU outpatients is still low (4.7%).

Human T-cell lymphotropic virus (HTLV) type I (HTLV-I) is the etiological agent of adult T-cell leukemia and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-II is a closely related virus, and this infection is not clearly associated with clinical disease, although neurologic disorders are observed resembling HAM/TSP. Prevalence rates for HTLV-I infection in the general population are greater than 1% in the Caribbean Basin, Central Africa, and South Japan. In most other areas in the world, as far as we know, HTLV-I/II infections are mainly found in high-risk groups (ie, immigrants from endemic areas, their offspring, their sexual contacts and in patients and intravenous injection users attending sexually transmitted disease clinics). Also, a high rate of infection for both HTLV-I and HTLV-II infection was observed in the native Amerindian population in North America as well as South America. Blood donors are routinely screened for HTLV-I/II in North America, several countries in Europe, Japan, and Taiwan.

In order to asses the soroprevalence of HTLV- I/II, HIV, siphylis, and toxoplasmosis infection among pregnant women seen at Basic Health Units in the municipality of Botucatu - São Paulo - Brazil, and risk factors for HTLV- I/II infection, sorologic surveys were carried out and results of sorologic surveys carried in pregnance routine evaluation were assessed. Seroprevalence was 0.1% (1 in 913) for both HTLV-I and HTLV-II. Seroprevalence was 0.1% (1 in 913) for both HTLV-I and HTLV-II. Siphylis, toxoplasmosis and HIV were identified. None of the factors or characteristics risks was found to be useful to identify those prenant women HTLV-II infected. Infection among pregnant women and southeast brazilian blood donnors were not diferent in statistical evaluation.

The presence of the human T cell lymphotropic virus (HTLV-I/II) in South America is well established. Its origin and spectrum in the continent still remain a matter of debate. There are signs now that HTLV-I/II was already present in the Amerindian population coming originally from Asia and that HTLV-I was also introduced with African slave trade and with immigration of individuals from endemic areas of Japan. South America has approximately 350 million inhabitants in its 13 countries. The presence of HTLV-I/II has been reported with impressive numbers in most of them and may be considered endemic in this continent. The distribution of HTLV I/II among native Amerindian populations has shown a geographic clustering of type I in the Andean highlands and Brazilian coast, while type II predominates in lowlands of South America. Although comparability between studies conducted among blood donors in different countries may be difficult, the data indicate that the viruses are also circulating among otherwise healthy individuals. Undoubtedly, HTLV-I/II infection and its related diseases should be considered a public health concern in South America and measures to prevent its spread should be emphasized., (Copyright 2002 National Science Council, ROC and S. Karger AG, Basel)

Human T-cell lymphotrophic virus (HTLV)-I/II infection has been considered a contra-indication to organ donation due to the risk of transmission of infection and the subsequent development of either adult T-cell leukemia or HTLV-I-associated myelopathy. However, neither the incidence of HTLV-I/II infection in organ donors nor the risk of transmission of HTLV-I/II by solid organ transplantation has been defined. Further, it is not known if HTLV infection contributes to significant morbidity in solid organ recipients. The purpose of this study was to evaluate the incidence of HTLV-I/II infection in organ donors in USA and to determine if transplanting these organs resulted in HTLV-related morbidity or mortality. We utilized the UNOS database to: (i) identify organ donors that were positive for HTLV-I or II infection between 1988 and 2000, and (ii) evaluate outcomes in the recipients of these organs. There were 25 HTLV-I/II-positive organ donors reported to UNOS between 1988 and 2000. Based on organ donors with a known HTLV-I/II status, the prevalence of HTLV-I infection in organ donors is 0.027% and the prevalence of HTLV-II is 0.064%. Twenty-two organs were transplanted from these HTLV-positive donors. There have been no reports of HTLV-I/II-related disease in the recipients with a median follow-up of 11.9 months. At our center, over the last 1.5 years there have been four multiorgan donors with false-positive HTLV-I/II screening assays, which resulted in the decision not to use organs from these donors. Based on the minimal chance of HTLV-related disease following transplantation of HTLV-I/II organs in this series, we recommend that careful consideration be given to transplanting organs from HTLV-I/II-positive organ donors.

Purpose: A literature review was performed of the three principal subpopulations most commonly associated with human T-cell lymphotropic virus type II (HTLV-II) with the view of identifying the prevalence and transmission routes of HTLV-II. These included blood donors (BDs), intravenous drug users (IVDUs), and Amerindians (Indian populations from the Americas). We used the major criterion of serological and molecular distinction between human T-cell lymphotropic virus types I (HTLV-I) and II (HTLV-II). Three questions were formulated in addressing the possibility that HTLV-II might be responsible for the reported prevalence and transmission of this virus in these groups. Question One: Which population groups have the highest HTLV-II seroprevalence rates? Question Two: Are worldwide HTLV infection rates among the three sub-populations associated predominantly with the HTLV-II retrovirus type? Question three: What are the principal modes of transmission of HTLV-II?, Methods: Since earlier epidemiologic studies did not routinely use assays capable of distinguishing between HTLV-I and HTLV-II antibodies, their findings are necessarily inaccurate. However, with the more recent development of enhanced serologic assays, using recombinant antigens that are capable of accurately making this differentiation, it is now possible to more precisely define the epidemiology of HTLV-II. We reviewed only those studies where serological and molecular methods of accurately distinguishing between the two retroviruses were utilized. Initially, we located 36 studies, which met this particular review criterion. Of the five different assays we identified, the most prevalent were the polymerase chain reaction (PCR) (n = 14) and the synthetic peptide-based enzyme-linked immunoassay (Synth EIA) (n = 13). Our BD, IVDU, and Amerindian groups were also evaluated according to this differentiation schema. We were able to locate over 100 prevalence studies where focus was on some aspect of analysis of at least one or more of these three groups. By using many search terms - such as HTLV-II endemic population, seroepidemiological, as well as case control and cohort studies - we were able to create a comprehensive bibliographic database., Results: The two groups identified with high HTLV-II prevalence rates are the IVDUs and Amerindian population. The importance of breast-feeding, IVDU, and contaminated blood products in the HTLV-II transmission process is confirmed. Sexual intercourse, however, as a mode of HTLV-II transmission remains problematic., Conclusions: By confining our evaluation to only those studies that used serological and/or molecular methods capable of distinguishing between the two retroviruses, we have been able to establish with confidence that there are consistent emerging patterns of HTLV-II infection in these populations.

Blood samples from native Indians in the Kararao village (Kayapo), were analysed using serological and molecular methods to characterize infection and analyse transmission of HTLV-II. Specific reactivity was observed in 3/26 individuals, of which two samples were from a mother and child. RFLP analysis of the pX and env regions confirmed HTLV-II infection. Nucleotide sequence of the 5' LTR segment and phylogenetic analysis showed a high similarity (98%) between the three samples and prototype HTLV-IIa (Mot), and confirmed the occurrence of the HTLV-IIc subtype. There was a high genetic similarity (99.9%) between the mother and child samples and the only difference was a deletion of two nucleotides (TC) in the mother sequence. Previous epidemiological studies among native Indians from Brazil have provided evidence of intrafamilial and vertical transmission of HTLV-IIc. The present study now provides molecular evidence of mother-to-child transmission of HTLV-IIc, a mechanism that is in large part responsible for the endemicity of HTLV in these relatively closed populations. Although the actual route of transmission is unknown, breast feeding would appear to be most likely.

Screening for the human T-cell lymphotropic virus type I (HTLV-I) and-II in blood donors was implemented in Taiwan beginning in February 1996. The purpose of the present study was to investigate the changes in HTLV-I seroprevalence in all unpaid blood donors in Taiwan during the period from February 1996 to December 1999 and to determine the influence of age and sex on the HTLV-I seropositivity of donors. HTLV-I and HTLV-II screening was performed using combined HTLV-I/II immunoassay. Repeated reactive samples were confirmed by Western blot analysis. Of a total of 3,701,087 donors in all 6 blood centers in Taiwan, 2,311 (0.058%) were seropositive for HTLV-I. The HTLV-I seropositivity was 0.130%, 0.063%, 0.044%, and 0.032% in the years 1996, 1997,1998, and 1999, respectively. There was a linear increase of HTLV-I seropositivity with advancing age. The HTLV-I carrier rate for female donors was twice that for the male donors. Ninty-seven percent of HTLV-I seropositive results came from first-time donors. Our findings suggest that Taiwan is a low-prevalence nonendemic area for HTLV-I infection. The large-scale HTLV-I screening program has decreased HTLV-I seropositivity among blood donors and is useful for preventing HTLV-I transmission via blood transfusion.

Introduction: Published results of donor blood screening in Denmark were used to calculate the risks of window phase donations., Methods: The main parameter was the frequencies of a confirmed positive donation from regular donors per 100,000 donations are: 0.34, for HIV; 0.47 for hepatitis C virus; 0.53 for hepatitis B virus; and nil for HTLVI/II. The mean interdonation interval between donations from regular donors is six months year. Window phase duration were estimated to be 22 days for anti-HIV; 10 weeks for anti-HCV; and 56 days for HBsAg. Blood from candidate donors is not used in Denmark. Thus, the risk of a window phase donation equals the risk of a window phase donation in donations from regular donors., Results: The risks of window phase donations in Denmark are: 1 in 2,000,000 for HIV; 1 in 500,000 for hepatitis C; 1 in 250,000 for hepatitis B; and immeasurably low for HTLVI/II., Discussion: The measures taken nowadays to prevent infection from allogeneic blood transfusion have resulted in a risk reduction of HIV transmission by a factor 50 and of HCV transmission by a factor 400, compared with the risks prevailing in Denmark in the early 1980s. The present very low risk renders obsolete predeposited autologous blood solely on the indication to prevent infection. Zero risk of transmission of HIV and HCV might be approached by introducing NAT screening for these viruses.

Breastfeeding is not contraindicated in association with environmental hazards in the United States under ordinary circumstances. Unusual massive exposure should be assessed on an individual basis. In the face of any possible contraindication to breastfeeding, the tremendous benefits of being breastfed should be compared with the theoretic risk for the hazard involved and a decision made on an individual basis.

Background: Human T-cell lymphotropic virus type I and II (HTLV-I and II) are human retroviruses that can be transmitted by transfusion of whole blood. An HTLV-I infection is associated with adult T-cell leukaemia (ATL) and with tropical spastic paraparesis (TSP). Antibody tests from 5.5 million European blood donors have shown that the HTLV prevalence is low, ranging from 0 to 0.02%. This paper examines costs and effects associated with the intervention of testing all new blood donors for HTLV., Methods: A mathematical model was used to calculate the number of cases prevented by the intervention. For a given prevalence of HTLV in the blood donor population, the model calculates the number of recipients infected by transfusion, and the number of partners and offspring that will in turn be infected. The model then calculates the number of subjects with disease due to HTLV-I infection and the number of deaths from disease. From these numbers the measures of cost and effect are calculated., Results: Testing all new blood donors for HTLV is calculated to cost US$ 9.2 million per life saved, or US$ 420,000 per quality adjusted life year gained by the intervention, when the HTLV prevalence among donors is 1 per 100,000. When the prevalence among donors is 10 per 100,000 the intervention will cost US$ 0.9 million per life saved, or US$ 41,000 per quality adjusted life year gained. The same analysis shows that testing blood donors for human immunodeficiency virus (HIV) saves money when the HIV prevalence among donors is above 0.7 per 100,000., Conclusion: For Norway, studies suggest a willingness to pay to save a statistical life of approximately US$ 1.2 million. The costs fall under this value when the number of infected persons is > or = 8 per 100,000 donors. The results are uncertain because of the uncertainty in HTLV infection and disease parameters.

Representatives of various population groups in Azerbaijan were tested for infection with human T-lymphotropic (HTLV-I and HTLV-II) and hepatotropic viruses (HCV and HBV). A total of 835 sera were studied by screening and specific tests for virus-specific antibodies and/or antigens. Thirty-five DNA specimens from peripheral blood lymphocytes were analyzed in the PCR for HTLV-I-specific sequences. No HTLV-I or HIV were detected, but two cases with integration of the HTLV-I LTR gene into cellular DNA genome were detected. A high rate of infection with hepatitis B and C was revealed. The level of anti-HCV was 8.7%, HBsAg 4.1%, and antiHBs 23.4%. Six cases with double HBV-HCV infection were detected. High values of ALT among HBV/HCV-seronegative subjects prompts their testing for other types of hepatitis viruses.

To examine risk factors for human T cell lymphotropic virus type II (HTLV-II) infection, a case-control study was conducted among the Guaymi Indians of Panama. In females, HTLV-II seropositivity was associated with early sexual intercourse (15 years; odds ratio [OR], 2.50; 95% confidence interval [CI], 1.11-6.14) and number of lifetime sex partners. One partner increased risk of seropositivity by 30% (OR, 1.30; CI, 1.05-1.64), and risk increased with number of partners. Similar risk was associated with number of long-term sexual relationships. Among males, intercourse with prostitutes was associated with HTLV-II seropositivity (OR, 1.68; CI, 1.04-2.72). These data support a role for sexual transmission in HTLV-II infection. Association of seropositivity with primary residence in a traditional village (OR, 3.75; CI, 1.02-15.38) and lack of formal education (0 vs. >6 years [OR, 3.89; CI, 1.67-9.82]) observed in males may reflect differences in sexual practices associated with acculturation.