Prevalence Of Human T-lymphotropic Virus Type 1 Research Articles

Immigrating and vicinity are not risk factors in the prevalence and transmission rate of human T-lymphotropic virus type 1: A Survey in an endemic region of Iran and Afghan refugees.

Human T-lymphotropic virus type 1 (HTLV-1) is a retrovirus associated with two life-threatening diseases; HAM/TSP and ATLL. Due to the slow-growing HTLV-1 infection worldwide, WHO urged for elimination. A large border with Afghanistan, northeast Iran is an endemic region for HTLV-1 infection. Historically, Afghanistan has common sociocultural similarities to Persian peoples. This study was conducted to evaluate HTLV-1 prevalence in Afghan refugees. Also, the HTLV-1 transmission rate and understanding of whether or not the Silk Road has been the route of HTLV-1 infection to Iran were investigated. This case-control study was conducted in a rural area of Fariman city, with Afghan residents who migrated around 165 years ago, from 1857, the Treaty of Paris at the end of the Anglo-Persian war, and a refugee camp in Torbat-e-Jam city. These populations in HTLV-1 endemic area were compared to a segregated population of Afghan refugees in Semnan, the centre of Iran. Blood samples of 983 volunteers were assessed with the ELISA method for the presence of HTLV-1 antibodies and then confirmed by PCR technique. All samples from Afghan refugee camps, Semnan and Torbat-e-Jam, were negative for HTLV-1 infection. However, the prevalence of HTLV-1 infection in Fariman, a rural population of Afghan origin, was approximately 2.73%. The results showed that HTLV-1 is not endemic in Afghanistan, a war-stricken region with refugees distributed worldwide. The land Silk Road has not been the route of HTLV-1 transmission to Northeastern Iran. Importantly, HTLV-1 endemicity might occur during a long time of living in an endemic area.

HTLV-1 and Co-infections.

Human T lymphotropic virus type 1 (HTLV-1) is a retrovirus that causes lifelong T-cell infection in humans, impacting the host immune response. This virus causes a range of clinical manifestations, from inflammatory conditions, including neuronal damage (HTLV-1 associated myelopathy, HAM) to life-threatening leukemia (adult T-cell leukemia, ATL). Human T lymphotropic virus type 1 is also associated with increased risk of all-cause mortality, but the mechanisms remain unclear. As a blood-borne and sexually transmitted infection (STI), HTLV-1 shares transmission routes to many other pathogens and although it has worldwide distribution, it affects mainly those in low- and middle-income tropical areas, where the prevalence of other infectious agents is high. These factors contribute to a high incidence of co-infections in people living with HTLV-1 (PLHTLV). This comprehensive review addresses the impact of HTLV-1 on several co-infections and vice-versa. There is evidence of higher rates of HTLV-1 infection in association with other blood borne (HCV, HBV) and sexually transmitted (Syphilis, Chlamydia, HPV, HSV) infections but whether this represents increased susceptibility or opportunity is unclear. Higher frequency of Mycobacterium tuberculosis (MTb) and Mycobacterium leprae (M. leprae) is observed in PLHTLV. Reports of opportunistic infections and high frequency of crusted scabies in patients with HTLV-1 points to immune impairment in those individuals. Human T lymphotropic virus type 1 may influence the persistence of pathogens, exemplified by the higher rates of Schistosoma mansoni and Strongyloides stercoralis (St. stercoralis) treatment failure observed in PLHTLV. This retrovirus is also associated with increased tuberculosis (TB) severity with some evidence pointing to a deleterious impact on leprosy outcome as well. These findings are supported by immune alterations observed in those co-infected individuals. Although the role of HTLV-1 in HCV outcome is debatable, most data indicate that HTLV may negatively impact the clinical course of hepatitis C. Co-infections may also influence the risk of developing HTLV-1 associated disease, but data are still limited. The impact of HTLV-1 on the response to more common infections, might contribute to the increased mortality rate of HTLV-1. Large scale prospective controlled studies on the prevalence and impact of HTLV-1 in co-infections and vice-versa are needed. Human T lymphotropic virus type 1 impact in public health is broad. Measures to increase awareness and to prevent new infections are needed.

Prevalence of human T-lymphotropic virus type 1 and 2 (HTLV-1/-2) infection in pregnant women in Brazil: a systematic review and meta-analysis

Human T-lymphotropic virus type 1 (HTLV-1) infection may cause serious disease, while pathogenicity of HTLV-2 is less certain. There are no screening or surveillance programs for HTLV-1/-2 infection in Brazil. By performing this systematic review, we aimed to estimate the prevalence of HTLV-1/-2 infections in pregnant women in Brazil. This review included cohort and cross-sectional studies that assessed the presence of either HTLV-1/-2 infection in pregnant women in Brazil. We searched BVS/LILACS, Cochrane Library/CENTRAL, EMBASE, PubMed/MEDLINE, Scopus, Web of Science and gray literature from inception to August 2020. We identified 246 records in total. Twenty-six of those were included in the qualitative synthesis, while 17 of them were included in the meta-analysis. The prevalence of HTLV-1 in Brazilian pregnant women, as diagnosed by a positive screening test and a subsequent positive confirmatory test, was 0.32% (95% CI 0.19–1.54), while of HTLV-2 was 0.04% (95% CI 0.02–0.08). Subgroup analysis by region showed the highest prevalence in the Northeast region (0.60%; 95% CI 0.37–0.97) for HTLV-1 and in the South region (0.16%; 95% CI 0.02–1.10) for HTLV-2. The prevalence of HTLV-1 is much higher than HTLV-2 infection in pregnant Brazilian women with important differences between regions. The prevalence of both HTLV-1/-2 are higher in the Northeast compared to Center-West region.

Prevalence and phylogenetic analysis of HTLV-1 in blood donors in Golestan Province, in the Northeast of Iran

The human T-lymphotropic virus type 1 (HTLV-1) can cause ATL or TSP. This study evaluates the prevalence of HTLV-1 infection in blood donors in Golestan province. The study was conducted among 4226 blood donors and ELISA test was performed for the initial HTLV-1 screening. Reactive samples were confirmed by Western blot and Electrochemiluminescence tests. Then recalling donors with reactive results was done and genomic DNA from the new sample was extracted and tested using the Nested PCR method and phylogenetic analysis was performed. At first, 8 samples were reactive with ELISA test and 4 samples were confirmed with western blot, Electrochemiluminescence and Nested PCR tests.The sequences of isolates was related to the HTLV-1 virus and subtype a (cosmopolitan) subgroup A.The prevalence of HTLV-1 virus in Golestan province was about 0.09 %.The genotype of virus isolates had a common ancestor with isolates of the Khorasan region.

First Description of Seronegative HTLV-1 Carriers in Argentina.

In some areas of Argentina endemic for human T-lymphotropic virus type 1 (HTLV-1), tropical spastic paraparesis is frequent in subjects who lack antibodies against the virus; however, the relevance of this seronegative status in the country has not been investigated. In neighboring countries, HTLV-1 seronegative status has been described in patients with different diseases; however, data regarding features of seronegative HTLV-1 carriers are scarce. We investigated the seronegative status in 124 relatives of 28 HTLV-1 infected subjects from an endemic area in Northwest Argentina. Blood samples and clinical/epidemiological data were collected. Human T-lymphotropic virus type 1 infection was diagnosed by serology and long terminal repeat (LTR) sequence, env and tax gene detection. IgG anti-Tax HTLV-1 antibody, tax gene sequence, and DNA proviral load were also evaluated. Seventy-five percent of the 124 relatives were negative for HTLV-1/2 antibodies; 35.5% were also negative by molecular assays and 64.5% were negative for HTLV-1 LTR and env sequences, but positive for two sequences of HTLV-1 tax gene. Also, 35.7% of these subjects had IgG anti-Tax antibodies. The seronegative HTLV-1 status was significantly associated with male gender, youth, and sensory symptoms/autonomic nervous system dysfunction. High rates of seronegative symptomatic and asymptomatic HTLV-1 carriers in Argentina are described. The evidence highlights that HTLV-1 prevalence may be underestimated worldwide. Larger cohort studies are required to assess disease outcome in these seronegative subjects. Also, the findings emphasize the limitations of ongoing screening assays for diagnosis and blood safety. Therefore, algorithms for HTLV-1 diagnosis should include not only serological but also molecular assays.

Current approaches for detection of human T-lymphotropic virus Type 1: A systematic review.

Human T-lymphotropic virus Type 1 (HTLV-1) is a retrovirus that is endemic in some regions of the world. It is known to cause several diseases like adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Serology and molecular methods have been used to detect this virus. Of these, enzyme-linked immunosorbent assay (ELISA) is used as a primary screening method and this is usually followed by western blotting (WB) and polymerase chain reaction (PCR) methods as confirmatory tests. We conducted a systematic review of the different techniques used in the diagnosis of HTLV-1 infection. Our search was limited to original papers in the English language from 2010 to 2018 using several databases including Pubmed, Scopus, Google Scholar, Iranmedex, and Scientific Information Database. A manual search of references provided in the included papers was also performed. Of 101 electronically searched citations, 43 met the inclusion criteria. ELISA is commonly used for qualitative and screening detection, and WB and PCR techniques are used to confirm infection. Among all the reported methods for detection of HTLV-1, only serological and molecular tests are used as the most common technical assays for HTLV-1.The ELISA assay, without a confirmatory test, has several limitations and affect the accuracy of the results. Owing to the prevalence of HTLV-1 and limitations of the current detection methods, further evaluation of the accuracy of these methods is needed. There are new opportunities for applying novel technological advances in microfluidics, biosensors, and lab-on-a-chip systems to perform HTLV-1 diagnostics.

Epidemiology of Human T-lymphotropic Virus Type 1 Among Blood Donors and General Population in Iran: A meta-analysis

Aim: The present meta-analysis aims to assess the epidemiology of human T-lymphotropic virus type 1 (HTLV-1) among blood donors and general population in Iran. Methods: The present study was designed according to PRISMA guidelines. Results: The prevalence of HTLV-1 in 34 studies with a sample size of 3,626,364 blood donors was 0.20% (95% CI: 0.15–0.26) and the prevalence of this virus among men and women blood donors was 0.20% (95% CI: 0.15–0.27) and 0.64% (95% CI: 0.13–3.01), respectively and the female-male odds ratio was 3.13 (1.35–7.25, p = 0.008). In five studies consisting of 4763 individuals, the prevalence of HTLV-1 among the general population who lived in the main HTLV-1 endemic regions (Khorasan provinces, in northeastern Iran) was 2.5% (95% CI: 1.3–4.7) and the prevalence of this virus among men and women was 2.4% (95% CI: 0.8–7.1) and 3.4% (95% CI: 2.0–5.7), respectively. According to the systematic review, the prevalence of HTLV-1 in general population living in non-endemic regions of HTLV-1 was reported to be 0.07% to 1.8%. Conclusion: Considering the high prevalence of HTLV-1 in the main HTLV-1 endemic regions of Iran, persistent prevention programs are required in blood transfusion centers in these regions.

Human T- Lymphotropic Virus Type 1 in Blood Donors from Babol County Blood Transfusion Center: A Pilot Study From Northern Iran

Background: Human T-lymphotropic virus type 1 (HTLV-1) infection is a major health problem that effects a variety of endemic regions, including the Northeast of Iran. There is a lack of information about HTLV-1 prevalence among blood donors from Mazandaran province, Northern Iran. Objectives: The aim of the present study was to investigate the prevalence of HTLV-1 infection among blood donors in Babol County, the most populated county in Mazandaran province with screening and confirmatory assays. Methods: The present cross-sectional study was conducted on 503 blood donors. Serum samples from each blood donor were screened for HTLV-1 specific antibodies using the Enzyme-Linked Immunosorbent Assay (ELISA). Samples that were repeatedly reactive for HTLV-1 specific antibodies on serological screening were additionally confirmed by real time polymerase chain reaction (PCR) of HTLV-1 proviral DNA in Peripheral Blood Mononuclear Cells (PBMCs). Results: Among 503 samples tested by serological enzyme linked immunosorbent assay (ELISA), 13 samples (2.6%) were repeatedly reactive (i.e. on at least 2 of 3 occasions). All repeatedly reactive samples were examined for the presence of the HTLV-1 proviral DNA in PBMCs by real time PCR confirmatory test, of which 1 sample was positive, resulting in HTLV-1 prevalence of 0.2%. Conclusions: The present investigation contributes with new epidemiologic data reporting low prevalence rate for HTLV-1 among blood donors in Babol county of the Mazandaran province. Despite the low prevalence rate, the practice of screening of donated bloods in blood transfusion centers of Mazandaran province should be considered to decrease the risk of virus transmission in this region.

Prevalence and phylogenetic analysis of HTLV-1 in a segregated population in Iran.

Human T-lymphotropic virus type 1 (HTLV-1) infection is an important health issue that affects a variety of endemic areas. The Khorasan province, mainly its capital Mashhad in northeastern Iran, was reported to be as one of these endemic regions. Torbat-e Heydarieh, a large city Southwest border to Mashhad with a segregated population was investigated for the prevalence and associated risk factors of HTLV-1 infection in 400 randomly selected individuals. Blood samples were tested for the presence of HTLV-1 antibodies via the ELISA method and then were confirmed by an Immunoblot test. For the presence of HTLV-1 in lymphocytes of infected subjects, PCR was performed on LTR and TAX regions. DNA sequencing of LTR fragment was also carried out to determine the phylogenetic of HTLV-1, using the Maximum likelihood method. HTLV-1 sero-reactivity (sero-prevalence) among the study population was 2% (8/400), of which 1.25% had HTLV-1 provirus in lymphocytes (actual prevalence). HTLV-1 infection was significantly associated with the age, marital status, and history of blood transfusion (P < 0.05). However, there were no statistical differences between HTLV-1 infection, and gender, surgery, and hospitalization. In regression analysis, age showed the most significant correlation with the infection (P = 0.006, OR = 4.33). Based on our phylogenetic study, the HTLV-1 prevalent sequence type of Torbat-e Heydarieh belongs to the cosmopolitan subtype A. HTLV-1 prevalence in Torbat-e Heydarieh (1.25%) is low comparing to those of both Mashhad (2-3%) and Neishabour (3.5-5%) in the province of Khorasan. Thus, traveling mobility and population mixing such as marriage, bureaucratic affairs, occupation, and economic activities could be the usual routs of HTLV-1 new wave of spreading in this segregated city.

High prevalence of HTLV-1 infection among Japanese immigrants in non-endemic area of Brazil.

BackgroundHuman T-lymphotropic virus type 1 (HTLV-1) has worldwide distribution and is considered endemic in many world regions, including southwestern Japan and Brazil. Japanese immigrants and their descendants have a high risk of acquiring this infection due to intense population exchange between Brazil and Japan.ObjectiveThis cross-sectional study aimed to estimate the prevalence of HTLV, analyze the main risk factors associated with this infection, identify the main circulating types and subtypes of HTLV in Japanese immigrants and descendants living in Campo Grande-MS (Middle-West Brazil), as well as analyze the phylogenetic relationship among isolates of HTLV.Study DesignA total of 219 individuals were interviewed and submitted to blood collection. All collected blood samples were submitted for detection of anti-HTLV-1/2 using the immunoassay ELISA and confirmed by immunoblot method. The proviral DNA of the 14 samples HTLV- 1 positive were genotyped by nucleotide sequencing.ResultsThe overall prevalence of HTLV-1 was 6.8% (IC 95%: 3,5-10,2). Descriptive analysis of behavioral risk factors showed statistical association between HTLV-1 and age greater than or equal to 45 years. The proviral DNA of HTLV-1 was detected in all HTLV-1 positive samples. Of these, 14 were sequenced and classified as Cosmopolitan subtype, and 50% (7/14) belonged to subgroup A (transcontinental) and 50% (7/14) to the subgroup B (Japanese).ConclusionThe high prevalence of HTLV-1 found evidence of the importance of early diagnosis and counseling of individuals infected with HTLV-1 for the control and prevention of the spread of this infection among Japanese immigrants and their descendants in Central Brazil.

The prevalence of human T-lymphotropic virus infection among blood donors in southeast China, 2004-2013.

BackgroundThe human T-lymphotropic virus type 1 (HTLV-1) which is associated with the diseases of adult T-cell leukemia/lymphoma, HTLV-1 associated myelopathy / tropical spastic paraparesis (HAM/TSP) and HTLV-associated uveitis, can cause transfusion-transmitted infections. Although HTLV screening of blood donors was already routinely performed in developed countries, little is know about the HTLV prevalence among blood donors in developing countries which do not perform HTLV screening, such as China.Objectives &AimsTo systematically characterize the prevalence of HTLV infection among bloods in southeast China.MethodsA 10-year survey for HTLV prevalence in blood donors was performed in Xiamen, southeast China, during 2004-2013. The HTLV-1/2 of blood donations were screened by enzyme-linked immunosorbent assay, following with confirmation by western blot assay and 9nucleic acid testing. The HTLV-1 prevalences in donors from different cities were calculated. Viral sequences derived from identified HTLV-positive cases were sequenced and analyzed.ResultsAmong 253,855 blood donors, 43 were confirmed to be seropositive for HTLV-1 (16.9 per 100,000 95% CI: 12.3-22.8) and none HTLV-2 infection was found. The HTLV-1 prevalence varied significantly in donors from different cities. Donors from cities in Fujian province (24.3 per 100,000, 95%CI: 17.4-33.1) had a significantly higher (p=0.001) HTLV-1 seroprevalence than those who were born in non-Fujian cities (3.4 per 100,000, 95%CI: 0.7-9.8). Among nine cities in Fujian province, the highest prevalence was found in blood donors from Ningde (171.3 per 100,000, 95%CI: 91.3-292.8) which is a coastal city in the northeast of Fujian. Molecular characterization of viral sequences from 27 HTLV-1 carriers revealed 25 were Transcontinental subtype of genotype A and 2 were Japanese subtype of genotype A. Interestingly, 12 of 25 Transcontinental subtype sequences harbored a characteristic L55P mutation in viral gp46 protein, which was only presented in the Transcontinental subtype sequences from Japan and Taiwan but not in that from other countries.ConclusionsAlthough China is considered to be a non-endemic region for HTLV, the HTLV-1 prevalence in blood donors is significantly higher in Fujian province, southeast China. A higher prevalence of HTLV-1 in the Fujian may be attributed to endemic foci in the city of Ningde.

Stopping breastfeeding to prevent vertical transmission of HTLV-1 in resource-poor settings: beneficial or harmful?

In a recent issue of this journal Mylonas et al. [1] reviewed human T-lymphotropic virus type 1 (HTLV-1) infection and its implications in gynecology and obstetrics. Although HTLV-1 is rare in many populations, it occurs worldwide and is associated with a substantial disease burden and a high risk of vertical transmission. The authors provide recommendations for prevention of sexual and vertical transmission of HTLV-1. One of the recommendations is the following: ‘If stopping breastfeeding is not possible, for example due to socio-economical circumstances, short-term breastfeeding for 3 to a maximum of 6 months should be advocated’. The recommendation in the review is based on two studies from Japan showing reductions of vertical transmission by limiting or avoiding breastfeeding. To our knowledge, no international guidelines exist (e.g. from the WHO or CDC) on breastfeeding and HTLV-1 prevention in resource-poor, developing countries. Therefore, it is important to carefully take into account the risks versus the benefits of advocating short-term breastfeeding in developing countries. Various studies have shown that prolonged breastfeeding is associated with an increased risk of HTLV-1 transmission and avoiding breastfeeding can lead to a dramatic reduction in transmission [2]. A high maternal proviral load in combination with waning antibodies in the child leads to an increased risk of HTLV-1 transmission, especially after 6–12 months after birth [3]. However, the key question is whether the benefits of avoiding HTLV-1 infection outweigh the risks of not breastfeeding. As the review points out, HTLV-1 causes adult T-cell leukemia (ATL) or tropical spastic paraparesis (TSP) in about 5% of infected individuals and is associated with a number of infections and inflammations. On the other hand, the risks of early weaning are substantial. The promotion of breastfeeding for 6–11 months has been estimated to be the most effective strategy to prevent child mortality in resource-limited settings and the WHO recommends at least 6 months of exclusive breastfeeding [4]. Our work in Guinea-Bissau, one of the poorest countries in Sub Saharan Africa with a high prevalence of HTLV-1 (5%) [5, 6], has shown that early weaning (before 12 months) is associated with increased mortality and increased risk of diarrheal diseases among children [7, 8]. For example, the mortality among weaned children was sixfold higher compared to breastfed children during the civil war in Guinea-Bissau in 1996–1997 [7]. In many Sub Saharan countries, vertical transmission of HIV is of major concern. In an editorial from 2010, Humphrey points out the increasing amount of data supporting the fact that in Sub Saharan Africa the risks of early weaning do not outweigh the risks of a possible HIV infection [9]. The 2010 UNAIDS guidelines advice at least 6 months of exclusive breastfeeding and advice to continue breastfeeding after this time if replacement feeding is not feasible, even when anti-retroviral (ARV) drugs are not available (if available, ARVs are recommended for mother and child to reduce the risk of transmission) [10]. Thus, for an infection that has much larger health implications than HTLV-1, breastfeeding longer than 6 months is recommended in certain settings where replacement feeding is not feasible. HTLV-1 infected pregnant women from a poor socio-economic background in a developed country merit extra attention and the advice about not breastfeeding should be tailored to the exact circumstances of the woman. However, it is very likely that these women will have access to good replacement feeding and therefore it seems rational to advise them similarly as women from higher socio-economic status, i.e., to refrain from breastfeeding altogether. In conclusion, in resource-poor settings, like Guinea-Bissau, the immediate health risks of the advocated weaning at 3–6 months are likely to be bigger than the risks of HTLV-1 related morbidity and mortality. This is likely to vary by country and will strongly depend on the socio-economic circumstances and current breastfeeding practices in the country. The available data so far do not support early weaning to prevent vertical transmission of HTLV-1 in resource-limited settings.

Neurological morbidity among human T-lymphotropic-virus-type-1-infected individuals in a rural West African population

Background: Community-based neurological data about human T lymphotropic virus type 1 (HTLV-1) morbidity in sub-Saharan Africa are scarce. Objectives: To ascertain the prevalence of neurological morbidity, in particular tropical spastic...

Description of a “Trans-Saharan” Strain of Human T-Lymphotropic Virus Type 1 in West Africa

The aim of this study was to assess the prevalence and the molecular epidemiology of human T-lymphotropic virus type 1 (HTLV-1) in a group of pregnant women living in Guinea Bissau. We studied 427 consecutive pregnant women attending 10 centers for HIV-1 infection monitoring in Bissau. HTLV-1 infection was found in 2.6% of the patients. Phylogenetic analysis of the long terminal repeat region showed that 10 isolates were of the cosmopolitan subtype (HTLV-1a) and that only 1 was of the widespread Central African subtype (HTLV-1b). All the cosmopolitan isolates belonged to the HTLV-1aD subgroup, which was first described in North Africa and clustered with other Senegal and Guinea isolates to form a significant West African clade. Our data show a high prevalence of HTLV-1 in Guinea Bissau and suggest the existence of a trans-Saharan strain distributed in North and West Africa, which probably crossed the desert in the past as a result of contacts between nomadic and sedentary populations or along trading routes.

HTLV in the Americas: challenges and perspectives

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.

Increased Risk of Tuberculosis With Human T-Lymphotropic Virus-1 Infection

To investigate whether infection with human T-lymphotropic virus type 1 (HTLV-1) increases the risk of tuberculosis. A case-control study. City of Salvador, Brazil. A total of 375 patients with tuberculosis (cases) and 378 individuals without tuberculosis (controls), matched by age and sex. Tuberculosis of lung or lymph node. Human HTLV-1 infection. The prevalence of HTLV-1 infection was 4.27% (16/375) in patients with tuberculosis and 1.32% (5/378) in controls, resulting in a crude odds ratio of 3.31 (95% CI, 1.20-9.13) and an adjusted odds ratio of 3.01 (95% CI, 1.06-8.58). HTLV-1 infection is associated with a first diagnosis of tuberculosis. This may have implications for tuberculosis control in places with high prevalence of HTLV-1.

High prevalence of human T-lymphotropic virus type 1 (HTLV-1) in immigrant male-to-female transsexual sex workers with HIV-1 infection.

Human T-lymphotropic virus type 1 and 2 (HTLV-1 and HTLV-2) infections in Europe are limited to intravenous drug users and migrants coming from areas in which they are endemic. A survey was undertaken of HTLV-1 and HTLV-2 infections in 393 recent immigrants: 167 HIV-1 positive subjects (including 52 male-to-female transsexual sex workers) and 226 pregnant HIV-1 negative women. The prevalence of HTLV-1 was 3.6% in the HIV-1 positive group and 0.9% in the HIV-1 negative group. The highest HTLV-1 prevalence in both groups was found in persons from Latin America, particularly those born in Peru (up to 26% in the HIV-1 positive group). All of the HIV-1/HTLV-1 co-infected individuals were male-to-female transsexual sex workers in whom the overall prevalence of HTLV-1 infection was 11.5%. HTLV-2 was only found in the HIV-1 positive group (prevalence 1.2%); all of the infected subjects were transsexual sex workers from Brazil (overall prevalence 6.4%). Phylogenetic analysis showed that all of the HTLV-1 isolates were of the cosmopolitan type, clustering with other strains circulating in the patients' birthplaces; the HTLV-2 isolates were of subtype 2a, and clustered significantly with other Brazilian strains. These results suggest the independent origin of each infection in the patient's birthplace. The data raise concerns about the further spread of HTLV infections mainly through the sexual route.