In HTLV infection, cell-to-cell contact and Tax-induced clonal expansion of infected cells are the primary modes of virus replication, which causes difficulty in detection of the virus during the viremic stage. Cabral et al. Of these samples, seven were excluded from the analysis. However, the effect of this phenomenon the routes of HTLV transmission, particularly sexual transmission, remains to be determined.
This mode of replication might influence HTLV transmission rates, which are significantly higher in women than in men research that address these critical knowledge gaps might contribute to the prevention of HTLV transmission and to improved care for HTLV-infected individuals. Japanese efforts have demonstrated that preventive measures, such as screening blood bank donations, counseling serodiscordant couples, and abstinence from breastfeeding by carrier mothers, might reduce the prevalence of HTLV. Nature ; Science ; Retrovirology ; Emergence of unique primate T-lymphotropic viruses among central African bushmeat hunters.
Virology ; Oncogene ; Gesssain A, Cassar O. Epidemiological aspects and world distribution of HTLV-1 infection. Front Microbiol ; Rev Soc Bras Med Trop ; J Infect Dis ; Virus Research ; Emerg Infect Dis ; CID ; Identification of human T cell lymphotropic virus type IIa infection in the Kayapo, an indigenous population of Brazil. HTLV in the Americas: challenges and perspectives. Rev Panam Salud Publica ; Araujo A, Hall WW. Human T-lymphotropic virus type II and neurological disease. Ann Neurol ; In vivo genomic variability of human T-cell leukemia virus Type I depends more upon geography than upon pathologies.
J Virol ; Mem Inst Oswaldo Cruz ; Nat Med ; Biofilm-like extracellular viral assemblies mediate HTLV-1 cell-to-cell transmission at virological synapses. Sattentau Q.
40 years of the human T-cell leukemia virus: past, present, and future
Avoiding the void: cell-to-cell spread of human viruses. Nat Rev Microbiol ; Fujino T, Nagata Y.
HTLV-I transmission from mother to child. J of Reprod Immunol ; Hino S. A prospective study of transmission by transfusion of HTLV-I and risk factors associated with seroconversion. Int J Cancer ; Human T cell lymphotropic virus types I and II in intravenous drug users in San Francisco: risk factors associated with seropositivity.
N Engl J Med ; Blood ; Eur J Epidemiol ; J Acquir Immune Defic Syndr ; J Clin Virol ; Lancet ; Ann Epidemiol ; AIDS Review ; Infection with human T-lymphotropic virus type I in organ transplant donors and recipients in Spain. J Med Virol ; Iatrogenic transmission of human T cell lymphotropic virus type 1 and hepatitis C virus through parenteral treatment and chemoprophylaxis of sleeping sickness in colonial Equatorial Africa. Clin Infect Dis ; Lopes BP. World Health Organization. Biological agents. A review of human carcinogens. Rev Bras Epidemiol ; Human T cell lymphotropic virus type I infection among female sex workers in Peru.
Ann Intern Med ; Retroviral infection in Peruvian men who have sex with men. Am J Trop Med Hyg ; HIV Med ; 9 suppl 1 Sexual transmission of human T-lymphotropic virus type I among female prostitutes and among patients with sexually transmitted diseases in Fukuoka, Kyushu, Japan. Am J Epidemiol ; JAMA ; Cervical shedding of human T cell lymphotropic virus type I is associated with cervicitis.
Sexual transmission of human T-lymphotropic virus type I in Peruvian prostitutes. Portaria No 1. Intrafamilial transmission of adult T-cell lleukemia virus. Virus markers associated with vertical transmission of human T lymphotropic virus type 1 in Jamaica. Provirus load in breast milk and risk of mother-to-child transmission of human T lymphotropic virus type I.
Male-to-female transmission of human T-cell lymphotropic virus types I and II: association with viral load. J Neurovirol ; Braz J Med Biol Res ; 38 Starling AL. Braz J Med Biol Res ; Pulmonary involvement in human T-cell lymphotropic virus type-I uveitis: Tlymphocytosis and high proviral DNA load in bronchoalveolar lavage fluid. Eur Respir J ; Human T cell lymphotropic virus type I-associated infective dermatitis in Jamaica: a case report of clinical and biologic correlates.
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This finding confirms previous reports indicating that Salvador is highly affected by this virus Dourado et al. This regional center is home to important commercial, service, and industrial activities.
Human T-Lymphotropic Viruses
The economic importance of this region grew during the golden era of cocoa production. Nowadays, the economy is based on tourism and other activities related to the seaport. By contrast, the Jacobina microregion has a tropical climate with a dry season. Surrounding lakes, mountains, rivers and waterfalls favor ecological tourism.
Human T-Lymphotropic Virus Types I and II: Screening and Seroprevalence in Blood Donors
Regarding the Barreiras microregion, located in the westernmost part of Bahia, to the best of our knowledge no previous studies reported this area being endemic to HTLV infection. We cannot exclude the possibility that these microregions received samples from surrounding areas. Barreiras is the most important municipality located in the microregion, and the city borders Tocantins state. This microregion has a tropical climate and the predominant vegetation is the arboreal cerrado.
The regional economy is mainly based on agribusiness, and migrants from all over Brazil moved here in the s and s. HTLV-2 infection has been predominantly reported in indigenous populations residing in northern Brazil Ishak et al. Of note, a progressive increase in the incidence of HTLV infection was observed throughout the study period.
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This is likely due to an expansion in the number of municipal primary health clinics provided by the federal Family Health Program, as well as increases in testing and counseling centers aimed primarily at sexually transmitted diseases in the countryside of the state. In addition, awareness surrounding HTLV infection increased during the study period and HTLV was included on the list of compulsory disease notifications for the state of Bahia in HTLV infection is known to be more prevalent in women, and its prevalence increases with age Dourado et al.
Herein, a higher proportion of HTLVinfected women was detected in the 31—50 age range among most mesoregions. This could be due to the non-random nature of the sample, which was young median age of 31 years and consisted mostly of females. Increased sexual activity is more common in this age range, and virus transmission is known to be more efficient from men to women Murphy et al. It is also possible that compulsory serological HTLV screening for pregnant women, in effect in Bahia, contributed to the higher proportion of women detected in this age range.
Both mesoregions are highly productive agricultural zones containing municipalities of high population density.
In addition, the Centro Norte Baiano mesoregion attracts young men to work in the mining industry. Accordingly, it is theoretically possible that the higher prevalence observed in men of this age range could be due to increased exposure to illicit drugs, as well as to an increased incidence of STDs, such as HIV, gonorrhea and syphilis. In addition, lower levels of formal education and income have been attributed to a higher risk of acquiring HTLV infection Dourado et al.
Moreover, despite the greater efficiency of male-female transmission, evidence of female-male transmission has also been reported Brodine et al. Concerning the possible route of the HTLV transmission, it has been suggested that in Salvador the sexual route predominates, since almost no children was found to be infected Dourado et al.
In the present study the HTLV infection was observed in 42 individuals under 15 years, indicating that in addition to sexual transmission, the vertical route may be an important route. However, the prevalence of this infection in the country varies according to the geographic region, being higher in the North and Northeast Galvao-Castro et al. The origin of HTLV in Brazil is linked to the introduction of the virus in the post-Colombian era, by the slave trade from Africa mainly to the northeastern cities of the country Alcantara et al.
The population in Bahia is highly mixed, consisting of mostly black and mixed Western African and Portuguese descendants Azevedo et al. However, the information available prevents us from making direct correlations between ethnic profile and the distribution of HTLV types. Interestingly, the data herein indicate that the microregions with the highest rates of infection in the state of Bahia were areas where communities recognized as quilombos predominated. Originally, quilombos were places of refuge for the African and Afro-descendant slaves who fled slavery.
Their descendants often remained in these areas and were then termed quilombolas. Bahia is one of the states with the highest number of quilombolas recognized 4 , Figure 6 Black. Figure 6. One limitation of the present study was the non-random sample, which was predominantly female. To explain this, we can only speculate that perhaps local health authorities chose to outsource testing to private laboratory services instead of sending samples to LACEN, or that authorities in these municipalities did not properly implement actions designed to increase HTLV detection.
While population-based studies are considered the gold standard for estimating infection prevalence, high cost and methodological difficulties can present significant challenges Hlela et al. Accordingly, estimates of HTLV prevalence are often based on data obtained from blood banks, pregnant women and other population groups Verdonck et al.
In addition, the present study is unable to offer any insight into virus phylogeny, as the retrospective nature of this investigation precluded the performance of molecular analysis to accurately assess results considered indeterminate by Western Blot. In conclusion, the present study serves to highlight previously unreported data regarding clusters of HTLV infection throughout the state of Bahia, which is considered to be the Brazilian state with the highest HTLV infection rate.
HTLV infection cannot be considered as restricted to the area of Salvador, the capital of Bahia, as the data reported herein identified new endemic areas. Had Further studies are needed to better describe the epidemiological profile of the infected population and to reinforce public policies designed to prevent HTLV transmission, especially in pregnant women. As the present study has a retrospective design, evaluating HTLV serologies performed in a 10 years-period in the Public Health Laboratory of Bahia, the Institutional Research Board of Fiocruz approved a study, dispensing the signing of written informed consent.
All authors read and approved the final version of the manuscript, analyzed and interpreted the data, and drafted the manuscript. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. We thank Andris K. Walter for providing English language revision and manuscript copyediting assistance, and Dr. Graham Taylor for his valuable suggestions. Alcantara, L. Globin haplotypes of human T-cell lymphotropic virus type I-infected individuals in Salvador, Bahia, Brazil, suggest a post-Columbian African origin of this virus.
Immune Defic. Azevedo, E. Spread and diversity of human populations in Bahia, Brazil. PubMed Abstract Google Scholar. Bittencourt, A.
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Human T-cell lymphotropic virus type 1 infection among pregnant women in northeastern Brazil. Boa-Sorte, N. Brites, C. AIDS 16, — Britto, A. Brodine, S. III, Corwin, A. Marines stationed in a hyperendemic area: evidence for female-to-male sexual transmission. Calattini, S. Retrovirology Castro-Lima Vargens, C. Virol 52, —