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Gessain A, Ramassamy JL, Afonso PV, Cassar O. Geographic distribution, clinical epidemiology and genetic diversity of the human oncogenic retrovirus HTLV-1 in Africa, the world's largest endemic area. Front Immunol 2023; 14:1043600. [PMID: 36817417 PMCID: PMC9935834 DOI: 10.3389/fimmu.2023.1043600] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 01/04/2023] [Indexed: 02/05/2023] Open
Abstract
The African continent is considered the largest high endemic area for the oncogenic retrovirus HTLV-1 with an estimated two to five million infected individuals. However, data on epidemiological aspects, in particular prevalence, risk factors and geographical distribution, are still very limited for many regions: on the one hand, few large-scale and representative studies have been performed and, on the other hand, many studies do not include confirmatory tests, resulting in indeterminate serological results, and a likely overestimation of HTLV-1 seroprevalence. For this review, we included the most robust studies published since 1984 on the prevalence of HTLV-1 and the two major diseases associated with this infection in people living in Africa and the Indian Ocean islands: adult T-cell leukemia (ATL) and tropical spastic paraparesis or HTLV-1-associated myelopathy (HAM/TSP). We also considered most of the book chapters and abstracts published at the 20 international conferences on HTLV and related viruses held since 1985, as well as the results of recent meta-analyses regarding the status of HTLV-1 in West and sub-Saharan Africa. Based on this bibliography, it appears that HTLV-1 distribution is very heterogeneous in Africa: The highest prevalences of HTLV-1 are reported in western, central and southern Africa, while eastern and northern Africa show lower prevalences. In highly endemic areas, the HTLV-1 prevalence in the adult population ranges from 0.3 to 3%, increases with age, and is highest among women. In rural areas of Gabon and the Democratic Republic of the Congo (DRC), HTLV-1 prevalence can reach up to 10-25% in elder women. HTLV-1-associated diseases in African patients have rarely been reported in situ on hospital wards, by local physicians. With the exception of the Republic of South Africa, DRC and Senegal, most reports on ATL and HAM/TSP in African patients have been published by European and American clinicians and involve immigrants or medical returnees to Europe (France and the UK) and the United States. There is clearly a huge underreporting of these diseases on the African continent. The genetic diversity of HTLV-1 is greatest in Africa, where six distinct genotypes (a, b, d, e, f, g) have been identified. The most frequent genotype in central Africa is genotype b. The other genotypes found in central Africa (d, e, f and g) are very rare. The vast majority of HTLV-1 strains from West and North Africa belong to genotype a, the so-called 'Cosmopolitan' genotype. These strains form five clades roughly reflecting the geographic origin of the infected individuals. We have recently shown that some of these clades are the result of recombination between a-WA and a-NA strains. Almost all sequences from southern Africa belong to Transcontinental a-genotype subgroup.
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Affiliation(s)
- Antoine Gessain
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité d'Épidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | - Jill-Léa Ramassamy
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité d'Épidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | - Philippe V Afonso
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité d'Épidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | - Olivier Cassar
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Unité d'Épidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
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Afonso PV, Cassar O, Gessain A. Molecular epidemiology, genetic variability and evolution of HTLV-1 with special emphasis on African genotypes. Retrovirology 2019; 16:39. [PMID: 31842895 PMCID: PMC6916231 DOI: 10.1186/s12977-019-0504-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 12/07/2019] [Indexed: 02/01/2023] Open
Abstract
Human T cell leukemia virus (HTLV-1) is an oncoretrovirus that infects at least 10 million people worldwide. HTLV-1 exhibits a remarkable genetic stability, however, viral strains have been classified in several genotypes and subgroups, which often mirror the geographic origin of the viral strain. The Cosmopolitan genotype HTLV-1a, can be subdivided into geographically related subgroups, e.g. Transcontinental (a-TC), Japanese (a-Jpn), West-African (a-WA), North-African (a-NA), and Senegalese (a-Sen). Within each subgroup, the genetic diversity is low. Genotype HTLV-1b is found in Central Africa; it is the major genotype in Gabon, Cameroon and Democratic Republic of Congo. While strains from the HTLV-1d genotype represent only a few percent of the strains present in Central African countries, genotypes -e, -f, and -g have been only reported sporadically in particular in Cameroon Gabon, and Central African Republic. HTLV-1c genotype, which is found exclusively in Australo-Melanesia, is the most divergent genotype. This reflects an ancient speciation, with a long period of isolation of the infected populations in the different islands of this region (Australia, Papua New Guinea, Solomon Islands and Vanuatu archipelago). Until now, no viral genotype or subgroup is associated with a specific HTLV-1-associated disease. HTLV-1 originates from a simian reservoir (STLV-1); it derives from interspecies zoonotic transmission from non-human primates to humans (ancient or recent). In this review, we describe the genetic diversity of HTLV-1, and analyze the molecular mechanisms that are at play in HTLV-1 evolution. Similar to other retroviruses, HTLV-1 evolves either through accumulation of point mutations or recombination. Molecular studies point to a fairly low evolution rate of HTLV-1 (between 5.6E−7 and 1.5E−6 substitutions/site/year), supposedly because the virus persists within the host via clonal expansion (instead of new infectious cycles that use reverse transcriptase).
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Affiliation(s)
- Philippe V Afonso
- Unité d'Epidémiologie et Physiopathologie des Virus Oncogènes, CRNS-UMR 3569, Département de Virologie, Institut Pasteur, Bâtiment Lwoff, 28 rue du Dr. Roux, 75724, Paris cedex 15, France.
| | - Olivier Cassar
- Unité d'Epidémiologie et Physiopathologie des Virus Oncogènes, CRNS-UMR 3569, Département de Virologie, Institut Pasteur, Bâtiment Lwoff, 28 rue du Dr. Roux, 75724, Paris cedex 15, France
| | - Antoine Gessain
- Unité d'Epidémiologie et Physiopathologie des Virus Oncogènes, CRNS-UMR 3569, Département de Virologie, Institut Pasteur, Bâtiment Lwoff, 28 rue du Dr. Roux, 75724, Paris cedex 15, France.
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Diagnosis | T-cell lymphoma associated with simian T-cell lymphotropic virus 1. Lab Anim (NY) 2011. [DOI: 10.1038/laban0611-180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Zehender G, Colasante C, De Maddalena C, Bernini F, Savasi V, Persico T, Merli S, Ridolfo A, Santambrogio S, Moroni M, Galli M. High prevalence of human T-lymphotropic virus type 1 (HTLV-1) in immigrant male-to-female transsexual sex workers with HIV-1 infection. J Med Virol 2004; 74:207-15. [PMID: 15332268 DOI: 10.1002/jmv.20165] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
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.
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Affiliation(s)
- Gianguglielmo Zehender
- Istituto di Malattie Infettive e Tropicali-Università di Milano, Centro Interdisciplinare per gli Studi Biomolecolari e le Applicazioni Industriali (CISI), Milan, Italy.
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Meertens L, Gessain A. Divergent simian T-cell lymphotropic virus type 3 (STLV-3) in wild-caught Papio hamadryas papio from Senegal: widespread distribution of STLV-3 in Africa. J Virol 2003; 77:782-9. [PMID: 12477886 PMCID: PMC140582 DOI: 10.1128/jvi.77.1.782-789.2003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Among eight samples obtained from a French primatology research center, six adult guinea baboons (Papio hamadryas papio), caught in the wild in Senegal, had a peculiar human T-cell leukemia virus type 2 (HTLV-2)-like Western blot seroreactivity (p24(+), GD21(+), K55(+/-)). Partial sequence analyses of the tax genes (433 bp) indicated that these baboons were infected by a novel divergent simian T-cell lymphotropic virus (STLV). Analyses of the complete proviral sequence (8,892 bp) for one of these strains (STLV-3/PPA-F3) indicate that this STLV was highly divergent from the HTLV-1 (61.6% of nucleotide similarity), HTLV-2 (61.2%), or STLV-2 (60.6%) prototype. It was, however, much more closely related to the few other known STLV-3 strains, exhibiting 87 and 89% of nucleotide similarity with STLV-3/PHA-PH969 (formerly PTLV-L/PH969) and STLV-3/CTO-604, respectively. The STLV-3/PPA-F3 sequence possesses the major HTLV or STLV open reading frames corresponding to the structural, enzymatic, and regulatory proteins. However, its long terminal repeat comprises only two 21-bp repeats. In all phylogenetic analyses, STLV-3/PPA-F3 clustered together in a highly supported single clade with the other known strains of STLV-3, indicating an independent evolution from primate T-cell lymphotropic virus type 1 (PTLV-1) and PTLV-2. The finding of a new strain of STLV-3 in a West African monkey (Guinea baboon) greatly enlarges the geographical distribution and the host range of species infected by this PTLV type in the African continent. The recent discovery of several different STLV-3 strains in many different African monkey species, often in contact with humans, strongly suggests potential interspecies transmission events, as it was described for STLV-1, between nonhuman primates but also to humans.
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Affiliation(s)
- Laurent Meertens
- Unité d'Epidémiologie et Physiopathologie des Virus Oncogènes, Département Ecosystèmes et Epidémiologie des Maladies Infectieuses, Institut Pasteur, 75724 Paris Cedex 15, France
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Nerrienet E, Meertens L, Kfutwah A, Foupouapouognigni Y, Gessain A. Molecular epidemiology of simian T-lymphotropic virus (STLV) in wild-caught monkeys and apes from Cameroon: a new STLV-1, related to human T-lymphotropic virus subtype F, in a Cercocebus agilis. J Gen Virol 2001; 82:2973-2977. [PMID: 11714973 DOI: 10.1099/0022-1317-82-12-2973] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A serological survey for human T-lymphotropic virus (HTLV)/simian T-lymphotropic virus (STLV) antibodies was performed in 102 wild-caught monkeys and apes from 15 (sub)species originating from Cameroon. Two animals (a Mandrillus sphinx and a Cercocebus agilis) exhibited a complete HTLV-1 seroreactivity pattern while two others lacked either the p24 (a Mandrillus sphinx) or the MTA-1/gp46 bands (a Pan troglodytes). Sequence comparison and phylogenetic analyses, using a 522 bp env gene fragment and the complete LTR, indicated that the two mandrill STLV strains belonged to the HTLV/STLV subtype D clade while the chimpanzee strain clustered in the HTLV/STLV subtype B clade. The Cercocebus agilis STLV strain, the first one found in this species, was closely related to the two HTLV/STLV subtype F strains. Such data indicate that the African biodiversity of STLV-1 in the wild is far from being known and reinforces the hypothesis of interspecies transmission of STLV-1 from monkeys and apes to humans leading to the present day distribution of HTLV-1 in African inhabitants.
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Affiliation(s)
| | - Laurent Meertens
- Unité d'Epidémiologie et Physiopathologie des Virus Oncogènes, Département du SIDA et des Rétrovirus, Institut Pasteur, 25-28 rue du Dr Roux, 75724 Paris Cedex 15, France2
| | | | | | - Antoine Gessain
- Unité d'Epidémiologie et Physiopathologie des Virus Oncogènes, Département du SIDA et des Rétrovirus, Institut Pasteur, 25-28 rue du Dr Roux, 75724 Paris Cedex 15, France2
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Bhigjee AI, Tarin ML, Bill PL, De Oliveira T, York D. Sequence of the env gene of some KwaZulu-Natal, South African strains of HTLV type I. AIDS Res Hum Retroviruses 1999; 15:1229-33. [PMID: 10480636 DOI: 10.1089/088922299310322] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Phylogenetic analysis of HTLV-I suggests three main subtypes, namely, cosmopolitan, Central African, and Australo-Melanesian. HTLV-I is endemic in KwaZulu-Natal, South Africa. However, sequence data on the local strains are limited to the LTR region. The env gene of the local strain was amplified and sequenced from the peripheral blood of five seropositive individuals. Four had HTLV-I-associated myelopathy and one had infective eczema. The sequence analysis of the env gene showed a greater then 99% homology of the local strains. They were closely related to the North American strains (99.3%), followed by the Japanese strains (98.3-98.9%). Phylogenetic studies linked the local strains to the cosmopolitan subtype. This study provides new sequence data on the env gene of the local HTLV-I strain.
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Affiliation(s)
- A I Bhigjee
- Department of Neurology, University of Natal, Wentworth Hospital, Jacobs, South Africa.
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van Rensburg E, Engelbrecht S, Robson B, Langat D, Isahakia M, Mwenda J. Phylogenetic analysis of simian T lymphotropic virus type I from Kenyan olive baboons (Papio anubis), lowland Sykes monkeys (Cercopithecus mitis), and vervet monkeys (Cercopithecus aethiops pygerythrus). AIDS Res Hum Retroviruses 1999; 15:781-4. [PMID: 10357474 DOI: 10.1089/088922299310872] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- E van Rensburg
- Department of Medical Virology, University of Stellenbosch, and Tygerberg Hospital, South Africa.
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Engelbrecht S, Koulinska I, Smith TL, Robson BA, Barreto J, van Rensburg EJ. Subtyping of human T cell lymphotropic virus type I from tropical spastic paraparesis/HTLV-associated myelopathy patients in Mozambique. AIDS Res Hum Retroviruses 1999; 15:71-2. [PMID: 10024055 DOI: 10.1089/088922299311736] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- S Engelbrecht
- Department of Medical Virology, University of Stellenbosch and Tygerberg Hospital, South Africa
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Ellerbrok H, Fleischer C, Salemi M, Reinhardt P, Ludwig WD, Vandamme AM, Pauli G. Sequence analysis of the first HTLV-I infection in Germany without relations to endemic areas. AIDS Res Hum Retroviruses 1998; 14:1199-203. [PMID: 9737591 DOI: 10.1089/aid.1998.14.1199] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In most parts of Europe only a limited number of sporadic cases of HTLV-I infections have been identified. So far, the few cases found in Germany have always been linked to individuals with relations to endemic areas. Here we report the first HTLV-I infection from a German ATL patient without any known risk for HTLV-I infection and with no relations to known endemic areas. The DNA sequence of the provirus was determined, and a phylogenetic analysis based on the LTR sequence established a close relationship with HTLV-I sequences previously found in two Romanian patients. Our data suggest the existence of a previously unrecognized cluster of HTLV-I infections in southeastern or central Europe.
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Affiliation(s)
- H Ellerbrok
- Department of Virology, Robert Koch Institut, Berlin, Germany
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Yamashita M, Picchio G, Veronesi R, Ohkura S, Bare P, Hayami M. HTLV-Is in Argentina are phylogenetically similar to those of other South American countries, but different from HTLV-Is in Africa. J Med Virol 1998; 55:152-60. [PMID: 9598937 DOI: 10.1002/(sici)1096-9071(199806)55:2<152::aid-jmv12>3.0.co;2-k] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To understand the origin and past dissemination of human T-cell leukemia/lymphotropic virus type I (HTLV-I) in Latin America, we conducted a phylogenetic study of five new HTLV-I isolates from Argentina. We sequenced partial fragments of long terminal repeats (LTR) of the new HTLV-Is, and then the sequences were subjected to a phylogenetic analysis for comparison with other HTLV-Is of various geographical origins. Our results indicated that all the isolates were members of the Cosmopolitan group. Furthermore, most (four out of five isolates) of the new HTLV-Is belonged to the Transcontinental (A) subgroup, the most widespread subgroup of the four subgroups in the Cosmopolitan group. In this subgroup, they were closely related to HTLV-Is found in other South American countries including those of Amerindians, and were different from those found in Africa. In contrast, the remaining one HTLV-I (ARGMF) did not show any clear similarity to known HTLV-I isolates belonging to the Cosmopolitan group. The close similarity of South American HTLV-Is strongly suggests a common origin of the virus in this continent. Our results do not support the proposed idea of recent introduction of HTLV-I into South America as a consequence of the slave trade from Africa, where phylogenetically different HTLV-Is predominate.
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Affiliation(s)
- M Yamashita
- Laboratory of Pathogenic Virus, Institute for Virus Research, Kyoto University, Japan
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