Discovery of a new human T-cell lymphotropic virus (HTLV-3) in Central Africa

Human T-cell Leukemia virus type 1 (HTLV-1) and type 2 (HTLV-2) are pathogenic retroviruses that infect humans and cause severe hematological and neurological diseases. Both viruses have simian counterparts (STLV-1 and STLV-2). STLV-3 belongs to a third group of lymphotropic viruses which infect numerous African monkeys species. Among 240 Cameroonian plasma tested for the presence of HTLV-1 and/or HTLV-2 antibodies, 48 scored positive by immunofluorescence. Among those, 27 had indeterminate western-blot pattern. PCR amplification of pol and tax regions, using HTLV-1, -2 and STLV-3 highly conserved primers, demonstrated the presence of a new human retrovirus in one DNA sample. tax (180 bp) and pol (318 bp) phylogenetic analyses demonstrated the strong relationships between the novel human strain (Pyl43) and STLV-3 isolates from Cameroon. The virus, that we tentatively named HTLV-3, originated from a 62 years old Bakola Pygmy living in a remote settlement in the rain forest of Southern Cameroon. The plasma was reactive on MT2 cells but was negative on C19 cells. The HTLV 2.4 western-blot exhibited a strong reactivity to p19 and a faint one to MTA-1. On the INNO-LIA strip, it reacted faintly with the generic p19 (I/II), but strongly to the generic gp46 (I/II) and to the specific HTLV-2 gp46. The molecular relationships between Pyl43 and STLV-3 are thus not paralleled by the serological results, as most of the STLV-3 infected monkeys have an "HTLV-2 like" WB pattern. In the context of the multiple interspecies transmissions which occurred in the past, and led to the present-day distribution of the PTLV-1, it is thus very tempting to speculate that this newly discovered human retrovirus HTLV-3 might be widespread, at least in the African continent

Modes of transmission and genetic diversity of foamy viruses in a Macaca tonkeana colony

BACKGROUND: Foamy viruses are exogenous complex retroviruses that are highly endemic in several animal species, including monkeys and apes, where they cause persistent infection. Simian foamy viral (SFV) infection has been reported in few persons occupationally exposed to non-human primates (NHP) in zoos, primate centers and laboratories, and recently in few hunters from central Africa. Most of the epidemiological works performed among NHP populations concern cross-sectional studies without long-term follow-up. Therefore, the exact timing and the modes of transmission of SFVs remain not well known, although sexual and oral transmissions have been suspected. We have conducted a longitudinal study in a free-breeding colony of Macaca tonkeana in order (1) to determine the prevalence of the infection by foamy viruses, (2) to characterize molecularly the viruses infecting such animals, (3) to study their genetic variability overtime by long-term follow-up of several DNA samples in a series of specific animals, and (4) to get new insights concerning the timing and the modes of SFVs primary infection in these monkeys by combining serology and molecular means, as well as studies of familial structures and long-term behavioral observations. RESULTS/CONCLUSION: We first demonstrated that this colony was highly endemic for SFVs, with a clear increase of seroprevalence with age. Only 4.7% of immatures, and 43,7% of sub-adults were found seropositive, while 89.5% of adults exhibited antibodies directed against SFV. We further showed that 6 different strains of foamy viruses (exhibiting a very low intra-strain and overtime genetic variability in the integrase gene) are circulating within this group. This suggests a possible infection by different strains within an animal. Lastly, we provide strong evidence that foamy viruses are mostly acquired through severe bites, mainly in sub-adults or young adults. Most cases of seroconversion occur after 7 years of age; from this age individuals competed for access to sexual partners, thus increasing the likelihood of being wounded. Furthermore, all the serological and molecular data, obtained in this free-breeding colony, argue against a significant transmission of SFVs from mother or father to infants as well as between siblings

Epidemiological determinants and PCR results in Central African inhabitants with a new and frequent HTLV indeterminate Western Blot pattern exhibiting mostly p28, p32, p36, and a shifted GD21

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Novel Human Herpesvirus 8 Subtype D Strains in Vanuatu, Melanesia

We show human herpesvirus 8 with diverse molecular subtype D variants to be highly endemic among the Ni-Vanuatu population. Most K1 genes were nearly identical to Polynesian strains, although a few clustered with Australian or Taiwanese strains. These results suggest diverse origins of the Ni-Vanuatu population and raise questions about the ancient human population movements in Melanesia

Human Herpesvirus 8, Southern Siberia

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High frequency of HTLV-1 infection in Bantus and Pygmies from rural Cameroon bitten by non-human primates during hunting: High frequency of HTLV-1 infection in Bantus and Pygmies from rural Cameroon bitten by non-human primates during hunting

International audienceHTLV-1 infection is endemic in Central Africa, as well as the closely related STLV-1 found in several non-human primates (NHPs). Like other retroviruses, acquisition through interspecies transmission is strongly suggested but needs to be investigated. We analyzed 269 selected individuals (254 men, 15 women, average age 43.5 years) for whom a direct contact (mainly a severe bite) with a NHP occurred. This happened mostly during hunting activities and involved bleeding and body fluids exchange with at least saliva/blood contact. The same number of persons who live in the same villages/settlements but did not report any bite by NHPs was matched according to sex, age and ethnicity. Both groups include either Pygmies or Bantus living in the rain forest of South Cameroon. Plasma were tested for HTLV serology by WB, and proviral DNA was searched in buffy-coat DNA by 3 HTLV generic and one HTLV-1 specific PCR. HTLV-1 prevalence was of 8.5% (23/269) among bitten individuals versus 1.5% (4/269) observed in the controls (p<0.001). The 23 HTLV-1+ bitten individuals reported a gorilla (17), chimpanzee (3) or monkey (3) bite. Interestingly, 13/23 were coinfected by a simian foamyvirus, for which cross-species transmission from NHP to humans through bites is demonstrated. Moreover, familial studies excluded the other established routes of virus acquisition among some positive bitten individuals. Lastly, a phylogenetic analysis showed a HTLV-1 subtype F in a bitten subject closely related to the STLV-1 strain from a Cercocebus agilis with whom he was in contact, thus strengthening these new findings