Two distinct STLV-1 subtypes infecting Mandrillus sphinx follow the geographic distribution of their hosts

The mandrill (Mandrillus sphinx) has been shown to be infected with an STLV-1 closely related to HTLV-1. Two distinct STLV-1 subtypes (D and F) infect wild mandrills with high overall prevalence (27.0%) but are different with respect to their phylogenetic relationship and parallel to the mandrills' geographic range. The clustering of these new STLV-1mnd sequences with HTLV-1 subtype D and F suggests first, past simian-tohuman transmissions in Central Africa and second, that species barriers are easier to cross over than geographic barriers

Frequent and Recent Human Acquisition of Simian Foamy Viruses Through Apes' Bites in Central Africa

Human infection by simian foamy viruses (SFV) can be acquired by persons occupationally exposed to non-human primates (NHP) or in natural settings. This study aimed at getting better knowledge on SFV transmission dynamics, risk factors for such a zoonotic infection and, searching for intra-familial dissemination and the level of peripheral blood (pro)viral loads in infected individuals. We studied 1,321 people from the general adult population (mean age 49 yrs, 640 women and 681 men) and 198 individuals, mostly men, all of whom had encountered a NHP with a resulting bite or scratch. All of these, either Pygmies (436) or Bantus (1085) live in villages in South Cameroon. A specific SFV Western blot was used and two nested PCRs (polymerase, and LTR) were done on all the positive/borderline samples by serology. In the general population, 2/1,321 (0.2%) persons were found to be infected. In the second group, 37/198 (18.6%) persons were SFV positive. They were mostly infected by apes (37/39) FV (mainly gorilla). Infection by monkey FV was less frequent (2/39). The viral origin of the amplified sequences matched with the history reported by the hunters, most of which (83%) are aged 20 to 40 years and acquired the infection during the last twenty years. The (pro)viral load in 33 individuals infected by a gorilla FV was quite low (<1 to 145 copies per 105 cells) in the peripheral blood leucocytes. Of the 30 wives and 12 children from families of FV infected persons, only one woman was seropositive in WB without subsequent viral DNA amplification. We demonstrate a high level of recent transmission of SFVs to humans in natural settings specifically following severe gorilla bites during hunting activities. The virus was found to persist over several years, with low SFV loads in infected persons. Secondary transmission remains an open question

Conference highlights of the 15th international conference on human retrovirology: HTLV and related retroviruses, 4-8 june 2011, Leuven, Gembloux, Belgium

The June 2011 15th International Conference on Human Retrovirology: HTLV and Related Viruses marks approximately 30 years since the discovery of HTLV-1. As anticipated, a large number of abstracts were submitted and presented by scientists, new and old to the field of retrovirology, from all five continents. The aim of this review is to distribute the scientific highlights of the presentations as analysed and represented by experts in specific fields of epidemiology, clinical research, immunology, animal models, molecular and cellular biology, and virology

High natural polymorphism in the gag gene cleavage sites of non-B HIV type 1 isolates from Gabon

The main goal of the present study was to determine the frequency of substitutions in the cleavage sites (CS) of gag gene among non-B HIV-1 isolates from Gabon. Fifty plasma specimens, collected in 2010-2011, from HIV-1-infected patients failing first-line antiretroviral (ARV) regimens (constituted of two nucleoside reverse transcriptase inhibitors+one nonnucleoside reverse transcriptase inhibitor) (n = 38) and from HIV-1-infected individuals untreated with ARV (n = 12) were analyzed in the gag and gag-pol cleavage sites. Compared to HXB2 reference sequence, the total median number of substitutions in gag and gag-pol CS was 10 (range, 5-18). The cleavage site p2/NC was the most variable of the four gag CS with 100% (50/50) isolates carrying at least 1 substitution (range, 1-9). The two gag-pol TFP/p6(pol) and p6(pol)/PR CS sites were also highly variable (at least one substitution, 50/50, 100% in both cases). Substitutions at position G381 (p2/NC), L449 (p1/p6(gag)), and K444 (TFP/p6(pol)) were significantly more frequent in CRF02_AG strains, compared to other non-B strains (30.4% vs. 3.7%, p = 0.03; 87.0% vs. 59.3%, p = 0.03; and 91.3% vs. 59.3%, p = 0.01, respectively). Other non-B subtypes were significantly more likely to harbor substitutions at position N487 (p6(pol)) (70.4%) than CRF02_AG (39.1%) (p = 0.02). In Gabon, gag and gag-pol cleavage sites were highly polymorphic in protease inhibitor-naive patients harboring non-B HIV-1 strains. In sub-Saharan Africa, further studies are definitively required to better understand the impact of gag mutations among subjects receiving second-line LPV/r-containing regimens (monotherapy or triple combinations)

Significant impact of non-B HIV-1 variants genetic diversity in Gabon on plasma HIV-1 RNA quantitation

Evaluations of HIV-1 RNA viral load assays are lacking in Central Africa. The main objective of our study was to assess the reliability of HIV-1 RNA results obtained with three different assays for samples collected in Gabon. A total of 137 plasma specimens were assessed for HIV-1 RNA using the Abbott RealTime HIV-1 (R) and Nuclisens HIV-1 EasyQ (R) version 2.0 assays. It included HIV-1 non-B samples (n = 113) representing six subtypes, 10 CRFs and 18 URFs from patients infected with HIV-1 and treated with antiretrovirals that were found HIV-1 RNA positive (>= 300 copies/ml) with the Generic HIV viral load (R) assay; and samples (n = 24) from untreated individuals infected with HIV-1 but showing undetectable (<300 copies/ml) results with the Biocentric kit. For samples found positive with the Generic HIV viral load (R) test, correlation coefficients obtained between the three techniques were relatively low (R = 0.65 between Generic HIV viral load (R) and Abbott RealTime HIV-1 (R), 0.50 between Generic HIV viral load (R) and Nuclisens HIV-1 EasyQ (R), and 0.66 between Abbott RealTime HIV-1 (R) and Nuclisens HIV-1 EasyQ (R)). Discrepancies by at least one log(10) were obtained for 19.6%, 33.7%, and 20% of samples, respectively, irrespective of genotype. Most of samples (22/24) from untreated study patients, found negative with the Biocentric kit, were also found negative with the two other techniques. In Central Africa, HIV-1 genetic diversity remains challenging for viral load testing. Further studies are required in the same area to confirm the presence of HIV-1 strains that are not amplified with at least two different viral load assays. J. Med. Virol. 86:52-57, 2014

HIV type-1 group O infection in Gabon : low prevalence rate but circulation of genetically diverse and drug-resistant HIV type-1 group O strains

The goals of this study conducted in Gabon were to determine the prevalence rate of HIV-1 group O (HIV-1/O) infections and to characterize the genetic diversity of HIV-1/O strains as well as implications on antiretroviral (ARV) drug resistance. During 2010-2011, 1,176 samples from HIV-positive subjects were tested at the CIRMF (Centre International de Recherches Medicales de Franceville) retrovirology laboratory using an in-house serotyping assay. Plasma HIV-1/O RNA viral loads (VL) were determined using the Abbott RealTime HIV-1 assay. After full genome sequencing, drug resistance patterns were analyzed using two different algorithms (Agence Nationale de Recherches sur le SIDA et les hepatites virales and Stanford). Overall, four subjects (0.34%) were diagnosed as HIV-1/O infected. One subject, untreated by ARVs, died 2 months after HIV-1/O diagnosis. One was lost to follow-up. Two additional patients, treated with nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens, showed CD4 counts = 15 substitutions) and gp41 (N42D mutation) genes, as well as in the gag and gag-pol cleavage sites. No resistance mutation was detected in the integrase gene. These two strains harbored the Y181C mutation making them resistant to NNRTIs. M41L, M184V, and T215Y mutations were also found for one strain, making it resistant to all NRTIs by the Stanford algorithm. Even if HIV-1/O infection is low in Gabon, an accurate diagnosis and a reliable virological follow-up are required in Central Africa to optimize ARV treatments of HIV-1/O-infected patients

Full-length genome sequence of a simian immunodeficiency virus from a wild-captured sun-tailed monkey in Gabon provides evidence for a species-specific monophyletic SIVsun lineage

Since the first characterization of SIVsun (L14 strain) from a sun-tailed monkey (Cercopithecus solatus) in Gabon in 1999, no further information exists about the evolutionary history and geographic distribution of this lentivirus. Here, we report the full-length molecular characterization of a second SIVsun virus (SIVsunK08) naturally infecting a wild-caught sun-tailed monkey. The SIVsunK08 strain was most closely related to SIVsunL14 and clustered with members of the SIVmnd-1/SIVlhoest group. SIVsunK08 shared identical functional motifs in the LTR, Gag and Env proteins with SIVsunL14. Our data indicate that C. solatus is naturally infected with a monophyletic SIVsun strain

Early introduction and delayed dissemination of pandemic influenza, Gabon

Active surveillance in health care centers in Gabon during 2009-2011 detected 72 clinical cases of pandemic (H1N1) 2009 (pH1N1). We found that pH1N1 virus was introduced in mid-2009 but spread throughout the country in 2010. Thus, Gabon was also affected by pH1N1

T-cell tropism of simian T-cell leukaemia virus type 1 and cytokine profiles in relation to proviral load and immunological changes during chronic infection of naturally infected mandrills (Mandrillus sphinx)

Background Although a wide variety of non-human primates are susceptible to simian T-cell leukaemia virus type 1 (STLV-1), little is known about the virological or molecular determinants of natural STLV-1 infection. Methods We determined STLV-1 virus tropism in vivo and its relation to the immune response by evaluating cytokine production and T-cell subsets in naturally infected and uninfected mandrills. Results With real-time PCR methods, we found that STLV-1 in mandrills infects both CD4+ and CD8+ T cells; however, proviral loads were significantly higher (P = 0.01) in CD4+ than in CD8+ cells (mean STLV-1 copies number per 100 cells (\ub1 SD) was 7.8 \ub1 8 in CD4+ T cells and 3.9 \ub1 4.5 in CD8+ T cells). After culture, STLV-1 provirus was detected in enriched CD4+ but not in enriched CD8+ T cells. After 6 months of culture, STLV-1-transformed cell lines expressing CD3+, CD4+ and HLADR+ were established, and STLV-1 proteins and tax/rex mRNA were detected. In STLV-1 infected monkeys, there was a correlation between high proviral load and elevated levels of interleukin (IL)-2, IL-6, IL-10, interferon-gamma and tumour necrosis factor-alfa. The two monkeys with the highest STLV-1 proviral load had activated CD4+HLADR+ and CD8+HLADR+ T-cell subsets and a high percentage of CD25+ in CD4+ and CD8+ T cells. Conclusions Our study provides the first cellular, immunological and virological characterization of natural STLV-1 infection in mandrills and shows that they are an appropriate animal model for further physiopathological studies of the natural history of human T-cell leukaemia viruse