Forest Elephant Crisis in the Congo Basin

Debate over repealing the ivory trade ban dominates conferences of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Resolving this controversy requires accurate estimates of elephant population trends and rates of illegal killing. Most African savannah elephant populations are well known; however, the status of forest elephants, perhaps a distinct species, in the vast Congo Basin is unclear. We assessed population status and incidence of poaching from line-transect and reconnaissance surveys conducted on foot in sites throughout the Congo Basin. Results indicate that the abundance and range of forest elephants are threatened from poaching that is most intense close to roads. The probability of elephant presence increased with distance to roads, whereas that of human signs declined. At all distances from roads, the probability of elephant occurrence was always higher inside, compared to outside, protected areas, whereas that of humans was always lower. Inside protected areas, forest elephant density was correlated with the size of remote forest core, but not with size of protected area. Forest elephants must be prioritised in elephant management planning at the continental scale

Le Bonobo : Origine des HTLV mais pas du VIH

Les grands singes d’Afrique sont les réservoirs du VIH et HTLV responsables d’épidémies et de pandémies. Cependant, chez les bonobos, un grand singe endémique de la RDC, peu de données sont disponibles sur les infections rétrovirales. Cette étude vise à caractériser les rétrovirus simiens de bonobos sauvages en RDC, pays où l'épidémie de VIH a commencé.Entre 2010 et 2012, des échantillons de matières fécales de bonobos (P. paniscus) sauvages ont été recueillis sur du RNAlater® dans les différentes forêts de la RDC. La confirmation des espèces a été faite par l’analyse de l’ADN mitochondrial. La recherche des anticorps anti-SIV/VIH a été réalisée en utilisant le test INNO-LIA VIH. L’infection SIV a été confirmée par PCR et séquençage d'un fragment du gène pol (400bp) pour SIV. L'infection STLV a été recherchée en utilisant des amorces spécifiques universelles du gène tax (200pb) ainsi que des LTR (450bp), suivis par les analyses phylogénétiques des séquences obtenues en utilisant la méthode de maximum de vraisemblance. Un total de 633 échantillons de selles a été prélevé et l’analyse de l’ADN mitochondrial a confirmé que tous les échantillons provenaient de bonobos. Huit (1,2 %) des 633 échantillons ont donné une amplification positive du fragment de tax de STLV. Parmi eux, six échantillons ont été identifiés comme STLV-2 et deux comme STLV-3 par l'analyse phylogénétique. Les analyses phylogénétiques de tax de LTR ont montré que le nouveau STLV-2 à partir de bonobos sauvages se regroupe avec les souches STLV-2 décrites précédemment chez les bonobos en captivité. Les STLV-3 identifiés chez les bonobos dans cette étude se regroupaient avec STLV-3 de petits singes vivant dans la même région. Par ailleurs, tous les échantillons fécaux ont été négatifs pour les anticorps croisés SIV/VIH. Notre étude a confirmé pour la première fois l’infection STLV-2 et 3 chez les bonobos sauvages en RDC et a montré que les bonobos, contrairement aux autres grands singes d’Afrique, ne semblent pas être infectés par le SIV, l’ancêtre du VIH

Genetic diversity of STLV-2 and interspecies transmission of STLV-3 in wild-living bonobos

There are currently four known primate T-cell lymphotropic virus groups (PTLV1-4), each of which comprises closely related simian (STLV) and human (HTLV) viruses. For PTLV-1 and PTLV-3, simian and human viruses are interspersed, suggesting multiple cross-species transmission events; however, for PTLV-2 this is not so clear because HTLV-2 and STLV-2 strains from captive bonobos (Pan paniscus) form two distinct clades. To determine to what extent bonobos are naturally infected with STLV, we screened fecal samples (n = 633) from wild-living bonobos (n = 312) at six different sites in the Democratic Republic of Congo (DRC) for the presence of STLV nucleic acids. STLV infection was detected in 8 of 312 bonobos at four of six field sites, suggesting an overall prevalence of 2.6% (ranging from 0 to 8%). Six samples contained STLV-2, while the two others contained STLV-3, as determined by phylogenetic analysis of partial tax and Long Terminal Repeats (LTR) sequences. The new STLV-2 sequences were highly diverse, but grouped with previously identified STLV-2 strains as a sister clade to HTLV-2. In contrast, the new STLV-3 sequences did not cluster together, but were more closely related to STLVs from sympatric monkey species. These results show for the first time that fecal samples can be used to detect STLV infection in apes. These results also show that wild-living bonobos are endemically infected with STLV-2, but have acquired STLV-3 on at least two occasions most likely by cross-species transmission from monkey species on which they prey. Future studies of bonobos and other non-human primate species in Central Africa are needed to identify the simian precursor of HTLV-2 in humans

Erratum to: High Prevalences and a Wide Genetic Diversity of Simian Retroviruses in Non-human Primate Bushmeat in Rural Areas of the Democratic Republic of Congo

International audienc

Results of Fitting a Logistic Regression Model to Elephant and Human Presence/Absence Megatransect Data

<p>Distance to road (in kilometres) and location within or outside the protected areas were used as explanatory variables. (A) shows the elephant data, and (B) shows the human data. The observations and regression lines are colour-coded to correspond to within or outside the protected areas and the dashed line shows the regression line with only the distance to road covariate. The covariates distance to road and location within or outside the protected areas are significant for both elephant and human probability of occurrence.</p