Diversity and prevalence of gastrointestinal parasites in farmed pigs in Southeast Gabon, Central Africa

Background and Aim: Gastrointestinal infestations caused by intestinal parasites are the most important diseases and the most common in pigs in the tropics. These parasites are often associated with a huge economic loss. This study aimed to assess the diversity and prevalence of gastrointestinal parasites in farmed pigs from Haut-Ogooue Province, in South East Gabon. Materials and Methods: From March 2018 to July 2018, 156 samples of pig feces collected from nine different farms were analyzed under light microscopy. The identification of eggs, cysts, and oocysts in fecal samples was done using two qualitative techniques: Flotation and sedimentation. Results: After examination, the results obtained revealed an overall infestation level of 98.7% (154/156). We found ten parasite types with infestation levels that varied from species: Balantidium coli (120/156), Oesophagostomum spp. (100/156), Isospora suis (102/156), Ancylostoma spp. (17/156), Trichostrongylus spp. (28/156), Hyostrongylus spp. (13/156), Strongyloides spp. (7/156), Ascaris suum (8/156), Globocephalus spp. (1/156), and spirurida (1/156). The study of risk factors revealed that factors such as sex, age, and physiological condition may influence the diversity and level of infestation of animals by gastrointestinal parasites. Conclusion: For better prevention of parasitism in these farms, it would be interesting to implement health monitoring and to ensure good hygiene. Finally, further studies would be needed to better evaluate the distribution of these parasites in Gabon and the involvement of these animals in the transmission cycle of parasitic zoonoses

Evidence for circulation of Rift Valley fever virus in wildlife and domestic animals in a forest environment in Gabon, Central Africa.

Rift Valley fever (RVF) is a mosquito-borne viral zoonosis caused by the Rift Valley fever virus (RVFV) that can infect domestic and wild animals. Although the RVFV transmission cycle has been well documented across Africa in savanna ecosystems, little is known about its transmission in tropical rainforest settings, particularly in Central Africa. We therefore conducted a survey in northeastern Gabon to assess RVFV circulation among wild and domestic animals. Among 163 wildlife samples tested using RVFV-specific RT-qPCR, four ruminants belonging to subfamily Cephalophinae were detected positive. The phylogenetic analysis revealed that the four RVFV sequences clustered together with a virus isolated in Namibia within the well-structured Egyptian clade. A cross-sectional survey conducted on sheep, goats and dogs living in villages within the same area determined the IgG RVFV-specific antibody prevalence using cELISA. Out of the 306 small ruminants tested (214 goats, 92 sheep), an overall antibody prevalence of 15.4% (95% CI [11.5-19.9]) was observed with a higher rate in goats than in sheep (20.1% versus 3.3%). RVFV-specific antibodies were detected in a single dog out of the 26 tested. Neither age, sex of domestic animals nor season was found to be significant risk factors of RVFV occurrence. Our findings highlight sylvatic circulation of RVFV for the first time in Gabon. These results stress the need to develop adequate surveillance plan measures to better control the public health threat of RVFV. [Abstract copyright: Copyright: © 2024 Becquart et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

African army ants at the forefront of virome surveillance in a remote tropicalforest: A groundbreaking study using ants revealed a spectacular diversity of viruses in hardly accessible ecosystems like tropical forests

International audienceIn this study, we used a predator-enabled metagenomics strategy to sample the virome of a remote and difficult-to-access densely forested African tropical region. Specifically, we focused our study on the use of army ants of the genus Dorylus that are obligate collective foragers and group predators that attack and overwhelm a broad array of animal prey. Using 209 army ant samples collected from 29 colonies and the virion-associated nucleic acid-based metagenomics approach, we showed that a broad diversity of bacterial, plant, invertebrate and vertebrate viral sequences were accumulated by army ants: including sequences from 157 different viral genera in 56 viral families. This suggests that using predators and scavengers such as army ants to sample broad swathes of tropical forest viromes can shed light on the composition and the structure of viral populations of these complex and inaccessible ecosystems

List of wild animal species screened for the RVFV genome.

List of wild animal species screened for the RVFV genome.</p

Phylogenetic tree derived from nucleotide sequence data of the entire S segment.

The phylogenetic analyses were carried out after multiple alignments of the obtained sequences along with the GenBank reference sequences (including all published sequences). Maximum likelihood (ML) methods were used to construct trees based on full sequences of the S segment (1690 nt). The GenBank accession numbers for the S gene are OR528950, OR528951, OR528952, OR528953 for samples 7, 108, 120 and 166, respectively.</p

RVFV-specific IgG antibodies detection in livestock (sheep and goats) and dogs using ELISA according to sampled route and village.

RVFV-specific IgG antibodies detection in livestock (sheep and goats) and dogs using ELISA according to sampled route and village.</p

RVFV genome detection in wildlife using RT-qPCR according to sampled route and village.

RVFV genome detection in wildlife using RT-qPCR according to sampled route and village.</p

Map of the study area, Zadié Department, Gabon.

Gray dots indicate the sampled villages and red dots, the villages where hunters brought back Cephalophinae detected positive for RVFV.</p