The role of Africa in the dynamics of the global spread of a zoonotic and economically-important virus, such as the highly pathogenic avian influenza (HPAI) H5Nx of the Gs/GD lineage, remains ...unexplored. Here we characterise the spatiotemporal patterns of virus diffusion during three HPAI H5Nx intercontinental epidemic waves and demonstrate that Africa mainly acted as an ecological sink of the HPAI H5Nx viruses. A joint analysis of host dynamics and continuous spatial diffusion indicates that poultry trade as well as wild bird migrations have contributed to the virus spreading into Africa, with West Africa acting as a crucial hotspot for virus introduction and dissemination into the continent. We demonstrate varying paths of avian influenza incursions into Africa as well as virus spread within Africa over time, which reveal that virus expansion is a complex phenomenon, shaped by an intricate interplay between avian host ecology, virus characteristics and environmental variables.
Since November 2018, several countries in West and Central Africa have reported mortalities in donkeys and horses. Specifically, more than 66,000 horses and donkeys have succumbed to disease in ...Burkina Faso, Chad, Cameroon, The Gambia, Ghana, Mali, Niger, Nigeria, and Senegal. Strangles caused by Streptococcus equi subsp equi, African Horse Sickness (AHS) virus, and Equine influenza virus (EIV) were all suspected as potential causative agents. This study reports the identification of EIV in field samples collected in Niger and Senegal. Phylogenetic analysis of the hemagglutinin and neuraminidase genes revealed that the identified viruses belonged to clade 1 of the Florida sublineage and were very similar to viruses identified in Nigeria in 2019. Interestingly, they were also more similar to EIVs from recent outbreaks in South America than to those in Europe and the USA. This is one of the first reports providing detailed description and characterization of EIVs in West and Central Africa region.
The causative agent of Newcastle disease (ND) of poultry is the avian paramyxovirus-1, also commonly known as ND virus (NDV). Like in many developing countries, ND is endemic in Niger and has ...significant economic impact on commercial and backyard poultry production. NDVs were characterized in Niger between 2006 and 2008 and shown to belong to genotypes XIV.1 and XVII. In order to determine the current situation regarding the virus in Niger, tracheas (
n
= 384) were collected for the detection of NDV from both healthy (
n
= 335) and sick (
n
= 49) backyard poultry in 2019. Of these samples, 24 from sick chickens were positive for NDV by conventional RT-PCR. Sequencing of the fusion protein gene and phylogenetic analysis revealed that the viruses belonged to either genotype XIV.2 or XVIII.2. No NDVs of genotype XIV.1 or XVII were identified in the current study highlighting the dynamic nature of NDV circulation in Niger and the region.
La distribution et la dynamique des populations des tiques est un élément clé dans la connaissance des maladies transmises par ces vecteurs. C’est ainsi que cette étude a été conduite afin de mieux ...connaître l’épidémiologie de la Fièvre Hémorragique de Crimée-Congo (FHCC) dans les 8 communes du département de Boboye au Niger, où 355 sérums de bovins ont été collectés. En plus des sérums, des tiques ont été collectées sur 144 bovins, soit 18 par commune. Les sérums ont été soumis à un test ELISA (Enzyme Linked Immunosorbent Assay) indirect pour la détection d’anticorps anti-FHCC. Soixante-douze (72) éleveurs ont été interviewés sur leur connaissance de l’écologie des tiques, vecteurs du virus de la FHCC. Les résultats de l’enquête ont révélé que les éleveurs n’ont pas recours aux acaricides et que, dans leur majorité (55/72 soit 76,4 %), ils pratiquent la transhumance. L’étude a permis l’identification de 1342 tiques réparties en trois genres : Hyalomma (91,7%), Amblyomma (5,7%) et Rhipicephalus (Boophilus) (2,6%). La séroprévalence globale a été de 9,1±0,03%. Les communes de Harikanassou et Kiota ont été celles où les fortes prévalences ont été observées de 26,7 ± 12,9% et 22,5 ±12,9%. Le virus de la FHCC est en circulation chez la population animale, alors des investigations doivent être faites chez la population humaine.Mots clés : Anticorps anti-FHCC, Enzyme Linked Immunosorbent Assay Indirecte, Prévalence, Sérums, Tiques.
English Title: Crimean-Congo Hemorrhagic Fever (CCHF) ’s Epidemiology in cattle in Boboye’s department of Niger Republic
To understand disease transmission by ticks, knowledge of population dynamics and distribution of these vectors are essentials. To sought that, the epidemiology of Crimean-Congo Hemorrhagic Fever (CCHF) in Niger Republic was studied by sampling 355 bovines (sera and ticks) in eight (8) local governments in Boboye’s department. Eighteen (18) bovines were sampled for ticks collection per local government making them a total of 144 bovine. Indirect ELISA test (enzyme-linked immunosorbent assay) was used to detect anti- CCHF antibodies. Seventy-two (72) farmers were surveyed on their knowledge on ticks’ ecology, main vectors of CCHF virus. The results revealed that farmers are not using acaricides, and their majority (55/72 thus 76.4%) practice Transhumance. The study allowed the identification of 1342 ticks distributed in 3 genus: Hyalomma (91.7%), Amblyomma (5.7%) and Rhipicephalus (Boophilus) (2.6%). The global seroprevalence against CCHF was (9.1 ± 0.03) %. Harikanassou and Kiota were the most affected local governments with respectively (26.7±12.9) % and (22.5±12,9) % prevalence. CCHV virus is circulating in animal population, so investigations must be made in human population.
Keywords: Anti-CCHF antibodies, Indirect Enzyme Linked Immunosorbent Assay, Prevalence, Sera, Ticks.
Like many West African countries, outbreaks of peste des petits ruminants (PPR), an economically important disease of goats and sheep, are regularly reported in Niger. The causative virus, peste des ...petits ruminants virus (PPRV), can be differentiated into four genetically distinct lineages. A publication in 2018 identified three PPRV lineages circulating in the country in 2001 (lineages I and II) and 2013 (lineage IV), respectively. In this present study, more recent samples were collected from goats and sheep in locations throughout Niger between 2011 and 2017. Twelve PPRV‐positive samples were characterized by sequencing of a segment of the nucleocapsid protein (N) gene. Phylogenetic analysis of the sequences identified viruses from lineages II and IV only. The analysis also indicated a shared origin of the viruses from Niger with PPRVs from neighbouring countries suggesting transboundary movement.
L’épizoo-épidémie de la Fièvre de la Vallée du Rift (FVR), survenue suite à une pluviométrie marquée par de fortes précipitations dans la région de Tahoua frontalière au département d’Ingal qui ...accueille l’événement de la cure salée chaque année, a engendré de nombreuses pertes en vies humaines. Au niveau du secteur animal, l’impact économique et sanitaire est également considérable, compte-tenu des lourdes pertes engendrées dans le cheptel. Ces pertes sont une forte mortalité chez les jeunes, des taux d’avortements élevés chez les femelles gravides et une baisse de la productivité des élevages touchés. Afin d’évaluer la séroprévalence de la FVR chez les ruminants de la région, des échantillons de sérums prélevés lors du seromonitoring des campagnes de vaccination contre la peste des petits ruminants et la péripneumonie contagieuse des bovidés financé par le Projet Régional d’Appui au Pastoralisme au Sahel (PRAPS) en février 2017, ont été analysés pour la détection d’anticorps du virus de la FVR au moyen du test ELISA de compétition. Les séroprévalences obtenues chez les espèces étudiées sont assez élevées chez les bovins (30,62%) et les caprins (18,40%), suivies de celle des ovins qui est de 14,90%.Les résultats sérologiques répartis dans les communes montrent que les bovins de Ibohaman et Tassara sont significativement les plus affectés avec une prévalence de 50,00% chacune (P=0,00224). Par contre, chez les petits ruminants, les communes de Tchintabaraden et Abalak ont significativement les prévalences les plus élevées tant chez les ovins (22,07% et 40,90%) que chez les caprins (8,69% et 37,21%).Toutefois, il n’y a pas de différence significative entre les prévalences d’infection des ovins et caprins pour chaque commune. Les résultats révèlent que la prévalence est plus élevée chez les mâles que chez les femelles (32,35±11,11 contre 18,49±3,43), mais la différence n’est pas significative. En somme, la mise en place d’une stratégie privilégiant l’approche « One Health » est nécessaire pour une lutte efficace contre la FVR, mais aussi la nécessité d’études entomologiques complémentairesMots clés: Sérologie, c-ELISA, Fièvre de la vallée de Rift, Bovins, Ovins, Caprins. English Title: Rift valley fever seroprevalence in domestic ruminants in Tahoua region/NigerThe epizoo-epidemic outbreak of Rift Valley Fever (RVF) that occurred following a heavy rainfall in the region of Tahoua, along the border of Ingal’s department that hosts every year, the salt cure event has caused considerable human deaths. Considerable economic and health losses were reported in livestock sector. These losses include high mortality in young animals, high abortion rates in pregnant females and decrease productivity in affected farms. To assess the seroprevalence of RVF of ruminants from that region, sera samples collected in February 2017, for the Seromonitoring of vaccination campaigns against Peste des Petits Ruminants (PPR) and Contagious Bovine Peri Pneumonia (CBPP), Supported by the Regional Project for Pastoralism in the Sahel (PRAPS), were tested for antibodies against RVF virus using the competitive ELISA test. The seroprevalence of RVF in the studied species, reveal a high prevalence in cattle (30.62%) and goats (18.40%) followed by sheep (14.90%).Cattle, from Ibohaman and Tassara are significantly affected with a prevalence of 50.00% each (P=0.00224) compared to other districts. Small ruminants from the districts of Tchintabaraden and Abalak have significantly the highest prevalence both in sheep (22.07% and 40.90%) and goats (8.69% and 37.21%). However, there is no significant difference between the prevalence of infection of sheep and goats in each district. Seroprevalence is higher in males than females (32.35±11.11) versus (18.49±3.43), with no significant difference between the two species. Based on the above results, for effective control of RVF it, is necessary to implement a one heath approach in the country couple with additional entomological investigations.Keywords: Serology, c-ELISA, Rift Valley Fever, Cattle, Sheep, Goats.
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