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1.
PLoS One ; 16(5): e0251263, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34010292

RESUMO

Rift Valley fever virus (RVFV), an arbovirus belonging to the Phlebovirus genus of the Phenuiviridae family, causes the zoonotic and mosquito-borne RVF. The virus, which primarily affects livestock (ruminants and camels) and humans, is at the origin of recent major outbreaks across the African continent (Mauritania, Libya, Sudan), and in the South-Western Indian Ocean (SWIO) islands (Mayotte). In order to be better prepared for upcoming outbreaks, to predict its introduction in RVFV unscathed countries, and to run efficient surveillance programmes, the priority is harmonising and improving the diagnostic capacity of endemic countries and/or countries considered to be at risk of RVF. A serological inter-laboratory proficiency test (PT) was implemented to assess the capacity of veterinary laboratories to detect antibodies against RVFV. A total of 18 laboratories in 13 countries in the Middle East, North Africa, South Africa, and the Indian Ocean participated in the initiative. Two commercial kits and two in-house serological assays for the detection of RVFV specific IgG antibodies were tested. Sixteen of the 18 participating laboratories (88.9%) used commercial kits, the analytical performance of test sensitivity and specificity based on the seroneutralisation test considered as the reference was 100%. The results obtained by the laboratories which used the in-house assay were correct in only one of the two criteria (either sensitivity or specificity). In conclusion, most of the laboratories performed well in detecting RVFV specific IgG antibodies and can therefore be considered to be prepared. Three laboratories in three countries need to improve their detection capacities. Our study demonstrates the importance of conducting regular proficiency tests to evaluate the level of preparedness of countries and of building a network of competent laboratories in terms of laboratory diagnosis to better face future emerging diseases in emergency conditions.


Assuntos
Febre do Vale de Rift/diagnóstico , África/epidemiologia , Animais , Anticorpos Antivirais/sangue , Doenças Endêmicas/veterinária , Ensaio de Imunoadsorção Enzimática/normas , Ensaio de Imunoadsorção Enzimática/estatística & dados numéricos , Ensaio de Imunoadsorção Enzimática/veterinária , Humanos , Imunoglobulina G/sangue , Oceano Índico/epidemiologia , Laboratórios/normas , Oriente Médio/epidemiologia , Garantia da Qualidade dos Cuidados de Saúde , Reprodutibilidade dos Testes , Febre do Vale de Rift/epidemiologia , Febre do Vale de Rift/imunologia , Vírus da Febre do Vale do Rift/imunologia , Fatores de Risco , Testes Sorológicos/normas , Testes Sorológicos/estatística & dados numéricos , Testes Sorológicos/veterinária
2.
Vet Med Sci ; 7(3): 979-986, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33570262

RESUMO

Mycoplasma mycoides subsp. mycoides (Mmm) is the aetiological agent of contagious bovine pleuropneumonia (CBPP). The aim of the present study was to identify the profiles of the Mmm strains isolated in Niger using the 'Multilocus Sequence Analysis' (MLSA) typing technique based on polymorphism analysis of housekeeping and non-coding genes. The investigation was conducted on samples (n=22) comprising of lung tissues, lymph node and pleural fluids. Following classical PCR, Mmm positive amplicons (n=6) were identified. These positive amplicons were then amplified using eight loci of the PG1 reference strain (LocPG1-0001, Loc-PG1-0103, Loc-PG1-0287, Loc-PG1-0431, Loc-PG1-0489, Loc-PG1-0523, Loc-PG1-0710 and Loc-PG1-0827). Sequencing followed by the determination of the profile of each strain by the combination of the allele numbers revealed three different MLSA profiles namely; A11, E01 and A15. The profiles A11 and E01 were previously identified. The novel profile identified in this study was named profile A15. The difference was detected while comparing sequences of non-coding loci. This novel profile was named 'A15' according to the similarities with African reference strain profile 'A00' at the seven loci level (loc-0103, loc-0287, loc-0431, loc-0489, loc-0523, loc-0710 and loc-0827). For CBPP control measures, identification and molecular characterization of Mmm strains is very important. Thus, the use of MLSA technique is relevant to identify profiles of Mmm circulating in Niger. Other countries where CBPP is still endemic are encouraged to use a MLSA scheme to address this issue and, most importantly, to rapidly trace back the origin of outbreaks, which will help reduce the transmission and spread of the disease. In addition, mapping the profiles of strains circulating in each of the countries of the sub-region is necessary for effective control of CBPP.


Assuntos
Doenças dos Bovinos/microbiologia , Doenças das Cabras/microbiologia , Infecções por Mycoplasma/veterinária , Mycoplasma/isolamento & purificação , Doenças dos Ovinos/microbiologia , Alelos , Animais , Sequência de Bases , Bovinos , DNA Bacteriano/análise , Cabras , Tipagem de Sequências Multilocus/veterinária , Infecções por Mycoplasma/microbiologia , Níger , Ovinos , Carneiro Doméstico
3.
Virus Genes ; 57(1): 100-105, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33130962

RESUMO

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.


Assuntos
Doença de Newcastle , Vírus da Doença de Newcastle/isolamento & purificação , Doenças das Aves Domésticas , Aves Domésticas/virologia , Animais , Genótipo , Doença de Newcastle/epidemiologia , Doença de Newcastle/virologia , Vírus da Doença de Newcastle/genética , Níger/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/virologia , RNA Viral , Proteínas Virais/genética
4.
Transbound Emerg Dis ; 68(3): 1253-1262, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32770642

RESUMO

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.


Assuntos
Surtos de Doenças/veterinária , Doenças dos Cavalos/epidemiologia , Vírus da Influenza A Subtipo H3N8/genética , Infecções por Orthomyxoviridae/veterinária , Animais , Genes Virais , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Doenças dos Cavalos/transmissão , Doenças dos Cavalos/virologia , Cavalos , Vírus da Influenza A Subtipo H3N8/classificação , Neuraminidase/genética , Níger/epidemiologia , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/virologia , Filogenia , Senegal/epidemiologia
5.
Transbound Emerg Dis ; 67(3): 1388-1392, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31838763

RESUMO

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.


Assuntos
Doenças das Cabras/virologia , Epidemiologia Molecular , Proteínas do Nucleocapsídeo/genética , Peste dos Pequenos Ruminantes/epidemiologia , Vírus da Peste dos Pequenos Ruminantes/genética , Doenças dos Ovinos/virologia , África Ocidental , Animais , Surtos de Doenças/veterinária , Doenças das Cabras/epidemiologia , Cabras/virologia , Níger/epidemiologia , Peste dos Pequenos Ruminantes/virologia , Filogenia , Ruminantes , Ovinos , Doenças dos Ovinos/epidemiologia
6.
Nat Commun ; 10(1): 5310, 2019 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-31757953

RESUMO

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.


Assuntos
Influenza Aviária/transmissão , Influenza Humana/transmissão , Doenças das Aves Domésticas/transmissão , África , África Ocidental , Animais , Humanos , Virus da Influenza A Subtipo H5N1/genética , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A/genética , Influenza Aviária/economia , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Influenza Humana/economia , Influenza Humana/epidemiologia , Influenza Humana/virologia , Filogenia , Aves Domésticas , Doenças das Aves Domésticas/economia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/virologia
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