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Rural households remained the access-marginalized demographic in Africa despite massive land rushes by both domestic and foreign enterprises. As a result, investment decisions made by agricultural households are affected. To resolve this issue, a study that examines how exposure to large-scale land acquisition (LSLA) impacts people's agricultural investment decisions is required. Using data from 664 households selected using a multistage sampling technique, we examined the nexus between LSLA under local and foreign organizations and short-term investment (STI) and long-term investments (LTI) in land-improving measures. The results revealed that although LSLA under domestic and foreign entities tends to have a negative and statistically significant impact on the probability of LTI, it has a positive and significant impact on the probability of doing so for STI. The results also showed a simultaneity between LSLA and farm investment. Thus, giving farmers legal ownership safeguards them as they undertake LTI. To encourage household investment and reduce further exposure to LSLA, improvements in legal land ownership can be made.
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Peste des petits ruminants virus (PPRV) causes a highly infectious disease affecting mainly goats and sheep in large parts of Africa, Asia, and the Middle East and has an important impact on the global economy and food security. Full genome sequencing of PPRV strains has proved to be critical to increasing our understanding of PPR epidemiology and to inform the ongoing global efforts for its eradication. However, the number of full PPRV genomes published is still limited and with a heavy bias towards recent samples and genetic Lineage IV (LIV), which is only one of the four existing PPRV lineages. Here, we generated genome sequences for twenty-five recent (2010-6) and seven historical (1972-99) PPRV samples, focusing mainly on Lineage II (LII) in West Africa. This provided the first opportunity to compare the evolutionary pressures and history between the globally dominant PPRV genetic LIV and LII, which is endemic in West Africa. Phylogenomic analysis showed that the relationship between PPRV LII strains was complex and supported the extensive transboundary circulation of the virus within West Africa. In contrast, LIV sequences were clearly separated per region, with strains from West and Central Africa branched as a sister clade to all other LIV sequences, suggesting that this lineage also has an African origin. Estimates of the time to the most recent common ancestor place the divergence of modern LII and LIV strains in the 1960s-80s, suggesting that this period was particularly important for the diversification and spread of PPRV globally. Phylogenetic relationships among historical samples from LI, LII, and LIII and with more recent samples point towards a high genetic diversity for all these lineages in Africa until the 1970s-80s and possible bottleneck events shaping PPRV's evolution during this period. Molecular evolution analyses show that strains belonging to LII and LIV have evolved under different selection pressures. Differences in codon usage and adaptative selection pressures were observed in all viral genes between the two lineages. Our results confirm that comparative genomic analyses can provide new insights into PPRV's evolutionary history and molecular epidemiology. However, PPRV genome sequencing efforts must be ramped up to increase the resolution of such studies for their use in the development of efficient PPR control and surveillance strategies.
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Rift Valley fever (RVF) is a re-emerging zoonotic disease of domestic ruminants and humans. While neighbouring countries have reported outbreaks of RVF, Ghana has not yet identified any cases. The aim of this study was to determine whether RVF virus (RVFV) was circulating in livestock and herders in the southern part of Ghana, to estimate its seroprevalence, and to identify associated risk factors. The study surveyed 165 livestock farms randomly selected from two districts in southern Ghana. Serum samples of 253 goats, 246 sheep, 220 cattle, and 157 herdsmen were tested to detect IgG and IgM antibodies against RVFV. The overall seroprevalence of anti-RVF antibodies in livestock was 13.1% and 30.9% of farms had RVFV seropositive animals. The species-specific prevalence was 24.1% in cattle, 8.5% in sheep, and 7.9% in goats. A RVFV IgG seroprevalence of 17.8% was found among the ruminant herders, with 8.3% of all herders being IgM positive. RVFV was shown, for the first time, to have been circulating in southern Ghana, with evidence of a recent outbreak in Kwahu East; however, it was clinically undetected despite significant recent human exposure. A One Health approach is recommended to better understand RVF epidemiology and socio-economic impact in Ghana.
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Enfermedades de los Bovinos , Fiebre del Valle del Rift , Virus de la Fiebre del Valle del Rift , Enfermedades de las Ovejas , Animales , Bovinos , Ovinos , Humanos , Ganado , Estudios Seroepidemiológicos , Ghana/epidemiología , Anticuerpos Antivirales , Enfermedades de las Ovejas/epidemiología , Rumiantes , Cabras , Inmunoglobulina M , Inmunoglobulina GRESUMEN
Most emerging economies and the South American Countries are no exception to the negative consequences of trade-off between economic growth and environmental sustainability decisions. This study draws strength from the United Nations Sustainable Development Goals (UN-SDGs-7, 11, 12, and 13). Therefore, this study examines the environmental nexus between economic growth, globalization, renewable, and non-renewable energy, in South America from 1995 to 2020. We deployed the pooled mean group (PMG), mean group (MG), and dynamic fixed effects (DFE). Cross-sectional dependence, panel unit root, and cointegration tests were performed. Finally, we used the Dumitrescu and Hurlin test of causality to determine the long-run association between variables. The finding indicates that while environmental pollution increases with increasing economic growth, it decreases with increasing renewable energy both in the short and long term. Whereas economic globalization positively affects environmental pollution in the long term, social globalization and the moderation effect between political globalization and renewable energy improves environmental quality in the long run. Finally, a bidirectional causality was found between economic growth and environmental pollution, with a unidirectional causality running from economic, political, and social globalization, renewable, and non-renewable energy to environmental pollution. Given these findings, we discussed potential policy measures.
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Dióxido de Carbono , Desarrollo Económico , Estudios Transversales , Dióxido de Carbono/análisis , Contaminación Ambiental , Internacionalidad , América del SurRESUMEN
PURPOSE: The study examined Covid-19 vaccinations intentions among literate Ghanaians and how it is been influenced by vaccine mistrust and the fear of the unforeseen side effects. DESIGN/METHODOLOGY/APPROACH: We used cross sectional data collected from 223 respondents by means of questionnaire disseminated through social media from 16th to 20th April, 2021. Likert-scale questions were asked regarding the knowledge, attitudes and perceptions of literate Ghanaians towards COVID-19 vaccines. Kruskal-Wallis and sample t-test were performed to ascertain the differences in vaccination intentions between key socioeconomic variables. A pairwise correlation was performed to examine the relationship between vaccination intensions and fear of the unforeseen, mistrust of the vaccine and concerns of profiteering. Finally, a binary probit regression model was fitted to examine the predictive effect of key variables on respondent's vaccination intentions. FINDINGS: The results revealed a relatively low level of knowledge about the safety and efficacy of the COVID-19 vaccines. The sample t-test showed that males have a relatively positive attitude towards the COVID-19 vaccines than females at 5% level of significance. Mistrust of vaccine safety and efficacy have a significant negative influence on vaccination intensions at 1% significance level. ORIGINALITY/VALUE: This study provides the Ghanaian government and other stakeholders with useful information to aid in educational campaigns on the safety and effectiveness of the COVID-19 vaccine. More campaign efforts towards females could help increase uptake given their relatively poor attitudes towards the vaccine.
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COVID-19 , Vacunas , COVID-19/prevención & control , Vacunas contra la COVID-19 , Estudios Transversales , Miedo , Femenino , Ghana , Conocimientos, Actitudes y Práctica en Salud , Humanos , Intención , Masculino , Confianza , Vacunación , Eficacia de las Vacunas , Vacunas/efectos adversosRESUMEN
BACKGROUND: In Ghana, the conversion of land to agriculture, especially across the vegetative belt has resulted in fragmented forest landscapes with increased interactions among humans, domestic animals, and wildlife. METHODS: We investigated viruses in bats and rodents, key reservoir hosts for zoonotic viral pathogens, in a small agricultural community in the vegetation belt of Ghana. We also administered questionnaires among the local community members to learn more about people's awareness and perceptions of zoonotic disease risks and the environmental factors and types of activities in which they engage that might influence pathogen transmission from wildlife. RESULTS: Our study detected the RNA from paramyxoviruses and coronaviruses in rodents and bats, including sequences from novel viruses with unknown zoonotic potential. Samples collected from Epomophorus gambianus bats were significantly more likely to be positive for coronavirus RNA during the rainy season, when higher numbers of young susceptible individuals are present in the population. Almost all community members who responded to the questionnaire reported contact with wildlife, especially bats, rodents, and non-human primates in and around their homes and in the agricultural fields. Over half of the respondents were not aware or did not perceive any zoonotic disease risks associated with close contact with animals, such as harvesting and processing animals for food. To address gaps in awareness and mitigation strategies for pathogen transmission risks, we organized community education campaigns using risk reduction and outreach tools focused around living safely with bats and rodents. CONCLUSIONS: These findings expand our knowledge of the viruses circulating in bats and rodents in Ghana and of the beliefs, perceptions, and practices that put community members at risk of zoonotic virus spillover through direct and indirect contact with bats and rodents. This study also highlights the importance of community engagement in research and interventions focused on mitigating risk and living safely with wildlife.
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This research explores, through active surveillance, influenza A prevalence at different production levels in the Greater Accra region of Ghana, a study area with previous outbreak of highly pathogenic avian influenza H5N1 virus. The prevalence of influenza A was determined by rtRTPCR. This was achieved by screening 2040 samples comprising tracheal and cloacal swabs from chicken, ducks, pigeons, guinea fowls, and turkeys. Influenza A prevalence by production levels and species was computed at 95% confidence interval (CI) using the exact binomial interval. Structured questionnaires were also administered to 50 randomly selected poultry traders in the live bird markets. The overall influenza A prevalence was 7.7% (95% CI, 6.6, 8.9). Live bird market recorded 13.5% (n = 139, 95% CI, 11.5, 15.7), backyard poultry was 1.4% (95% CI, 0.6, 2.7), and commercial poultry 2.4% (95% CI, 1.2, 4.3). There was evidence of influenza A in all the poultry species sampled except for turkey. Subtyping of the M-gene has revealed the circulation of H9 in the three production levels. Live bird market has demonstrated high prevalence coupled with low level of biosecurity consciousness among the poultry operators. This is suggestive of live bird market serving as a potential basket for genetic reassortment with unpredictable future consequences.
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Subtipo H5N1 del Virus de la Influenza A , Gripe Aviar , Gripe Humana , Animales , Pollos , Ghana/epidemiología , Humanos , Subtipo H5N1 del Virus de la Influenza A/genética , Gripe Aviar/epidemiología , Gripe Aviar/prevención & control , Aves de CorralRESUMEN
In late 2018, unusual patterns of very high mortality (>50% production) were reported in intensive tilapia cage culture systems across Lake Volta in Ghana. Samples of fish and fry were collected and analysed from two affected farms between October 2018 and February 2019. Affected fish showed darkening, erratic swimming and abdominal distension with associated ascites. Histopathological observations of tissues taken from moribund fish at different farms revealed lesions indicative of viral infection. These included haematopoietic cell nuclear and cytoplasmic pleomorphism with marginalization of chromatin and fine granulation. Transmission electron microscopy showed cells containing conspicuous virions with typical iridovirus morphology, that is enveloped, with icosahedral and/or polyhedral geometries and with a diameter c.160 nm. PCR confirmation and DNA sequencing identified the virions as infectious spleen and kidney necrosis virus (ISKNV). Samples of fry and older animals were all strongly positive for the presence of the virus by qPCR. All samples tested negative for TiLV and nodavirus by qPCR. All samples collected from farms prior to the mortality event were negative for ISKNV. Follow-up testing of fish and fry sampled from 5 additional sites in July 2019 showed all farms had fish that were PCR-positive for ISKNV, whether there was active disease on the farm or not, demonstrating the disease was endemic to farms all over Lake Volta by that point. The results suggest that ISKNV was the cause of disease on the investigated farms and likely had a primary role in the mortality events. A common observation of coinfections with Streptococcus agalactiae and other tilapia bacterial pathogens further suggests that these may interact to cause severe pathology, particularly in larger fish. Results demonstrate that there are a range of potential threats to the sustainability of tilapia aquaculture that need to be guarded against.
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Cíclidos , Infecciones por Virus ADN/veterinaria , Enfermedades de los Peces/diagnóstico , Iridoviridae/aislamiento & purificación , Animales , Acuicultura , Infecciones por Virus ADN/diagnóstico , Infecciones por Virus ADN/virología , Enfermedades de los Peces/virología , GhanaRESUMEN
Avian influenza viruses (AIV) are negative sense RNA viruses posing a major threat to the poultry industry worldwide, with the potential to spread to mammals, including humans; hence, an accurate and rapid AIV diagnosis is essential. To date AIV detection relies on molecular methods, mainly RT-qPCR directed against AIV M gene segment. The evolution of AIV represents a relevant issue in diagnostic RT-qPCR due to possible mispriming and/or probe-binding failures resulting in false negative results. Consequently, RT-qPCR for AIV detection should be periodically re-assessed both in silico and in vitro. To this end, a specific workflow was developed to evaluate in silico the complementarity of primers and probes of four published RT-qPCR protocols to their target regions. The four assays and one commercially available kit for AIV detection were evaluated both for their analytical sensitivity using eight different viral dilution panels and for their diagnostic performances against clinical specimens of known infectious status. Differences were observed among the tests under evaluation, both in terms of analytical sensitivity and of diagnostic performances. This finding confirms the importance of continuously monitoring the primers and probes complementarity to their binding regions.
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Simulación por Computador , Variación Genética , Virus de la Influenza A/clasificación , Virus de la Influenza A/genética , Gripe Aviar/diagnóstico , ARN Viral/análisis , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Proteínas Virales/genética , Animales , Aves , Técnicas In Vitro , Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/genética , Gripe Aviar/virología , ARN Viral/genética , Curva ROCRESUMEN
Soybean is an important cash crop especially for farmers in the north of Ghana. However, cultivation of the commodity is dominated by smallholders equipped with traditional tools, coupled with low or no adoption of improved soybean production technologies. Using primary data collected from 300 soybean farmers across northern Ghana, the study employed count data modelling to estimate the determinants of adoption intensity of sustainable soybean production technologies. The study accounted for potential estimation errors due to under-dispersion and over-dispersion, by using a model based on the generalized Poisson distribution. On the average, a farmer adopted 50% of the identified sustainable soybean production technologies. Age, education, extension visits, mass media through radio, and the perception of adoption of soybean production technologies being risky are significant with positive influence on the adoption intensity of sustainable soybean production technologies. The study therefore recommends among others, that various extension programmes should intensify education on the benefits of adopting sustainable soybean production practices. There is the need to set up many technology demonstration farms to give farmers hands-on training during field days.
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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.
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Gripe Aviar/transmisión , Gripe Humana/transmisión , Enfermedades de las Aves de Corral/transmisión , África , África Occidental , Animales , Humanos , Subtipo H5N1 del Virus de la Influenza A/genética , Subtipo H5N8 del Virus de la Influenza A/genética , Virus de la Influenza A/genética , Gripe Aviar/economía , Gripe Aviar/epidemiología , Gripe Aviar/virología , Gripe Humana/economía , Gripe Humana/epidemiología , Gripe Humana/virología , Filogenia , Aves de Corral , Enfermedades de las Aves de Corral/economía , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/virologíaRESUMEN
Between November 2017 and February 2018, Ghanaian poultry producers reported to animal health authorities a dramatic increase in mortality rate and a relevant drop in egg production in several layer hen farms. Laboratory investigations revealed that the farms had been infected by the H9N2 influenza subtype. Virological and molecular characterization of the viruses identified in Ghana is described here for the first time. Whole genome analysis showed that the viruses belong to the G1-lineage and cluster with viruses identified in North and West Africa. The low pathogenicity of the virus was confirmed by the intravenous pathogenicity index assay. Further investigations revealed co-infection with infectious bronchitis virus of the GI-19 lineage, which very likely explained the severity of the disease observed during the outbreaks. The H9N2 outbreaks in Ghana highlight the importance of performing a differential diagnosis and an in-depth characterization of emerging viruses. In addition, the detection of a potentially zoonotic subtype, such as the H9N2, in a region where highly pathogenic avian influenza H5Nx is currently circulating highlights the urgency of implementing enhanced monitoring strategies and supporting improved investments in regional diagnostic technologies. RESEARCH HIGHLIGHTS Influenza A H9N2 subtype was detected in layer hens in Ghana in 2017-2018 Whole genome characterization of seven H9N2 viruses was performed Phylogenetic trees revealed that the H9N2 viruses belong to the G1 lineage The HA protein possesses the amino acid mutations 226L and 155T Co-infection with infectious bronchitis virus of the GI-19 lineage was identified.
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Infecciones por Coronavirus/veterinaria , Brotes de Enfermedades/veterinaria , Genoma Viral/genética , Virus de la Bronquitis Infecciosa/aislamiento & purificación , Subtipo H9N2 del Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/epidemiología , Animales , Pollos , Coinfección/veterinaria , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/virología , Ghana/epidemiología , Virus de la Bronquitis Infecciosa/genética , Virus de la Bronquitis Infecciosa/patogenicidad , Subtipo H9N2 del Virus de la Influenza A/genética , Subtipo H9N2 del Virus de la Influenza A/patogenicidad , Gripe Aviar/virología , FilogeniaRESUMEN
Foot-and-mouth disease (FMD) is considered to be endemic in Ghana. However, our knowledge of the local epidemiology of the disease is restricted by a lack of serological information and data for characterized viruses causing field outbreaks. In order to improve our understanding of the prevailing situation, this study was initiated to establish the FMD viruses (FMDV) circulating in the country. During 2016, sera (n = 93) and epithelia/oral swab (n = 20) samples were collected from cattle from four districts in Southern Ghana that experienced FMD outbreaks. Sera were analyzed using the PrioCHECK® FMDV non-structural protein (NSP) ELISA whereas the epithelia/oral swab samples were examined by virus isolation, antigen ELISA, reverse transcription polymerase chain reaction (RT-PCR), and sequencing of VP1 followed by phylogenetic analysis. Assay for antibodies against FMDV NSPs provided evidence of exposure to FMDV in 88.2% (82/93) of the sera tested. Serotypes O and A viruses were detected from clinical samples by RT-PCR and sequencing of VP1. Phylogenetic analysis of VP1 coding sequences revealed that the serotype O viruses belonged to the West Africa (WA) topotype and were most closely related to viruses from Niger and Benin, while the serotype A viruses clustered within genotype IV (G-IV) of the Africa topotype and were most closely related to viruses from Nigeria. This study provides useful information on FMDV serotypes and viral lineages that circulate in Ghana and West Africa that may aid in the formulation of effective FMD control strategies.
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Enfermedades de los Bovinos/virología , Brotes de Enfermedades/veterinaria , Virus de la Fiebre Aftosa/genética , Fiebre Aftosa/virología , Animales , Bovinos , Enfermedades de los Bovinos/epidemiología , Ensayo de Inmunoadsorción Enzimática/veterinaria , Fiebre Aftosa/epidemiología , Virus de la Fiebre Aftosa/inmunología , Genotipo , Ghana/epidemiología , Filogenia , SerogrupoAsunto(s)
Subtipo H5N1 del Virus de la Influenza A/clasificación , Subtipo H5N1 del Virus de la Influenza A/genética , Gripe Aviar/epidemiología , Gripe Aviar/virología , Aves de Corral , Animales , Genes Virales , Ghana/epidemiología , Historia del Siglo XXI , Subtipo H5N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/historia , FilogeniaRESUMEN
The phylum Apicomplexa includes parasites of medical, zoonotic and veterinary significance. Understanding the global distribution and genetic diversity of these protozoa is of fundamental importance for efficient, robust and long-lasting methods of control. Eimeria spp. cause intestinal coccidiosis in all major livestock animals and are the most important parasites of domestic chickens in terms of both economic impact and animal welfare. Despite having significant negative impacts on the efficiency of food production, many fundamental questions relating to the global distribution and genetic variation of Eimeria spp. remain largely unanswered. Here, we provide the broadest map yet of Eimeria occurrence for domestic chickens, confirming that all the known species (Eimeria acervulina, Eimeria brunetti, Eimeria maxima, Eimeria mitis, Eimeria necatrix, Eimeria praecox, Eimeria tenella) are present in all six continents where chickens are found (including 21 countries). Analysis of 248 internal transcribed spacer sequences derived from 17 countries provided evidence of possible allopatric diversity for species such as E. tenella (FST values ⩽0.34) but not E. acervulina and E. mitis, and highlighted a trend towards widespread genetic variance. We found that three genetic variants described previously only in Australia and southern Africa (operational taxonomic units x, y and z) have a wide distribution across the southern, but not the northern hemisphere. While the drivers for such a polarised distribution of these operational taxonomic unit genotypes remains unclear, the occurrence of genetically variant Eimeria may pose a risk to food security and animal welfare in Europe and North America should these parasites spread to the northern hemisphere.
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ADN Protozoario/genética , Eimeria/genética , Enfermedades de las Aves de Corral/parasitología , Animales , Biodiversidad , Pollos/parasitología , Clasificación , Coccidiosis/epidemiología , Coccidiosis/parasitología , Coccidiosis/veterinaria , Genotipo , Filogenia , Filogeografía , Enfermedades de las Aves de Corral/epidemiología , Análisis de Secuencia de ADNRESUMEN
To trace the evolution of highly pathogenic influenza A(H5N1) virus in West Africa, we sequenced genomes of 43 viruses collected during 2015 from poultry and wild birds in 5 countries. We found 2 co-circulating genetic groups within clade 2.3.2.1c. Mutations that may increase adaptation to mammals raise concern over possible risk for humans.
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Variación Genética , Subtipo H5N1 del Virus de la Influenza A/genética , Gripe Aviar/epidemiología , Gripe Aviar/virología , Aves de Corral/virología , África Occidental/epidemiología , Animales , Genoma Viral , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Humanos , Subtipo H5N1 del Virus de la Influenza A/clasificación , Subtipo H5N1 del Virus de la Influenza A/patogenicidad , Mutación , Filogenia , Virulencia , Secuenciación Completa del GenomaRESUMEN
Village poultry and their owners were frequently implicated in disease transmission in the early days of the highly pathogenic avian influenza (HPAI) H5N1 pandemic. With improved understanding of the epidemiology of the disease, it was recognized that village poultry raised under extensive conditions pose less of a threat than intensively raised poultry of homogeneous genetic stock with poor biosecurity. This paper provides an overview of village poultry production and the multiple ways that the HPAI H5N1 pandemic has impacted on village poultry, their owners, and the traders whose livelihoods are intimately linked to these birds. It reviews impact in terms of gender and cultural issues; food security; village poultry value chains; approaches to biosecurity; marketing; poultry disease prevention and control; compensation; genetic diversity; poultry as part of livelihood strategies; and effective communication. It concludes on a positive note that there is growing awareness amongst animal health providers of the importance of facilitating culturally sensitive dialogue to develop HPAI prevention and control options.
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Brotes de Enfermedades/economía , Brotes de Enfermedades/veterinaria , Abastecimiento de Alimentos/economía , Subtipo H5N1 del Virus de la Influenza A , Gripe Aviar/epidemiología , Enfermedades de las Aves de Corral/economía , Animales , Comercio , Países en Desarrollo/economía , Cadena Alimentaria , Indonesia/epidemiología , Subtipo H5N1 del Virus de la Influenza A/patogenicidad , Gripe Aviar/prevención & control , Gripe Aviar/virología , Masculino , Aves de Corral , Enfermedades de las Aves de Corral/prevención & control , Enfermedades de las Aves de Corral/virología , Productos Avícolas/economía , Factores de Riesgo , Población Rural , Factores Sexuales , Factores Socioeconómicos , Vietnam/epidemiologíaRESUMEN
Small-scale commercial poultry production is emerging as an important form of livestock production in Africa, providing sources of income and animal protein to many poor households, yet the occurrence and impact of coccidiosis on this relatively new production system remains unknown. The primary objective of this study was to examine Eimeria parasite occurrence on small-scale commercial poultry farms in Ghana, Tanzania and Zambia. Additionally, farm economic viability was measured by calculating the farm gross margin and enterprise budget. Using these economic measures as global assessments of farm productivity, encompassing the diversity present in regional husbandry systems with a measure of fundamental local relevance, we investigated the detection of specific Eimeria species as indicators of farm profitability. Faecal samples and data on production parameters were collected from small-scale (less than 2,000 birds per batch) intensive broiler and layer farms in peri-urban Ghana, Tanzania and Zambia. All seven Eimeria species recognised to infect the chicken were detected in each country. Furthermore, two of the three genetic variants (operational taxonomic units) identified previously in Australia have been described outside of Australia for the first time. Detection of the most pathogenic Eimeria species associated with decreased farm profitability and may be considered as an indicator of likely farm performance. While a causal link remains to be demonstrated, the presence of highly pathogenic enteric parasites may pose a threat to profitable, sustainable small-scale poultry enterprises in Africa.
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Agricultura/economía , Pollos , Coccidiosis/veterinaria , Eimeria/genética , Filogenia , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/parasitología , Animales , Secuencia de Bases , Análisis por Conglomerados , Coccidiosis/epidemiología , Cartilla de ADN/genética , ADN Espaciador Ribosómico/genética , Heces/parasitología , Ghana/epidemiología , Funciones de Verosimilitud , Modelos Genéticos , Datos de Secuencia Molecular , Oocistos/citología , Prevalencia , Alineación de Secuencia , Análisis de Secuencia de ADN/veterinaria , Tanzanía/epidemiología , Zambia/epidemiologíaRESUMEN
Highly pathogenic avian influenza virus A/H5N1 was first officially reported in Africa in early 2006. Since the first outbreak in Nigeria, this virus spread rapidly to other African countries. From its emergence to early 2008, 11 African countries experienced A/H5N1 outbreaks in poultry and human cases were also reported in three of these countries. At present, little is known of the epidemiology and molecular evolution of A/H5N1 viruses in Africa. We have generated 494 full gene sequences from 67 African isolates and applied molecular analysis tools to a total of 1,152 A/H5N1 sequences obtained from viruses isolated in Africa, Europe and the Middle East between 2006 and early 2008. Detailed phylogenetic analyses of the 8 gene viral segments confirmed that 3 distinct sublineages were introduced, which have persisted and spread across the continent over this 2-year period. Additionally, our molecular epidemiological studies highlighted the association between genetic clustering and area of origin in a majority of cases. Molecular signatures unique to strains isolated in selected areas also gave us a clearer picture of the spread of A/H5N1 viruses across the continent. Mutations described as typical of human influenza viruses in the genes coding for internal proteins or associated with host adaptation and increased resistance to antiviral drugs have also been detected in the genes coding for transmembrane proteins. These findings raise concern for the possible human health risk presented by viruses with these genetic properties and highlight the need for increased efforts to monitor the evolution of A/H5N1 viruses across the African continent. They further stress how imperative it is to implement sustainable control strategies to improve animal and public health at a global level.