Bushmeat genetics: setting up a reference framework for the DNA typing of African forest bushmeat

The bushmeat trade in tropical Africa represents illegal, unsustainable off‐takes of millions of tons of wild game – mostly mammals – per year. We sequenced four mitochondrial gene fragments (cyt b, COI, 12S, 16S) in >300 bushmeat items representing nine mammalian orders and 59 morphological species from five western and central African countries (Guinea, Ghana, Nigeria, Cameroon and Equatorial Guinea). Our objectives were to assess the efficiency of cross‐species PCR amplification and to evaluate the usefulness of our multilocus approach for reliable bushmeat species identification. We provide a straightforward amplification protocol using a single ‘universal’ primer pair per gene that generally yielded >90% PCR success rates across orders and was robust to different types of meat preprocessing and DNA extraction protocols. For taxonomic identification, we set up a decision pipeline combining similarity‐ and tree‐based approaches with an assessment of taxonomic expertise and coverage of the GENBANK database. Our multilocus approach permitted us to: (i) adjust for existing taxonomic gaps in GENBANK databases, (ii) assign to the species level 67% of the morphological species hypotheses and (iii) successfully identify samples with uncertain taxonomic attribution (preprocessed carcasses and cryptic lineages). High levels of genetic polymorphism across genes and taxa, together with the excellent resolution observed among species‐level clusters (neighbour‐joining trees and Klee diagrams) advocate the usefulness of our markers for bushmeat DNA typing. We formalize our DNA typing decision pipeline through an expert‐curated query database – DNAbushmeat – that shall permit the automated identification of African forest bushmeat items.     

Qualitative analysis of the risk of introducing Gyrodactylus salaris into the United Kingdom

Gyrodactylus salaris is a freshwater, monogenean ectoparasite of Baltic strains of Atlantic salmon Salmo salar on which it generally causes no clinical disease. Infection of other strains of Atlantic salmon in Norway has resulted in high levels of juvenile salmon mortality and highly significant reductions in the population. The parasite is a major exotic disease threat to wild Atlantic salmon in the UK. This paper qualitatively assesses the risk of introduction and establishment of G. salaris into the UK. The current UK fish health regime prevents the importation of live salmonids from freshwater in territories that have not substantiated freedom from G. salaris. The importation of other species, e.g. eels Anguilla anguilla and non-salmonid fish, represents a low risk because the likelihood of infection is very low and the parasite can only survive on these hosts for less than 50 d. Importation of salmon carcasses presents a negligible risk because harvested fish originate from seawater sites and the parasite cannot survive full strength salinity. The importation of rainbow trout Oncorhynchus mykiss carcasses from G. salaris infected freshwater sites might introduce the parasite, but establishment is only likely if carcasses are processed on a salmonid farm in the UK. A number of mechanical transmission routes were considered (e.g. angling equipment, canoes, ballast water) and the most important was judged to be the movement of live fish transporters from farms on mainland Europe direct to UK fish farms. In the future, territories may have to substantiate freedom from G. salaris and economic drivers for live salmonid imports may strengthen. Under these circumstances, legal or illegal live salmonid imports would become the most significant risk of introduction.     

Zoonotic viruses associated with illegally imported wildlife products

The global trade in wildlife has historically contributed to the emergence and spread of infectious diseases. The United States is the world's largest importer of wildlife and wildlife products, yet minimal pathogen surveillance has precluded assessment of the health risks posed by this practice. This report details the findings of a pilot project to establish surveillance methodology for zoonotic agents in confiscated wildlife products. Initial findings from samples collected at several international airports identified parts originating from nonhuman primate (NHP) and rodent species, including baboon, chimpanzee, mangabey, guenon, green monkey, cane rat and rat. Pathogen screening identified retroviruses (simian foamy virus) and/or herpesviruses (cytomegalovirus and lymphocryptovirus) in the NHP samples. These results are the first demonstration that illegal bushmeat importation into the United States could act as a conduit for pathogen spread, and suggest that implementation of disease surveillance of the wildlife trade will help facilitate prevention of disease emergence.     

Do bushmeat consumers have other fish to fry?

The overexploitation of tropical forests for bushmeat and of the oceans for fish are two of the most important threats to global biodiversity. Both phenomena also have manifold implications for human livelihoods and food security. A recent article by Brashares et al. indicates that these two resources are linked: when regional fish supplies are low, local bushmeat hunting intensifies. Although coordinated management of bushmeat and fisheries is thus needed, gaps in our knowledge of these systems must first be filled.     

The pattern of poaching signs in Ugalla Game Reserve,western Tanzania

Illegal harvesting of wildlife resources is an important challenge facing protected areas in Africa. A better understanding of its nature would improve the way in which it is managed. We investigated the degree of poaching into different types of natural resources and its management implications in Ugalla Game Reserve, western Tanzania, using data on spatial distribution of poaching signs. Poaching signs were distributed nonrandomly through the reserve, which suggested that poachers targeted particular resources at certain areas of the reserve. Logging was the predominant illegal activity, followed by bushmeat hunting and illegal fishing. Logging signs were widespread at Ugalla east and Ugalla south. The latter also contained the highest encounter rate of bushmeat signs. Illegal fishing was extensive around the main rivers in the reserve. For improved conservation enforcement in western Tanzania and similar ecosystems, conservation efforts should take into consideration the distribution and composition of different types of poaching.     

Does illegal hunting affect density and behaviour of African grassland birds? A case study on ostrich (Struthio camelus)

Widespread bushmeat hunting represents one of the major threats to many mammals and birds in Africa. We studied the influence of illegal bushmeat hunting on large grassland birds in the Serengeti National Park (SNP) and adjoining protected areas, by using the ostrich (Struthio camelus) as a case study. First, we documented illegal hunting of both small and large birds by using a questionnaire in the villages on the western and eastern side of the SNP. Second, we studied the effect of illegal hunting on density by driving 4,659 km of transects inside SNP and on the adjacent protected areas, where the data were analysed by DISTANCE sampling. Last, we used flight initiation distance (FID, i.e. the distance between an approaching predator (human) and prey when flight is started), to assess possible impacts on behaviour from illegal hunting. We found that people from the western side of the SNP admitted to hunting both small and large grassland birds, and collect ostrich feathers and eggs. Although the Maasai also hunted small birds, only ostrich feathers and eggs of the large grassland birds were used. Surprisingly, we found no significant differences in densities between the SNP and adjoining partially protected areas, but ostriches had longer FID to an approaching human outside the SNP. Currently illegal hunting does not appear to affect the ostrich population, but given the extensive use of birds for consumption more awareness educational programs accompanied by provision of agricultural incentives within the protected areas are needed.     

Zoonotic Disease Risk and the Bushmeat Trade: Assessing Awareness Among Hunters and Traders in Sierra Leone

The bushmeat industry has been a topic of increasing importance among both conservationists and public health officials for its influence on zoonotic disease transmission and animal conservation. While the association between infectious diseases and the bushmeat trade is well established in the research community, risk perception among bushmeat hunters and traders has not been well characterized. I conducted surveys of 123 bushmeat hunters and traders in rural Sierra Leone to investigate hunting practices and awareness of zoonotic disease risk associated with the bushmeat trade. Twenty-four percent of bushmeat hunters and traders reported knowledge of disease transmission from animals to humans. Formal education did not significantly affect awareness of zoonotic disease transmission. Individuals who engaged exclusively in preparation and trading of bushmeat were more likely to accidentally cut themselves compared to those who primarily engaged in bushmeat hunting (P < 0.001). In addition, women involved in the bushmeat trade were at greater risk of exposing themselves to potential zoonotic pathogens through accidental self-cutting compared to men (P < 0.01). This study collected preliminary information on risk perception among bushmeat hunters that could guide the creation of a future public health-based education program to minimize zoonotic disease transmission risk among vulnerable communities.     

The Importance of Bushmeat in the Livelihoods of West African Cash-Crop Farmers Living in a Faunally-Depleted Landscape

Bushmeat is an important resource in the livelihoods of many rural communities in sub-Saharan Africa and may be a crucial safety-net for the most vulnerable households, especially during times of economic hardship. However, little is known about the impacts of wildlife depletion on these functions. This study quantifies the role of bushmeat in diversified rural household economies in a wildlife depleted forest-farm landscape in Ghana, assessing its importance overall, as well as differentiated by the relative vulnerability of households. Using repeat socioeconomic questionnaires (N=787) among 63 households over a one-year period, the following hypotheses were tested: (a) vulnerable households harvest more bushmeat; (b) bushmeat contributes a greater proportion of household production in vulnerable households; (c) bushmeat is more important for cash income than consumption in vulnerable households; and (d) bushmeat sales are more important for vulnerable households. The bushmeat harvest value averaged less than US$1.0 per day for 89% of households and comprised less than 7% of household production value. Household wealth and gender of the household head had little effect on the importance of bushmeat. However, bushmeat harvest and sales were highest during the agricultural lean season. Overall, most harvested bushmeat (64%) was consumed, enabling households to spend 30% less on meat/fish purchases. These findings suggest that, despite heavily depleted wildlife and diversified livelihoods, bushmeat continues to have an important role in rural livelihoods by acting as a safety net for income smoothing and reducing household expenditure during times of economic hardship.     

Inhibitory activity of antibiotic-producing marine bacteria against fish pathogens

The activity of antibiotic-producing marine bacteria was assayed against bacterial fish pathogens belonging to the genera Vibrio, Aeromonas, Pasteurella, Edwardsiella, Yersinia and Pseudomonas with the aim of evaluating the possible use of these marine strains for controlling epizootics in aquaculture. Inhibition tests on solid medium showed that, in general, the majority of fish bacteria were strongly sensitive to the marine bacteria. Only two strains ( Edwardsiella tarda and Pseudomonas aeruginosa ), were resistant to all the antibiotic-producing strains. The results of antagonism assays in sea water, however, varied according to the fish pathogens examined. Experiments conducted using cell-free supernatant fluids of marine bacteria demonstrated the involvement of antibiotic substances in the inhibition of fish pathogens.     

Inhibitory activity of antibiotic-producing marine bacteria against fish pathogens

The activity of antibiotic-producing marine bacteria was assayed against bacterial fish pathogens belonging to the genera Vibrio, Aeromonas, Pasteurella, Edwardsiella, Yersinia and Pseudomonas with the aim of evaluating the possible use of these marine strains for controlling epizootics in aquaculture. Inhibition tests on solid medium showed that, in general, the majority of fish bacteria were strongly sensitive to the marine bacteria. Only two strains (Edwardsiella tarda and Pseudomonas aeruginosa), were resistant to all the antibiotic-producing strains. The results of antagonism assays in sea water, however, varied according to the fish pathogens examined. Experiments conducted using cell-free supernatant fluids of marine bacteria demonstrated the involvement of antibiotic substances in the inhibition of fish pathogens.     

Public health significance of zoonotic bacterial pathogens from bushmeat sold in urban markets of Gabon, Central Africa

Wild animal meat represents an important source of protein for many people in central Africa. Also known as bushmeat, this meat commodity is derived from wild animals hunted under uncontrolled conditions, transported to distant markets under rudimentary or no hygienic methods, and often eviscerated >24 hr after death. Considering the plausible role of wildlife as a reservoir for bacterial zoonotic pathogens, bushmeat may be an important public health risk in Central Africa. This cross-sectional survey served to evaluate the presence of Campylobacter, Salmonella, and Shigella in the muscle tissue of 128 wild animal carcasses from several hunted wildlife species (guenons [Cercopithecus spp.], collared mangabeys [Cercocebus torquatus], gray-cheeked mangabeys [Lophocebus albigena], African crested porcupines [Atherurus africanus], duikers [Cephalophus spp.], and red river hogs [Potamocherus porcus]) sold in two markets of Port-Gentil, Gabon, in July and August 2010. Salmonella was detected from one carcass; no Campylobacter or Shigella was detected. If Campylobacter and Shigella were present, the maximum expected prevalence was estimated at 6% and 1%, respectively. In light of such very low apparent muscle contamination levels, bushmeat likely does not represent a health risk per se with respect to Campylobacter, Salmonella, or Shigella. However, because carcass evisceration and skinning can take place within households prior to consumption, consumers should follow strict hygiene and food safety practices to avoid potential health hazards associated with the handling, preparation, or consumption of bushmeat.     

Mapping Bushmeat Hunting Pressure in Central Africa

Hunting and trade of wild animals for their meat (bushmeat), especially mammals, is commonplace in tropical forests worldwide. In West and Central Africa, bushmeat extraction has increased substantially during recent decades. Currently, such levels of hunting pose a major threat to native wildlife. In this paper, we compiled published data on hunting offtake of mammals, from a number of studies conducted between 1990 and 2007 in Cameroon, Central African Republic, Democratic Republic of Congo, Equatorial Guinea, Gabon, and Republic of Congo. From these data sources, we estimated annual extraction rates of all hunted species and analyzed the relationship between environmental and anthropogenic variables surrounding each hunting rate and levels of bushmeat extraction. We defined hunting pressure as a function of bushmeat offtake and number of hunted species and confirm that hunting pressure is significantly correlated with road density, distance to protected areas and population density. These correlations are then used to map hunting pressure across the Congo Basin. We show that predicted risk areas show a patchy distribution throughout the study region and that many protected areas are located in high‐risk areas. We suggest that such a map can be used to identify areas of greatest impact of hunting to guide large‐scale conservation planning initiatives for central Africa.     

Occurrence of Drug-Resistant Bacteria in Two European Eel Farms

The occurrence of strains that are resistant to oxolinic acid, oxytetracycline, sulfamethoxazole-trimethoprim, and nitrofurantoin among heterotrophic bacteria, including human and fish pathogens, in two freshwater eel farms was investigated. High levels of individual- and multiple-drug-resistant bacteria were detected, although sampling events were not correlated with clinical outbreaks and drug therapy.     

Occurrence of drug-resistant bacteria in two European eel farms

The occurrence of strains that are resistant to oxolinic acid, oxytetracycline, sulfamethoxazole-trimethoprim, and nitrofurantoin among heterotrophic bacteria, including human and fish pathogens, in two freshwater eel farms was investigated. High levels of individual- and multiple-drug-resistant bacteria were detected, although sampling events were not correlated with clinical outbreaks and drug therapy.     

Comparison of antibodies in marine fish from clean and polluted waters of the New York Bight: relative levels against 36 bacteria.

Fish from polluted waters are subject to increased prevalence of disease. Because they respond to bacterial pathogens by producing serum antibodies, it was possible to construct a seasonal serological record in three fish species from clean and polluted waters of the New York Bight. Antibody levels were determined by testing sera for agglutinating activity against 36 strains of bacteria. Evaluation of 5,100 antibody titrations showed the following. During warm months, summer flounder (Paralichthys dentatus) from the polluted area had significantly higher antibody levels and antibody to a greater diversity of bacteria than fish from the unpolluted area. Weakfish (Cynoscion regalis) from the same polluted area shared with summer flounder raised titers to many bacteria. The greatest proportion of raised titers was against Vibrio species, although prominent titers were also seen against Aeromonas salmonicida and Haemophilus piscium, bacteria usually associated with diseases in freshwater but not marine fish. Differences between polluted and clean waters were not as evident in winter flounder (Pseudopleuronectes americanus) during cold months. This could be due, in part, to reduced antibody production at colder temperatures. The data illustrate the usefulness of the serum antibody record in identifying environmental exposure to bacteria in marine fish and indicate that the polluted New York Bight apex has increased levels and diversity of bacteria during warm months.     

Comparison of antibodies in marine fish from clean and polluted waters of the New York Bight: relative levels against 36 bacteria

Fish from polluted waters are subject to increased prevalence of disease. Because they respond to bacterial pathogens by producing serum antibodies, it was possible to construct a seasonal serological record in three fish species from clean and polluted waters of the New York Bight. Antibody levels were determined by testing sera for agglutinating activity against 36 strains of bacteria. Evaluation of 5,100 antibody titrations showed the following. During warm months, summer flounder (Paralichthys dentatus) from the polluted area had significantly higher antibody levels and antibody to a greater diversity of bacteria than fish from the unpolluted area. Weakfish (Cynoscion regalis) from the same polluted area shared with summer flounder raised titers to many bacteria. The greatest proportion of raised titers was against Vibrio species, although prominent titers were also seen against Aeromonas salmonicida and Haemophilus piscium, bacteria usually associated with diseases in freshwater but not marine fish. Differences between polluted and clean waters were not as evident in winter flounder (Pseudopleuronectes americanus) during cold months. This could be due, in part, to reduced antibody production at colder temperatures. The data illustrate the usefulness of the serum antibody record in identifying environmental exposure to bacteria in marine fish and indicate that the polluted New York Bight apex has increased levels and diversity of bacteria during warm months.     

Comparative skin mucus and serum humoral defence mechanisms in the teleost gilthead seabream (Sparus aurata)

Mucosal surfaces of fish, including skin, gill and gut, contain numerous immune substances poorly studied that act as the first line of defence against a broad spectrum of pathogens. This study aimed to identify and characterize for the first time different constitutive humoral defence mechanisms of the skin mucus of gilthead seabream (Sparus aurata). To do this, the levels of total immunoglobulin M, several enzymes and proteins (peroxidase, lysozyme, alkaline phosphatase, esterases, proteases and antiproteases), as well as the bactericidal activity against opportunist fish pathogens (Vibrio harveyi, Vibrio angillarum, Photobacterium damselae) and non-pathogenic bacteria (Escherichia coli, Bacillus subtilis) were measured in the skin mucus and compared with those found in the serum. This study demonstrates that gilthead seabream skin mucus contains lower levels of IgM, similar levels of lysozyme, alkaline phosphatase and proteases, and higher esterase, peroxidase and antiprotease activities than serum. In addition, skin mucus revealed stronger bactericidal activity against tested fish pathogen bacteria compared to the serum activity, while human bacteria can even grow more in the presence of mucus. The results could be useful for better understanding the role of the skin mucus as a key component of the innate immune system with potential application for the aquaculture.     

Introduction of African Swine Fever into the European Union through Illegal Importation of Pork and Pork Products

Transboundary animal diseases can have very severe socio-economic impacts when introduced into new regions. The history of disease incursions into the European Union suggests that initial outbreaks were often initiated by illegal importation of meat and derived products. The European Union would benefit from decision-support tools to evaluate the risk of disease introduction caused by illegal imports in order to inform its surveillance strategy. However, due to the difficulty in quantifying illegal movements of animal products, very few studies of this type have been conducted. Using African swine fever as an example, this work presents a novel risk assessment framework for disease introduction into the European Union through illegal importation of meat and products. It uses a semi-quantitative approach based on factors that likely influence the likelihood of release of contaminated smuggled meat and products, and subsequent exposure of the susceptible population. The results suggest that the European Union is at non-negligible risk of African swine fever introduction through illegal importation of pork and products. On a relative risk scale with six categories from negligible to very high, five European Union countries were estimated at high (France, Germany, Italy and United Kingdom) or moderate (Spain) risk of African swine fever release, five countries were at high risk of exposure if African swine fever were released (France, Italy, Poland, Romania and Spain) and ten countries had a moderate exposure risk (Austria, Bulgaria, Germany, Greece, Hungary, Latvia, Lithuania, Portugal, Sweden and United Kingdom). The approach presented here and results obtained for African swine fever provide a basis for the enhancement of risk-based surveillance systems and disease prevention programmes in the European Union.     

Bushmeat,over-fishing and covariates explaining fish abundance declines in the Central Congo Basin

Fish stocks are declining at alarming rates in the Central African forests but little is known about patterns of fishing pressure for different areas. To contribute to the understanding of covariates that could explain these trends, this study documented the relative abundances of fish in eleven sites in the western Democratic Republic of Congo in relation to human density, distance from the nearest markets and mean numbers of fishing nets. Linear regression indicated that, taken alone, 88 % of observed differences in fish relative abundance correlated with the mean number of fishing nets and 60 % of these differences were attributable to distance from the nearest market. Human density was marginally associated with fish abundance. The study also shows that fish and wildlife relative abundances followed the same trends: where more wildlife species remain, there are more abundant fish stocks. The two conservation messages of this paper are that, as is the case for bushmeat, fishing becomes a problem when the commercial market is its prime driver and a solution to the bushmeat crisis could also reduce over-fishing.     

Analysis of patterns of bushmeat consumption reveals extensive exploitation of protected species in eastern Madagascar

Understanding the patterns of wild meat consumption from tropical forests is important for designing approaches to address this major threat to biodiversity and mitigate potential pathways for transmission of emerging diseases. Bushmeat consumption has been particularly poorly studied in Madagascar, one of the world's hottest biodiversity hotspots. Studying bushmeat consumption is challenging as many species are protected and researchers must consider the incentives faced by informants. Using interviews with 1154 households in 12 communes in eastern Madagascar, as well as local monitoring data, we investigated the importance of socio-economic variables, taste preference and traditional taboos on consumption of 50 wild and domestic species. The majority of meals contain no animal protein. However, respondents consume a wide range of wild species and 95% of respondents have eaten at least one protected species (and nearly 45% have eaten more than 10). The rural/urban divide and wealth are important predictors of bushmeat consumption, but the magnitude and direction of the effect varies between species. Bushmeat species are not preferred and are considered inferior to fish and domestic animals. Taboos have provided protection to some species, particularly the Endangered Indri, but we present evidence that this taboo is rapidly eroding. By considering a variety of potential influences on consumption in a single study we have improved understanding of who is eating bushmeat and why. Evidence that bushmeat species are not generally preferred meats suggest that projects which increase the availability of domestic meat and fish may have success at reducing demand. We also suggest that enforcement of existing wildlife and firearm laws should be a priority, particularly in areas undergoing rapid social change. The issue of hunting as an important threat to biodiversity in Madagascar is only now being fully recognised. Urgent action is required to ensure that heavily hunted species are adequately protected.