Prevention and identification of Salmonella Enteritidis infection via novel diagnostic stained antigens and polyclonal antibodies

Analysis of Salmonella Enteritidis with specific antisera and stained antigen helps to reduce the identification time of the infection and offers clinical and epidemiological advantages both for poultry health and food industry for the control of salmonellosis. In this study, S. Enteritidis O and H specific antisera were obtained from rabbits immunised subcutaneously using formalin-treated whole bacterial cells as antigens. S. Enteritidis specific stained O and H antigens were prepared and tested for their diagnostic usefulness. In order to eliminate cross reactivity, Salmonella Adeyo was used as an antigen for the production of H specific polyclonal antibody and stained H antigen. Enzyme-linked immunosorbent assay results of antisera were obtained, ranging from 273,300±0.041–312,200±0.028 A492 nm. Stained O and H antigen preparations were achieved with a stronger binding degree to the hyperimmune rabbit sera and without being shown cross-reactivity between O and H antigens.     

Bacillus spp. as direct-fed microbial antibiotic alternatives to enhance growth,immunity, and gut health in poultry

The increasing occurrence of antibiotic-resistant bacteria combined with regulatory pressure and consumer demands for foods produced without antibiotics has caused the agricultural industry to restrict its practice of using antibiotic growth promoters (AGP) in food animals. The poultry industry is not immune to this trend, and has been actively seeking natural alternatives to AGP that will improve the health and growth performance of commercial poultry flocks. Bacillus probiotics have been gaining in popularity in recent years as an AGP alternative because of their health-promoting benefits and ability to survive the harsh manufacturing conditions of chicken feed production. This review provides an overview of several modes of action of some Bacillus direct-fed microbials as probiotics. Among the benefits of these direct-fed microbials are their production of naturally synthesized antimicrobial peptides, gut flora modulation to promote beneficial microbiota along the gastrointestinal tract, and various immunological and gut morphological alterations. The modes of action for increased performance are not well defined, and growth promotion is not equal across all Bacillus species or within strains. Appropriate screening and characterization of Bacillus isolates prior to commercialization are necessary to maximize poultry growth to meet the ultimate goal of eliminating AGP usage in animal husbandry.     

Genetic Characterization of Highly Pathogenic Avian Influenza (H5N8) Virus from Domestic Ducks,England, November 2014

Genetic sequences of a highly pathogenic avian influenza (H5N8) virus in England have high homology to those detected in mainland Europe and Asia during 2014. Genetic characterization suggests this virus is an avian-adapted virus without specific affinity for zoonoses. Spatio-temporal detections of H5N8 imply a role for wild birds in virus spread.     

Understanding Pig and Poultry Trade Networks and Farming Practices Within the Pacific Islands as a Basis for Surveillance

Pacific Island countries have large pig and poultry populations. Yet little is known about patterns of contact between animals and how this influences disease spread in these islands. The objectives of this study were to examine farmer practices and the movements of pig and poultry within the Pacific Islands using questionnaires and social network analysis (SNA) tools to understand disease spread in the region. Questionnaire‐based surveys were conducted in Fiji, Papua New Guinea (PNG), Solomon Islands and Vanuatu with interviews of 310 pig farmers and 491 poultry farmers. Pacific Island farmers were found to have few animals (median = 7 pigs/farm, IQR 4–12), (median = 50 chicken/farm, IQR 23–52), (median = 10 ducks/farm, IQR 4–25), (median = 12 Muscovy ducks/farm, IQR 7–28) and a diversified number of species. A large proportion of farmers (44.6–61.3%) do not implement any preventive or control measures, yet the majority (80.6–88%) did not experience any animal diseases over the past 12 months. Most farmers never ask for veterinary care, never engage in laboratory testing and do not report when their animals show clinical signs. Many pig farmers (31.8%) trade within their communities only and sell (24.5%) directly to consumers which reduces the risk of diseases spreading. Our results show an association between farmers that report having had disease on their farm in the past 12 months and movements of animals on and off their farms. The capitals of the studied provinces in PNG, Vanuatu and Solomon Islands were identified as the most connected nodes of both pig and poultry trade, while Fiji networks appeared much less connected. Our study found that farmer practices increased the risk of disease spread, but this was currently limited by trading practices. The SNA results serve as a basis for more targeted disease surveillance and better use of available resources for disease prevention and control.     

Influenza surveillance on ‘foie gras’ duck farms in Bulgaria, 2008–2012

Objectives

Ducks can shed and spread influenza A viruses (IAVs) while showing no disease signs. Our objective was to clarify the role of ‘foie gras’ ducks in the circulation of IAVs in Bulgaria.

Methods

Monthly avian influenza surveillance was conducted on 63 ‘foie gras’ duck farms, 52 of which were surveyed throughout the study between November 2008 and April 2012. Virologic and serologic samples were collected and tested. During this time, wild bird samples were collected at major wild bird‐resting areas near the Black Sea coast and Danube River.

Results

The study showed high isolation frequency of low‐pathogenicity avian influenza viruses. In the raising population (<75 days old), subtypes H3, H4, and H6 were detected monthly and H5 LPAIV, sporadically. Different subtypes (H1, H10, H11) were isolated from the fattening premises (75‐ to 100‐day‐old ducks), suggesting different routes of introduction. Only 6 of the 52 farms that were surveyed both virologically and serologically were influenza‐free throughout the study, possibly due to higher biosecurity measures implemented. No evidence of direct transmission of IAV from wild birds was found. Wild bird surveillance showed low isolation frequency of IAV. IAV prevalence of 0·55% for migratory ducks and 0·53% for migratory geese was estimated in November–December 2011 and January–February 2012, respectively, at two ornithologically important locations near the Black Sea coast.

Conclusions

The ‘foie gras’ duck farms in Bulgaria are an optimal niche where Eurasian‐like IAVs are maintained and reassorted unapparent to farmers and veterinarians.     

Influenza A(H5N8) Virus Similar to Strain in Korea Causing Highly Pathogenic Avian Influenza in Germany

Highly pathogenic avian influenza (H5N8) virus, like the recently described H5N8 strain from Korea, was detected in November 2014 in farmed turkeys and in a healthy common teal (Anas crecca) in northeastern Germany. Infected wild birds possibly introduced this virus.     

Novel Reassortant Influenza A(H5N8) Viruses among Inoculated Domestic and Wild Ducks,South Korea, 2014

An outbreak of highly pathogenic avian influenza, caused by a novel reassortant influenza A (H5N8) virus, occurred among poultry and wild birds in South Korea in 2014. The aim of this study was to evaluate the pathogenesis in and mode of transmission of this virus among domestic and wild ducks. Three of the viruses had similar pathogenicity among infected domestic ducks: the H5N8 viruses were moderately pathogenic (0%–20% mortality rate); in wild mallard ducks, the H5N8 and H5N1 viruses did not cause severe illness or death; viral replication and shedding were greater in H5N8-infected mallards than in H5N1-infected mallards. Identification of H5N8 viruses in birds exposed to infected domestic ducks and mallards indicated that the viruses could spread by contact. We propose active surveillance to support prevention of the spread of this virus among wild birds and poultry, especially domestic ducks.     

Identification of the source of A (H10N8) virus causing human infection

A novel H10N8 influenza A virus has been detected in three humans in China since December 2013. Although this virus was hypothesized to be a novel reassortant among influenza viruses from wild birds and domestic poultry, its evolutionary path leading to human infection is unknown. Sporadic surveillance at the live poultry market (LPM) suspected to be the source of infection for the first H10N8 patient has shown a gradual increase in influenza virus prevalence culminating with a predominance of H10N8 viruses. Influenza viruses detected in the LPM up to 8 months prior to human infection contributed genetic components to the zoonotic virus. These H10N8 viruses have continued to evolve within this LPM subsequent to the human infection, and continuous assessments of these H10N8 viruses will be necessary. Serological surveillance showed that the virus appears to have been present throughout the LPM system in Nanchang, China. Reduction of the influenza virus burden in LPMs is essential in preventing future emergence of novel influenza viruses with zoonotic and pandemic potential.     

Effects of an integrated poultry value chain,nutrition, gender and WASH intervention (SELEVER) on hygiene and child morbidity and anthropometry in Burkina Faso: A secondary outcome analysis of a cluster randomised trial

Nutrition-sensitive agriculture programmes have the potential to improve child nutrition outcomes, but livestock intensification may pose risks related to water, sanitation and hygiene (WASH) conditions. We assessed the impact of SELEVER, a nutrition- and gender-sensitive poultry intervention, with and without added WASH focus, on hygiene practices, morbidity and anthropometric indices of nutrition in children aged 2−4 years in Burkina Faso. A 3-year cluster randomised controlled trial was implemented in 120 villages in 60 communes (districts) supported by the SELEVER project. Communes were randomly assigned using restricted randomisation to one of three groups: (1) SELEVER intervention (n = 446 households); (2) SELEVER plus WASH intervention (n = 432 households); and (3) control without intervention (n = 899 households). The study population included women aged 15−49 years with an index child aged 2−4 years. We assessed the effects 1.5-years (WASH substudy) and 3-years (endline) post-intervention on child morbidity and child anthropometry secondary trial outcomes using mixed effects regression models. Participation in intervention activities was low in the SELEVER groups, ranging from 25% at 1.5 years and 10% at endline. At endline, households in the SELEVER groups had higher caregiver knowledge of WASH-livestock risks (∆ = 0.10, 95% confidence interval [CI] [0.04−0.16]) and were more likely to keep children separated from poultry (∆ = 0.09, 95% CI [0.03−0.15]) than in the control group. No differences were found for other hygiene practices, child morbidity symptoms or anthropometry indicators. Integrating livestock WASH interventions alongside poultry and nutrition interventions can increase knowledge of livestock-related risks and improve livestock-hygiene-related practices, yet may not be sufficient to improve the morbidity and nutritional status of young children.