Backyard Chickens Research Articles

Serological and Molecular Investigation of Infectious Laryngotracheitis Virus in Chickens from Robe Town, Southeastern Ethiopia

Infectious laryngotracheitis virus (ILTV) is responsible for avian infectious laryngotracheitis (ILT), a highly contagious acute respiratory disease affecting chickens. However, there is limited information on ILTV and its distribution in Ethiopia, particularly in the southeastern region. The aim of this study was to establish the serological prevalence and molecular evidence in commercial and backyard chickens from Robe town, Southeastern Ethiopia. A cross-sectional study was conducted between December 2021 and June 2022, collecting 240 serum samples from randomly selected chickens belonging to eight kebeles (farms) using systematic random sampling. ILTV-specific antibodies were detected using a commercial indirect enzyme-linked immunosorbent assay (ELISA). From 240 serum samples, 26.7% were positive for ILTV antibodies. Logistic regression analysis identified the type of poultry farm (backyard) and the introduction of chickens from other farms as potential risk factors associated with ILTV exposure. Tracheal tissue and oropharyngeal and tracheal swabs were collected from suspected chickens for isolation and molecular detection. A total of six samples were successfully isolated in embryonated eggs (40%), with four of them verified with a specific PCR. These findings documented the presence of ILTV in the study area, which needs further insight to fully understand the actual spread of ILTV and quantify the damage caused to the poultry sector.

The Chicken for the Egg: Australian Motivations for Raising Backyard Chickens

The Chicken for the Egg: Australian Motivations for Raising Backyard Chickens

Unscrambling why plastics aren't detectable in chicken eggs

Several food groups have been reported to contain varying concentrations of plastics. This study was designed to quantitatively investigate for the first time in Australia the presence of plastics in store-bought chicken eggs. Three commonly consumed brands of free-range, free-range organic, barn-laid and backyard (home-laid) chicken egg samples were analyzed for seven common polymers (i.e., polypropylene, polyethylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, poly-(methylmethacrylate) and polycarbonate). Samples were extracted by enzyme digestion and pressurized liquid extraction, followed by quantitative analysis through double-shot microfurnace pyrolysis coupled to gas chromatography-mass spectrometry. No plastics were detected at concentrations > limit of detection (LOD) (from 0.04 μg/g for PS to 0.22 μg/g for PVC) in the egg samples analyzed, regardless of brand and category, suggesting limited exposure of Australians to plastics from consuming eggs This study provides valuable baseline data and underscores the importance of continued monitoring to ensure the safety and integrity of food supplies in the face of rising environmental plastic pollution.

Global and regional prediction of heterakidosis population prevalence in extensive backyard chickens in low-income and middle-income countries

Extensive backyard chickens are one of the most common production systems in low-income and middle-income countries (LMICs). In this production system, chickens are exposed to infectious forms of parasites as a result of the outdoor access and scavenging behaviour. Heterakis gallinarum is one of the most common nematode parasites present in the environment, and estimating its global and regional prevalence is essential for attributing the economic losses in extensive backyard chickens. The objective of this study is to predict the prevalence of heterakidosis in extensive backyard chickens at global and regional levels in LMICs using regression imputation methods. A binomial random effect model was developed using empirical data on heterakidosis prevalence and climatic factors as main predictors. Prevalence data were then imputed in all regions based on the regression model. Global and country prevalence were estimated based on regional predictions and their beta distributions. Minimum precipitation, minimum temperature and maximum temperature were selected as significant predictors. The population prevalence of heterakidosis was 0.24 (0.19–0.29). Countries with continental and dry climates had a higher mean prevalence, whereas countries with tropical climates had a lower mean prevalence of heterakidosis. As more empirical data on heterakidosis prevalence become available, this model and predictions should be redefined and updated to capture a more representative association and increase the accuracy of the predictions. The results of this study can be used to attribute the economic losses of extensive backyard chickens, taking into account a holistic approach as promoted by the GBADs programme and therefore, to identify which diseases are more costly to backyard farmers. Furthermore, results can be also served as a proxy for the risk of histomoniasis in extensive backyard chickens.

Sentinel chicken surveillance reveals previously undetected circulation of West Nile virus in the Netherlands

ABSTRACT West Nile virus (WNV) was first detected in the Netherlands in 2020, with circulation observed in birds, mosquitoes, and humans in two geographical areas. Usutu virus (USUV) has been circulating in the Netherlands since 2016. Following the detection of WNV in the Netherlands, we investigated the possible use of petting zoos as urban sentinel sites to examine the extent of WNV and USUV circulation around the two WNV outbreak locations. Chickens at petting zoos and in backyards were sampled within a 15-kilometer radius of the confirmed WNV circulation areas at three timepoints over one year (2021–2022). Sera were analysed using a protein microarray for binding antibodies to orthoflavivirus NS1 antigens and reactive samples were confirmed through micro-focus reduction neutralization tests (mFRNT). Furthermore, mosquitoes at sampling locations were collected to assess their blood feeding behaviour. This serosurvey detected the circulation of USUV and WNV in petting zoo and backyard chickens in 2021, both within and outside the 2020 outbreak areas. The WNV circulation was not detected by other existing surveillance schemes in mosquitoes, wild birds, horses and humans. In addition, the results show rapid decay of USUV antibodies in approximately 20 weeks. Our findings support the utility and the added value of petting zoo chickens as sentinels for monitoring USUV and WNV circulation compared to other available methods. Seroconversions observed in petting zoos and backyard chickens living in or near densely populated urban areas further highlighted potential public health risks that went undetected.

Survey of the husbandry and biosecurity practices of backyard chicken keepers in the UK.

This survey investigated the housing, feeding, health and welfare of backyard chickens kept in the UK. Information was collected via an online questionnaire active from May to July 2021. The survey asked about flock demographics, housing, diet, enrichment provision, if the flock was registered with the Animal Plant and Health Agency (APHA) and the reason, preventative health care and biosecurity, and the incidence and methods of euthanasia. The majority of flocks (48.8%) consisted of one to five birds, were located in rural areas (58%) and were kept as pets (77%) and/or for eggs (71.6%). Enrichment was provided by 78.4% of keepers. Most respondents (69%) were aware of the Animal Plant and Health Agency poultry registration scheme, with 32.8% being registered with the scheme. Kitchen scraps were fed by 29% of keepers. Veterinary services were used by 63.6% of keepers, although 4% said they struggled to find a veterinarian willing to treat backyard poultry. New additions to the flock were isolated by 70.2% of keepers. The survey was distributed through poultry-specific Facebook groups and via chicken rescue centres, so it is not a truly random sample of backyard chicken keepers. All survey-based studies have an inherent element of subjectivity. The survey identified biosecurity, humane euthanasia training, veterinary training in backyard poultry medicine, and enrichment provision as areas where improvements can be made to improve poultry health and welfare and reduce the risks of infectious disease transmission.

Amplification of avian influenza virus circulation along poultry marketing chains in Bangladesh: A controlled field experiment

The prevalence of avian influenza viruses is commonly found to increase dramatically as birds are transported from farms to live bird markets. Viral transmission dynamics along marketing chains are, however, poorly understood. To address this gap, we implemented a controlled field experiment altering chicken supply to a live bird market in Chattogram, Bangladesh. Broilers and backyard chickens traded along altered (intervention) and conventional (control) marketing chains were tested for avian influenza viruses at different time points. Upon arrival at the live bird market, the odds of detecting avian influenza viruses did not differ between control and intervention groups. However, 12 h later, intervention group odds were lower, particularly for broilers, indicating that viral shedding in live bird markets resulted partly from infections occurring during transport and trade. Curtailing avian influenza virus prevalence in live bird markets requires mitigating risk in marketing chain nodes preceding chickens’ delivery at live bird markets.

Prevalence data on chicken diseases in low-resource settings.

The presence of transmissible disease in livestock has a major impact on welfare and economics in animal and public health. A lack of data enables the spread of diseases due to misinformed decision-making on prevention and control. Low-resource settings face challenges in providing data, turning data availability into a development issue. For this study, a large dataset (n = 997) was collected on prevalence and seroprevalence estimates on viral (n = 224), bacterial (n = 83) and parasitic (n = 690) diseases in backyard chickens in low- and middle-income countries (LMICs). These estimates originate from 306 studies identified during the screening phase of a systematic literature review. An attempt was made to classify the studies according to the Food and Agriculture Organization of the United Nations'classification system for family poultry production systems. Of the studies, 98.7% (302/306) focused on a single poultry production system, while 1.3% (4/306) targeted two different production systems. Within the group of studies that covered one production system, 85.4% (258/302) were classified as ‘small extensive scavenging or extensive scavenging,'‘small extensive scavenging'and/or ‘extensive scavenging'. In addition, 52% (159/306) of the studies did not report information on chicken breed type. No data were found on any relevant disease for 56.9% (78/137) of LMICs, signifying a potential data gap. Of the estimates on viral and bacterial diseases, 71.0% (218/307) corresponded to diseases notifiable to the World Organisation for Animal Health, highlighting a tendency to measure disease occurrence for diseases relevant to trade. The latter might not necessarily be priority diseases for the producers, however. Furthermore, 72.3% (222/307) of the estimates originate from random samples and could be used to estimate prevalence in backyard chickens using imputation methods, thus bridging the data gap.

Seroprevalence of infectious bursal disease in backyard chickens of selected districts of Buno Bedelle zone, Southwestern Ethiopia.

Infectious bursal disease (IBD) is a viral infectious disease that affects young chicks. A cross-sectional study was conducted from October 2020 to June 2021 to determine seroprevalence and associated risk factors of IBD on backyard chickens of purposively selected three districts of Buno Bedelle Zone, Southwestern Ethiopia. The study was carried out via a collection of serum samples, questionnaire surveys, and a total of 768 serum samples were collected from randomly selected backyard chickens of the study areas and examined for the presence of IBD virus. These serum samples were processed by using an indirect enzyme-linked immunosorbent assay test procedure in laboratories. SPSS version 20 was used for data analysis and descriptive statics techniques were used. Out of a total serum samples collected, 361 of them were found positive for the disease with an overall seroprevalence of 47%. Different seroprevalence rates of IBD with 55.9%, 43.3% and 41.2% were recorded in Didessa, Chora and Gechi districts, respectively. The result indicated that there was statistically significant difference (p<0.05) of the disease among the three districts. Among the nine Peasant Associations (PAs) observed for seroprevalence of IBD, highest (62.9%) and lowest (34.20%) seroprevalence of the disease was recorded in Yembero and Shengela PAs, respectively. However, IBD was statistically significant in only Shengela PA of Chora district (p=0.04, OR=1.93 and 95% CI 1.04-3.58) and Seko PA of Gechi district (p=0.05, OR=1.79 and 95% CI 1.01-3.16). Even though sex, breed, age, source and management-based seroprevalence was observed in the present study, the result indicated that there was only statistical significant difference (p=0.004, OR=0.62 and 95% CI 0.45-0.86) seen in which higher seroprevalence of IBD was determined in exotic (50.3%) than in local (38.6%) chickens breeds of the study areas. Generally, higher seroprevalence of IBD in the present study indicates a widely distribution of the disease and one of the potential threats for poultry production in the study areas. So, chicken vaccination and improved management system should be warranted in order to control the disease effectively.

Global and regional prediction of coccidiosis and ascaridiosis prevalence in extensive backyard chickens in low-income and middle-income countries

Backyard chickens usually have open housing and scavenge for food, facilitating contact with infective forms of parasites present in the environment and increasing the risk of parasitic infections. Coccidiosis and ascaridiosis are two internal parasites in scavenging chickens that cause production losses to farmers. Prevalence data of these two diseases are scarce in low-income and middle-income countries (LMICs) but necessary to assess the burden of disease in backyard chickens. This study estimates the clinical prevalence of coccidiosis and ascaridiosis at the country and regional levels in all LMICs using regression imputation methods. Regression models were developed with data of known prevalence of these parasites and using primarily climatic factors as predictors. A binomial random effects model was developed for each disease to impute prevalence. The overall estimated prevalence of coccidiosis was 0.39 (95 % CI: 0.37–0.42), with a higher mean prevalence in tropical countries. The overall estimated prevalence of ascaridiosis was 0.23 (95 % CI: 0.22–0.25) with a higher mean prevalence in countries with tropical, temperate and continental climates. The findings of this study can aid to identify the burdens of coccidiosis and ascaridiosis infections across countries and regions, which can inform disease control plans and, and encourage international alliances to facilitate access to preventive measures, improving animal health and reducing production losses.

Transcriptomics of pectoralis major muscles uncovers a footprint of enriched pathways in five diverse backyard chicken breeds of India

Genetic diversity existing between the chicken breeds can be used as a means to unravel the biological mechanisms affecting traits of commercial prominence. The present study attempted to compare the biological pathways enriched in pectoralis major muscles in five diverse chicken breeds. RNA sequencing data was generated from four biological replicates of pectoralis major muscles from Ankleshwar, Aseel, Kadaknath, Punjab Brown and Nicobari chicken. A total of 40 genes each for Nicobari and Aseel, 46 for Punjab Brown, 65 for Kadaknath and 86 for Ankaleshwar were found to be unique. The Neuroactive ligand-receptor interaction pathway was enriched in Ankaleshwar, Aseel and Kadaknath. However, the set of genes identified in this pathway were associated with different ligand receptors in each of the three breeds. The Wnt signaling pathway showed significant enrichment in Nicobari chicken while the Steroid biosynthesis pathway showed prominent expression in Punjab Brown chicken. The significant pathways pinpoint to genetic characteristics associated with each breed suggesting a transcriptome footprint. Our study is a first step toward determining the genetic basis of phenotypic diversity in chicken.

Modelling the transmission dynamics of H9N2 avian influenza viruses in a live bird market

H9N2 avian influenza viruses (AIVs) are a major concern for the poultry sector and human health in countries where this subtype is endemic. By fitting a model simulating H9N2 AIV transmission to data from a field experiment, we characterise the epidemiology of the virus in a live bird market in Bangladesh. Many supplied birds arrive already exposed to H9N2 AIVs, resulting in many broiler chickens entering the market as infected, and many indigenous backyard chickens entering with pre-existing immunity. Most susceptible chickens become infected within one day spent at the market, owing to high levels of viral transmission within market and short latent periods, as brief as 5.3 hours. Although H9N2 AIV transmission can be substantially reduced under moderate levels of cleaning and disinfection, effective risk mitigation also requires a range of additional interventions targeting markets and other nodes along the poultry production and distribution network.

Consumer Preferences for Native Chicken Meat in India: Implications for Sustainable Production and Household Dynamics

Indigenous and native chickens play a pivotal role in rural economies, providing income and food security. India is one of the world's top producers of poultry, with a total chicken population of 851.8 million in 2019 and 37.2% representing native or indigenous breeds. In recent years, the rising demand for native chicken meat and government-backed projects in India have led to a shift from traditional backyard chicken raising to semi-intensive and intensive farms, empowering marginalized communities and women. Consumer preferences for native chicken meat in India was examined in this study, employing a two-part model with a logit model and log-normal OLS model to analyse responses from 503 consumers. Additionally, factor analysis revealed nine key factors influencing attitudes. Gender, age, income, education, marital status, cohabitation, household size, the presence of seniors or children, and consumption frequency significantly shaped preferences. Factors such as psychological well-being, affordability, knowledge, nutrition, food quality, fitness, purity, and sustainability had negative effects on preference and quantity purchased. The study reveals a strong consumer preference for native chicken meat, attributed to its organic nature, including traditional farming and sustainable production. To enhance sustainability of semi-intensive and intensive native chicken farming, it is imperative to address pricing disparities and ensure the consistent availability of native chicken meat. Achieving long-term sustainability in native chicken farming requires aligning consumer demand with ethical and environmentally sustainable farming practices.

Molecular analysis of ESBL- and AmpC-producing Enterobacteriaceae in fecal samples from broiler and backyard chickens

ObjectiveTo analyse the molecular profile of antibiotic resistance in Enterobacteriaceae isolates from fecal samples of healthy broilers and backyard chickens in Tamil Nadu, India. MethodsA total of 115 and 57 bacterial strains were isolated from fecal samples of broiler and backyard chickens, respectively using conventional bacterial culture tests. Bacterial isolates were screened for antibiotic susceptibility by Kirby-Bauer’s disk diffusion method. Colistin susceptibility was tested using the broth microdilution method. Extended-spectrum β-lactamase (ESBL), AmpC β-lactamase and metallo-β-lactamase (MBL) producers were screened by combination disk method. The drug-resistant genes’ positivity was analysed by polymerase chain reaction (PCR) method. ResultsEscherichia coli was the predominant bacterium isolated from both broiler (53%) and backyard (64.9%) chickens. Bacterial isolates from broilers and backyard chickens showed 100% resistance to ampicillin, piperacillin, and piperacillin-tazobactam. Five bacterial isolates from broiler chickens were resistant to colistin. ESBL producers were 34.7% in broilers and 19.1% in backyard chickens. AmpC production was detected in 44.3% of the isolates from broilers and 26.2% of those from backyard chickens. Molecular analysis revealed that bacterial isolates from broiler chickens were positive for drug-resistant genes such as blaTEM (25%), blaSHV (5%), blaCTX-M (4%), blaAmpC (56%), integron (39%), sul1 (30%), and sul2 (23%). Bacterial isolates from backyard chickens were positive for the blaTEM (22%), blaSHV (14%), blaAmpC (54.3%), and integron (20%) genes. None of the isolates from either broiler or backyard chickens harboured New Delhi metallo-β-lactamase (blaNDM) or colistin-resistant genes (mcr-1 to −3). ConclusionsBacterial isolates from broiler chickens harboured a higher number of drug resistance genes, especially blaTEM, blaCTX-M, sul1, sul2, and integron, than those from backyard chickens.

Prevalence of Bumble Foot Disease in Backyard Chickens in Qarabagh District of Kabul, Afghanistan

‌Bumble foot is a condition in which the feet and toes of birds (especially chickens) become inflamed and necrotic. The main causes of the disease are bacteria (Staphylococcus aureus, Pseudomonas spp, and Escherichia coli), fungi, or yeasts. Bumble foot disease was first reported in 1980 as a skin disease of broilers. Bumble foot is extremely important due to its high incidence and mortality rate. But in Afghanistan, there are no accurate statistics about the prevalence of bumble foot disease in backyard and broiler chickens, so the purpose of this research is to study the prevalence and identify different grades of bumble foot disease in backyard chickens in Qarabagh district of Kabul province. This research was conducted on 2025 backyard chickens in 18 villages of Qarabagh district. In this research, both a questionnaire and a visual assessment system were used. A 5-point scoring system was used for the visual assessment of Bumble Foot. Skin without lesion (grade 0), superficial lesion ≤ 0.5 cm (grade 1), superficial lesion &gt; 0.5 cm (grade 2), deep lesion &gt; 1.0 cm (grade 3), and one or more deeper lesions on the toe (grade 4). All data was gathered by a veterinarian using a random sampling method, and then analyzed by (MS Excel) and (SPSS statistical software Version 23). As a result of this research, it was found that 128 chickens were affected by bumble foot disease, with a prevalence rate of 6.3%. The results of this research show that the prevalence of bumble foot disease is higher in hens (62.5%) than in roosters (37.5). Among the 128 infected chickens, 5.4% were grade 0, 34.3% were grade 1 32.8% were grade 2, 21.8% were grade 3, and 5.4% were grade 4. The prevalence rate of bumble foot disease in backyard chickens was lower than in broiler chickens. Among the 128 infected chickens, most of them had moderate and severe disease.

Protection Against Infectious Bronchitis Virus Vaccine Recombinants and Chicken-Selected Vaccine Subpopulations.

Outbreaks of infectious bronchitis (IB) continue to occur from novel variants of IB virus (IBV) emerging from selection of vaccine subpopulations and/or naturally occurring recombination events. S1 sequencing of Arkansas (Ark) -type viruses obtained from clinical cases in Alabama broilers and backyard chickens shows both Ark Delmarva Poultry Industry (ArkDPI) vaccine subpopulations as well as Ark vaccine viruses showing recombination with other IB vaccine viruses. IB Ark-type isolates AL5, most similar to an ArkDPI vaccine subpopulation selected in chickens, AL4, showing a cluster of three nonsynonymous changes from ArkDPI subpopulations selected in chickens, and AL9, showing recombination with Massachusetts (Mass) -type IBV, were examined for pathogenicity and ability to break through immunity elicited by vaccination with a commercial ArkDPI vaccine. Analysis of predicted S1 protein structures indicated the changes were in regions previously shown to comprise neutralizing epitopes. Thus, they were expected to contribute to immune escape and possibly virulence. Based on clinical signs, viral load, and histopathology, all three isolates caused disease in naïve chickens, although AL9 and AL5 viral loads in trachea were statistically significantly higher (30- and 40-fold) than AL4. S1 gene sequencing confirmed the stability of the relevant changes in the inoculated viruses in the chickens, although virus in some individual chickens exhibited additional S1 changes. A single amino acid deletion in the S1 NTD was identified in some individual chickens. The location of this deletion in the predicted structure of S1 suggested the possibility that it was a compensatory change for the reduced ability of AL4 to replicate in the trachea of naïve chickens. Chickens vaccinated with a commercial ArkDPI vaccine at day of hatch and challenged at 21 days of age showed that vaccination provided incomplete protection against challenge with these viruses. Moreover, based on viral RNA copy numbers in trachea, differences were detected in the ability of the vaccine to protect against these IBV isolates, with the vaccine protecting the most poorly against AL4. These results provide additional evidence supporting that IBV attenuated vaccines, especially ArkDPI vaccines, contribute to perpetuating the problem of IB in commercial chickens.

Overview of Ecology and Aspects of Antibiotic Resistance in Campylobacter spp. Isolated from Free-Grazing Chicken Tissues in Rural Households.

Rural households all over the world rear backyard chicken mainly for their own consumption and, to a lesser extent, for barter trade. These chickens represent a staple dish with numerous culinary variations and a cheap source of protein. Although some Campylobacter species, and particularly Campylobacter jejuni and Campylobacter coli, have been associated with industrial poultry carcasses, studies concerning the ecology of this genus in rural households do not exist. To assess the prevalence of Campylobacter species in the tissues of backyard chickens, samples were collected from birds Gallus domesticus bred in households in the rural area of Epirus (Greece), and Campylobacter strains were isolated by quantitative methods at 37 °C and 42 °C. In total, 256 strains were identified, belonging to 17 Campylobacter species, with C. jejuni and C. coli being the most prevalent. From the four ecological parameters studied (size of the flock, presence of small ruminants in the same household, presence of other poultry species in the same household, and feeding leftovers of the household), the size of the flock and the presence of small ruminants and/or pigs in the same household mostly affected the distribution of these strains. To study the phenotypical resistance against 14 antibiotics, 215 strains were selected. The results showed a high prevalence of multidrug-resistance (MDR) strains extending to all classes of antibiotics. Further genome analysis revealed the presence of genes coding resistance (blaOxA-61, tet(O), tet(A) cmeA, cmeB, cmeC, and gyrA (Thr-86-Ile mutation)), with the efflux pump CmeABC being the most prevalent. All antimicrobial resistance-encoded genes co-circulated, except for blaOXA-61, which moved independently. The minimum inhibitory concentration (MIC) values of two out of three antibiotics (representing different classes) were reduced when the strains tested were exposed to carbonyl cyanide 3-chlorophenylhydrazone (CCCP), a known efflux pump inhibitor. The same result was obtained with the addition of CCCP to the MIC values of bile salts. These results lead to the conclusion that Campylobacter species are present in an impressive diversity in backyard chicken tissues and that they exert a significant resistance to antibiotics, raising a potential danger for public health.

Prediction of coccidiosis prevalence in extensive backyard chickens in countries and regions of the Horn of Africa

Coccidiosis is one of the leading morbidity causes in chickens, causing a reduction of body weight and egg production. Backyard chickens are at risk of developing clinical and subclinical coccidiosis due to outdoor housing and scavenging behaviour, jeopardizing food security in households. The objectives of this study were to estimate clinical prevalence of coccidiosis at country and regional levels in the Horn of Africa in extensive backyard chickens. A binomial random effects model was developed to impute prevalence of coccidiosis. Previously gathered prevalence data (n = 40) in backyard chickens was used to define the model. Precipitation (OR: 1.09 (95% CI: 1.05–1.13) and the presence of seasonal rainfall (OR: 1.85, 95% CI: 1.27–2.70) significantly increase prevalence. Results showed an overall prevalence of coccidiosis in the Horn of Africa of 0.21 (95% CI: 0.15–0.29). Ethiopia, the Republic of South Sudan and Kenya showed the highest prevalence and Djibouti the lowest. Significant differences between Djibouti and the countries with highest prevalence were found. However, no evidence of a significant difference between the rest of the countries. Kenya and Ethiopia showed larger prevalence differences between regions. Results could assist with the targeting of testing for coccidiosis, the observation for clinical disease of chickens living in specific regions and as a baseline for the evaluation of future control measures.

Belgian Cross-Sectional Epidemiological Study on Zoonotic Avian Chlamydia spp. in Chickens.

Chlamydia psittaci, Chlamydia gallinacea, and Chlamydia abortus are the most common Chlamydia spp. in chickens and have a confirmed or suggested zoonotic potential. No recent data are available on their prevalence and impact in the Belgian chicken industry or in the recreational chicken branch. Therefore, a cross-sectional epidemiological study was executed where samples were collected from both factory-farmed and backyard chickens. More specifically, pharyngeal chicken swabs were obtained from 20 chicken farms, 5 chicken abattoirs, and 38 different backyard locations and were analyzed using species-specific Polymerase Chain Reactions (PCRs) for the presence of the three avian Chlamydia spp. To investigate their zoonotic potential, samples were simultaneously collected from 54 backyard chicken caretakes and 37 professional chicken caretakers or abattoir employees and analyzed using species-specific PCRs as well. This study confirmed the presence of DNA of all three Chlamydia species in both the chicken industry and backyard settings. Chlamydia psittaci was the most prevalent in the industry chickens (11.0%), whereas Chlamydia gallinacea was the dominant species in the backyard chickens (14.5%). Chlamydia abortus infections were more common in the commercial chickens (9.0%) compared to the backyard chickens (2.6%). The DNA of all three species was also detected in humans (3.9% Chlamydia psittaci, 2.9% Chlamydia gallinacea, and 1.0% Chlamydia abortus).

Influenza A virus antibodies in dogs, hunting dogs, and backyard pigs in Campeche, Mexico.

This study aimed to identify exposure to human, swine, and avian influenza A virus subtypes in rural companion and hunting dogs, backyard pigs, and feral pigs. The study took place in a region of southeastern Mexico where the sampled individuals were part of backyard production systems in which different domestic and wild species coexist and interact with humans. We collected blood samples from pigs and dogs at each of the sites. We used a nucleoprotein enzyme-linked immunosorbent assay to determine the exposure of individuals to influenza A virus. Haemagglutination inhibition was performed on the positive samples to determine the subtypes to which they were exposed. For data analysis, a binomial logistic regression model was generated to determine the predictor variables for the seropositivity of the individuals in the study. We identified 11 positive individuals: three backyard pigs, four companion dogs, and four hunting dogs. The pigs tested positive for H1N1 and H1N2. The dogs were positive for H1N1, H1N2, and H3N2. The model showed that dogs in contact with backyard chickens are more likely to be seropositive for influenza A viruses. We demonstrated the essential role hunting dogs could play as intermediate hosts and potential mixing vessel hosts when exposed to human and swine-origin viral subtypes. These results are relevant because these dogs interact with domestic hosts and humans in backyard systems, which are risk scenarios in the transmission of influenza A viruses. Therefore, it is of utmost importance to implement epidemiological surveillance of influenza A viruses in backyard animals, particularly in key animals in the transmission of these viruses, such as dogs and pigs.