Prevalence In Chickens Research Articles

Prevalence of Toxoplasma gondii infection in chickens in China during 1993-2021: a systematic review and meta-analysis.

Toxoplasma gondii is an important intracellular parasitic protozoan with a variety of hosts, including chickens, which poses a potential threat to public health. However, little is known regarding overall T. gondii infection in chickens in China. Herein, the prevalence and risk factors associated with T. gondii infection in chickens in China were investigated using a meta-analysis. Forty studies regarding the prevalence of T. gondii in chickens in China from 1993 to 2021 were identified using five databases (PubMed, Science Direct, CNKI, Wang Fang, and VIP). Quantitative and potential sources were analyzed through subgroup analysis and meta-regression in R v3.5.2. The overall prevalence of T. gondii in chickens in China was 13.4% (95% confidence interval (CI): 10.9-16.0). In the region subgroup, the lowest prevalence was presented in Northwestern China (6.0%, 95% CI: 3.2-9.5; P < 0.001). Seasonally, T. gondii prevalence was the highest in spring (17.9%, 95% CI: 7.7-30.9; P = 0.007). Among detection methods, the prevalence in the ELISA subgroup was the highest (22.8%, 95% CI: 17.1-29.1; P < 0.001). According to the farming mode, the prevalence of T. gondii in free-range chickens (19.5%, 95% CI: 15.4-23.9) was significantly higher than that in chickens raised by intensive farming (7.4%, 95% CI: 5.1-10.2; P < 0.001). We also estimated the relationships between region, sampling year, chicken age, chicken application, gender, sample classification, study quality, and T. gondii prevalence in chickens in China. Our study showed that region, season, and farming model played important roles in T. gondii infection of chickens. Integrated control measures should be undertaken to reduce the losses caused by T. gondii infection to the chicken industry.

Interdependence and biodiversity of pathogens in intestinal channel parasitocenoses of chickens in the eastern region of Ukraine

Changes in the forms of management, the concentration of poultry in limited territories lead to a violation of homeostasis in biotopes and parasitic systems. The research aimed to find out the peculiarities of distribution, biodiversity, and interdependence of pathogens in parasitocenoses of the intestinal tract of chickens in the Eastern region of Ukraine. According to the results of research, the biodiversity of pathogens in parasitocenoses of the chicken intestinal tract in poultry farms in the Eastern region of Ukraine has been determined. 17 species of pathogens were identified, including 10 species of protists (from Apicomplexa and Zoomastygophora), and 7 species of helminths: 5 species from Nematoda, 2 species from Cestoda. The influence of breeding technologies and systems of keeping chickens on the prevalence, biodiversity of parasitocenoses, species indices of parasitocenosis (SIP, %), and correlations between components of parasitocenoses have been determined. For the industrial technology of raising chickens in cages, the parasitocenosis was formed by 6 species of Eimeria (SIP — 100%, prevalence — 15.72%). When poultry was kept on a deep when kept on a deep unchanging litter in the structure of the parasitocenosis the share of eimeriosis was 87.72%, ascariasis — 12.28%. For the traditional extensive technology of raising chickens using pastures (farms and homestead farms), the prevalence in chickens was 64.07%. In the parasitocenosis of the intestinal tract in chickens there are relationships between pathogens — a high correlation between eimeriosis, histomonosis, trichomoniasis and helminthiasis (0.718–0.944) and between histomonosis, ascariasis, heterococcus and capillary (0.975–0.998), and a low correlation between histomonosis and trichomoniasis (0.449), which indicates the presence of synergetic (high correlation) and competitive (low correlation) relationships between the components of parasitocenoses of the intestinal tract

Infectious Laryngotracheitis Virus in Commercial and Backyard Chicken Production Systems in Central and South Ethiopia (First report) ILT in Ethiopian Poultry Production

Infectious laryngotracheitis virus (ILT) affects the respiratory tracts of chickens with profound effects in the world poultry industry. The aims of this study are to determine the prevalence and risk factors associated with ILT. The overall prevalence for ILT was 19.4% of which 13.3% (66/496) and 34.4% (74/215) accounted for commercial and backyard poultry production systems, respectively. The prevalence was significantly different between commercial and backyard poultry production systems (P < 0.05). Study areas, breed, and purpose had no significant effect on the prevalence of ILT in commercial production systems. However, study areas significantly affect (P < 0.05) the prevalence in backyard production systems. The mean antibody titer was significantly higher (P < 0.05) in backyard production system (mean = 1209.9) over commercial production systems (mean = 334.1). As the first report in Ethiopia, this study revealed that ILT is prevalent in the country with a higher prevalence in chickens raised in backyard production systems. This indicates further studies are encouraged to determine the role of backyard chickens in the epidemiology of ILT in Ethiopia and develop vaccine(s) to prevent and control the disease.

Poultry trading behaviours in Vietnamese live bird markets as risk factors for avian influenza infection in chickens.

Vietnamese poultry are host to co‐circulating subtypes of avian influenza viruses, including H5N1 and H9N2, which pose a great risk to poultry productivity and to human health. AIVs circulate throughout the poultry trade network in Vietnam, with live bird markets being an integral component to this network. Traders at LBMs exhibit a variety of trading practices, which may influence the transmission of AIVs. We identified trading practices that impacted on AIV prevalence in chickens marketed in northern Vietnamese LBMs. We generated sequencing data for 31 H9N2 and two H5N6 viruses. Viruses isolated in the same LBM or from chickens sourced from the same province were genetically closer than viruses isolated in different LBMs or from chickens sourced in different provinces. The position of a vendor in the trading network impacted on their odds of having AIV‐infected chickens. Being a retailer and purchasing chickens from middlemen was associated with increased odds of infection, whereas odds decreased if vendors purchased chickens directly from large farms. Odds of infection were also higher for vendors having a greater volume of ducks unsold per day. These results indicate how the spread of AIVs is influenced by the structure of the live poultry trading network.

The PB2 and M genes of genotype S H9N2 virus contribute to the enhanced fitness of H5Nx and H7N9 avian influenza viruses in chickens

Genotype S H9N2 viruses frequently donate their internal genes to facilitate the generation of novel influenza viruses, e.g., H5N6, H7N9, and H10N8, which have caused human infection. Genotype S was originated from the replacement of F/98-like M and PB2 genes of the genotype H with those from G1-like lineage. However, whether this gene substitution will influence the viral fitness of emerging influenza viruses remains unclear. We found that H5Nx and H7N9 viruses with G1-like PB2 or M gene exhibited higher virulence and replication than those with F/98-like PB2 or M in chickens. We also determined the functional significance of G1-like PB2 in conferring increased polymerase activity and improved nucleus transportation efficiency, and facilitated RNP nuclear export by G1-like M. Our results suggest that G1-like PB2 and M genes optimize viral fitness, and thus play a crucial role in the genesis of emerging influenza viruses that cause rising prevalence in chickens.

Seroprevalence of &lt;i&gt;Mycoplasma gallisepticum&lt;/i&gt; in domestic chickens, East Shewa, Ethiopia

Cross sectional study was conducted to estimate the sero-prevalence of Mycoplasma gallisepticumin domestic chickens and to assess risk factors associated with the disease in commercial and local chickens in East Shewa, Ethiopia. A total of 514 sera were collected (from187 commercial chickens and 327 local chickens) and tested using an indirect enzyme linked immunosorbant assay (ELISA) to detect antibodies against M. gallisepticum. The overall seroprevalence of M. gallisepticum was 49.4% (254/514). A statistically significant association (p&lt;0.05) was observed in prevalence between chicken type with prevalence of 64.5% in local and 23% in commercial chickens. Variation in prevalence was observed among the three commercial farms, the highest being in farm-B (46.8%) and the lowest in farm-C (4.25%). Prevalence in local chickens was significantly highest in Lume (72.7%) and lowest in Ada’a (47.5%) (p&lt;0.05). Age was significantly associated with sero-prevalence (p&lt;0.05). Prevalence was 67.3% in layers of (18 to 76 weeks) and 0% in layer chicks of (1 to 8 weeks old). Prevalence was also significantly different between layers (41.7%) and broilers (7.8%) (p&lt;0.05). In commercial chickens, prevalence was significantly higher in females (32.4%) than males (10.1%) (p&lt;0.05). The current study revealed M. gallisepticum is prevalent in chicken in East Shewa, Ethiopia.Keywords: Domestic chickens; East Shewa; Ethiopia; Mycoplasma gallisepticum; Sero-prevalence

From genomes to genotypes: molecular epidemiological analysis of Chlamydia gallinacea reveals a high level of genetic diversity for this newly emerging chlamydial pathogen

BackgroundChlamydia (C.) gallinacea is a recently identified bacterium that mainly infects domestic chickens. Demonstration of C. gallinacea in human atypical pneumonia suggests its zoonotic potential. Its prevalence in chickens exceeds that of C. psittaci, but genetic and genomic research on C. gallinacea is still at the beginning. In this study, we conducted whole-genome sequencing of C. gallinacea strain JX-1 isolated from an asymptomatic chicken, and comparative genomic analysis between C. gallinacea strains and related chlamydial species.ResultsThe genome of C. gallinacea JX-1 was sequenced by single-molecule, real-time technology and is comprised of a 1,059,522-bp circular chromosome with an overall G + C content of 37.93% and sequence similarity of 99.4% to type strain 08-1274/3. In addition, a plasmid designated pJX-1, almost identical to p1274 of the type strain, except for two point mutations, was only found in field strains from chicken, but not in other hosts. In contrast to chlamydial species with notably variable polymorphic membrane protein (pmp) genes and plasticity zone (PZ), these regions were conserved in both C. gallinacea strains. There were 15 predicted pmp genes, but only B, A, E1, H, G1 and G2 were apparently intact in both strains. In comparison to chlamydial species where the PZ may be up to 50 kbp, C. gallinacea strains displayed gene content reduction in the PZ (14 kbp), with strain JX-1 having a premature STOP codon in the cytotoxin (tox) gene, while tox gene is intact in the type strain. In multilocus sequence typing (MLST), 15 C. gallinacea STs were identified among 25 strains based on cognate MLST allelic profiles of the concatenated sequences. The type strain and all Chinese strains belong to two distinct phylogenetic clades. Clade of the Chinese strains separated into 14 genetically distinct lineages, thus revealing considerable genetic diversity of C. gallinacea strains in China.ConclusionsIn this first detailed comparative genomic analysis of C. gallinacea, we have provided evidence for substantial genetic diversity among C. gallinacea strains. How these genetic polymorphisms affect C. gallinacea biology and pathogenicity should be addressed in future studies that focus on phylogenetics and host adaption of this enigmatic bacterial agent.

M Gene Reassortment in H9N2 Influenza Virus Promotes Early Infection and Replication: Contribution to Rising Virus Prevalence in Chickens in China.

Segment reassortment and base mutagenesis of influenza A viruses are the primary routes to the rapid evolution of high-fitness virus genotypes. We recently described a predominant G57 genotype of avian H9N2 viruses that caused countrywide outbreaks in chickens in China during 2010 to 2013, which led to the zoonotic emergence of H7N9 viruses. One of the key features of the G57 genotype is the replacement of the earlier A/chicken/Beijing/1/1994 (BJ/94)-like M gene with the A/quail/Hong Kong/G1/1997 (G1)-like M gene of quail origin. We report here the functional significance of the G1-like M gene in H9N2 viruses in conferring increased infection severity and infectivity in primary chicken embryonic fibroblasts and chickens. H9N2 virus housing the G1-like M gene, in place of the BJ/94-like M gene, showed an early surge in viral mRNA and viral RNA (vRNA) transcription that was associated with enhanced viral protein production and with an early elevated release of progeny virus comprising largely spherical rather than filamentous virions. Importantly, H9N2 virus with the G1-like M gene conferred extrapulmonary virus spread in chickens. Five highly represented signature amino acid residues (37A, 95K, 224N, and 242N in the M1 protein and 21G in the M2 protein) encoded by the prevalent G1-like M gene were demonstrated to be prime contributors to enhanced infectivity. Therefore, the genetic evolution of the M gene in H9N2 virus increases reproductive virus fitness, indicating its contribution to the rising virus prevalence in chickens in China.IMPORTANCE We recently described the circulation of a dominant genotype (genotype G57) of H9N2 viruses in countrywide outbreaks in chickens in China, which was responsible, through reassortment, for the emergence of H7N9 viruses that cause severe human infections. A key feature of the genotype G57 H9N2 virus is the presence of the quail-origin G1-like M gene, which had replaced the earlier BJ/94-like M gene. We found that H9N2 virus with the G1-like M gene, but not the BJ/94-like M gene, showed an early surge in progeny virus production and more severe pathology and extrapulmonary virus spread in chickens. Five highly represented amino acid residues in the M1 and M2 proteins derived from the G1-like M gene were shown to mediate enhanced virus infectivity. These observations enhance what we currently know about the roles of reassortment and mutations in virus fitness and have implications for assessing the potential of variant influenza viruses that can cause a rising prevalence in chickens.

Genotypic and pathotypic characterization of Newcastle disease virus isolated from racing pigeons in China

A Newcastle disease virus (NDV) isolated from an outbreak in racing pigeons in China was characterized in this study. Complete gene of the NDV isolate was sequenced and phylogenetic analysis. Pathogenicity experiment was carried out in pigeons, chickens, and ducks. Phylogenetic analysis revealed that the strain clustered with the Class II viruses, has highly phylogenetically similar to NDV strains isolated from pigeons in China, but was distant from the viruses prevalence in chickens and vaccine strains used in China. The deduced amino acid sequence of the cleavage site of the fusion (F) protein confirmed that the isolate contained the virulent motif 112 RRQKRF117 at the cleavage site, but it caused no appearance disease in chickens and ducks. However, the isolate had virulence in pigeons, resulting in severe nervous signs and highly mortality. Pigeons were considered as a potential source of NDV infection and disease for commercial poultry flocks. Therefore, new vaccines to prevent the NDV infection in the pigeon flocks should be developed as soon as possible, and strict biosecurity measures should be taken to reduce the risk of pigeon Newcastle disease outbreaks.

Prevalence of Salmonella in Apparently Healthy Chickens in Mymensingh, Bangladesh

Salmonella spp. are the most frequently reported cause of food-borne illnesses worldwide that are closely associated with the consumption of contaminated poultry and egg products. This study was designed to isolate and identify Salmonella, and evaluate its prevalence in chickens of different lines and ages during summer and rainy seasons. Cloacal swab samples (n=200) of apparently healthy chickens were collected. Isolated Salmonella were characterized using cultural, biochemical and serological examinations. A total of 104 samples (52%) were found to be positive for Salmonella spp. The prevalence of Salmonella spp. was significantly higher (p&lt;0.01) during summer (67.78%) as opposed to rainy season (39.09%). Prevalence of Salmonella was 71.11% in broiler, 38.89% in layer and 25% in indigenous chicken. Broilers showed significantly higher prevalence of Salmonella as compared to layer and indigenous chickens (p&lt;0.01). Among the five age groups, the highest prevalence was observed in chickens of 18-week of age (65%) and the lowest was in chickens of 2-week age (16.67%). The data of this study showed higher prevalence of Salmonella in broilers and underscored the need for detail epidemiological investigations as well as strict hygienic practices in farm and live bird markets all over Bangladesh. DOI: http://dx.doi.org/10.3329/mh.v1i1.13711 Microbes and Health Vol.1(1) June 2012 pp.30-33

Anticipating the Prevalence of Avian Influenza Subtypes H9 and H5 in Live-Bird Markets

An ability to forecast the prevalence of specific subtypes of avian influenza viruses (AIV) in live-bird markets would facilitate greatly the implementation of preventative measures designed to minimize poultry losses and human exposure. The minimum requirement for developing predictive quantitative tools is surveillance data of AIV prevalence sampled frequently over several years. Recently, a 4-year time series of monthly sampling of hemagglutinin subtypes 1–13 in ducks, chickens and quail in live-bird markets in southern China has become available. We used these data to investigate whether a simple statistical model, based solely on historical data (variables such as the number of positive samples in host X of subtype Y time t months ago), could accurately predict prevalence of H5 and H9 subtypes in chickens. We also examined the role of ducks and quail in predicting prevalence in chickens within the market setting because between-species transmission is thought to occur within markets but has not been measured. Our best statistical models performed remarkably well at predicting future prevalence (pseudo-R2 = 0.57 for H9 and 0.49 for H5), especially considering the multi-host, multi-subtype nature of AIVs. We did not find prevalence of H5/H9 in ducks or quail to be predictors of prevalence in chickens within the Chinese markets. Our results suggest surveillance protocols that could enable more accurate and timely predictive statistical models. We also discuss which data should be collected to allow the development of mechanistic models.

Staphylococcus aureus and methicillin-resistant Staphylococcus aureus in retail raw chicken in China

The aim of this study was to determine the prevalence of Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) in whole raw chickens in China. A total of 1152 whole chicken samples were collected from three types of retail markets (large supermarket, small supermarket, and farmers market) in six provinces and two national cities in China and screened for the presence of. S. aureus, then the S. aureus isolates were further examined for the presence of MRSA. The overall positive rate for S. aureus was 24.2%. S. aureus prevalence was highest in Shaanxi province (39.6%), followed by Fujian province (31.3%), then Sichuan and Guangdong provinces (26.4% in each province), Shanghai (23.6%), Beijing (19.4%), Henan province (13.9%), the lowest prevalence was found in Guangxi province (13.2%). S. aureus prevalence was significantly different among the six provinces and two national cities (P < 0.05). Among 1152 chicken samples, twenty samples (1.7%) were positive for MRSA. MRSA prevalence was highest in Shaanxi province and Sichuan province (3.5% for each), then Fujian province (2.8%), Guangdong province and Shanghai (2.1% for each); MRSA isolates were not detected from Beijing, Henan province and Guangxi province. The overall S. aureus prevalence in chickens collected from large supermarket, small supermarket, and farmers market were 26.3%, 25%, and 21.4%, respectively, but differences were not significant (P > 0.05). These findings indicate the need for identifying the factors contributing to the contamination at the farm, processing and retail level, and for the implementation of good manufacturing practice to better control the pathogen throughout poultry industry.

Large-scale survey of Cryptosporidium spp. in chickens and Pekin ducks (Anas platyrhynchos) in Henan, China: prevalence and molecular characterization

Few data are available on the molecular characterization of Cryptosporidium spp. in chickens and ducks in China. In this study, 2579 faecal samples from 46 chicken farms and eight Pekin duck farms in 21 prefectures in Henan Province were examined. The overall infection rate of Cryptosporidium was 10.6% (163/1542) in layer chickens (10 out of 17 farms), 3.4% (16/473) in broilers (five out of 29 farms), and 16.3% (92/564) in Pekin ducks (four out of eight farms), respectively. The highest infection rates were observed in 31-day-old to 60-day-old layer chickens (24.6%) and 11-day-old to 30-day-old Pekin ducks (40.3%). The season of highest prevalence in chickens was spring (15.6%) and the lowest was winter (P<0.01). One hundred and eighty-seven Cryptosporidium-positive samples were analysed by polymerase chain reaction (PCR)–restriction fragment length polymorphism analysis of the small subunit rRNA gene, and 55 were further analysed by DNA sequencing of the PCR products. Two Cryptosporidium species were identified: Cryptosporidium baileyi (184/187) on 15 chicken farms and four duck farms, and Cryptosporidium meleagridis (3/187) on three layer chicken farms. C. baileyi was the predominant Cryptosporidium species, found in all age groups of chickens and all Cryptosporidium-positive ducks examined, whereas C. meleagridis was only identified in 31-day-old to 120-day-old layer chickens. Considering the large size of the chicken industry and the close contact between chickens and humans, and that C. meleagridis is the third most common Cryptosporidium parasite in humans, then C. meleagridis could potentially become an emerging zoonosis in some areas in China.

West Nile Virus in Guadeloupe

In July 2002, a surveillance system was implemented on Guadeloupe to detect for the potential introduction and monitor the spread of West Nile virus (WNV). From 2002 to 2004, equines and chickens were serologically assayed for antibodies to WNV by IgG and IgM enzyme-linked immunosorbent assay (ELISA), epitope-blocking ELISA, and plaque reduction neutralization tests. After introduction, probably through migratory birds at the end of 2001, many seroconversions occurred between July and October 2002 resulting in a high seroprevalence (19.3%) in equines in 2003. WNV circulation levels decreased dramatically in 2003 and 2004 as assessed by the absence of seroconversion in equine and the very low prevalence in chickens. This decrease coincided with a 7-month drought that presumably caused a decrease in vector populations. In 2005, a sentinel survey was implemented in equines and chickens placed in areas at high risk and the very low rate of seroconversion (1 equine out of 106, no chicken) demonstrated that WNV circulation is now occurring at a very low level.

West Nile Virus Epizootiology in the Southeastern United States, 2001

We investigated mosquito and bird involvement in West Nile virus (WNV) transmission in July 2001 in Jefferson County, FL, and Lowndes County, GA. We detected 16 WNV-infected pools from Culex quinquefasciatus, Cx. salinarius, Cx. nigripalpus, and Culiseta melanura. In Florida, 11% of 353 bird sera neutralized WNV. Antibody prevalence was greatest in northern cardinal (Cardinalis cardinalis, 75%), northern mockingbird (Mimus polyglottus, 50%), common ground-dove (Columbina passerina, 25%), common grackle (Quiscalus quiscula, 15%), domestic chicken (Gallus gallus, 16%), and house sparrow (Passer domesticus, 11%). Antibody-positive birds were detected in nine of 11 locations, among which prevalence in chickens ranged from 0% to 100%. Seropositive chickens were detected in Georgia as well. The primary transmission cycle of WNV in the southeastern United States apparently involves Culex mosquitoes and passerine birds. Chickens are frequently infected and may serve as effective sentinels in this region.