Chicken Infectious Anemia Research Articles

Epidemiological investigation of outbreaks of fowl adenovirus infections in commercial chickens in China

One hundred and five fowl adenovirus (FAdV) strains were isolated in China from 2015 to 2016 from poultry with inclusion body hepatitis (IBH) and hydropericardium syndrome (HPS). Polymerase chain reactions determined that 68 were FAdV species C, five were FAdV species D, two were FAdV species E, and 30 contained two or more different FAdV strains. A phylogenetic analysis showed that the isolated FAdV strains clustered into three major groups: FAdV-C, FAdV-D and FAdV-E. Based on a hexon gene sequencing analysis, these viruses were genetically related to FAdV-4, FAdV-7, FAdV-8b and FAdV-11, of which FAdV-4 was dominant (93% of the strains). An epidemiological analysis showed that FAdVs had been circulating in broilers, domestic chickens, and layers, and co-infections with other immunosuppressive pathogens, such as chicken infectious anaemia virus, Marek's disease virus and reticuloendotheliosis virus, were identified. To control FAdVs, strict biosecurity protection measures are necessary, and a continued surveillance of FAdVs is needed to increase our understanding of the epidemiology of the viruses that are associated with IBH and HPS.

Molecular characterization of chicken infectious anemia virus from contaminated live-virus vaccines

The aim of this study was to investigate possible causes of the pervasiveness of chicken infectious anemia virus (CIAV) infection in chickens in recent years in China. A total of 14 batches of live-virus vaccines were examined using PCR to detect CIAV contamination, of which only 2 samples (a Newcastle disease vaccine and a fowl pox vaccine) tested positive for CIAV. These Newcastle and fowl pox vaccines were then inoculated into 1-day-old specific-pathogen-free chickens. Serum samples were collected from chickens infected with the PCR-positive vaccines, and these tested positive for CIAV-specific antibodies as tested using ELISA. In addition, DNA samples isolated from the serum samples also tested positive by PCR. The results indicated that the samples were contaminated with CIAV and identified 2 exogenous CIAV strains, designated CIAV-N22 and CIAV-F10, in the respective samples. The full genome sequences of these novel CIAV strains were sequenced and analyzed. Phylogenetic tree analysis indicated that the CIAV-F10 strain might represent a recombinant viral strain arising from the parental CIAV strains JQ690762 and KJ728816. Overall, the results suggested that vaccination with CIAV-contaminated vaccines contributed to the prevalence and spread of CIAV infection in chickens. Furthermore, the CIAV contaminant was likely subsequently transmitted to commercial chickens through congenital transmission. Our findings therefore highlight the need for more extensive screening of live-virus vaccines for poultry in China to reduce the threat of contamination with exogenous viruses.

Immunomodulatory and prophylactic efficacy of herbal extracts against experimentally induced chicken infectious anaemia in chicks: assessing the viral load and cell mediated immunity

Chicken infectious anaemia virus (CIAV) is an economically important and a highly immunosuppressive virus affecting poultry industry worldwide. In this study we assessed the immunomodulatory effects of four herbal preparations namely Withania somnifera, Tinospora cordifolia, Azadirachta indica and E Care Se Herbal in resisting the viral multiplication and immunosuppression inflicted by CIAV in chicks. Day-old chicks (n=90) were randomly and equally divided into six groups (Groups A-F). Groups A-D were administered with purified extracts of W. somnifera, T. cordifolia, A. indica and E Care Se Herbal, respectively followed by the evaluation of viral load in lymphoid organs by quantitative real-time PCR and cell mediated immune response by flow cytometric analysis of CD4+ and CD8+ T cells. Groups A-D were found to resist CIAV multiplication and pathogenesis with significant reduction of viral load compared with the infected control (P<0.05). Group A-C chicks showed significantly higher (P<0.05) CD4+ and CD8+ T cell counts compared to control birds while of E Care Se Herb had minimal effect on T cell count. The findings suggested that the herbal preparations used during the study were effective as both prophylactic and immunomodulatory agents and thus have potential of being used against CIAV induced immunosuppression in poultry.

Pathology of chicken infectious anaemia virus infection in natural outbreaks in Chhattisgarh

Pathology of chicken infectious anaemia virus infection in natural outbreaks in Chhattisgarh

Seroprevalence of chicken infectious anemia virus infection among some poultry species in Maiduguri, Nigeria

Seroprevalence of chicken infectious anemia virus infection among some poultry species in Maiduguri, Nigeria

Genetic Analysis of Two Chicken Infectious Anemia Virus Variants-Related Gyrovirus in Stray Mice and Dogs: The First Report in China, 2015.

Chicken infectious anemia virus (CIAV) causes acute viral infection in chickens worldwide. It can infect chickens of all ages, but the disease is seen only in young chickens and is characterized by hemorrhagic lesions in the muscles, atrophic changes in the lymphoid organs, aplastic bone marrow, and immunosuppression causing increased mortality. Previous studies have demonstrated that CIAV can be isolated from blood specimens of humans and fecal samples of stray cats. In the present study, two variants of CIAV were isolated from fecal samples of mice (CIAV-Mouse) and stray dogs (CIAV-Dog), respectively. The genome of the two CIAV variants was sequenced and the results of the recombination detection program suggested that the CIAV-Dog strain could be a recombinant viral strain generated from parental CIAV strains, AB119448 and GD-1-12, with high confidence. Particularly, these findings were obtained from the comparison of genetic diversity and the relationship of CIAV between different hosts. This is the first report indicating that there is a significant difference in the number of transcription factor binding sites in CIAV noncoding regions from different hosts. Further studies are required to investigate the large geographic distribution of CIAV and monitor the variants, host range, and associated diseases.

A survey for selected avian viral pathogens in backyard chicken farms in Finland

ABSTRACTBackyard poultry are regaining popularity in Europe and increased interest in the health and management of non-commercial farms has resulted. Furthermore, commercial poultry farm owners have become concerned about the risk represented by contagious avian diseases that nearby backyard poultry could transmit. Fifty-one voluntary backyard chicken farms were visited between October 2012 and January 2013. Blood samples and individual cloacal swabs were collected from 457 chickens. In 44 farms (86%), one or more of the tested chickens had antibodies against avian encephalomyelitis and chicken infectious anaemia viruses, 24 farms (47%) had chickens seropositive for infectious bronchitis virus, 10 farms (20%) had chickens seropositive for infectious bursal disease virus, six farms (12%) had chickens seropositive for infectious laryngotracheitis virus and two farms (5.4%) had chickens seropositive for avian influenza virus. No farms had chickens seropositive for Newcastle disease virus. Of the 51 farms, five (10%) had chickens positive for coronavirus reverse transcription polymerase chain reaction. A phylogenetic analysis showed that all backyard chicken coronaviruses collected were QX type infectious bronchitis viruses. All chickens tested for avian influenza and Newcastle disease viruses using real time reverse transcription polymerase chain reaction were negative. To our knowledge, there is no evidence to date to suggest that these diseases would have been transmitted between commercial and non-commercial flocks.

Field study of seroconversion of three different commercial vaccines of chicken infectious anemia virus in Thailand

Field study of seroconversion of three different commercial vaccines of chicken infectious anemia virus in Thailand

The Negative Impact of Chicken Infectious Anemia Virus Infection on Immune Responses to Different Newcastle Disease Virus Vaccination Programs

Chicken infectious anemia virus (CIAV) is among the naturally occurring viruses that cause immunosuppression in chickens. In the present study, the impact of CIAV infection on both NDV vaccination immune responses and bird performance were demonstrated. Post CIAV infection, the mean live body weights of the ND-vaccinated groups showed improvement compared with the non-NDV vaccinated groups. The immunosuppressive effects of CIAV infection was higher and more obvious on live ND vaccinated group compared with the other vaccinated groups. The vaccination with combination of live and inactivated vaccines showed better HI-NDV Ab responses especially when inactivated vaccine was administrated at 9 days (group II). In consistent, both the phagocytic Percent and Index were lower in case of vaccination with live NDV vaccine only and CIAV infection. Birds were vaccinated with both live and inactivated NDV vaccines at different time points showed superior protection rate (100%) compared with the other groups. Microscopically, CIAV infection led to severe deterioration in the lymphoid tissues (thymus, bursa, spleen and bone marrow) such as focal to diffuse depletion of lymphocytes and hematopoietic cells. This study highlights the negative impact of CIAV infection on both bird performance and immune status.

Isolation and pathogenic analysis of virulent Marek's disease virus field strain in China

Marek's disease (MD) has become increasingly common in China, resulting in considerable economic loss. The etiological agent is unclear. In this study, we isolated a field MD virus (MDV) strain, designated SX1301, from CVI988/Rispens-vaccinated chickens with tumors. Co-infection of avian leukosis virus, reticuloendotheliosis virus, and chicken infectious anemia virus was excluded by polymerase chain reaction, enzyme-linked immunosorbant assay, DNA blotting hybridization, and indirect immunofluorescence assay. As with most strains isolated in China, SX1301 had the same amino acid mutation of meq protein at positions 77E, 80Y, and 115A. Animal experimental results showed development of lethal MD in 57% and MD tumor in 23% of the specific pathogen-free chickens inoculated with SX1301, with tumors mainly distributed in spleen, liver, and kidney. CVI988/Rispens protected 83% of chickens upon challenge with SX1301, with a mortality rate and tumor incidence of 10% and 7%, respectively. These results implicated SX1301 as a virulent MDV strain, with commercial MDV vaccine CVI988/Rispens unable to confer adequate protection against SX1301. There have been no reports of very virulent (vv) plus MDV in China, but frequently occurring virulent MDV may account for the repeated outbreaks of MD. Vaccines with greater efficacy are needed to protect against MDV.

Combined administration of the apoptin gene and poly (I:C) induces potent anti-tumor immune response and inhibits growth of mouse mammary tumors

BackgroundMany viral proteins exhibit selective cytotoxicity for tumor cells without affecting the normal diploid cells. The apoptin protein of chicken infectious anemia virus is one of such proteins, which has been shown to kill tumor cells specifically. However, an effective cancer treatment strategy also requires assistance from the immune system. Recently, poly (I:C) has been shown to be an effective cancer vaccine adjuvant. AimIn this study, we assessed the anti-tumor potential of apoptin gene transfer alone and in combination with poly (I:C) in a 4T1 mouse mammary tumor model. Methods4T1 cells were used to induce mammary tumor in Balb/c mice. Mice bearing tumors were divided into 6 groups, and each group received six intratumoral injections during a period of one month. After the last immunization, the animals were sacrificed, and peripheral blood, spleen, lungs, liver, heart, kidney and tumor tissues were collected for immunological, molecular and pathological analysis. ResultsWe report that intratumoral administration of apoptin plasmid along with poly (I:C) not only significantly inhibited the growth of mammary tumor, but also induced a potent anti-tumor immune response as indicated by the increase in blood CD4+, CD8+ cells and infiltration of immune cells in the tumor tissue. Further, blood serum analysis of the cytokines revealed increased secretion of Th1 cytokines (IFN-γ and IL-2). ConclusionsThe results of our study demonstrate that the inclusion of poly (I:C) significantly enhanced the anti-tumor activity of apoptin mainly by inducing a potent anti-tumor immune response. Therefore, we report the use of apoptin and poly (I:C) combination as a novel and powerful strategy for cancer immunotherapy.

Study of mortality in young chickens by chicken infectious anaemia virus (CIAV) in Nagpur region

In the present investigation 30 poultry flocks suspected for chicken infectious anaemia (CIA) from central India were studied. Out of 30 flocks, 26 were confirmed to be positive for presence of VP1 gene of CIAV in bone marrow, thymus and bursa. Mortality was ranging from 10% to 93% in these birds and incidence was found to be higher in cockerels as compared to broilers. CIA positive cases showed pale comb and wattle with poor body condition. Thymus, bursa and spleen showed atrophy, bone marrow was gelatinous and pale. Liver, kidney and other visceral organs were found pale. Haematological investigation revealed reduction in TEC, Hb and PCV values indicating anaemia in CIA affected birds. Values of ALT, AST and creatinine were found increased indicating damage to visceral organs. Heterophilia with lymphopenia was prominent observation in all the affected birds. Microscopically there was severe depletion of lymphocyte from thymus, bursa and spleen. Reticular hyperplasia was prominent in these organs. Bone marrow revealed depletion of haemopoitic cells and parenchyma was replaced by adipose tissue. Above study confirms the presence of CIAV in and around Nagpur of the central India. Therefore extensive molecular epidemiological studies are required at national level to assess the prevalence of disease.

Ultra-structural changes in the thymus of chickens experimentally infected with chicken infectious anemia virus

The present investigation was undertaken to studythe ultra-structural changes in thymus following chicken infectious anemia virus (CIAV) infectionin chicks. Some thymocytes with electron-dense rings in their nuclei and few thymocytes showing chromatin aggregation were noticed in the cortex region with scarcity of the cells on 7 days post infection (DPI). At day 14, the cortex was severely depleted of thymocytes with some thymocytes showing apoptotic nuclei and some with broken nuclear fragments. The aggregations of virus-like particles surrounded by membrane like structures were also observed in the cortex region. The cortex started repopulating with thymocytes whereas some cells with apoptotic bodies were detected on day 21, whereas on day 28 the cortex area of infected group became comparable to the cortex of the control chickens after repopulation of cells. Findings of the study indicate that CIAV causes apoptotic death of the thymocytes following experimental infection.

Genomic Analysis of the Chicken Infectious Anemia Virus in a Specific Pathogen-Free Chicken Population in China

The antibody to chicken infectious anemia virus (CIAV) was positive in a specific pathogen-free (SPF) chicken population by ELISA test in our previous inspection, indicating a possible infection with CIAV. In this study, blood samples collected from the SPF chickens were used to isolate CIAV by inoculating into MSB1 cells and PCR amplification. A CIAV strain (SD1403) was isolated and successfully identified. Three overlapping genomic fragments were obtained by PCR amplification and sequencing. The full genome sequence of the SD1403 strain was obtained by aligning the sequences. The genome of the SD1403 strain was 2293 bp with a nucleotide identity of 94.8% to 98.5% when compared with 30 referred CIAV strains. The viral proteins VP2 and VP3 were highly conserved, but VP1 was not relatively conserved. Both amino acids 139 and 144 of VP1 were glutamine, which was in accord with the low pathogenic characteristics. In this study, we first reported that CIAV exists in Chinese SPF chicken populations and may be an important reason why attenuated vaccine can be contaminated with CIAV.

Concurrent Infections of Chicken Infectious Anemia and Infectious Bursal Disease in 5 Weeks Old Pullets in Jos, Plateau State, Nigeria

Concurrent Infections of Chicken Infectious Anemia and Infectious Bursal Disease in 5 Weeks Old Pullets in Jos, Plateau State, Nigeria

Clinicopathological studies on chicken infectious anemia disease live virus vaccines

Clinicopathological studies on chicken infectious anemia disease live virus vaccines

Assessing the efficacy of an inactivated chicken anemia virus vaccine

BackgroundChicken anemia virus (CAV) is an immunosuppressive virus that causes chicken infectious anemia (CIA) which is a highly contagious avian disease. CAV causes major economic losses in the poultry industry worldwide. The current CAV vaccine is a live attenuated strain administered in the drinking water that risks horizontal infection of other chickens. The purpose of this study was to develop a novel vaccine against CAV that can be administered safely using a highly pathogenic isolate inactivated with β-propiolactone hydrolysis that would protect chicks from CAV. MethodsHens were vaccinated twice intramuscularly with a novel CAV GD-G-12 inactivated vaccine and the humoral immune responses of the hens and offspring were monitored by ELISA. A heterologous intramuscular challenge using the CAV strain GD-E-12 was conducted in the chicks hatched from vaccinated or unvaccinated hens. ResultsThe vaccine strain, GD-G-12, was shown to be highly pathogenic prior to inactivation evidenced by thymic atrophy and bleeding, and weight loss. The inactivated vaccine was considered safe and showed no signs of pathogenicity. High titers of CAV specific antibodies were detected in the vaccinated hens and in their chicks, indicating vertical transfer of maternal antibodies. Furthermore, the chicks hatched from vaccinated hens were resistant to a heterologous CAV challenge and showed no signs of weight loss and thymic atrophy and bleeding. ConclusionOur studies are proof of principle that inactivated GD-G-12 might be a novel vaccine candidate to prevent CAV infection, and highlight the utility of using an inactivated virus for this vaccine.

Pathology and molecular diagnosis of chicken infectious anemia in Rhode Island Red (RIR) flocks in natural outbreaks

The present study was carried out to investigate the outbreak of chicken infectious anaemia (CIA) in field condition of Vidharbha region of Maharashtra. A total of 45 birds were brought from four flocks for systemic necropsy. The samples were collected for histopathology as well as PCR analysis for characterization of CIA infections. The necropsy showed that there was severe anemia indicated by paleness of comb, wattle and visceral organs. Atrophy of the thymus along with the mild atrophy of bursa was also noticed. Liver and bone marrow were pale in appearance. Kidneys were swollen and pale. Microscopically, marked hypoplasia of haemopoitic cells in the bone marrow, severe depletion of lymphocytes from lymphoid organs such as thymus, bursa and spleen were noticed along with mild to severe hemorrhages in the visceral organs of affected birds. PCR assay using specific primers for VP1 gene (1300bp) of CIA virus confirmed the CIA infection. The results of present study confirmed the presence of CIAV infection in RIR birds in current outbreaks.

Immunomodulatory and Therapeutic Prospective of a Protein Supplement with Vitamins and Selenium (Multimune) against Chicken Infectious Anaemia in Broiler Chicks

Immunomodulatory and Therapeutic Prospective of a Protein Supplement with Vitamins and Selenium (Multimune) against Chicken Infectious Anaemia in Broiler Chicks

Seroprevalence of Newcastle Disease, Chicken Infectious Anemia and Avian Influenza in Indigenous Chickens in Grenada, West Indies

This study was conducted to determine the seroprevalence of antibodies against Newcastle disease virus (NDV), Chicken infectious anemia virus (CIAV) and Avian influenza virus (AIV) in indigenous chickens in Grenada, West Indies. Indigenous chickens are kept for eggs and meat for either domestic consumption or local sale. These birds are usually kept in the backyard of the house with little or no shelter. The mean size of the flock per household was 14 birds (range 5–40 birds). Blood was collected from 368 birds from all the six parishes of Grenada and serum samples were tested for antibodies against NDV, CIAV and AIV using commercial enzyme-linked immunosorbent assay (ELISA) kits. The seroprevalence of antibodies against NDV, AIV and CIA was 66.3% (95% CI; 61.5% to 71.1%), 59.5% (95% CI; 54.4% to 64.5%) and 10.3% (95% CI; 7.2% to 13.4%), respectively. Since indigenous chickens in Grenada are not vaccinated against poultry pathogens, these results indicate exposure of chickens to NDV, AIV and CIAV Indigenous chickens are thus among the risk factors acting as vectors of pathogens that can threaten commercial poultry and other avian species in Grenada