Seroprevalence of Newcastle Disease Virus Among Different Non-Vaccinated Rural Poultry Species in Ardabil Province, Northwest of Iran

Newcastle Disease (ND) has been identified as a major constraint to local poultry production with its impact being felt more in rural poultry production which forms about 80% of Ghana poultry population. However documented evidence on ND virus activity in rural poultry in Ghana is still lacking. Hence, this study was conducted to evaluate the level of circulating antibodies against ND using the Haemagglutination Inhibition (HI) technique. Sera collected from unvaccinated 292 chickens and 153 guinea fowls randomly selected from households and a live bird market in Kumasi and its environs were evaluated for Newcastle disease virus antibodies. Results showed 81.8 % (239/292) of local chickens and 24.2 % (37/153) of guinea fowls tested positive for ND antibodies. Comparison was made between the seroprevalence of ND antibodies in household and live bird market as well as between sexes. Significantly higher prevalence rate (p<0.05) was observed with chickens sampled from households compared to those from the live bird market. Higher ranges of titers were also observed in chickens from households than those from live bird markets. The presence of ND antibodies in these unvaccinated local chickens and guinea fowls indicated the presence of the virus amongst the rural poultry population, hence aneed for improvement in vaccine campaignand delivery against ND for rural poultry especially with the use of thermostable and improved oral or feed-based vaccine delivery systems.

Newcastle disease (ND) in ostriches was first reported in zoo birds in the 1950s. An outbreak of ND in commercial ostriches in Israel was reported in 1989, but of more significance were the ND infections of ostriches in southern Africa during the 1990s as a result of assumed spread from commercial domestic fowl. The latter outbreaks were of particular concern due to the boom in international trade in ostriches and their products at that time. ND virus appeared to spread only slowly through affected ostrich flocks, and the clinical signs and mortality seen varied considerably with age. In field and experimental infections, morbidity, mainly in the form of nervous signs, and mortality could be extremely high in young birds but low or absent in adults. Characterization of ND viruses isolated during outbreaks in ostriches has shown them to be indistinguishable from viruses infecting chickens in the locality. Experimental challenge has shown ND poultry vaccines to be protective in ostriches, and several workers have proposed vaccine regimens employing both live and inactivated vaccines, usually given more frequently and employing much higher doses than recommended for chickens. Indirect and blocking enzyme-linked immunosorbent assay (ELISA) tests have been developed for the detection of ND antibodies in ostrich sera. Although some reports have suggested problems using the haemagglutination inhibition(HI)tests, others have recorded good correlation between ELISA, HI and virus neutralization tests. Because of their size and, as a consequence, the method of rearing, ostriches are quite different to conventional poultry and respond differently, in terms of disease and spread, when infected with ND virus. However, at present, for the international control of ND, there would appear to be little alternative to treating ostriches as poultry for the purposes of trade.

Seroconversion of 3 lentogenic commercial Newcastle disease (ND) vaccines and experimental V4 vaccines was compared based on the haemagglutination inhibition (HI) test against ND. It was found that for primary vaccination all the vaccines produced similar response but for vaccinations V4 and LaSota were better than RDVF. Eight-five samples each of serum, tears and feather pulp were collected from respective birds and antibody assessment was done against ND by HI test. The geometric mean HI titres (GMT) of serum samples were highest followed by tears and feather pulp samples before vaccination and 3 weeks after vaccination by oculonasal route and the difference was statistically significant (p < 0.01). Three weeks after booster vaccination by oculonasal route, however, the GMT of serum samples were highest followed by feather pulp and tear samples. The ease of collection of feather pulp samples and their role in ND serology is discussed.

Newcastle Disease (ND), caused by Newcastle Disease Virus (NDV) is one of the most devastating diseases of the domestic fowl. Domestic pigeon (Columba livia) are related as host and disseminating of ND to poultry and wild birds, but some aspects of epidemiology are still unclear. In this study, conventional microtiter hemagglutination inhibition (HI) test was performed to evaluate the antibodies production of experimentally infected pigeons with a pathogenic strain of NDV and vaccinated pigeons with live vaccine strains LaSota and Ulster. The tests were performed using two different antigens to evaluate the possible differences between the results. The use of different antigens had influenced the HI test results for both experimentally infected and vaccinated pigeons. While higher HI titers of experimentally infected pigeons were obtained using LaSota as antigen, the opposite was observed with vaccinated pigeons, where the occurrence of higher titers were observed using Ulster as antigen. Our data suggest that these aspects should be considered in HI tests procedure, in order to obtain results closer to the real immune response of birds infected with NDV. DOI: http://dx.doi.org/10.17525/vrr.v15i1.41

Summary Reactivity of ostrich sera to Newcastle disease virus (NDV) by enzyme‐linked immunosorbent assay (ELISA) and haemagglutination inhibition (HI) test were compared. Ten‐month old ostriches séronégative by both tests were vaccinated with an oil‐based NDV vaccine on days 0 and 11. Significant levels of reactive antibodies were first detected on day 11 by ELISA (sample/positive ratio > 0.2 in 11/20 birds; 55%) and HI (titre > 1/8 in 10/20 birds; 50%). At the end of the experiment (day 37) all birds had significant antibody levels by ELISA, but only 16/20 (80%) by HI test. There was a sigmoidal relationship (r= 0.62, 3rd degree polynomial) between antibody levels detected by ELISA and by HI test. Antibodies reactive with NDV in naturally exposed ostriches from Zimbabwe and Botswana were also detected by ELISA (112/165; 68%) and HI (85/165; 52%).

Simple SummaryNewcastle disease (ND) is a worldwide distributed highly infectious disease of wild and domestic birds. Regardless of vaccination procedures, little information is available about the pathogenicity and genetic characteristics of the circulating virus in the Egyptian environment. The current study was undertaken to estimate the role of the different inoculation routes in the pathogenicity of NDV. Therefore, induction of the infection was done with NDV-CH-EGYPT-F42-DAKAHLIA-2019 (VNDV) isolated strain in 28 day old white Ross male broiler chicks via intraocular, choanal, intranasal, mixed oculo-nasal routes. Interestingly, a series of findings including mortality rates, severity of clinical and histopathological lesions, and intensity of viral nucleoprotein immunolabeling were reported to be different according to the routes of inoculation. Clearly, the present findings provide novel descriptive and comparative histopathological and immunohistochemical findings about this virus in Egypt, and the obtained data may be useful for different vaccination strategies against NDV. Newcastle disease virus (NDV) remains a constant threat to the poultry industry. There is scarce information concerning the pathogenicity and genetic characteristics of the circulating velogenic Newcastle disease virus (NDV) in Egypt. In the present work, NDV was screened from tracheal swabs collected from several broiler chicken farms (N = 12) in Dakahlia Governorate, Egypt. Real-time reverse transcriptase polymerase chain reaction (RRT-PCR) was used for screening of velogenic and mesogenic NDV strains through targeting F gene fragment amplification, followed by sequencing of the resulting PCR products. The identified strain, namely, NDV-CH-EGYPT-F42-DAKAHLIA-2019, was isolated and titrated in the allantoic cavity of 10 day old specific pathogen-free (SPF) embryonated chicken eggs (ECEs), and then their virulence was determined by mean death time (MDT) and intracerebral pathogenicity index (ICPI). The pathogenicity of the identified velogenic NDV strain was also assessed in 28 day old chickens using different inoculation routes as follows: intraocular, choanal slit, intranasal routes, and a combination of both intranasal and intraocular routes. In addition, sera were collected 5 and 10 days post inoculation (pi) for the detection of NDV antibodies by hemagglutination inhibition test (HI), and tissue samples from different organs were collected for histopathological and immunohistochemical examination. A series of different clinical signs and postmortem lesions were recorded with the various routes. Interestingly, histopathology and immunohistochemistry for NDV nucleoprotein displayed widespread systemic distribution. The intensity of viral nucleoprotein immunolabeling was detected within different cells including the epithelial and endothelium lining, as well as macrophages. The onset, distribution, and severity of the observed lesions were remarkably different between various inoculation routes. Collectively, a time-course comparative pathogenesis study of NDV infection demonstrated the role of different routes in the pathogenicity of NDV. The intranasal challenge was associated with a prominent increase in NDV lesions, whereas the choanal slit route was the route least accompanied by severe NDV pathological findings. Clearly, the present findings might be helpful for implementation of proper vaccination strategies against NDV.

Objective: Isolation, serological and molecular identification and differentiation between velogenic and lentogenic of Newcastle disease virus (NDV) strains. Design: Descriptive study. Procedures: In this study, A total of 24 Pooled samples were collected from Dakahlia, Egypt, from 2017 to 2018 .The virus was isolated in 10 days old (ECEs) and serologically identified in third egg passage allantoic fluid by Haemagglutination (HA), Haemagglutination inhibition test (HIT) and agar gel precipitation test (AGPT). Molecular confirmation was done by reverse transcriptase-polymerase chain reaction (RT-PCR). Genetic diversity between velogenic and lentogenic NDV strains was done by RT-PCR amplification of 254bp F gene fragment from velogenic NDVs and sequence analysis of 362bp NDV F gene fragment. Results: Out of 24 tested samples, 20 samples were collected from allontoic fluid of 3rd passage positive by HA test, 18 samples by HIT, 16 samples by AGPT and 18 isolates were positive with RT-PCR amplification of 362bp F gene fragment. LaSota strain gave positive results in HA, HIT, AGPT and RT-PCR amplification of 362bp fragment. Interestingly, 254bp fragment failed to be amplified from LaSota strain. The phylogenic analysis revealed that our isolates were related to Egyptian velogenic genotype VII NDVs. The deduced amino acid sequence of the F protein cleavage site of our isolates was characteristic of velogenic NDVs (112R-R-Q-K-R↓F117) while LaSota strain had characteristic lentogenic NDVs cleavage site (112G-R-Q-G-R↓L117). Conclusion and clinical relevance: RT-PCR and sequence analysis in this study can be used for differentiation between velogenic and lentogenic NDV strains.

Purpose: To investigate the antibody effect of immunace on the adjuvanticity of 1,2-dioleoyl-3- trimethylammoniumpropane (DOTAP)- based liposomes.Method: The vesicles of the liposome-based ND vaccine were prepared by lipid film hydration method and physically characterized for shape, particle size and zeta potential. Forty experimental birds were divided into an unvaccinated group, a liposomal Newcastle disease (ND) vaccine group, combined liposomal ND vaccine and immunace group, and a live La Sota® vaccine group. The liposomal ND vaccine, liposomal ND vaccine and immunace and a live La Sota® vaccine groups were vaccinated orally at 3 and 6 weeks of age. Haemagglutination inhibition test was carried out after primary and booster doses.Results: The log2 mean antibody titre induced by the liposomal ND vaccine after secondary immunization of the birds was 9.60 ± 0.95 while that of the combined liposomal ND vaccine and immunace group was 7.00 ±1.71, and that of the live La Sota vaccine® was 6.00 ±0.63. There was no detectable antibody in the unvaccinated group throughout the experiment. At p &lt; 0.05, the liposomal ND vaccine group, after secondary immunization, produced antibodies which were significantly higher than those of the combined immunace-liposomal ND vaccine group.Conclusion: There was a boost in the immune response of the birds immunized with liposomal ND vaccine and immunace after primary immunization only.Keywords: Antibody, Newcastle disease vaccine, La Sota, DOTAP, Immunace, Immunity, Adjuvant

Two flocks of chicks from parents not immune to Newcastle disease (ND) virus and six flocks from immune parents were vaccinated intranasally with 106.03 to 106.86 mean embryo infective doses of F strain ND virus on the fifth day of life. A group of chicks from each flock was left unvaccinated. Vaccinated and unvaccinated chicks from each flock were killed on days one to ten and then every other day until 39 to 61 days. Serums were examined by the ND virus haemagglutination-inhibition (HI) test, and tissues were inoculated into fertile hens' eggs for recovery of vaccine virus. Vaccine virus was recovered from vaccinated nonparentally-immune chicks daily from two to 14 days post-vaccination. Their serological response was detectable two days post-vaccination and reached peak levels nine to 14 days post-vaccination. In contrast, vaccine virus was recovered rarely or not at all from parentally-immune chicks and their serological response was much less than in chicks with no parental immunity. It is concluded that parentally-acquired antibodies neutralised vaccine virus so reducing the amount of immunizing virus antigen to which the host was exposed.

Background and Aim:Newcastle disease (ND) and avian influenza (AI) are two devastating diseases of poultry, which cause great economic losses to the poultry industry and disrupt food security in our country. The use of ND-AI inactive bivalent vaccine is very effective and economical to prevent and control ND and AI disease. Bivalent ND LaSota-AI H9N2 vaccine is not yet available in Indonesia. The inactivated vaccines used in poultry industry often require oil adjuvant to elicit a sufficient immune response. This study aimed to develop the bivalent inactive vaccines containing ND LaSota and AI H9N2 Sidrap isolate which are local isolates as poultry vaccine candidates, and formulated with two different commercial adjuvants, then compared.Materials and Methods:Two vaccines bivalent were prepared by emulsifying inactivated Newcastle disease virus (LaSota strain) and AI H9N2 Sidrap isolate viruses with Marcol white mineral oil and Montanide ISA70 adjuvants. Both of bivalent vaccines were tested for safety (physical and histopathological at the injection site) and efficacy in specific-pathogen-free chickens. Parameters used for the evaluation of the efficacy were immunogenicity by hemagglutination inhibition and protection percentage.Results:Both bivalent vaccines are safe to use. Post-vaccination (PV) immune response was observed using a hemagglutination inhibition test at 2, 3, 4, 5, 6, 7, and 8 weeks of PV. The bivalent vaccine B gives a better immune response to ND at 2, 3, and 4 weeks of PV (p<0.05) compared to the bivalent vaccine A, but in 5, 6, 7, and 8 weeks, the PV does not show differences in the immune response. The immune response to AI H9N2 showed differences at weeks 2 and 3 PV (p<0.05) with the bivalent vaccine B indicated higher immunity. A single immunization with both bivalent vaccines induces 100% protection in chickens that have been vaccinated against the deadly challenge with the virulent ND virus.Conclusion:Both of bivalent vaccines are safe to use and provide good efficacy against virulent ND viruses, but bivalent vaccine B (with Montanide ISA70 adjuvant) shows better immune response than bivalent vaccine A (Marcol white mineral oil adjuvant).

Serum samples from 191 ostriches (Struthio camelus) in Japan were tested for antibodies to Newcastle disease virus (NDV) and avian influenza virus (AIV). Twenty-two (12%) contained NDV-specific neutralizing antibodies by a virus-neutralization (VN) test without vaccination. Antibodies to AIV were not detected in the any sera by an agar gel precipitation test. Seven serum samples that had vaccinated with live NDV by eye drop were all positive by the VN test at 1 month post vaccination. A haemagglutination inhibition (HI) test for NDV seemed not to be suitable for ostriches because of non-specific agglutination of chicken red blood cells. No haemagglutinating viruses were isolated. This is the first report on detection of antibodies against NDV in ostriches in Japan.

A longitudinal study was carried out from September 2014 to May 2015 on village chicken of Lume district for the aim of determining incidence rate of mortality of Newcastle disease (NCD) and infectious bursal disease ( IBD) and the associated risk factors. In addition in a retrospective survey past occurrence of these diseas e was assessed. Simple random sampling method was used to select the peasant associations (PAs) and the households. Owners and veterinary field workers perception on chicken diseases was collect ed from 120 respondents through structured questionnaire. The majority (75%) of the respondents put diseases as major causes of village chicken mortality, out of which 78.3% of the respondents indicated NCD locally known as “Fangle” as the leading disease that cause mortality of chicken in the village.Of the 1358 reg istered chicken, 202 (14.9%) survived the entire follow - up period. A total of 843 chickens found dead of NCD outbreak during the follow - up period. The general mortality rate was 62.1% whereas the incidence rate was113.2 cases per 1000 chicken month.Over th e duration of the study, serum samples of 521 chickens were collected to confirm the cause of the outbreak, 242 from sick and 279 from apparently health chicken. Serology using HAI and I - ELISA test were conducted to determine the seroprevalence of NCD and IBD, respectively. In total 28.6% (149/521) and 20.7% (108/521) were positive for NCD and IBD, respectively. Among the 242 sera collected from clinically diseased chicken 61.6% (149/242) and 38.4% (93/242) were positive for NCD and IBD, respectively. Statis tically significant ( p&lt;0.05 ) difference in prevalence of NCD was found between highland and lowland; chicken flock size and sampling months. Statistically significant ( p&lt;0.05 ) difference in seroprevalence of IBD was found between different age groups; hous ehold flock size and sampling months. This study has shown that NCD and IBD are one of the major infectious diseases threatening the survival and productivity of traditionally managed local chickens in East Showa zone. Thu s, routine vaccination program is recommended.

Newcastle Disease (ND) is regarded as one of the major diseases of poultry because of the devastating losses that the virulent form of the virus can impose on both commercial and village chicken. However, the disease can be controlled through the administration of effective vaccines. Almost all the commercially available vaccines require refrigeration and begin to deteriorate rapidly after 1-2 hours if left at room temperature (around 25°C). Subsequently, because maintaining an adequate supply of refrigerated facilities may be a difficult task in many developing countries with unreliable electrical supplies, the development and large scale production and utilization of an effective thermo-stable Newcastle disease vaccine seems imperative to support rural poultry industry. Participatory/action research on vaccination of village poultry against Newcastle disease (ND) was carried out in two selected villages of Bullie district of Gedio zone, southern Ethiopia; with an objective to demonstrate community based thermo-stable ND vaccination scheme and thereby; to increase the population of chicken in backyard production system. We have selected four community vaccinators, two per each village and trained on diagnosis of major poultry diseases, with the major emphasis on Newcastle disease, on preparation, handling and administration of thermo-sable ND vaccine. From the two villages, we have vaccinated 362 chicken of all age ranges of 54 households, in the two rounds. For the vaccination we have selected a site which is suitable for household members to bring their chicken for vaccine administration. We used eye drop technique to administer a vaccine, by preparing one eye drop in one dose base for all age groups. We administered a vaccine before a pick prevalence of Newcastle disease in the study area, for the remaining three months, data was collected on the mortality rate of the chicken. The result shows that, of the total vaccinated chicken (362) from the two villages on the two rounds, 51 chicken were dead due to diseases, of the cases with a clinical sign not related with Newcastle disease. The total mortality rate of 14%, in this study shows that, thermo-stable Newcastle disease vaccine applied via eye drop is the most effective method for control Newcastle disease in village chicken. Therefore; with proper use of vaccine and vaccination programs using well trained community vaccinators, we can reduce village chicken mortality highly to enhance productivity of rural community at large.

Evaluation of the Newcastle disease virus genotype VII–mismatched vaccines in SPF chickens: A challenge efficacy study

Newcastle disease (ND) is a pandemic viral disease of poultry. It is highly contagious and causes high morbidity and mortality in affected flocks. The disease is caused by Avian orthoavulavirus 1, commonly known as Newcastle disease virus (NDV) belongs to the family Paramyxoviridae. The virus affects almost 241 species of birds. Based on the pathogenicity, the virus is classified into five pathotypes viz., viscerotropic velogenic, neurotropic velogenic, mesogenic, lentogenic and asymptomatic enteric NDV. The severity of the disease varies with the viral pathotype. Isolation and identification along with pathotyping of the virus provides a basis for understanding the type of virus circulating in the region. In the present study, tissue samples from dead/ ailing birds showing lesions/clinical signs suggestive of ND were collected. They were subjected to virus isolation in embryonated chicken eggs and identified by haemagglutination test and confirmed by haemagglutination inhibition test. Eight NDV isolates were obtained out of 55 tissue samples and were classified into pathotypes by intracerebral pathogenicity index (ICPI) and mean death time (MDT). The ICPI values varied from 0.75 to 1.53 and MDT from 54 h. to 79.2 h. Out of eight isolates, three belonged to velogenic group and five were of mesogenic pathotype. The study revealed the circulation of virulent NDV in Kerala. The pathogenicity tests provide a basis for understanding the epidemiology of ND.