• Parasites, Hosts and Diseases
• /
• v.36 no.2
• /
• pp.121-126
• /
• 1998

Hemagglutination-inhibition titers (log2) to Newcastle disease (ND) vims were chronologically observed in chicks, which were orally inoculated with 5 × 105 oocysts of Cwptospori,drum bcileyi at 2 days of age and subsequently vaccinated with inactivated ND virus at 4 and 21 days postinoculation. In general, the titers were considerably lower in the infected chicks than those in the uninfected control throughout the experimental period (p < 0.01), and rapid negative seroronversions were observed in the infected chicks. The titers reached a peak on weeks 2 and 4 post-booster-vaccination in the control and infected chicks, respectively. Thus, C. bciLeWi infection was shown to have an immunosuppressive effect on ND vaccination when the agent was given to 2-day-old chicks. It is suggested that C. bniLeWi infection in chicks may increase the host susceptibility to ND virus.

• Korean Journal of Veterinary Service
• /
• v.26 no.3
• /
• pp.215-219
• /
• 2003

This study was conducted to investigate the similarity between hemagglutination inhibition (HI) test and enzyme-linked immunosorbent assay(ELISA) titers and sample to positive ratio (S/P ratio) of Newcastle disease(ND) virus. To perform this study, the 372 sera of broiler chicks and 120 sera of layers and breed chicks were collected from slaughter house and farms, respectively. As a result of HI test out of different chicks, the positive percentage of ND antibody titer of broiler, layer and breeder, when a standard positive HI titer were '2', was 84.4%, 100% and 100%, respectively. The positive percentage of ND antibody titer by ELISA was shown 38.4%, 100% and 100% and S/P ratio were also shown 81.5%, 98.2% and 99.2%, respectively. The results of comparative survey with same sera by two experimental methods were as follows; In low HI titer, ELISA titer was not similar to HI titer, but S/P ratio was similar to it. In high HI titer, ELISA titer was not similar to HI titer. Therefore, HI titer was more similar to S/P ratio than ELISA titer.

• Korean Journal of Veterinary Research
• /
• v.42 no.3
• /
• pp.351-362
• /
• 2002

Newcastle disease (ND) is a highly contagious infection of poultry, Two pathology-based techniques, in situ RT-PCR and in situ hybridization (ISH) were applied to formalin-fixed, paraffin-embedded tissues from chickens naturally infected with velogenic ND virus (VNDV). Two pairs of primers and a probe for ISH and in situ RT-PCR, respectively, were selected from highly conserved region of matrix gene of NDV. The ISH experiment was carried out using MicroProbe$^{TM}$ capillary action system within 2 hours. In situ RT-PCR was performed using MicroProbe$^{TM}$ capillary action system and GeneAmp In Situ PCR system. With ISH and in situ RT-PCR, viral nucleic acid was detected in the central nervous system of chickens from infected with neurotropic velogenic Newcastle disease virus (NVNDV), whereas viral nucleic acid was detected in various organs or tissues of chickens from infected with viscerotropic velogenic Newcastle disease virus (VVNDV). In the NVND group, positive signals were characteristically defined in the cytoplasm of neuron, vascular endothelial cells, and perivascular mononuclear macrophages in the central nervous system. One of NVND group, chicken from one farm exhibited positive signals in the bronchial epithelium. The VVND group chickens showed positive reaction in the macrophages, vascular endothelium, and bronchiolar epithelium. Markedly, viral nucleic acid was detected in the macrophages of morphologically normal tissues which were peripheral or located in distant areas from lesions. The central nervous system of chickens infected with VVND virus had positive signals in the vascular endothelial cell, perivascular mononuclear macrophages and some neuron. The number and intensity of the positive cells by in situ RT-PCR were more and stronger, respectively, in comparison with those by ISH. Particularly, positive reaction was detected in macrophages infiltrating in cardiac muscle by in situ RT-PCR, but not obtained by ISH. Therefore, these results demonstrated that ISH is a rapid diagnostic method for detection of NDV and in situ RT-PCR can be used as an efficient method for detection of low viral load infection or subclinical viral infection of NDV.

• Korean Journal of Veterinary Service
• /
• v.24 no.3
• /
• pp.217-222
• /
• 2001

Hemagglutination inhibition(HI) titers of Newcastle disease(ND) were measured to investigate the vaccination times on three different species of broiler chicks in Chonbuk province. Each 330 of Cobb, Ross and White-semi broiler chicks were selected from 11 broiler farms. The primary vaccine were sprayed in hatchery at one day old chicks. Secondary and tertiary vaccine were used by drinking water at 7 to 24 days old chicks. The ND antibody titer were measured by HI from each different species of broiler chicks at the marketing date. Total average HI titers of Cobbs vaccinated with primary ones, secondary and tertiary ones were recorded 1.86, 1.52 and 2.76, respectively. The antibody titers were shown to 2.22, 2.13, 3.07 in terms of vaccination of Ross broiler chicks. They were also 2.56, 2.65 and 2.78 in terms of vaccination of White-semi broiler chicks. The value HI titer were not statistically different of all treatments. The results of this experiment suggested that HI titer of sera is scored less than defensive value of ND antibody titer at more than two times of vaccination.

• Korean Journal of Poultry Science
• /
• v.37 no.1
• /
• pp.89-99
• /
• 2010

Newcastle disease (ND), caused by Newcastle disease virus (NDV), has caused periodic epidemics in Korea at an interval of 3 to 5 years until the early 2000s. At least five distinct genotypes of NDV have been responsible for epizootic episodes in Korea; genotype III virus (before the 1970s), genotype V (the mid-1980s), genotype VI (the late 1980s to early 1990s), genotype VIIa (the mid-1990s), and genotype VIId viruses (the late 1990s to present). Recent epidemic strains of NDV (VIId viruses) shared geographical features with neighboring countries such as China and Japan. These VIId viruses as well as genotypes III and V viruses were viscerotropic and highly virulent for chickens. Antigenic variation occurred between VIId field viruses and LaSota vaccine strain, as found in other epidemic strains in past in Korea. Nevertheless the commercial vaccine was considered to effectively protect vaccinated birds from mortality against VIId viruses as well as other viruses belonging to genotypes III and V.

• Korean Journal of Veterinary Service
• /
• v.29 no.3
• /
• pp.267-276
• /
• 2006

To investigate serum antibody titers of Newcastle disease (ND) virus, serum samples were collected from 19,774 slaughtered chickens from 862 farms in Geoje, Goseong, Tongyung and other province during the period from January 2001 to December 2005. The results obtained are summarized as follows; 1. The negative percentage of ND antibody titer with below 1.0 levels decreased from 46.7% in 2001 to 40.5% in 2004 but those of it increased to 47.0% in 2005 and the positive percentage of ND antibody titer with higher 5 levels increased from 15.8% in 2001 to 26.2% in 2005. 2. The season levels of ND antibody titer showed various levels according to seasons but the general trend of ND antibody titer decreased in the later half of the year than those of the first half of the year. 3. The negative percentage of ND antibody titer on provinces decreased from 52.0% (2001) to 36.2% (2004) in Goseong but those of it increased to 51.4% in 2005. The negative percentage of ND antibody titer of Tongyung and other provinces increased from 51.0%, 28.5% (2001) to 55.0% and 44.3% (2005), respectively. 4. The year average levels of ND antibody titer increased from 2.2 to 2.6 during 2001- 2004 but those of it decreased to 2.4 in 2005. The provinces average levels of ND antibody titer increased from 2.0 to 2.8 during 2001 - 2005 and others provinces except Gyeongnam decreased from 3.3 to 2.6 during the 2001-2005. 5. The farm average levels of ND antibody titer with below 1.0 levels decreased from 26.3% in 2001 to 10.2% in 2004 but those of it increased to 17.6% in 2005 and those of below 1.0 or 2.0 levels increased from 17.9% (2001) to 27.7% (2005). The protective levels of ND antibody titer with higher 5.0 levels increased from 2.1% in 2001 to 8.8% in 2005.

• Korean Journal of Veterinary Research
• /
• v.46 no.3
• /
• pp.185-196
• /
• 2006

Newcastle disease (ND) is a highly contagious disease of poultry that can cause severe economic losses throughout the world. Vaccination has been used for a long time and proved as one of the most effective method to reduce the economic loss due to ND virus infection, The measurement of antibody titer such as hamagglutination-inhibition (Hl) test with sera has been used as a useful method to evaluate the immunity leve of host. However, Hl test is gradually being replaced by the enzyme linked-immunosorbent assay (ELISA), To evaluate the efficacy of ELISA in the chickens vaccinated with different procedure, present study has been performed. After SPF chicks and commercial broilers were vaccinated with different kinds of live vaccines such as V4, VG/GA and/or Bl at various time, the antibody level has been measured using both HI test and ELISA. Challenge test with velogenic viscerotropic NDV was also performed to measure the protective level of antibody. In the SPF chickens, the mean ELISA titer after vaccination and survival rate after challenge was increased and correlated with days post inoculation. More than 80% of chickens with higher than 1,000 ELISA titer after vaccination were survived after challenge with velogenic ND virus and had good correlation between survival rate and antibody titier. In commercial broiler chickens, most of them at market age had low level of ELISA titer regardless of the number of vaccination, and had a low correlation between survival rate and ELISA titer. However, the ELISA titer of remaining birds after challenge was increased. This result indicated that ELISA titer had good response against velogenic NOV infection compared to Hl titer.

• Korean Journal of Veterinary Service
• /
• v.42 no.3
• /
• pp.135-144
• /
• 2019

Low pathogenic avian influenza (LPAI; H9N2) and Newcastle disease (ND) are economically important poultry diseases in Korea. In this study, we investigated pathological features and virus distribution in the lymphoid tissues of chicks experimentally infected with H9N2 and/or ND virus. Six-weeks-old SPF chickens were divided into 4 groups, Control (C), H9N2 (E1), NDV (E2), and H9N2+NDV (E3). E1 group was challenged with 0.1 ml A/Kr/Ck/01310/01 (H9N2) $10^{5.6}$ $EID_{50}$ intranasally, E2 group was challenged with 0.5 ml KJW (NDV) $10^{5.0}{\sim}10^{6.0}$ $ELD_{50}$ intramuscularly, and E3 group was challenged with H9N2, followed 7 days later by NDV. In histopathological examination, E1 group showed depletion and necrosis in bursa of Fabricius, thymus, cecal tonsil, and spleen, whereas E2 and E3 groups were noted severe lymphocyte depletion and necrosis with destruction of lymphoid organs structures. In TUNEL assay, apoptotic bodies were detected in lymphoid organs of all experimental groups, which was most severe in E3 group. H9N2 and ND viruses were predominantly detected in cecal tonsil of E1, E2, and E3 groups by PCR and immunohistochemistry (ICH). In conclusion, co-infection of H9N2 with NDV caused severe pathologic lesions and apoptosis in lymphoid tissues compared to single infections.

• Korean Journal of Veterinary Service
• /
• v.24 no.1
• /
• pp.21-29
• /
• 2001

To compare of serum antibody titers using ELISA and HI, serum samples were collected from 100 breeders and their progeny 550 broilers. The breeders and broilers were vaccinated with infectious bronchitis(IB)- and Newcastle disease(ND)-viruses according to general vaccination program. The antibodies in serum samples against IB and ND viruses were detected by enzyme-linked immunosorbent assay(ELISA) using commercial ELISA kit and hemagglutination inhibition(HI) test. Geometric mean titer(GMT) of ELISA and In titers were monitored from 1-day-old to 35-day-old broilers and compared to those of breeder chickens. The antibody titers of breeders vaccinated with ]B virus showed 47,800, ELISA and 7.2, HI, respectively. Progeny chicks, 1-day-old, vaccinated with IBV showed high antibody titers than those of breed chickens. Those chicks were maintained protective antibody levels until 11-day-old. From 14-day-old, the antibody level decreased below protective levels. In ND, breeders serum antibody titers ELISA and Eiu were 30,200 GMT and 8.7 HI titer, respectively. On 1-day-old chicks, antibody levels was decreased to half in ELISA(16,270) compared with those of breeders, but In titers was 7.4. Progeny broilers, protective antibody level was maintained until 14- day-old by ELISA, but at 11-day-old by HI titers. After then, ND antibody titer was continuously decreased underdefense level. These result indicated that the ELISA method be more sensitive than HI titration to detect serum antibody level for IBV and NDV.

• Korean Journal of Veterinary Research
• /
• v.40 no.3
• /
• pp.563-573
• /
• 2000

Periodic outbreaks of Newcastle disease (ND) caused by velogenic viscerotropic ND virus (vvNDV) has become a major concern in Korea nowadays. Throughout last epidemic, the winter season in 2000, most chicken flocks infected early, under 2-4 weeks of age, showed high mortality up to 50-100%. Serum samples collected from 201 breeder, 284 layer and 112 broiler chicken flocks were examined to evaluate the efficacy of various vaccination methods and programs routinely used for mass vaccination in the field poultry farms. Despite repeated live vaccination, most poultry flocks vaccinated by drinking water route using nipple water supply system failed to produce solid active immune response to NDV during the growing time. In the present study, we applied the spray vaccination technique using Ulvavac or Desvac sprayer to the experimental poultry flocks and examined the efficacy of live vaccination effects induced by it under field condition. Measurable antibody to NDV as well as early protection against vvNDV challenge were found in poultry flocks vaccinated by spray route. Further, we did not found significant post vaccination reactions caused by spray vaccination if properly administered. These data indicate that the spray vaccination will be safe and reliable mass vaccination method for the prevention of ND.