• Korean Journal of Veterinary Research
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• v.11 no.2
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• pp.163-170
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• 1971

Since the report in 1946 on the first isolation of Japanese encephalitis virus in Korea, the disease is known to occur every year and has occasionally spread in epidemic proportion among human populations. Because of its public health importance, it was deemed highly desirable to gain specific information as to natural history of the disease in Korea if we are to accomplish our ultimate objective of controling the disease in Korea. There still remain, however, unknown factors as to the ecology of Japanese encephalitis virus in Korea. This paper presents the results of serologic study on Korean cattle, hog and horse by means of hemagglutination inhibition (H.I.) test. The serum specimens were collected from Korean cattle, hog and horse their estimated ages being 3 to 9 years, 6 to 24 months and 2 to 14 years respectively, by jugular puncture; in Seoul and Kyung-Ki are a from the first part of May to November last, 1968. The strain used was designated by M 5/596. The methods of H.I. test employed in this study were essentially simillar to those employed by Clark and Fred. The results obtained summarized as follows; 1. Of samples of cattle sera tested, 183 (98%) was found to be positive, H.I. antibodies showing the highest proportion, on September. The lowest proportion showed 81 (68%) of 117 samples, on June. 2. One hundred and ninety-five and 114 swine serum samples tested were all of positive in both on September and October respectively. The lowest proportion showed 92 (29%) of 314 on June too. 3. Ninety (99%) of 91 equine serum samples tested contained demonstrable H.I. antibodies the highest proportion, on August. The lowest proportion was 19 (27%) of 70 samples on June. 4. Implications of these findings in the ecology of Japanese encephalitis Seoul and Kyung-Ki area were discussed.

• Korean Journal of Veterinary Service
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• v.24 no.1
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• pp.21-29
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• 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 Poultry Science
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• v.15 no.3
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• pp.207-210
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• 1988

A total of 3 hybridoma clones producting menoclonal antibody (MCA) against Newcastle disease virus(NDV) was raised by cell fusion method. The MCAs did not cross react against other avian or mammalian viruses tested. However, these antibodies reacted with all strains of velogenic and lentogenic NDVs tested indicating that they are unable to discriminate the possible antigenic differences among NDVs. All. the MCAs were classified as IgG type and did not show neutralizing and hemagglutination inhibition (HAI) activity except one clone which has low HAI activity. One of these MCA raised in mouse ascites revealed the titer of $10^6$ by indirect immunofluorescent antibody (IFA) test Using the MCA, virulent NDV could easily be detected from tracheal and conjunctival smears made 2 to 3 days after experimental infection.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.366-370
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• 2004

One hundred and sixty day-old Hainan chicks were randomly allotted into eight pens to investigate the effect of different dietary concentrations of chromium (Cr) in the form of chromium chloride, and different dosages of florfenicol on humoral immune responses by determining antibody titers to Newcastle disease (ND) vaccines using the hemagglutination inhibition test. The results indicated that ND antibody titers were significantly higher in chicks receiving Cr at low (5 mg/kg feed) and middle (10 mg/kg feed) dose compared with the control (p<0.01). However, ND antibody titers were significantly decreased in chicks receiving Cr at a high dosage of 500 mg/kg feed (p<0.01), though the ND antibody titers of the early days (d 21 and d 28 of age) were higher than that of the control group. It is suggested that excessive Cr intake has detrimental effects on ND antibody production in chicks. No significantly lower response was measured in chicks that received florfenicol at a low dosage of 50 mg/kg feed (p>0.05), but the ND antibody titers were significantly decreased in chicks receiving 200 and 400 mg/kg feed of the drug (p<0.01). The ND antibody titers of group receiving 200 mg/kg feed of florfenicol plus 10 mg/kg Cr were slightly higher than that of the group receiving single florfenicol of 200 mg/kg although, no significant differences were observed between these two treatments. It is suggested that the humoral immune response impaired by florfenicol (200 mg/kg feed) could not be significantly reversed by Cr (10 mg/kg feed).

• Korean Journal of Veterinary Research
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• v.57 no.1
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• pp.31-36
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• 2017

Japanese encephalitis (JE) is an important zoonosis caused by the mosquito-transmitted JE virus (JEV), which is a causative agent of reproductive failure in pregnant sows. Detection of JEV antibodies in swine is performed by hemagglutination inhibition (HI), virus neutralization (VN), and the plaque reduction neutralization test (PRNT). The most stringent PRNT is the 90% endpoint PRNT ($PRNT_{90}$). These conventional assays are difficult to carry out in diagnostic laboratories with insufficient instruments or cell culture systems. An alternative assay that is easily conducted and time efficient is required. In this study, we improved the indirect enzyme-linked immunosorbent assay (I-ELISA) with clarified antigen for the detection of JEV antibodies. The I-ELISA results obtained from 175 swine serum samples were compared with HI, VN, and $PRNT_{90}$ results. The sensitivity of I-ELISA was 91.8%, 95.0%, and 94.7% compared with HI, VN, and $PRNT_{90}$ results, respectively. The specificity of I-ELISA was 92.2%, 94.7%, and 94.7% compared with HI, VN, and $PRNT_{90}$ results, respectively. Moreover, the I-ELISA results were significantly correlated with the HI (r = 0.93), VN (r = 0.95), and $PRNT_{90}$ (r = 0.92) results. These results suggest that the improved I-ELISA is useful for serosurveillance of JEV in swine.

• Parasites, Hosts and Diseases
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• v.36 no.3
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• pp.203-206
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• 1998

Two-day-old commercial chicks were inoculated orally with 2 × 106 oocysts of Cwptosporinium bailevi and vaccinated with 103.5 EID50/head of a commercially available avian infectious bronchitis (IB) live virus vaccine at 4 and 14 days following inoculation. Chicks infected with C. baileyi were shown to have an immunosuppressive effect on IB virus. It is concluded that infection with the protozoon in early life may increase their susceptibility to IB.

• Korean Journal of Veterinary Research
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• v.62 no.3
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• pp.24.1-24.7
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• 2022

Incidences of major feline viral diseases provide basic information for preventing viral disease in cats. Despite the growing interest in feline viral diseases, sero-surveillances have been lacking. In this study, we analyzed the diagnoses of feline viral diseases and conducted a sero surveillance of feline panleukopenia virus (FPV), feline calicivirus (FCV), feline herpesvirus-1 (FHV-1), and feline infectious peritonitis virus (FIPV) in Korean cats. Of the 204 confirmed cases since 2015, the numbers of diagnoses for FPV, FIPV, FCV, feline influenza virus, and FHV-1 were 156, 32, 12, 3, and 1 case, respectively. In total, 200 sera, collected between 2019 and 2021, were screened for the presence of antibodies against FPV, 2 FCVs, FHV-1, and FIPV using a hemagglutination inhibition test and a virus-neutralizing assay (VNA). The overall seropositive rates in cats tested for FPV, the 2 FCVs, FHV-1, and FIPV were 92.5%. 42.0%, 37.0%, 52.0%, and 14.0%, respectively. A low correlation (r = 0.466) was detected between the VNA titers of 2 FCV strains. The highest incidence and seropositive rate of FPV reveal that FPV is circulating in Korean cats. The low r-value between 2 FCVs suggests that a new feline vaccine containing the 2 kinds of FCVs is required.

• IMMUNE NETWORK
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• v.23 no.2
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• pp.18.1-18.15
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• 2023

It has been reported that some exercise could enhance the anti-viral antibody titers after vaccination including influenza and coronavirus disease 2019 vaccines. We developed SAT-008, a novel digital device, consists of physical activities and activities related to the autonomic nervous system. We assessed the feasibility of SAT-008 to boost host immunity after an influenza vaccination by a randomized, open-label, and controlled study on adults administered influenza vaccines in the previous year. Among 32 participants, the SAT-008 showed a significant increase in the anti-influenza antibody titers assessed by hemagglutination-inhibition test against antigen subtype B Yamagata lineage after 4 wk of vaccination and subtype B Victoria lineage after 12 wk (p<0.05). There was no difference in the antibody titers against subtype "A." The SAT-008 also showed significant increase in the plasma cytokine levels of IL-10, IL-1β, and IL-6 at weeks 4 and 12 after the vaccination (p<0.05). A new approach using the digital device may boost host immunity against virus via vaccine adjuvant-like effects.

• Korean Journal of Veterinary Research
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• v.62 no.4
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• pp.29.1-29.7
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• 2022

Vaccination against Newcastle disease (ND) is the most effective means of controlling the disease, and these vaccines are commercialized only after their safety and effectiveness have been verified through tests that comply with Korean Standards of National Lot Release for Veterinary Biologics. This study investigated whether a relatively convenient and safe serological test can be used in place of the challenge test using highly virulent ND virus. Hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA) were considered positive of log₂ 2 or more and cutoff value of 200 or more, respectively, in both live and inactivated vaccines. However, when the antibody levels of the live and inactivated vaccines induced using the Ulster 2C, KBNP-C4152R2L, and K148/08 strains were compared, the antibody titers for inactivated vaccines were significantly higher than those for live vaccines in both the HI assay and ELISA. A strong positive correlation was observed between HI and ELISA antibody titers. The live vaccines corresponded to a survival rates of ≥ 80% and the inactivated vaccines corresponded to 100% survival rates. This study confirmed that standard efficacy tests can serve as serological tests, and can replace the challenge test and that the vaccine approval process can be improved.

• Journal of Veterinary Clinics
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• v.23 no.4
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• pp.416-420
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• 2006

Compare to testing sera individually, pooled-serum testing has considered as a cost-effective method, particularly on a large population-based seroprevalence studies. This study was to determine the relationship between individual sera and pooled sera titers for detection of avian infectious bronchitis virus (IBV) and to evaluate suitability of pooled sera by comparing prevalences estimated from both samples. A total of 5,000 individual samples were collected from 500 flocks in Chungcheong, Gyunsgi, and Kangwon provinces between January 2005 and February 2006. Ten samples were randomly selected from each flock. Five-hundred pooled sera were prepared by mixing equal amount of each 10 individual serum from the original samples. IBV antibody titers were measured by hemagglutination inhibition (HI) test. The least squares regression analysis was performed to construct equation between pooled and mean individual titers. To determine whether the flock is infected 4 arbitrary criteria were used: detection of at least 1 chicken with HI titer ${\ge}$ 9 (criterion 1), detection of at least 2 samples with HI titer ${\ge}$9 (criterion 2), detection of at least 1 sample with HI titer ${\ge}$ 10 (criterion 3), and filially detection of at least 1 sample with HI titer ${\ge}$ 11 (criterion 4). The receiver operating characteristic (ROC) curve was used to examine the cut-off points of pooled titers showing optimal diagnostic accuracy. The area under the curve (AUC), sensitivities (Se), specificities (Sp), and positive (PPV) and negative (NPV) predictive values were calculated. The regression equation between pooled titers (pool) and mean individual titers (mean) was: $pool= 1.2498+0.8952{\times}mean$, with coefficient of determination of 87% (p< 0.0001). The optimal cut-off points of pooled titers were titer 8 for criterion 1 (AUC=0.975, Se=0.883, Sp=0.959, PPV=0.985, NPV=0.728), titer 8 for criterion 2 (AUC=0.969, Se=0.954, Sp=0.855, PPV=0.926, NPV=0.907), titer 9 for criterion 3 (AUC=0.970, Se=0.836, Sp=0.967, PPV=0.978, NPV=0.772), and titer 9 for criterion 4 (AUC= 0.946, Se=0.928, Sp=0.843, PPV=0.857, NPV=0.921). The difference of 'prevalence estimated by individual and pooled sample showed a minimum of 2% for criteria 2 and a maximum of 9.1:% for criteria 3. These results indicate that the use of pooled sera in HI test for screening IBV infection in laying hen flocks is considered as a cost-effective method of testing large numbers of samples with high diagnostic accuracy.