scholarly journals Type-specific seroprevalence of bluetongue in India during 2018 and 2019

2020 ◽  
Vol 13 (10) ◽  
pp. 2092-2096
Author(s):  
G. Naresh ◽  
Kalyani Putty ◽  
Y. Narasimha Reddy ◽  
Y. Krishna Jyothi

Background and Aim: Bluetongue (BT) is a major disease of sheep and goats and is endemic to India. It is known to cause significant economic losses to the sheep industry. The current study aimed to determine the type-specific seroprevalence of BT in sheep population of India during 2018-2019. Materials and Methods: Blood samples (n=405) were collected from 6 months to 1 year old sheep from six districts (Nalgonda, Karimnagar, Khammam, Mahabubnagar, Warangal, and Ranga Reddy) of Telangana state, India. Group- and type-specific seroprevalence (against BT virus [BTV] serotypes BTV-1, 2, 4, 5, 9, 10, 12, 16, 21, 23, and 24) was studied by competitive enzyme-linked immunosorbent assay and serum neutralization test, respectively. Results: Results showed an overall seroprevalence of 14.81% (n=60) with the highest seroprevalence of 50% in Khammam district. Seroprevalence of BTV-1, 2, 4, 5, 9, 10, 12, 16, 21, 23, and 24 was noted as 16.66%, 11.66%, 31.66%, 11.66%, 05%, 6.66%, 16.66%, 8.33%, 13.33%, 6.66%, and 16.66%, respectively. The majority of the sera neutralized more than 1 serotype, indicating superinfection or circulation of multiple serotypes in the sampled flocks. This mixed seroprevalence was observed in 43.33% of the sera with number of BTV serotype-specific antibodies ranging from two to eight in individual animals. Conclusion: Regular monitoring of circulating serotypes, especially in young herds, elucidates pattern of dominating serotypes in a particular area during a season. This knowledge can be applied to design appropriate vaccination strategies by including particular serotypes of virus as part of a multivalent vaccine for a particular period, in a particular area.

2001 ◽  
Vol 46 (No. 2) ◽  
pp. 29-34 ◽  
Author(s):  
K. Kovařčík

We developed an indirect enzyme-linked immunosorbent assay (ELISA) for detection of serum antibodies to bovine respiratory syncytial virus. For evaluation of the newly developed ELISA, field sera collected from 549 head of cattle in the Czech Republic were tested in parallel by a serum neutralization test. The tests showed 98.36% agreement. The specificity and sensitivity of the ELISA relative to serum neutralization test was 97.00% (226/233) and 99.37% (314/316), respectively. Tissue culture-grown viral antigen was used in the tests. The corrected optical density (COD) of each sample tested at dilution 1/100 was expressed as a percentage of the COD of a positive reference serum included on each plate, this value was the sample/positive (S/P) ratio. We determined the relationship between the S/P ratio (%) obtained at a dilution 1/100 and the end point titer calculated by serum neutralization test (r = 0.9743). The ELISA test was evaluated by testing acute and convalescent (3 wk later) serum pairs from 9 head of cattle with confirmed BRSV infection for demonstration of seroconversion. The ELISA test demonstrated a clear increase of the S/P ratio (%) between acute and convalescent serum pairs (on average 42.2 ± 13.1).


2011 ◽  
Vol 56 (No. 8) ◽  
pp. 395-399 ◽  
Author(s):  
M. Rahimi

Avian metapneumovirus causes an acute highly contagious upper respiratory tract infection primarily of turkeys and chickens. The disease can cause significant economic losses in turkey and chicken flocks, particularly when exacerbated by secondary pathogens. The purpose of this study was to determine the prevalence of avian metapneumovirus antibodies in broiler and broiler breeder flocks in Kermanshah province, west of Iran. All the flocks had not been vaccinated against avian metapneumovirus. The province were divided into four geographic areas; southwest, southeast, northwest, and northeast. Flocks in each area, and 14–15 birds in each flock, were randomly sampled. The blood samples were taken regardless of the presence of any signs of respiratory or any other clinical disease in the flocks. A total of 435 blood samples were collected from 30 commercial chicken flocks (24 broiler flocks, aged between six and eight weeks, and six broiler breeder flocks, aged between 56 and 72 weeks). The presence of antibodies against avian metapneumovirus in each serum sample was tested twice by enzyme-linked immunosorbent assay using a commercial kit which was able to determine antibodies against A, B and C subtypes of avian metapneumovirus. Out of 347 serum samples obtained from broiler chickens, 167 (48.1%) were positive to avian metapneumovirus antibodies, which represented 20 (83.3%) of 24 examined broiler flocks. Out of 88 samples obtained from broiler breeder chickens, 82 (93.2%) were positive to avian metapneumovirus antibodies, which belonged to six (100%) of examined broiler breeder flocks. Detection of anti-avian metapneumovirus antibodies among broiler breeder (100%) was higher than broiler (83.3%) flocks. A higher rate of seropositivity (83.3% of samples and 100% of broiler flocks) was observed in northwest. The results of this study may indicate the possible involvement of avian metapneumovirus in the respiratory disease we are seeing in chickens in Iran. Its prevalence has to be investigated in other parts of Iran. Future work may and should include the use of molecular methods and isolation of the virus. Isolation of avian metapneumovirus will allow the possibility of making autogenous vaccines.


2002 ◽  
Vol 14 (3) ◽  
pp. 240-242 ◽  
Author(s):  
Juan Francisco Alvarado ◽  
Gaby Dolz ◽  
Marco V. Herrero ◽  
Brian McCluskey ◽  
Mo Salman

A competitive enzyme-linked immunosorbent assay (C-ELISA) for the detection of antibodies against vesicular stomatitis virus New Jersey (VSV-NJ) and vesicular stomatitis virus Indiana (VSV-IN) was compared with the serum neutralization test (SNT) using 1,106 serum samples obtained from dairy cattle on sentinel study farms in the Poás region of Costa Rica. Kappa coefficients between the C-ELISA and the SNT were 0.8871 (95% confidence interval [CI]: 0.8587–0.9155) and 0.6912 (95% CI: 0.6246–0.7577) for the VSV-NJ and VSV-IN tests, respectively. These results indicate good to excellent agreement between the 2 tests under these conditions.


Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2851
Author(s):  
Zineb EL Brini ◽  
Ouafaa Fassi Fihri ◽  
Romain Paillot ◽  
Chafiqa Lotfi ◽  
Farid Amraoui ◽  
...  

This study reports the first equine herpesvirus-1 (EHV-1) and equine herpesvirus-4 (EHV-4) seroprevalence investigation in horse populations of Morocco in 24 years. It also aims to determine antibody titers in horses vaccinated under field conditions with a monovalent EHV-1 vaccine. Blood samples were collected from 405 horses, including 163 unvaccinated and 242 vaccinated animals. They were tested using a commercial type-specific enzyme-linked immunosorbent assay (ELISA) and a virus neutralization test (VNT). Overall, 12.8% unvaccinated, and 21.8% vaccinated horses were positive for EHV-1. All samples were positive for EHV-4 when tested with the type-specific ELISA. In the vaccinated group, the VNT revealed a mean antibody titer of 1:49 for EHV-1 and 1:45 for EHV-4.


2011 ◽  
Vol 80 (4) ◽  
pp. 331-336 ◽  
Author(s):  
Eddy Listeš ◽  
Sanja Bosnić ◽  
Miroslav Benić ◽  
Josip Madić ◽  
Željko Cvetnić ◽  
...  

The aim of this study was to provide a description of the first epidemic of bluetongue and the first survey on midges of the genus Culicoides in Croatia. Clinical signs were firstly observed on November 2001 in sheep in Konavle, Dubrovnik – Neretva County. During this epizootic the overall sheep morbidity and mortality were 5.2% (95% confidence interval (c.i.), 4.1-6.6%) and 2.29% (95% c.i., 1.6-3.3%), respectively. After the outbreak, 3,318 serum samples of ruminants from 53 villages of the Dubrovnik – Neretva County were examined for bluetongue virus (BTV) antibodies by competitive enzyme-linked immunosorbent assay (cELISA). In forty nine (92.45%, 95% c.i., 82.11-96.92%) of the 53 villages, animals with antibodies against bluetongue virus were found. In particular, a total of 178 cattle (49.86%, 95% c.i., 44.7-55.0%), 174 sheep (13.72%, 95% c.i., 11.9-15.7%) and 270 goats (15.95%, 95% c.i., 14.3-17.8%) were seropositive. Antibodies to bluetongue virus serotype 9 were detected in 212 positive sera by serum neutralization test. The percentage of positive animals decreased (P > 0.05) from the east to the west suggesting a possible east westward spreading of BTV infection. Fourteen light-trap midge collections from seven different sites were examined. Of the 4872 Culicoides spp. collected, 4,492 (92%, 95% c.i., 91.4-92.9%) of them belonged to the species of Obsoletus complex. This study showed for the first time that a pathogenic strain of BTV-9, probably from Montenegro, entered Croatia causing disease and death in local sheep and that C. obsoletus and C. scoticus were likely the major vectors of infection.


Pathogens ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 188 ◽  
Author(s):  
Madoka Tetsuo ◽  
Keita Matsuno ◽  
Tomokazu Tamura ◽  
Takasuke Fukuhara ◽  
Taksoo Kim ◽  
...  

A serum neutralization test (SNT) is an essential method for the serological diagnosis of pestivirus infections, including classical swine fever, because of the cross reactivity of antibodies against pestiviruses and the non-quantitative properties of antibodies in an enzyme-linked immunosorbent assay. In conventional SNTs, an immunoperoxidase assay or observation of cytopathic effect after incubation for 3 to 7 days is needed to determine the SNT titer, which requires labor-intensive or time-consuming procedures. Therefore, a new SNT, based on the luciferase system and using classical swine fever virus, bovine viral diarrhea virus, and border disease virus possessing the 11-amino-acid subunit derived from NanoLuc luciferase was developed and evaluated; this approach enabled the rapid and easy determination of the SNT titer using a luminometer. In the new method, SNT titers can be determined tentatively at 2 days post-infection (dpi) and are comparable to those obtained by conventional SNTs at 3 or 4 dpi. In conclusion, the luciferase-based SNT can replace conventional SNTs as a high-throughput antibody test for pestivirus infections.


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