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Khan MY, Barlaam A, Gazzonis AL, Ferrari N, Giangaspero A. Seroprevalence and risk factors of Toxoplasma gondii infection in goats from South Punjab Province, Pakistan. Vet Parasitol Reg Stud Reports 2024; 50:101018. [PMID: 38644047 DOI: 10.1016/j.vprsr.2024.101018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 03/04/2024] [Accepted: 03/29/2024] [Indexed: 04/23/2024]
Abstract
Layyah District in South Punjab Province of Pakistan offers the most intensive caprine economy in the country; its Indus riverine and desert environment makes the area peculiar and worthy of specific investigations. This study aimed to investigate the prevalence of anti-Toxoplasma gondii (T. gondii) IgG-antibody in goats in serum samples and the potential risk factors. The prevalence of T. gondii infection was estimated using a two-stage sample design. All caprine farms in the study area were stratified by size, and from these 110 were randomly selected. Twelve goats (>1-year-old) were selected from each farm and a total of 1320 serum samples were collected and tested by ELISA. A questionnaire on the conditions and management practices of each farm was administered to 110 farmers. Four hundred and sixteen out of 1320 sera samples (31.5%) were found positive and 89% of the flock had at least one seropositive goat. The proportion of seropositive goats tested within each flock ranged from 8.3% to 83.3%. with several factors contributing to this heterogeneity. Goat age played a significant role in the presence of cats. Significant interactions were related to goat farms having floor of dirt and kitten presence. Moreover, age class, abortion history and water source supply were modulated by owner education levels. This is the first study to determine the prevalence of anti-T. gondii antibodies in goats sera in Layyah district and the largest carried out so far in Pakistan. The remarkable presence of T. gondii among goats in areas where goat farming plays a significant economic role may pose a production threat to the small-stock industry, as well as to public health and food safety. Therefore, investigations to identify high-risk goat populations are highly recommended in order to facilitate the implementation of local control strategies.
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Affiliation(s)
- Muhammad Yaser Khan
- Department of Agricultural Sciences, Food, Natural Resources and Engineering (DAFNE), University of Foggia, Via Napoli 25, 71121 Foggia, Italy; Para Veterinary Institute, Layyah Campus, University of Veterinary & Animal Sciences, 54000, Karor Lal Eason, Lahore 31100, Pakistan.
| | - Alessandra Barlaam
- Department of Agricultural Sciences, Food, Natural Resources and Engineering (DAFNE), University of Foggia, Via Napoli 25, 71121 Foggia, Italy
| | - Alessia Libera Gazzonis
- Department of Veterinary Medicine and Animal Sciences, Università degli Studi di Milano, Via dell'Università 6, 26900 Lodi, Italy
| | - Nicola Ferrari
- Department of Veterinary Medicine and Animal Sciences, Università degli Studi di Milano, Via dell'Università 6, 26900 Lodi, Italy
| | - Annunziata Giangaspero
- Department of Agricultural Sciences, Food, Natural Resources and Engineering (DAFNE), University of Foggia, Via Napoli 25, 71121 Foggia, Italy
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Ni H, Koop G, Klugkist I, Nielen M. Evaluation of Bayesian Hui-Walter and logistic regression latent class models to estimate diagnostic test characteristics with simulated data. Prev Vet Med 2023; 217:105972. [PMID: 37499309 DOI: 10.1016/j.prevetmed.2023.105972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 05/08/2023] [Accepted: 06/28/2023] [Indexed: 07/29/2023]
Abstract
Estimation of the accuracy of diagnostic tests in the absence of a gold standard is an important research subject in epidemiology (Dohoo et al., 2009). One of the most used methods the last few decades is the Bayesian Hui-Walter (HW) latent class model (Hui and Walter, 1980). However, the classic HW models aggregate the observed individual test results to the population level, and as a result, potentially valuable information from the lower level(s) is not fully incorporated. An alternative approach is the Bayesian logistic regression (LR) latent class model that allows inclusion of individual level covariates (McInturff et al., 2004). In this study, we explored both classic HW and individual level LR latent class models using Bayesian methodology within a simulation context where true disease status and true test properties were predefined. Population prevalences and test characteristics that were realistic for paratuberculosis in cattle (Toft et al., 2005) were used for the simulation. Individual animals were generated to be clustered within herds in two regions. Two tests with binary outcomes were simulated with constant test characteristics across the two regions. On top of the prevalence properties and test characteristics, one animal level binary risk factor was added to the data. The main objective was to compare the performance of Bayesian HW and LR approaches in estimating test sensitivity and specificity in simulated datasets with different population characteristics. Results from various settings showed that LR models provided posterior estimates that were closer to the true values. The LR models that incorporated herd level clustering effects provided the most accurate estimates, in terms of being closest to the true values and having smaller estimation intervals. This work illustrates that individual level LR models are in many situations preferable over classic HW models for estimation of test characteristics in the absence of a gold standard.
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Affiliation(s)
- Haifang Ni
- Department Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, 3508 TD Utrecht, the Netherlands; Department of Methodology and Statistics, Faculty of Social and Behavioral Sciences, Utrecht University, 3508 TC Utrecht, the Netherlands.
| | - Gerrit Koop
- Department Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, 3508 TD Utrecht, the Netherlands
| | - Irene Klugkist
- Department of Methodology and Statistics, Faculty of Social and Behavioral Sciences, Utrecht University, 3508 TC Utrecht, the Netherlands
| | - Mirjam Nielen
- Department Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, 3508 TD Utrecht, the Netherlands
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Karimi O, Bitaraf Sani M, Bakhshesh M, Zareh Harofteh J, Poormirzayee-Tafti H. Prevalence of bovine herpesvirus 1 antibodies and risk factors in dairy cattle of Iran's central desert. Trop Anim Health Prod 2022; 55:23. [PMID: 36547722 DOI: 10.1007/s11250-022-03426-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022]
Abstract
Bovine herpesvirus type 1 (BoHV 1) is a major bovine pathogen spreading worldwide and causing extensive damage to the livestock industry. BoHV causes respiratory, genital, and neurological disorders. A cross-sectional study was performed for the first time to estimate the seroreactivity to BoHV 1 and related risk factors among Iran's central desert dairy cattle. A total of 800 blood samples was randomly collected from 76 unvaccinated herds. Samples were tested with an indirect enzyme-linked immunosorbent assay (ELISA) commercial kit to detect BoHV 1 antibodies. The logistic regression model was used to analyze the data. BoHV 1 seroreactivity at animal and herd levels was 50% and 65%, respectively. Herd size was recognized as a risk factor (OR = 2.65, CI = 1.61-4.37) for seroreactivity to BoHV using GLM (p < 0.05). The high prevalence of BoHV 1 antibodies in the study area indicates the need to implement educational programs on the importance of the disease and design methods to control and prevent virus distribution.
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Affiliation(s)
- Omid Karimi
- Department of Animal Viral Diseases Research, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran.
| | - Morteza Bitaraf Sani
- Animal Science Research Department, Yazd Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Yazd, Iran
| | - Mehran Bakhshesh
- Department of Animal Viral Diseases Research, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
| | - Javad Zareh Harofteh
- Animal Science Research Department, Yazd Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Yazd, Iran
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İnce ÖB, Şevik M. Risk assessment and seroprevalence of bovine herpesvirus type 1 infection in dairy herds in the inner Aegean Region of Turkey. Comp Immunol Microbiol Infect Dis 2021; 80:101741. [PMID: 34929412 DOI: 10.1016/j.cimid.2021.101741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/02/2021] [Accepted: 12/14/2021] [Indexed: 10/19/2022]
Abstract
This cross-sectional study was performed to investigate the seroprevalence and associated risk factors of bovine herpesvirus type 1 (BoHV-1) infection in dairy cattle herds in Afyonkarahisar province in the Aegean Region of Turkey. Blood samples were collected from 602 cattle from 56 unvaccinated dairy herds between May 2018 and June 2019. Animal and herd-level epidemiological information was collected with a questionnaire during blood collection. Specific antibodies against BoHV-1 and bovine viral diarrhea virus (BVDV) were detected by using a virus neutralization test and a commercial indirect ELISA kit, respectively. Univariable and multivariable logistic regression analyses were used to determine any association between categorical variables and BoHV-1 seropositivity. The animal-level and herd-level seroprevalences of BoHV-1 infection were determined to be 39.53% (95% confidence interval, CI: 35.71-43.50) and 73.21% (95% CI: 60.41-83.04), respectively. Within-herd prevalence was more than 50% in 34.14% of infected herds. Cattle age (odds ratio, OR= 2.34, 95% CI: 1.58-3.44), BVDV infection (OR= 7.74, 95% CI: 5.08-11.76), and the presence of goats in the herd (OR= 2.84, 95% CI: 1.91-4.19) were identified as risk factors for BoHV-1 seropositivity by the multivariable logistic regression model. This is the first study conducted in Turkey using two-layer sampling and logistic regression analyses to determine the herd-level and animal-level seroprevalence and associated risk factors of BoHV-1 infection.
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Affiliation(s)
- Ömer Barış İnce
- Animal Breeding and Genetic Research and Implementation Center, Pamukkale University, Pamukkale, 20100 Denizli, Turkey; Province Directorate, Ministry of Agriculture and Forestry, Afyonkarahisar, Turkey.
| | - Murat Şevik
- Department of Virology, Veterinary Faculty, Necmettin Erbakan University, Eregli, 42310 Konya, Turkey
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Establishment of a Suspension MDBK Cell Line in Serum-Free Medium for Production of Bovine Alphaherpesvirus-1. Vaccines (Basel) 2021; 9:vaccines9091006. [PMID: 34579242 PMCID: PMC8473029 DOI: 10.3390/vaccines9091006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 09/04/2021] [Accepted: 09/06/2021] [Indexed: 12/22/2022] Open
Abstract
The Madin–Darby bovine kidney (MDBK) cell line is currently used for the production of bovine alphaherpesvirus-1 (BoHV-1) vaccine. For the purpose of vaccine manufacturing, suspension cells are preferred over adherent ones due to simplified sub-cultivation and an easier scale-up process, both of which could significantly reduce production cost. This study aimed to establish a procedure for the culture of BoHV-1 in the suspended MDBK cell line in serum-free medium. We screened several commercially available serum-free media and chose ST503 for subsequent experiments. We successfully adapted the adherent MDBK cells to suspended growth in ST503 in the absence of serum. The maximum density of suspension-adapted MDBK cells could reach 2.5 × 107 cells/mL in ST503 medium with optimal conditions. The average size of suspension-adapted cells increased to 18 ± 1 µm from 16 ± 1 µm. Moreover, we examined tumorigenicity of the suspended cells and found no sign of tumorigenicity post adaptation. Next, we developed a protocol for the culture of BoHV-1 in the cell line described above and found that ultrasonic treatment could facilitate virus release and enhance virus yield by 11-fold, with the virus titer reaching 8.0 ± 0.2 log10TCID50/mL. Most importantly, the prototype inactivated BoHV-1 vaccine we generated using the suspension cultures of MDBK cells induced neutralizing antibodies to a titer comparable to that of the commercial inactivated BoHV-1 vaccine. Overall, we established and optimized a protocol for the production of inactivated BoHV-1 vaccine in MDBK cells adapted for suspension culture, which provides insights for future large-scale manufacturing of BoHV-1 vaccine.
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