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Kosaruk W, Brown JL, Towiboon P, Pringproa K, Punyapornwithaya V, Tankaew P, Kittisirikul N, Toonrongchang W, Janyamathakul T, Muanghong P, Thitaram C. Seasonal patterns of oxidative stress markers in captive Asian elephants in Thailand and relationships to elephant endotheliotropic herpesvirus shedding. Front Vet Sci 2023; 10:1263775. [PMID: 37795017 PMCID: PMC10546319 DOI: 10.3389/fvets.2023.1263775] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 09/06/2023] [Indexed: 10/06/2023] Open
Abstract
Introduction Oxidative stress refers to an imbalance between oxidant and antioxidant activity and accumulation of reactive oxygen species, which can have detrimental effects on animal health. Annual fluctuations in oxidative stress status can occur, increasing disease susceptibility during certain time periods. However, a full understanding of factors related to oxidative stress in Asian elephants and how to mitigate the negative consequences is lacking. Methods This study measured six serum oxidative stress markers [reactive oxygen species (ROS), malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), albumin, glutathione peroxidase (GPx), and catalase] and two stress markers [serum cortisol and fecal glucocorticoid metabolites (fGCM)] in 23 captive Asian elephants in Thailand over a 12 months period to examine relationships with age and season. Results Seasonal variations were observed, with several markers exhibiting significantly higher concentrations in the summer (ROS, MDA, 8-OHdG, albumin) and lower values during the rainy/winter seasons (MDA, 8-OHdG, albumin, catalase). By contrast, GPx was the only marker to be highest during the rainy season. For the stress markers, higher fGCM concentrations were noted during the rainy season, which contrasts with earlier studies showing more activity in the winter (tourist season). Positive correlations were found between the temperature-humidity index and ROS, GPx, and fGCM, while a negative correlation was observed with serum albumin. Elephant endotheliotropic herpesvirus (EEHV) shedding events were associated with higher concentrations of ROS and MDA. A moderate negative correlation was observed between 8-OHdG and the PCR threshold cycle of EEHV shedding (Ct), indicating DNA damage may be involved in EEHV shedding in elephants. Discussion Results revealed significant age and seasonal effects on several oxidative stress markers, indicating those factors should be considered in study design and data interpretation. There also may be physiological adaptations in oxidative stress conditions in relation to environmental changes that could impact health outcomes.
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Affiliation(s)
- Worapong Kosaruk
- Doctoral Degree Program in Veterinary Science, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
- Center of Elephant and Wildlife Health, Chiang Mai University Animal Hospital, Chiang Mai, Thailand
- Elephant, Wildlife, and Companion Animals Research Group, Chiang Mai University, Chiang Mai, Thailand
| | - Janine L. Brown
- Center of Elephant and Wildlife Health, Chiang Mai University Animal Hospital, Chiang Mai, Thailand
- Elephant, Wildlife, and Companion Animals Research Group, Chiang Mai University, Chiang Mai, Thailand
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA, United States
| | - Patcharapa Towiboon
- Center of Elephant and Wildlife Health, Chiang Mai University Animal Hospital, Chiang Mai, Thailand
| | - Kidsadagon Pringproa
- Center of Elephant and Wildlife Health, Chiang Mai University Animal Hospital, Chiang Mai, Thailand
- Elephant, Wildlife, and Companion Animals Research Group, Chiang Mai University, Chiang Mai, Thailand
- Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Veerasak Punyapornwithaya
- Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Pallop Tankaew
- Central Laboratory, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Narueporn Kittisirikul
- Elephant Hospital, National Elephant Institute, Forest Industry Organization, Lampang, Thailand
| | | | | | | | - Chatchote Thitaram
- Center of Elephant and Wildlife Health, Chiang Mai University Animal Hospital, Chiang Mai, Thailand
- Elephant, Wildlife, and Companion Animals Research Group, Chiang Mai University, Chiang Mai, Thailand
- Department of Companion Animal and Wildlife Clinic, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
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Effects of between and within Herd Moves on Elephant Endotheliotropic Herpesvirus (EEHV) Recrudescence and Shedding in Captive Asian Elephants (Elephas maximus). Viruses 2022; 14:v14020229. [PMID: 35215824 PMCID: PMC8877707 DOI: 10.3390/v14020229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/18/2022] [Accepted: 01/18/2022] [Indexed: 02/01/2023] Open
Abstract
Haemorrhagic disease associated with elephant endotheliotropic herpesvirus (Elephantid herpesvirus, EEHV) infections is the leading cause of death for Asian elephant (Elephas maximus) calves. This study assessed the effect of captive herd management on EEHV shedding, as evidence of latent infection reactivation, focusing on: (1) the influence of social change on the odds of recrudescence; (2) the respective effects of between and within herd moves; and (3) characteristics of recrudescent viral shedding. Trunk and conjunctival swabs (n = 165) were obtained from six elephants at an EAZA-accredited zoo, collected during a period of social stability, and at times of social change. Longitudinal sampling took place at times of moving two bulls out of the collection and one new bull into an adjacent enclosure to the cow herd (between herd moves), and during a period of mixing this new bull with the cow herd to facilitate mating (within herd moves). Quantitative PCR was employed to detect EEHV 1a/b, 4a/b, and EF–1–α (housekeeping gene). Generalised estimating equations determined EEHV recrudescence odds ratios (OR) and relative viral DNA load. Sixteen EEHV 1a/b shedding events occurred, but no EEHV 4a/b was detected. All management-derived social changes promoted recrudescence (social change OR = 3.27, 95% CI = 0.412–26, p = 0.262; and between herd moves OR = 1.6, 95% CI = 0.178−14.4, p = 0.675), though within herd movements posed the most significant increase of EEHV reactivation odds (OR = 6.86, 95% CI = 0.823−57.1, p = 0.075) and demonstrated the strongest relative influence (post hoc Tukey test p = 0.0425). Shedding onset and magnitude ranged from six to 54 days and from 3.59 to 11.09 ΔCts. Differing challenges are associated with between and within herd movements, which can promote recrudescence and should be considered an exposure risk to naïve elephants.
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ELEPHANT ENDOTHELIOTROPIC HERPESVIRUS HEMORRHAGIC DISEASE OUTBREAK IN AN INDIAN ZOO. J Zoo Wildl Med 2022; 52:1286-1297. [PMID: 34998302 DOI: 10.1638/2020-0156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2021] [Indexed: 11/21/2022] Open
Abstract
Elephant endotheliotropic herpesvirus hemorrhagic disease (EEHV HD) is an acute viral infection of growing Asian elephants (Elephas maximus). Four apparently healthy subadult Asian elephants aged between 6 and 10 yr at Nandankanan Zoological Park (NKZP), India, died of EEHV HD during August-September 2019. All four elephants were rescued from different reserved forests of Odisha state at less than 1 yr of age and hand reared in the NKZP. Elephants exhibited the clinical signs of lethargy, head swelling, fever, loss of appetite, abdominal distension, scant urination and defecation, signs of colic, lameness, trunk discharge, cyanosis/ulceration of tongue, erratic behavior, and recumbence before death. Period of illness varied between 28 and 42 h. Thrombocytopenia was the common significant hematological observation. No significant biochemical alterations were recorded except for higher creatinine concentrations. Analysis of blood samples in RT-PCR assay using two different sets of primers and probes that targeted terminase gene and major DNA-binding protein gene followed by cPCR and sequencing was positive for EEHV-1A in all four animals. Postmortem examination of all four carcasses showed hemorrhages in internal organs, including the hard palate, heart, lungs, stomach, mesenteric lymph nodes, mesentery, colon serosa, spleen, liver, kidney, and meninges. Histopathology showed congestion and/or hemorrhages in heart, lung, brain, kidney, and liver. There was presence of intranuclear inclusion bodies in the sinusoidal epithelial cells. The outbreak of EEHV HD that resulted in the acute death of four juvenile captive Asian elephants within <30 d, the first of its kind documented in India, is increasing the fear of similar outbreaks in the future.
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Boonprasert K, Yun Y, Kosaruk W, Towiboon P, Tankaew P, Punyapornwithaya V, Janyamathakul T, Muanghong P, Brown JL, Thitaram C, Somgird C. A Longitudinal Study of Hematology and Stress Biomarker Profiles in Young Asian Elephants ( Elephas Maximus) in Relation to Elephant Endotheliotropic Herpesvirus (EEHV) in Thailand. Animals (Basel) 2021; 11:ani11092530. [PMID: 34573496 PMCID: PMC8471699 DOI: 10.3390/ani11092530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/22/2021] [Accepted: 08/23/2021] [Indexed: 12/14/2022] Open
Abstract
Simple Summary A change in hematology profiles is one indicator of EEHV infection before clinical signs appear; however, to be effective, individual baselines and age-matched reference values are needed. A longitudinal investigation of viremia, hematology values, and stress biomarkers was performed in three non-EEHV and six prior infected EEHV calves to better understand EEHV-HD-associated factors. Blood, saliva, and feces were collected for 1 year for analysis of complete blood count (CBC), viral load, glucocorticoids (GCs), and Immunoglobulin A (IgA). Results did not differ between the groups, except for one elephant that presented with EEHV-HD during the study and exhibited high viremia, altered hematology profiles, and decreased stress biomarker concentrations. Thus, as in other studies, hematology changes were associated with EEHV infection, while preliminary data in one calf suggests that stress-response measures might also be informative and warrant further investigation. Abstract Elephant endotheliotropic herpesvirus hemorrhagic disease (EEHV-HD) is a virulent disease that causes severe hemorrhage and sudden death in Asian elephant calves. A change in hematology profiles is one indicator of infection before clinical signs appear; however, to be effective, individual baselines and age-matched reference values are needed. Stress has been speculated to be a factor in clinical EEHV cases, but relationships have not been demonstrated empirically. This study evaluated blood hematology and several stress response markers—salivary cortisol, fecal glucocorticoid metabolites (FGM), salivary Immunoglobulin A (SIgA), and fecal IgA (FIgA) in samples collected for 1 year from three healthy calves with no EEHV history (non-EEHV), and six that had previously been infected, developed clinical signs and survived (prior-EEHV). Hematology values between non-EEHV and prior-EEHV elephants were not different and within published reference ranges. Concentrations of salivary cortisol, FGM, SIgA, and FIgA also were variable and showed seasonal differences, but no relationships to prior EEHV status. One of the prior EEHV calves became re-infected, developed hemorrhagic disease (HD), and died during the study period. That calf exhibited lymphocytopenia, monocytopenia, and thrombocytopenia. Additionally, all stress biomarker concentrations were lower in the 12 days before viremia was observed. Thus, as in other studies, changes in hematology occur with EEHV infection, while preliminary data in one calf suggests that stress-response measures might also be informative and should be studied further.
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Affiliation(s)
- Khajohnpat Boonprasert
- Center of Elephant and Wildlife Research, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand; (K.B.); (Y.Y.); (W.K.); (P.T.); (P.T.); (J.L.B.); (C.T.)
| | - Yaoprapa Yun
- Center of Elephant and Wildlife Research, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand; (K.B.); (Y.Y.); (W.K.); (P.T.); (P.T.); (J.L.B.); (C.T.)
| | - Worapong Kosaruk
- Center of Elephant and Wildlife Research, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand; (K.B.); (Y.Y.); (W.K.); (P.T.); (P.T.); (J.L.B.); (C.T.)
| | - Patcharapa Towiboon
- Center of Elephant and Wildlife Research, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand; (K.B.); (Y.Y.); (W.K.); (P.T.); (P.T.); (J.L.B.); (C.T.)
| | - Pallop Tankaew
- Center of Elephant and Wildlife Research, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand; (K.B.); (Y.Y.); (W.K.); (P.T.); (P.T.); (J.L.B.); (C.T.)
| | - Veerasak Punyapornwithaya
- Department of Food Animal Clinic, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand;
- Veterinary Public Health Centre and Food Safety for Asia Pacific (VPHCAP), Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand
| | | | - Panida Muanghong
- Mae Taeng Elephant Park and Clinic, Mae Thang, Chiang Mai 50150, Thailand;
| | - Janine L. Brown
- Center of Elephant and Wildlife Research, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand; (K.B.); (Y.Y.); (W.K.); (P.T.); (P.T.); (J.L.B.); (C.T.)
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA 22630, USA
| | - Chatchote Thitaram
- Center of Elephant and Wildlife Research, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand; (K.B.); (Y.Y.); (W.K.); (P.T.); (P.T.); (J.L.B.); (C.T.)
- Department of Companion Animal and Wildlife Clinics, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand
| | - Chaleamchat Somgird
- Center of Elephant and Wildlife Research, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand; (K.B.); (Y.Y.); (W.K.); (P.T.); (P.T.); (J.L.B.); (C.T.)
- Department of Companion Animal and Wildlife Clinics, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand
- Correspondence: ; Tel.: +66-53-948015
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