Investigation of the outbreaks of abortions and orchitis in livestock in Namibia during 2016-2018.

Autor: Samkange A; School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia. alastersamkange@gmail.com., van der Westhuizen J; Directorate of Veterinary Services, Central Veterinary Laboratory, Private Bag 13187, Windhoek, Namibia., Voigts AS; Windhoek Veterinary Clinic, 8 Lossen Street, P.O. Box 5030, Windhoek, Namibia., Chitate F; School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia., Kaatura I; School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia., Khaiseb S; Directorate of Veterinary Services, Central Veterinary Laboratory, Private Bag 13187, Windhoek, Namibia., Hikufe EH; Directorate of Veterinary Services, Central Veterinary Laboratory, Private Bag 13187, Windhoek, Namibia., Kabajani J; Directorate of Veterinary Services, Central Veterinary Laboratory, Private Bag 13187, Windhoek, Namibia., Bishi AS; School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia., Mbiri P; School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia., Hawanga NN; School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia., Mushonga B; School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, P. Bag 13301, Windhoek, Namibia.
Jazyk: angličtina
Zdroj: Tropical animal health and production [Trop Anim Health Prod] 2022 Oct 15; Vol. 54 (6), pp. 346. Date of Electronic Publication: 2022 Oct 15.
DOI: 10.1007/s11250-022-03342-0
Abstrakt: This study investigated outbreaks of seemingly related abortions and orchitis which occurred in the Khomas, Omaheke and Otjozondjupa regions of Namibia from 2016 to 2018, affecting cattle, sheep and goats. Fifty-nine questionnaires were administered, and 48 were completed giving an 81.4% return. The outbreaks were limited to Namibia's east and central regions, mainly on farms rearing cattle, sheep and goats and on farms with a mixture of these species. There was no significant difference between Khomas and other regions on abortion reporting at the farm level [X 2  (1, N = 48) = 0.0002, p = 0.987851]. However, there was a significant difference in the abortions at the animal level among the three regions [X 2  (2, N = 6246) = 239.8339, p = .00001]. In addition, the proportions of abortions calculated at the animal level at each farm were significantly different when the Khomas region was compared to the other regions. Seventeen cattle sera, 35 sheep sera, 52 caprine sera, 18 bovine liver samples, one caprine liver, five aborted cattle foetuses, two cattle placentas, 18 testes (one bull, eight bucks and nine rams) and ten bull sheath scrapings were collected and tested. Histopathology, microbiology, serology, immunohistochemistry, real-time PCR and mineral analytical techniques were used to establish the aetiology of the abortion and orchitis outbreaks. The gross and histopathological findings on the 18 testicles were characteristic of chronic orchitis. In aborted foetuses, significant histopathological findings included meconium aspiration, funisitis and cardiomyopathy. Placentitis and endometritis were the primary pathologies observed in cows. The bacteria isolated from microbiological samples included Enterococcus spp. (65.5% [19/29]), Enterobacter spp. (6.9% [2/29]) and Streptococcus spp. (10.3% [3/29]), Trueperella pyogenes (3.4% [1/29]), Stenotrophomonas maltophilia (3.4% [1/29]), Staphylococcus epidermidis (3.4% [1/29]), Providencia rettgeri (3.4% [1/29]) and Acinetobacter lwoffii (3.4% [1/29]), mostly opportunistic bacteria. On mineral analysis, 28%, 33%, 83%, 33% and 17% (n = 18) of cattle livers were low in copper, zinc, manganese, selenium and iron, respectively. Twenty-three percent (12/52) of the caprine sera were positive for Brucella melitensis on the Rose Bengal and complement fixation tests. Thirty-five ovine sera were tested for B. melitensis, B. ovis and Coxiella burnetii, and the prevalence for each was 2.9% (1/35). PCR tests on foetuses were all negative for Brucella spp., Coxiella burnetii, Chlamydia spp., Listeria monocytogenes, Salmonella spp., Campylobacter fetus spp., Leptospira pathogenic strains, bovine viral diarrhoea virus, Rift Valley fever virus, Anaplasma phagocytophilum and bovine herpes virus 4 Campylobacter fetus spp. and Trichomonas foetus spp. The authors concluded that Brucella spp., Enterococcus spp., Escherichia coli, Streptococcus spp., Trueperella pyogenes and Coxiella burnetii could have contributed to this outbreak. Micronutrient imbalances and pathogenic abiotic nanoparticles were also identified as possible contributors to the abortion outbreaks.
(© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)
Databáze: MEDLINE
Externí odkaz: