1
|
Canevari JT, Firestone SM, Vincent G, Campbell A, Tan T, Muleme M, Cameron AWN, Stevenson MA. The prevalence of Coxiella burnetii shedding in dairy goats at the time of parturition in an endemically infected enterprise and associated milk yield losses. BMC Vet Res 2018; 14:353. [PMID: 30453951 PMCID: PMC6245909 DOI: 10.1186/s12917-018-1667-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 10/23/2018] [Indexed: 12/27/2022] Open
Abstract
Background This was a panel study of the prevalence of C. burnetii infection in does in an endemic dairy goat enterprise in Victoria, Australia. Our first objective was to determine the prevalence of does shedding C. burnetii at the time of parturition and to quantify the concentration of genome equivalents (GE) present in each C. burnetii positive sample. Our second objective was to determine the proportion of positive does that were persistent shedders. Our final objective was to quantify the association between C. burnetii qPCR status at the time of kidding and daily milk volumes produced during the subsequent lactation. Results Vaginal swabs (n= 490) were collected from does at the time of kidding and analysed using a quantitative polymerase chain reaction (qPCR) assay. Shedding of C. burnetii was detected in 15% (95% CI: 12% to 18%) of the sampled does. Does were classified as qPCR-negative, qPCR-positive low and qPCR-positive high based on the estimated concentration of GE from the qPCR. Persistent shedding at relatively low concentrations was detected in 20% (95% CI: 10% to35%) of shedding does sampled again at their subsequent parturition. After controlling for possible confounders and adjusting for variation in daily milk yields at the individual doe level, daily milk yields for qPCR-positive high does were reduced by 17% (95% CI: 3% to 32%) compared to qPCR-negative does (p= 0.02). Conclusions Shedding concentrations of C. burnetii were highly skewed, with a relatively small group of does shedding relatively high quantities of C. burnetii. Further, high shedding does had reduced milk yields compared to qPCR-negative does. Early detection and culling of high shedding does would result in increased farm profitability and reduce the risk of Q fever transmission.
Collapse
Affiliation(s)
- José T Canevari
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Corner Park Drive and Flemington Road, Parkville Victoria, 3010, Australia. .,Instituto de Investigación Animal del Chaco Semiárido, INTA, Leales, Tucumán, 4113, Argentina.
| | - Simon M Firestone
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Corner Park Drive and Flemington Road, Parkville Victoria, 3010, Australia
| | - Gemma Vincent
- Australian Rickettsial Reference Laboratory, Ballerine Street, Geelong Victoria, 3220, Australia
| | - Angus Campbell
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Corner Park Drive and Flemington Road, Parkville Victoria, 3010, Australia
| | - Tabita Tan
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Corner Park Drive and Flemington Road, Parkville Victoria, 3010, Australia
| | - Michael Muleme
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Corner Park Drive and Flemington Road, Parkville Victoria, 3010, Australia
| | | | - Mark A Stevenson
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Corner Park Drive and Flemington Road, Parkville Victoria, 3010, Australia
| |
Collapse
|
2
|
Canevari JT, Mangold AJ, Guglielmone AA, Nava S. Population dynamics of the cattle tick Rhipicephalus (Boophilus) microplus in a subtropical subhumid region of Argentina for use in the design of control strategies. Med Vet Entomol 2017; 31:6-14. [PMID: 27747901 DOI: 10.1111/mve.12199] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 07/12/2016] [Indexed: 06/06/2023]
Abstract
The population dynamics of Rhipicephalus microplus (Ixodida: Ixodidae) in northwest Argentina was analysed to support the design of strategic methods for its control. Both parasitic and non-parasitic phases were studied. The seasonal activity of R. microplus in its parasitic phase was characterized by three peaks in abundance: the first in mid-late spring; the second in summer, and the third in autumn. The non-parasitic phase of R. microplus was characterized by a long total non-parasitic period observed after exposures of females from mid-summer to early autumn, a short total non-parasitic period observed after exposures of females from late winter to late spring, a short period of larval longevity in early and mid-summer, and no hatch of the eggs produced by females exposed in mid- and late autumn and winter. Treatments of cattle administered during the period from late winter to late spring will act on small cohorts of R. microplus, preventing the emergence of larger generations in summer and autumn. A 17-week spelling period starting in late spring and early summer will be necessary to achieve optimal control of R. microplus free-living larvae. If spelling begins in mid- or late summer or in autumn, the required period will be 26-27 weeks.
Collapse
Affiliation(s)
- J T Canevari
- Instituto de Investigaciòn Animal del Chaco Semiárido (IIACS), Instituto Nacional de Tecnología Agropecuaria (INTA), Chañar Pozo, Argentina
| | - A J Mangold
- Departamento de Producción Animal, Estación Experimental Agropecuaria Rafaela, Instituto Nacional de Tecnología Agropecuaria, and Consejo Nacional de Investigaciones Científicas y Técnicas, Rafaela, Argentina
| | - A A Guglielmone
- Departamento de Producción Animal, Estación Experimental Agropecuaria Rafaela, Instituto Nacional de Tecnología Agropecuaria, and Consejo Nacional de Investigaciones Científicas y Técnicas, Rafaela, Argentina
| | - S Nava
- Departamento de Producción Animal, Estación Experimental Agropecuaria Rafaela, Instituto Nacional de Tecnología Agropecuaria, and Consejo Nacional de Investigaciones Científicas y Técnicas, Rafaela, Argentina
| |
Collapse
|
3
|
Nava S, Mangold AJ, Canevari JT, Guglielmone AA. Strategic applications of long-acting acaricides against Rhipicephalus (Boophilus) microplus in northwestern Argentina, with an analysis of tick distribution among cattle. Vet Parasitol 2015; 208:225-30. [DOI: 10.1016/j.vetpar.2015.01.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 01/14/2015] [Accepted: 01/19/2015] [Indexed: 10/24/2022]
|