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Vector-borne transmission of Besnoitia besnoiti by blood-sucking and secretophagous flies: epidemiological and clinicopathological implications.

Hornok S, Fedák A, Baska F, Basso W, Dencső L, Tóth G, Szeredi L, Abonyi T, Dénes B - Parasit Vectors (2015)

Bottom Line: Transmission through natural mating, as well as transplacental, colostral and tick-borne transmission of B. besnoiti was either unlikely or did not occur.Herd replacement and generation exchange (i.e. early weaning and artificial feeding) appear to be the successful strategies for the local eradication of bovine besnoitiosis.Adding to the already known mechanical transmission of B. besnoiti by blood-sucking flies, results of the present study suggest that secretophagous flies should also be evaluated as potential vectors of this coccidium species.

View Article: PubMed Central - PubMed

Affiliation: Department of Parasitology and Zoology, Faculty of Veterinary Science, Szent István University, Budapest, Hungary. hornok.sandor@aotk.szie.hu.

ABSTRACT

Background: Bovine besnoitiosis has been recently diagnosed in a three-parted herd of 796 Aubrac and Charolais beef cattle in Hungary. A large scale serological, histological and molecular survey was initiated in order to uncover important factors in the local epidemiology of the disease.

Findings: Blood samples were collected (three times from the whole herd, and repeatedly from selected animals) for serological screening by ELISA. In addition, various organs from aborted fetuses and newborn calves, skin and colostrum samples of seropositive heifers/cows, and ticks collected from the cattle were histologically and/or molecularly analysed for the presence of Besnoitia besnoiti. All fetal and calf tissues, as well as colostrum and tick samples from cows were PCR negative. Based on ELISA results, only very few local cows seroconverted after mating with imported, infected bulls, and not necessarily as a consequence of this event. Among calves that were born to seropositive, imported cows and stayed with their mother until weaning at seven months of age, seroprevalence decreased significantly, but remained high. At the same time, 28 calves born from seropositive cows, but separated from their dams immediately after receiving colostrum, were successfully reared and remained uninfected. Following a second herd-level screening, all Aubrac cattle (except for heifer calves) and all seropositive Charolais cows and bulls were culled. Manifestation of the disease is currently sporadic. Among chronically affected heifers two types of skin lesions were noted, and histological evaluation indicated marked distension of sweat gland ducts with membrane-bound structures (resembling cystozoites) in their contents.

Conclusions: Transmission through natural mating, as well as transplacental, colostral and tick-borne transmission of B. besnoiti was either unlikely or did not occur. However, the risk for spreading of the infection was high, when calves stayed with their mother during suckling, and if animals were kept in the same stable (although physically separated) during the main fly season. Herd replacement and generation exchange (i.e. early weaning and artificial feeding) appear to be the successful strategies for the local eradication of bovine besnoitiosis. Adding to the already known mechanical transmission of B. besnoiti by blood-sucking flies, results of the present study suggest that secretophagous flies should also be evaluated as potential vectors of this coccidium species.

No MeSH data available.


Related in: MedlinePlus

Herd management and temporal significance of ecological factors relevant to bovine besnoitiosis. Percentages next to a category show the proportion ELISA positive animals at the first herd level screening (November, 2013). Curved arrows indicate mating of cows with the bull shown at the basis of the arrow. Abbreviations: A - Aubrac breed, C - Charolais breed, Roman numerals – months
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Fig1: Herd management and temporal significance of ecological factors relevant to bovine besnoitiosis. Percentages next to a category show the proportion ELISA positive animals at the first herd level screening (November, 2013). Curved arrows indicate mating of cows with the bull shown at the basis of the arrow. Abbreviations: A - Aubrac breed, C - Charolais breed, Roman numerals – months

Mentions: The study herd consisted of three parts: (1) and (2) including original, locally kept Charolais cattle, and in (3) Aubrac cows and bulls imported in 2011–2012 (Fig. 1). These three groups were grazing separate pastures (approx. 1–2 km apart). Natural mating was scheduled in two periods (November-December and May-July), out of which the bulls were stabled, close to weak or diseased cows separated from the others (Fig. 1). Aubrac and Charolais cows were stabled together for calving during the winter. Between April and November, the cows and their calves were turned out to the pastures in the morning and afternoon each day, while spending the hottest hours (around noon) in a common stand. Calves, following weaning around seven months of age, were stabled collectively (Fig. 1).Fig. 1


Vector-borne transmission of Besnoitia besnoiti by blood-sucking and secretophagous flies: epidemiological and clinicopathological implications.

Hornok S, Fedák A, Baska F, Basso W, Dencső L, Tóth G, Szeredi L, Abonyi T, Dénes B - Parasit Vectors (2015)

Herd management and temporal significance of ecological factors relevant to bovine besnoitiosis. Percentages next to a category show the proportion ELISA positive animals at the first herd level screening (November, 2013). Curved arrows indicate mating of cows with the bull shown at the basis of the arrow. Abbreviations: A - Aubrac breed, C - Charolais breed, Roman numerals – months
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4559924&req=5

Fig1: Herd management and temporal significance of ecological factors relevant to bovine besnoitiosis. Percentages next to a category show the proportion ELISA positive animals at the first herd level screening (November, 2013). Curved arrows indicate mating of cows with the bull shown at the basis of the arrow. Abbreviations: A - Aubrac breed, C - Charolais breed, Roman numerals – months
Mentions: The study herd consisted of three parts: (1) and (2) including original, locally kept Charolais cattle, and in (3) Aubrac cows and bulls imported in 2011–2012 (Fig. 1). These three groups were grazing separate pastures (approx. 1–2 km apart). Natural mating was scheduled in two periods (November-December and May-July), out of which the bulls were stabled, close to weak or diseased cows separated from the others (Fig. 1). Aubrac and Charolais cows were stabled together for calving during the winter. Between April and November, the cows and their calves were turned out to the pastures in the morning and afternoon each day, while spending the hottest hours (around noon) in a common stand. Calves, following weaning around seven months of age, were stabled collectively (Fig. 1).Fig. 1

Bottom Line: Transmission through natural mating, as well as transplacental, colostral and tick-borne transmission of B. besnoiti was either unlikely or did not occur.Herd replacement and generation exchange (i.e. early weaning and artificial feeding) appear to be the successful strategies for the local eradication of bovine besnoitiosis.Adding to the already known mechanical transmission of B. besnoiti by blood-sucking flies, results of the present study suggest that secretophagous flies should also be evaluated as potential vectors of this coccidium species.

View Article: PubMed Central - PubMed

Affiliation: Department of Parasitology and Zoology, Faculty of Veterinary Science, Szent István University, Budapest, Hungary. hornok.sandor@aotk.szie.hu.

ABSTRACT

Background: Bovine besnoitiosis has been recently diagnosed in a three-parted herd of 796 Aubrac and Charolais beef cattle in Hungary. A large scale serological, histological and molecular survey was initiated in order to uncover important factors in the local epidemiology of the disease.

Findings: Blood samples were collected (three times from the whole herd, and repeatedly from selected animals) for serological screening by ELISA. In addition, various organs from aborted fetuses and newborn calves, skin and colostrum samples of seropositive heifers/cows, and ticks collected from the cattle were histologically and/or molecularly analysed for the presence of Besnoitia besnoiti. All fetal and calf tissues, as well as colostrum and tick samples from cows were PCR negative. Based on ELISA results, only very few local cows seroconverted after mating with imported, infected bulls, and not necessarily as a consequence of this event. Among calves that were born to seropositive, imported cows and stayed with their mother until weaning at seven months of age, seroprevalence decreased significantly, but remained high. At the same time, 28 calves born from seropositive cows, but separated from their dams immediately after receiving colostrum, were successfully reared and remained uninfected. Following a second herd-level screening, all Aubrac cattle (except for heifer calves) and all seropositive Charolais cows and bulls were culled. Manifestation of the disease is currently sporadic. Among chronically affected heifers two types of skin lesions were noted, and histological evaluation indicated marked distension of sweat gland ducts with membrane-bound structures (resembling cystozoites) in their contents.

Conclusions: Transmission through natural mating, as well as transplacental, colostral and tick-borne transmission of B. besnoiti was either unlikely or did not occur. However, the risk for spreading of the infection was high, when calves stayed with their mother during suckling, and if animals were kept in the same stable (although physically separated) during the main fly season. Herd replacement and generation exchange (i.e. early weaning and artificial feeding) appear to be the successful strategies for the local eradication of bovine besnoitiosis. Adding to the already known mechanical transmission of B. besnoiti by blood-sucking flies, results of the present study suggest that secretophagous flies should also be evaluated as potential vectors of this coccidium species.

No MeSH data available.


Related in: MedlinePlus