Application of the Neospora Caninum IgG Avidity ELISA in Assessment of Chronic Reproductive Losses after an Outbreak of Neosporosis in a Herd of Beef Cattle

Point-source infections are most likely the cause for Neospora caninum–induced abortion outbreaks in cattle, whereas an increased annual abortion rate may be a consequence of vertical transmission. The aims of the present study were to examine the reproductive effects of neosporosis in a beef herd for 3 years, after a point-source outbreak and to use IgG avidity serology to examine the chronicity of infections and patterns of transmission. During the study, 76–78% of animals were seropositive for N. caninum. The pregnancy rate varied from 88% to 94%, without any reduction in the pregnancy rate of seropositive cows compared with seronegative cows. The annual abortion rate was 2.5–5.5%, and all but 1 abortion occurred in seropositive dams. The efficiency of vertical transmission was estimated to be 85%. Several calves, born to seronegative dams, were seropositive at 6–13 months of age, indicating a 22% mean annual rate of horizontal transmission. The mean avidity in seropositive cows increased from 30 during the initial outbreak to 74 after 3 years. The mode of IgG avidity was 21–40 during the initial abortion outbreak, 41–60 after 1 year, and 61–80 after 2 and 3 years. The results reveal high annual rates of both vertical and horizontal transmission of N. caninum in a herd of beef cows and provide further validation on the ability of the N. caninum IgG avidity ELISA to accurately assess the chronicity of infection.

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Anti-Neospora caninum antibody detection and vertical transmission rate in pregnant zebu beef cows (Bos indicus): Neospora caninum in pregnant beef cows (Bos indicus)

Comparative Immunology Microbiology and Infectious Diseases ◽

10.1016/j.cimid.2014.08.002 ◽

2014 ◽

Vol 37 (4) ◽

pp. 267-270 ◽

Cited By ~ 3

Author(s):

Eudes Esteves do Nascimento ◽

Ana Sue Sammi ◽

Joeleni Rosa Dos Santos ◽

Beatriz de Souza Lima Nino ◽

Alexey Leon Gomel Bogado ◽

...

Keyword(s):

Vertical Transmission ◽

Neospora Caninum ◽

Transmission Rate ◽

Bos Indicus ◽

Beef Cows ◽

Antibody Detection ◽

Vertical Transmission Rate ◽

Caninum Antibody

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Seroepidemiological study of Neospora caninum in beef and dairy cattle in La Pampa, Argentina

Acta Parasitologica ◽

10.1515/ap-2015-0039 ◽

2015 ◽

Vol 60 (2) ◽

Cited By ~ 9

Author(s):

Marcelo Fort ◽

Martyn Edelsten ◽

Stephen Maley ◽

Elisabeth Innes

Keyword(s):

Dairy Cattle ◽

Neospora Caninum ◽

Horizontal Transmission ◽

Beef Cows ◽

Climatic Conditions ◽

Serum Samples ◽

Recent Infection ◽

Caninum Infection ◽

Cattle Disease ◽

Central Regions

AbstractNeospora caninum is considered one of the major causes of abortion in cattle. The aim of this study was to examine and quantify the extent of the infection in cattle in a representative region of Argentina (La Pampa, province). An average sample size of 36 sera per herd was selected from 97 beef and 24 dairy herds. A total of 4334 serum samples were tested for specific anti- Neospora caninum IgG using an indirect-ELISA and 302 seropositive-ELISA sera were re-examined using an Avidity-ELISA procedure for N.caninum. The overall estimated seroprevalence for N.caninun was 9.6% (95%CI: 8.7%; 10.5%). Levels of seroprevalence were significantly different in beef 7.0% and dairy 20.3% cattle. Disease distribution seems to be associated with climatic conditions as well as the management system. Cows in the east and central regions were at a 4.5-fold and 2.0-fold higher risk, respectively, of being N. caninum seropositive compared with cows in west region. Levels of recent infection were evaluated through an avidity ELISA in seropositive animals, being registered a 0.56% and a 1.71% of recent infection in beef and dairy cattle respectively (p = 0.006). The results revealed that dairy cows had 3.1(95%CI: 1.4; 7.0) higher risk of contracting Neoporosis through horizontal transmission than beef cows. A relationship between Brucella abortus and N. caninum seroprevalence was also observed. The risk of being N. caninum seropositive was two times higher where Brucellosis seroprevalence was >3.5%. These results reveal the distribution of N. caninum infection in the cattle population in La Pampa, Argentina

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Dynamics of Neospora caninum-Associated Abortions in A Dairy Sheep Flock and Results of a Test-and-Cull Control Programme

Pathogens ◽

10.3390/pathogens10111518 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1518

Author(s):

Roberto Sánchez-Sánchez ◽

Ángela Vázquez-Calvo ◽

Mercedes Fernández-Escobar ◽

Javier Regidor-Cerrillo ◽

Julio Benavides ◽

...

Keyword(s):

Neospora Caninum ◽

Horizontal Transmission ◽

Control Programme ◽

Abortion Rate ◽

Sheep Flock ◽

Dairy Sheep ◽

Lack Of Information ◽

Infection Dynamics ◽

Route Of Transmission ◽

The Relationship

Neospora caninum is an apicomplexan parasite that can cause abortions and perinatal mortality in sheep. Although ovine neosporosis has been described worldwide, there is a lack of information about the relationship between N. caninum serostatus and the reproductive performance. In this study, we described the infection dynamics in a dairy sheep flock with an abortion rate up to 25% and a N. caninum seroprevalence of 32%. Abortions were recorded in 36% and 9% of seropositive and seronegative sheep, respectively. Seropositive sheep were more likely to abort twice (OR = 4.44) or three or more times (OR = 10.13) than seronegative sheep. Endogenous transplacental transmission was the main route of transmission since 86% of seropositive sheep had seropositive offspring. Within dams that had any abortion, seropositive sheep were more likely than seronegative ones to have female descendants that aborted (OR = 8.12). The slight increase in seropositivity with the age, the low percentage of animals with postnatal seroconversion or with low avidity antibodies, and the seropositivity of one flock dog, indicated that horizontal transmission might have some relevance in this flock. A control programme based on selective culling of seropositive sheep and replacement with seronegative animals was effective in reducing the abortion rate to 7.2%.

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Quantification of vertical transmission of Neospora caninum in dairy cows in Minas Gerais, Brazil

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-29612012000300021 ◽

2012 ◽

Vol 21 (3) ◽

pp. 294-297 ◽

Cited By ~ 4

Author(s):

Raquel Ribeiro Dias Santos ◽

Christiane Maria Barcellos Magalhães da Rocha ◽

Tarcísio de Morais Gonçalves ◽

Antônio Marcos Guimarães

Keyword(s):

Dairy Cows ◽

Vertical Transmission ◽

Neospora Caninum ◽

Fluorescent Antibody ◽

Horizontal Transmission ◽

Antibody Test ◽

Cross Sectional Study ◽

Minas Gerais ◽

Negative Effects ◽

Cross Sectional

The objective of this cross-sectional study was to estimate the rate of vertical transmission and to investigate horizontal transmission of Neospora caninum and occurrences of reproductive abnormalities in seropositive dairy cows on two farms in the state of Minas Gerais, Brazil. The frequency of cows seropositive for N.caninum according to the indirect fluorescent antibody test (IFAT) was 39.4% (93/236) for Farm A and 31.4% (32/102) for the Farm B (p > 0.05). The mean vertical transmission rates for N. caninum were 29% and 9% for the herds of Farms A and B, respectively. No negative effects (p > 0.05) from infection by N.caninum were observed regarding milk production and occurrences of reproductive abnormalities in herds A and B.

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The role of the colostrum and milk in Neospora caninum transmission

Helminthologia ◽

10.2478/s11687-007-0019-3 ◽

2007 ◽

Vol 44 (3) ◽

pp. 126-129 ◽

Cited By ~ 2

Author(s):

B. Moskwa ◽

W. Cabaj

Keyword(s):

Vertical Transmission ◽

Neospora Caninum ◽

Dna Detection ◽

Horizontal Transmission ◽

In Utero ◽

Reproductive Failure ◽

Limited Data ◽

Economical Losses

AbstractNeospora caninum, an apicomplexan protozoan causes economical losses due to reproductive failure associated with abortion among cattle. The transmission of N. caninum is possible through vertical transmission in utero, or according to the modern nomenclature endogenous and exogenous infection modes and horizontal transmission through ingestion of oocysts. Limited data is available on the vertical transmission during suckling time, via colostrum and milk.In this paper the main scientific aim focused on N. caninum DNA detection in the milk and colostrum of seropositive cows have been reviewed. In this term, the risk of animals and humans infection has been discussed.

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Neospora caninum: evaluation of vertical transmission in slaughtered beef cows (Bos indicus)

Parasitology Research ◽

10.1007/s00436-010-2146-x ◽

2010 ◽

Vol 108 (4) ◽

pp. 1015-1019 ◽

Cited By ~ 12

Author(s):

F. A. C. Marques ◽

A. S. Headley ◽

V. Figueredo-Pereira ◽

A. Taroda ◽

L. D. Barros ◽

...

Keyword(s):

Vertical Transmission ◽

Neospora Caninum ◽

Bos Indicus ◽

Beef Cows

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142 Evaluation of estrus detection patches as a tool to classify postpartum beef cows as estrous cycling or anestrous prior to the start of the breeding season

Journal of Animal Science ◽

10.1093/jas/skaa278.212 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 116-117

Author(s):

Emily G Smith ◽

Rachael C Bonacker ◽

Carson M Andersen ◽

Jordan M Thomas

Keyword(s):

Pregnancy Rate ◽

Breeding Season ◽

Beef Cows ◽

Estrus Synchronization ◽

Serum Progesterone ◽

Estrus Detection ◽

Estrous Cyclicity ◽

Type Ii Errors ◽

Estrous Cycling

Abstract Estrus detection patches were evaluated as a tool to classify postpartum cows as estrous cycling or anestrous at the start of the breeding season. EstrotectTM Breeding Indicators were applied to 257 postpartum beef cows in three locations 25 days prior to the start of estrus synchronization. Coincident with the start of estrus synchronization, patches were scored using a 1 to 4 scale (1 = 0–25%; 2 = 25–50%; 3 = 50–75%; 4 = 75–100%) with scores of 3 or 4 considered activated. Blood samples were collected from each cow 10 days prior to, and at the start of the estrus synchronization. Serum progesterone concentrations were determined via radioimmunoassay; cows were considered estrous cycling if one or both samples exceeded a concentration of 0.5 ng/ml. Based on progesterone, 54.9% of cows were estrous cycling at the start of estrus synchronization. When missing patches were considered inconclusive results, use of patches to infer estrous cyclicity resulted in 85.0% sensitivity and 79.2% specificity with a positive predictive value of 87.2%. However, 75.1% of all cows presented with missing patches at the start of synchronization. If missing patches were considered activated, sensitivity was 95.7%, but specificity (16.4%) and PPV (58.2%) were poor, as 47.6% of cows presenting with missing patches were anestrous based on progesterone. Across all cows, pregnancy rate to AI was 58.0% (149/257). Cows with activated patches that were classified as false positives based on serum progesterone concentrations achieved a 71.4% (5/7) pregnancy rate to AI, raising questions as to whether sensitivity was underestimated due to inherent Type II errors in classification of cyclicity via progesterone. In summary, estrus detection aids are a sensitive tool to identify estrous cycling postpartum cows prior to the start of the breeding season; however, poor specificity and patch retention are limitations for this application.

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Confirmation of the prevention of vertical transmission of Neospora caninum in cattle by the use of embryo transfer

Australian Veterinary Journal ◽

10.1111/j.1751-0813.2002.tb12475.x ◽

2002 ◽

Vol 80 (8) ◽

pp. 502-503 ◽

Cited By ~ 22

Author(s):

JK LANDMANN ◽

D. JILLELLA ◽

PJ O'DONOGHUE ◽

MR McGOWAN

Keyword(s):

Embryo Transfer ◽

Vertical Transmission ◽

Neospora Caninum

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Calving sub-season and reproductive efficiency of beef cows

Revista Brasileira de Zootecnia ◽

10.1590/s1516-35982010001000012 ◽

2010 ◽

Vol 39 (10) ◽

pp. 2182-2186

Author(s):

Cristiane Reinher ◽

Júlio Otávio Jardim Barcellos ◽

Vanessa Peripolli ◽

Ênio Rosa Prates ◽

Maria Eugênia Andrighetto Canozzi

Keyword(s):

Pregnancy Rate ◽

Beef Cows ◽

Pregnancy Rates ◽

Reproductive Efficiency ◽

Climate Variations ◽

Southern Brazil ◽

Chi Square ◽

Chi Square Test

It was evaluated in this work the effect of calving sub-season on the pregnancy rate of 7,726 multiparous Hereford beef cows grazing on natural pastures in southern Brazil, from 1994 to 2007. Calving sub-season periods were divided in 20-day intervals from August 12th to 31st; from September 1st to 20th; from September 21st to October 10th; from October 11th to 31st; from November 1st to 20th. Calving in each sub-season and pregnancy rate (PR) were analyzed by the Chi-square test. Overall means of each sub-season were 92.7% (from August 12th to 31st), 90.6% (from September 1st to 20th), 82.1% (from September 21st to October 10th), 77.7% (from October 11th to 31st), and 70.6% (from November 1st to 20th). Calving sub-season significantly influenced pregnancy rate. Cows which calved in the initial sub-season showed higher pregnancy rates than cows which calved from the fourth calving sub-season. However this difference did not occur in 1999 and in 2007 since calving rates did not statistically differ among the five sub-seasons. In 1998 and 2004, calving rates were lower and the effects of calving sub-season on pregnancy rates were higher, possibly due to climate variations. In general, pregnancy rate decreases as calving occurs later in the year, particularly in years when the weather adversely affects pasture growth.

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