Association of serologic status for Neospora caninum with postweaning weight gain and carcass measurements in beef calves

Barling, Kerry S.; McNeill, John W.; Thompson, James A.; Paschal, Joe C.; McCollum, F. T.; Craig, Thomas M.; Adams, L. Garry

doi:10.2460/javma.2000.217.1356

Cited by 53 publications

(40 citation statements)

References 25 publications

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“…While there is also no direct evidence of N. caninum-associated morbidity in adult cattle, a positive association between the N. caninum antibody status of the calf and weight gain and a projected loss of $15.62 per calf has been shown by Barling et al (31) in a seroepidemiological study. In beef herds, the effects on culling (237,258), weaning weight (237), average daily weight during the feedlot period (31), and reproductive performance (465) have also been estimated. The risk of being culled for any reason was 1.9 times higher for seropositive cows in eight beef herds in Canada (465).…”

Section: Economic Losses and Cost-benefit Analysesmentioning

confidence: 97%

Epidemiology and Control of Neosporosis andNeospora caninum

2007

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SUMMARY Neospora caninum is a protozoan parasite of animals. Until 1988, it was misidentified as Toxoplasma gondii. Since its first recognition in dogs in 1984 and the description of the new genus and species Neospora caninum in 1988, neosporosis has emerged as a serious disease of cattle and dogs worldwide. Abortions and neonatal mortality are a major problem in livestock operations, and neosporosis is a major cause of abortion in cattle. Although antibodies to N. caninum have been reported, the parasite has not been detected in human tissues. Thus, the zoonotic potential is uncertain. This review is focused mainly on the epidemiology and control of neosporosis in cattle, but worldwide seroprevalences of N. caninum in animals and humans are tabulated. The role of wildlife in the life cycle of N. caninum and strategies for the control of neosporosis in cattle are discussed.

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Section: Economic Losses and Cost-benefit Analysesmentioning

confidence: 97%

Epidemiology and Control of Neosporosis andNeospora caninum

2007

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“…N. caninum infects a wide range of domestic and wild animals, among which cattle seem to be the most important, since the infection causes pregnancy failures, such as repeated abortions and stillbirths, producing enormous economic losses throughout the world (1,9). Recently, dogs and coyotes have been established as definitive hosts of N. caninum (12,17).…”

mentioning

confidence: 99%

Detection of Immunoglobulin G Antibodies toNeospora caninumin Humans: High Seropositivity Rates in Patients Who Are Infected by Human Immunodeficiency Virus or Have Neurological Disorders

Lobato

Silva

Mineo

et al. 2006

Clin Vaccine Immunol

109

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Considering that little is known about the epidemiology of Neospora caninum infection in humans, particularly in populations with high Toxoplasma gondii infection rates, the present study aimed to investigate the presence of antibodies to N. caninum in T. gondii-seropositive and -seronegative individuals. A total of 256 serum samples divided into four groups (61 samples from human immunodeficiency virus [HIV]-positive patients, 50 samples from patients with neurological disorders, 91 samples from newborns, and 54 samples from healthy subjects) were assessed for N. caninum and T. gondii serologies by indirect fluorescent-antibody test, enzyme-linked immunosorbent assay, and immunoblotting (IB). Immunoglobulin G antibodies to N. caninum were predominantly detected in HIV-infected patients (38%) and patients with neurological disorders (18%), while newborns and healthy subjects showed lower seropositivity rates (5% and 6%, respectively). Seropositivity to N. caninum was significantly associated with seropositivity to T. gondii in both HIV-infected patients and patients with neurological disorders. Seroreactivity to N. caninum was confirmed by IB, with positive sera predominantly recognizing the 29-kDa antigen of N. caninum. The results of this study indicate the presence of N. caninum infection or exposure in humans, particularly in HIV-infected patients or patients with neurological disorders, who could have opportunistic and concurrent infections with T. gondii. These findings may bring a new concern for the unstable clinical health of HIV-infected patients and the actual role of N. caninum infection in immunocompromised patients.

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“…Infection with Neospora caninum, an apicomplexan protozoan parasite, is reported as a significant cause of economic loss in dairy and beef cattle herds worldwide due primarily to abortion and reduced reproductive efficiency but also to poor milk production, increased culling, and poor feed efficiency (2,10,23,24,26). Similar to Toxoplasma gondii, N. caninum has a two-host herbivore-carnivore life cycle.…”

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confidence: 99%

Validation of a Commercially Available Monoclonal Antibody-Based Competitive-Inhibition Enzyme-Linked Immunosorbent Assay for Detection of Serum Antibodies toNeospora caninumin Cattle

Baszler

Adams²,

VanderSchalie

et al. 2001

J Clin Microbiol

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A previously described monoclonal antibody (MAb)-based competitive-inhibition enzyme-linked immunosorbent assay (cELISA) was modified to optimize performance, and the assay was validated in various defined cattle populations for detection of serum antibody to Neospora caninum, a major cause of bovine abortion. Modifications to the cELISA included capturing native N. caninum antigen with a parasite-specific MAb (MAb 5B6-25) and directly conjugating the competitor MAb (MAb 4A4-2), with both MAbs binding different epitopes of a conserved, immunodominant 65-kDa tachyzoite surface antigen. The assay was validated using three serum sets, a "gold standard" set of 184 cow sera defined by fetal histopathology and N. caninum immunohistochemistry and by maternal N. caninum indirect fluorescence assay (IFA) at a 1:200 serum dilution, a relative standard set of 330 cow sera defined by IFA alone, and a set of 4,323 cow sera of unknown N. caninum status. A test cutoff of 30% inhibition was identified. The diagnostic sensitivity was 97.6%, and diagnostic specificity was 98.6% for the gold standard abortion-defined sera. The diagnostic sensitivity was 96.4%, and diagnostic specificity was 96.8% for the relative standard IFA-defined sera. Testing of the 4,323 bovine sera of unknown N. caninum status revealed a distinct bimodal distribution and steep sigmoid frequency curve with only 1.8% of samples within 5% of the test cutoff, indicating a sharp discrimination between test-positive and test-negative samples. In summary, the modified N. caninum cELISA provided a simple, rapid, and versatile method to accurately identify N. caninum infection status in cattle using a single cutoff value.

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Association of serologic status for Neospora caninum with postweaning weight gain and carcass measurements in beef calves

Abstract: Significant reductions in postweaning weight gain, carcass weight, and economic return were associated with detection of antibodies to N caninum in beef calves in a feedlot.

Cited by 53 publications

References 25 publications

Epidemiology and Control of Neosporosis andNeospora caninum

Epidemiology and Control of Neosporosis andNeospora caninum

Detection of Immunoglobulin G Antibodies toNeospora caninumin Humans: High Seropositivity Rates in Patients Who Are Infected by Human Immunodeficiency Virus or Have Neurological Disorders

Validation of a Commercially Available Monoclonal Antibody-Based Competitive-Inhibition Enzyme-Linked Immunosorbent Assay for Detection of Serum Antibodies toNeospora caninumin Cattle

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