Bovine abortion associated withNeospora caninumin northern Spain

Abstract

During 1996, aborted bovine fetuses from dairy herds in norther Spain were examined by histopathological, immunohistochemical and serological methods for evidence of infection by Neospora caninum. Microscopical brain changes consistent with those of neosporosis were detected in 36 of 81 fetuses and specific antibodies (IFAT titres > or = 1/16) in 32 of 63. Eight fetuses with neurological lesions were seronegative, and eight without lesions were seropositive. In 25 of 34 fetal brains with lesions consistent with published descriptions of neosporosis, immunohistochemical analysis revealed the presence of N caninum antigen. Depending on the diagnostic criteria, the prevalence of neosporosis related to bovine abortion was between 32 and 57 per cent of the fetuses submitted and between 33 and 58 per cent of the herds involved. Data on the geographical, seasonal and fetal age distribution of the infection are given for the fetuses examined and the value of the different diagnostic methods is discussed.

Quantitative Detection ofNeospora caninumin Bovine Aborted Fetuses and Experimentally Infected Mice by Real-Time PCR

“…For the histopathological study, the tissues were fixed in 10% neutral formalin and dehydrated through graded alcohols before being embedded in paraffin wax. Bovine fetuses were classified as negative or positive based on the observation of characteristic or compatible histological lesions of neosporosis in the brain as described previously (15). A total of 12 frozen fetus brain samples (6 positive and 6 negative) and 9 frozen brain samples from experimentally infected BALB/c mice, six inoculated animals with or without compatible lesions, and three negative controls were used in this study.…”

“…However, in the acute and chronic phases of the infection the brain is the most consistently affected organ and where most protozoal tissue cysts have been observed (4,11,25). Diagnosis is based on the detection of parasite-specific antibodies in the adult population (8) and the visualization of characteristic and consistent lesions in brain, heart, and liver in aborted fetuses combined with immunohistochemical examination of positive tissues (1,2,15) and fetal serology (5,10,26). Immunohistochemistry (IHC) is a relatively insensitive technique for detecting the parasite in host tissues due to low parasite numbers and, sometimes, due to the low quality of the fetal tissue that could be autolyzed, mummified, or macerated (6,12).…”

Diagnosis of bovine neosporosis: Recent advances and perspectives

“…The demonstration of Neospora antigens by IHC depends to a large extent on the number of sections made and the time spent on microscopic examination (Wouda et al 1997b). Parasite tachyzoites and antigens are usually found associated with lesioned areas in the brain and other organs such as heart and liver (González et al 1999). The number of tissue cysts in the brain is low and generally not associated with cellular responses (Fig.…”

Neosporose em Animais Domésticos

“…Além disso, registros da doença são citados por Hornok et al (1998) na Hungria, Campero et al (1998 na Argentina, Paré et al (1998) no Canadá, Huong et al (1998) no Vietnam, Gottstein et al (1999 na Suíça, Fondevila et al (1998) e Gonzales et al (1999) na Espanha. No Brasil, no estado da Bahia, Gondim et al(1999) realizaram o primeiro estudo de soroprevalência do N. caninum em bovinos, ao examinarem soro sangüíneo de 447 vacas da raça Holandesa e mestiças, em 14 propriedades leiteiras do estado, sendo 80% dos animais constituído por vacas em lactação.…”