Infection by Neospora caninum in dairy cattle belonging to family farmers in the northern region of Brazil

Abstract

Neosporosis is considered a major cause of abortion among cattle worldwide. The aim of this study was to investigate the prevalence of anti-Neospora caninum antibodies in dairy cattle and correlate them with possible risk factors on 63 small farms (family farms) in the municipality of Ji-Paraná, the main milk-producing region of the state of Rondônia, northern Brazil. For this purpose, 621 serum samples were collected from cows and were evaluated by means of the indirect fluorescence antibody test (IFAT). The overall herd prevalence of N. caninum antibodies among the farms (38/63; 60.31%) showed that N. caninum are widespread among the dairy herds in this region, despite only infecting a small proportion of animals (66/621, 10.62%). Occurrences of abortion and birth of weak calves were the only variables that showed as risk factors for the presence of N. caninum. The result from the spatial lag model strongly indicated that birth of weak calves and presence of N. caninum are occurring on farms that are located close to each other, indicating aggregation of disease occurrence.Keywords: Neospora caninum, prevalence, family farming, Amazon. ResumoNeosporose é considerada uma das principais causas de aborto em rebanhos bovinos em todo o mundo. O objetivo deste estudo foi investigar a prevalência de anticorpos anti-Neospora caninum em bovinos de leite e correlacioná-los com possíveis fatores de risco em 63 pequenas propriedades rurais (agricultura familiar), no município de Ji-Paraná, uma das principais regiões produtoras de leite do Estado de Rondônia, norte do Brasil. Para este propósito, 621 amostras de soro foram coletadas de vacas leiteiras e avaliadas por meio da reação de imunofluorescência indireta (RIFI). A prevalência total de propriedades com animais positivos a anticorpos anti-N. caninum (38/63; 60,31%) indica que o parasito está difundido entre os rebanhos leiteiros da região, apesar de infectar uma pequena proporção de animais (66/621; 10,62%). Ocorrência de abortos e nascimento de bezerros fracos foram as únicas variáveis consideradas como fatores de risco para a ocorrência de N. caninum. O resultado do modelo de análise espacial indica que o nascimento de bezerros fracos e a presença de N. caninum estão aparecendo em fazendas localizadas próximas umas das outras, indicando a ocorrência de agregação da doença.

Retracted: Prevalence of Toxoplasma gondii and Neospora caninum in different types of raw milk and traditional dairy product samples

“…Toxoplasma gondii ( T. gondii ) and Neospora caninum ( N. caninum ) are two closely related intracellular cyst‐forming Apicomplexan Sarcocystidae protozoan parasites sharing structural, genetic, and immunological similarities (Belluco, Simonato, Mancin, Pietrobelli, & Ricci, ; Boas et al, ; Donahoe, Lindsay, Krockenberger, Phalen, & Šlapeta, ; Jones & Dubey, ). Nonetheless, the parasites can cause biologically diverse diseases, as T. gondii is a main cause of infectious abortion in ruminants and particularly sheep worldwide, and severe disease in humans as toxoplasmic encephalitis in immunocompromised patients and abortion or congenital defects in fetuses.…”

“…Furthermore, ingestion of undercooked infected meat, raw milk, and traditional dairy products is considered as an imperative risk factor for T. gondii infection (Belluco et al, ; Jones & Dubey, ). In contrast, N. caninum is a major cause of neonatal mortality and/or abortion in ruminants and neuromuscular disorders in dogs (Boas et al, ; Donahoe et al, ). There are no reports of human infection with N. caninum , whereas inoculation of pregnant monkeys with N. caninum results in transplacental transmission of the parasite and the induction of fetal encephalitis (Dubey, ; McCann et al, ; Oshiro et al, ).…”

“…contrast, N. caninum is a major cause of neonatal mortality and/or abortion in ruminants and neuromuscular disorders in dogs (Boas et al, 2015;Donahoe et al, 2015). There are no reports of human infection with N. caninum, whereas inoculation of pregnant monkeys with N. caninum results in transplacental transmission of the parasite and the induction of fetal encephalitis (Dubey, 2003;McCann et al, 2008;Oshiro et al, 2015).…”

“…Contrariwise, the only established definitive hosts of N. caninum are dogs, gray wolfs, coyotes, and dingoes that causes a serious disease particularly in ruminants (Belluco et al, 2017;Boas et al, 2015;Donahoe et al, 2015;Dubey, 2003;Hussain et al, 2017;Jones & Dubey, 2012;Klauck et al, 2016;McCann et al, 2008;Oshiro et al, 2015). Recorded data showed that intermediate hosts of T. gondii and N. caninum become infected in two ways of vertical (transplacental) and horizontal (ingestion of oocysts shed in milk and meat) (Belluco et al, 2017;Boas et al, 2015;Donahoe et al, 2015;Dubey, 2003;Hussain et al, 2017;Jones & Dubey, 2012;Klauck et al, 2016;McCann et al, 2008;Oshiro et al, 2015). Thus, contaminated milk and dairy products (particularly traditional dairy products) play an imperative role in the distribution of T. gondii and N. caninum infections to human (Ayinmode, Akinseye, Schares, & Cadmus, 2017;Gos et al, 2017).…”

Seroprevalence, spatial analysis and risk factors of infection with Neospora caninum in cattle in Brazil’s northern Pantanal wetland

“…No conglomeration, or clusters that indicate that high prevalence farms have neighbors with high prevalence and farms with low prevalence have neighbors with low prevalence, was observed in the region under study, and the occurrence of at least one animal positive for N. caninum was found to be independent of its geographic location in the northern Pantanal of Mato Grosso state. However, Boas et al (2015) reported the birth of weak calves and the presence of N. caninum on farms located near one another in northern Brazil, indicating the occurrence of aggregation of the disease.…”