Equine Monocytic Ehrlichiosis (EME) in Rio de Janeiro State, Brazil

Ferrão, Camile M.; Aboud-Dutra, A.E.

doi:10.1590/s0102-09352007000600034

Cited by 5 publications

(15 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Brazil, Ferrão et al (2007) found positivity in 79% of equines from metropolitan and mountain regions in the State of Rio de Janeiro, with clinical signs suggesting with EN, using the IFA.…”

Section: Discussionmentioning

confidence: 95%

“…Serological evidences shows the circulation of N. risticii, with clinical case occurrences found in the South and Southeast regions of Brazil (Coimbra et al 2005, Ferrão et al 2007). In the state of Rio de Janeiro, studies have shown variation in frequency of seroreactive equines for Neorickettsia risticii (Ferrão et al 2007, Moreira et al 2013).…”

Section: Discussionmentioning

confidence: 99%

“…In the state of Rio de Janeiro, studies have shown variation in frequency of seroreactive equines for Neorickettsia risticii (Ferrão et al 2007, Moreira et al 2013). The EN possibly occurs in other regions of the country with similar characteristics of the regions here studied.…”

Section: Discussionmentioning

confidence: 99%

“…Serological evidences also indicate the agent circulation among equines of the State of Rio de Janeiro, Sao Paulo and Santa Catarina (Ferrão et al 2007, Moreira et al 2013. However, there are few studies in Brazil and in the State of Rio de Janeiro addressing in detail the epidemiological aspects related to the agent infection and circulation among equines.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Epidemiological survey of Neorickettsia risticii in equids from the State of Rio de Janeiro, Brazil

et al. 2016

View full text Add to dashboard Cite

Equine neorickettsiosis (EN), also known as Potomac Horse Fever, is a non-contagious disease caused by the bacterium Neorickettsia risticii of the Anaplasmataceae family. The objectives of this study were to detect the presence of anti-N. risticii antibodies by the indirect immunofluorescence assay (IFA) and of its DNA by qPCR in equids at high and low altitude regions in the State of Rio de Janeiro, Brazil, and to identify factors associated with seropositive equids by multiple logistic regression analysis. The frequency of anti-N. risticii antibodies was 16.05% (n=113/704). The animal age and breeding region were the factors that influenced the seropositivity rate for N. risticii in the equids (p<0.05). Equids from the lowland region had higher seropositivity (p<0.05; OR=5.87) compared to those of the mountain region. The presence of snails on the farm was a factor associated with this result (p<0.05; OR=2.88). In the lowland region, age of the animal and site of breeding were protective factors for the detection of antibodies anti-N. risticii in equids, with lower frequency of seropositivity in younger animals (p<0.05; OR=0.06) and in animals raised in dry areas (p<0.05; OR=0.22). The presence of the target DNA of N. risticii by qPCR was not observed in any of the samples tested. The existence of seropositive equids for N. risticii demonstrates a possible circulation of this agent in the studied area, and that the age related characteristics and equids breeding region are important factors regarding seropositivity in the State of Rio de Janeiro.

show abstract

Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Epidemiological survey of Neorickettsia risticii in equids from the State of Rio de Janeiro, Brazil

et al. 2016

View full text Add to dashboard Cite

show abstract

“…In Brazil, compatible cases with the clinical disease were firstly described in the state of Rio Grande do Sul (Dutra et al, 2001;Coimbra et al, 2006). Serological evidence has also indicated that the agent circulates in horses in the states of Santa Catarina, São Paulo and Rio de Janeiro (Ferrão et al, 2007;Moreira et al, 2013).…”

Section: No Brasil Estudos Apontam a Circulação De Neorickettsia Rismentioning

confidence: 99%

Molecular investigation of Neorickettsia risticii in trematodes and snails in a region with serological evidence of this agent in horses, state of Rio de Janeiro

Costa

Vitari

Silva

et al. 2016

Arq. Bras. Med. Vet. Zootec.

View full text Add to dashboard Cite

In Brazil, some studies have indicated that Neorickettsia risticii circulates in horses, but it is unclear which are the possible intermediate vectors of this bacterium in the country. The aim of this study was to use molecular techniques in order to analyze the presence of N. risticii in snails and larval stages of trematodes in farms in a region with a history of seroreactive horses towards this bacterium, in Rio de Janeiro, Brazil. Convenience sampling was used in the studied region. The collected snails were exposed to incandescent light (60W) for 2-4 hours in order to investigate trematodes in larval forms. Deoxyribonucleic acid (DNA) was extracted from snail tissue and trematode. Real-time PCR (qPCR) technique was used to investigate the presence of a 16S rRNA gene fragment of N. risticii. Snail specimens (n=410) were collected from 11 horse-breeding farms, and the following species were identified: Melanoides tuberculata, Pomacea sp., Biomphalaria tenagophila, Physa acuta, Drepanotrema anatinum and Biomphalaria straminea. Only 3.17% (n=13/410) of the collected snails were infected by trematodes. The cercariae obtained from these snails were classified as Megalourous cercariae, Pleurolophocercus cercariae and Furcocercous cercariae. There was no amplification of the target DNA of N. risticii in the snail and trematode samples tested by qPCR. Based on these data, the transmission of N. risticii by trematodes using these snail species in this region does not appear to occur or occurs at very low rates. Thus, further studies are needed in order to clarify which species of invertebrate hosts are infected by this bacterium and potentially participate in the transmission chain of equine neorickettsiosis in the state of Rio de Janeiro, Brazil.

show abstract

Detection of Neorickettsia risticii, the agent of Potomac horse fever, in horses from Rio de Janeiro, Brazil

Paulino

Almosny

Oliveira

et al. 2020

Sci Rep

View full text Add to dashboard Cite

This study aims to report the presence of Neorickettsia risticii DNA in blood samples from naturally infected horses in Rio de Janeiro, provide clinicopathological findings related to the infection, and report the phylogenetic diversity of the 16S rDNA of N. risticii in order to evaluate its heterogeneity. Real-time quantitative polymerase chain reaction (qPCR) was performed to investigate the presence of N. risticii in samples collected from horses (n = 187). Five positive samples were found in the molecular screening. Hypoalbuminemia and high levels of creatine kinase and lactate dehydrogenase were the predominant findings in the biochemical analysis. The sequences were similar to those of N. risticii. Phylogenetic analysis revealed genotype segregation based on the geographical distribution in the N. risticii sequence clade. Dendrograms constructed with five hypervariable regions revealed that V4 distinguished Neorickettsia at the species level and produced a phylogeny that best represented the phylogeny obtained with the complete 16S rDNA sequence. This is the first report of N. risticii DNA in the blood of Brazilian horses based on sequences deposited in GenBank. Further studies are necessary to clarify the epidemiological chain of this vector-borne parasite in order to determine and establish appropriate preventive measures in the equine trading market.

show abstract

Equine Monocytic Ehrlichiosis (EME) in Rio de Janeiro State, Brazil

Cited by 5 publications

References 9 publications

Epidemiological survey of Neorickettsia risticii in equids from the State of Rio de Janeiro, Brazil

Epidemiological survey of Neorickettsia risticii in equids from the State of Rio de Janeiro, Brazil

Molecular investigation of Neorickettsia risticii in trematodes and snails in a region with serological evidence of this agent in horses, state of Rio de Janeiro

Detection of Neorickettsia risticii, the agent of Potomac horse fever, in horses from Rio de Janeiro, Brazil

Contact Info

Product

Resources

About