Molecular detection, histopathological analysis, and immunohistochemical characterization of equine infectious anemia virus in naturally infected equids

Genetic identification, clinical and epidemiological aspects of an equine infectious anemia outbreak in the Rio Grande do Sul State, Brazil

“…Nested-PCR detected proviral DNA in blood, lung, and spleen samples, and a DNA fragment (~ 203bp) corresponding to that described by DONG et al ( 2012) was amplified. Amplifying proviral DNA in tissue samples confirms the serology result and demonstrates that the virus is present in organs with a high concentration of macrophages (BUENO et al, 2020;OAKS et al, 1998). The PCR products were sequenced and the sequences obtained (Submission ID: ON639609) showed 98% to 100% identity with other EIAV samples (Figure 2).…”

“…No macroscopic changes were detected during the necropsy. The absence of clinical signs, hematological changes, and visible lesions are compatible with carrier status and are described in the literature as the most common form of infection (BUENO et al, 2020;COOK et al, 2013).…”

“…The spleen and liver are recognized as the main reservoirs of the virus due to the significant presence of macrophages (BUENO et al, 2020). This microscopic change is associated with the accumulation of ferric pigment, especially in resident macrophages, resulting from hemoglobin metabolism triggered after intra and extravascular hemolysis associated with the viral infection and expected in these diseases (BUENO et al, 2020;COOK et al, 2013). The other two stolen horses have remained missing and are probably still being transported illegally.…”

“…Several genetic analyses of EIA viruses present in Bahia, Rio Grande do Norte, and Pantanal have been performed (BUENO et al, 2020;CURSINO et al, 2018;TIGRE et al, 2017). The Rio Grande do Sul is the southernmost state in Brazil, and this is the first time that an EIAV sample from this region has been partially identified by sequencing.…”

“…Thus, the amplified region can be used in phylogeny studies for epidemiological research. However, other regions of the genome or the whole genome may be more suitable for this purpose (BUENO et al, 2020;CURSINO et al, 2018;MALOSSI et al, 2020;OAKS et al, 1998;TIGRE et al, 2017).…”