Characterization of isolates of equine infectious anemia virus in Brazil.

This research explores the detection and analysis of equine infectious anemia virus in Brazil, indicating that local strains are linked to those identified in the United States and that the nested-PCR detection method is more effective than the Agar Gel Immunodiffusion (AGID) technique.

Examination of Disease Control Methods

• The central focus of this research is on equine infectious anemia disease, which is a significant health concern for equids worldwide. The current method for controlling this disease is through the detection of the anti-p26 EIAV using Agar Gel Immunodiffusion (AGID).
• One aim of this research was to assess the effectiveness of AGID in detecting the presence of the virus. Sixty-two animals were examined using this technique
• Simultaneously, the same samples were tested using a method known as nested-PCR, a highly sensitive and specific molecular tool typically used for the detection of viruses, and which employs primers for the gag gene in this context.

Testing and Results

• The research found that, with the nested-PCR method, 85.5% of the samples (or 53 out of 62 animals) yielded a positive result, indicating the presence of the virus.
• Conversely, only 53% of the samples (or 33 out of 62 animals) were identified as positive for the virus when the AGID method was used.
• This demonstrates that using nested-PCR is a far more effective way of detecting equine infectious anemia compared to the use of AGID.

Phylogenetic Analysis

• Amplicons, fragments of DNA resulting from a PCR, from fifteen of the positively tested samples were sequenced and subjected to phylogenetic analysis.
• The aim of this was to understand the genetic relationship and evolutionary history between these isolates.
• The analysis revealed that the strains of the virus present in Brazil are related to the WSU5, EIAVUK, and Wyoming strains from the United States, forming a distinct cluster with these strains.

Implications of the Study

• This research holds significant implications for the future control of equine infectious anemia disease, as it not only identifies an improved detection method but also adds to our understanding of the virus’s evolutionary links.