Eastern equine encephalitis cases among horses in Brazil between 2005 and 2009.

This study focuses on the cases of Eastern Equine Encephalitis (a viral disease transmitted between animals and humans) among horses in Brazil between 2005 and 2009. Despite Eastern Equine Encephalitis Virus (EEEV) being identified previously, there were no recorded cases in horses in the last 24 years, making this documentation significant.

Research on Eastern Equine Encephalitis

• The researchers outlined the background of Eastern Equine Encephalitis- a viral zoonosis complex in distribution and epidemiology. They emphasized the need for greater public health attention to the disease.
• They noted that in Brazil, despite the identification of EEEV in vectors and antibodies being detected in horses and humans, no incidents of equine encephalitis in horses were recorded for 24 years.

Study Methodology

• The research covers eighteen cases of eastern equine encephalomyelitis that occurred across six Brazilian states over a span of five years, from 2005 to 2009.
• To identify the viral RNA, the researchers used a semi-nested RT-PCR method which is designed to detect members of the Alphavirus genus. Furthermore, genetic sequencing was deployed to gain more detailed findings.
• The gene encoding NSP1 was partially amplified, and upon genetic sequencing, eighteen sequences were generated from it.

Key Findings

• All eighteen sequenced strains, obtained from the horses infected with the virus during the study period, were classified as lineage III of the American EEEV.
• This classification indicates that the virus responsible for the disease in the analysed cases belongs specifically to the third lineage or variation of the American Eastern Equine Encephalitis Virus.

Implication and Importance

• This research underscores the importance of EEEV in animal and human public health. The identification and classification of eighteen cases of the viral disease in horses implies a potential health risk for both the equine population and humans in close contact with them.
• The findings could therefore inform health policies and practices aimed at preventing and managing the disease.