Encephalitis associated with Borrelia burgdorferi infection in a horse.

The research paper presents a case of encephalitis (brain inflammation) in a horse, caused by an infection with the bacteria Borrelia burgdorferi, known for causing Lyme disease. The case happened in an area of Wisconsin where B burgdorferi infection is prevalent.

Background of the Study

• The study was prompted by the development of encephalitis in a horse. Encephalitis is commonly caused by viral infections, but in this case, it came about due to bacterial infection.
• The bacterium in question, B. burgdorferi, is a Lyme disease-causing organism, primarily affecting humans and some mammalian species.
• The infected horse resided in an area of Wisconsin which is known to be endemic for B. burgdorferi infection, hinting at the possible source of infection.

Study Methodology and Results

• The researchers isolated B. burgdorferi from the horse’s brain, likely via post-mortem tissue sampling, which establishes the cause of the encephalitis.
• For thoroughness, they also conducted tests for the presence of rabies virus in the horse’s brain but found no such evidence, eliminating another potential cause for encephalitis.
• The serum of the horse was examined for the antibody titer against B. burgdorferi, and it was found to be 1:2,048. An ‘antibody titer’ refers to the concentration of antibodies in the blood, which inevitably rises in response to an infection. This high titer further establishes the presence of a B. burgdorferi infection.
• The serum was also found negative for antibodies against both eastern and western encephalomyelitis, ruling out these conditions as possible causes of the horse’s symptoms.

Conclusion of the Study

• The study concluded that the encephalitis observed in the horse was associated with the infection caused by B. burgdorferi. This sheds light on a not-so-common causative agent of encephalitis in horses.
• The research has implications for horse health management in areas endemic for B. burgdorferi infection and may influence prevention and treatment strategies for animals at risk.