Prevalence of hemagglutination-inhibition and neutralizing antibodies to arboviruses in horses of java.

The research study investigated the prevalence of certain antibodies, specifically hemaglutination-inhibition (HI) and neutralizing antibodies against two arboviruses (Chikungunya and Japanese encephalitis virus), in a selection of horses in Java, Indonesia. The study findings indicated a higher risk of Japanese encephalitis virus infection in comparison to Chikungunya in the tested horse population.

Methodology

• The research was carried out using blood samples from 112 horses located in two different stables: Pulo Mas, a racing track horse complex in North Jakarta, and Pamulang, a riding school in West Jaya.
• The chosen stables offered a variety in terms of their environments – Pulo Mas is located in an urban, residential area, while Pamulang is situated in a more rural region.

Testing

• The researchers tested the sample blood sera through the HI assay, a method used to measure the levels of HI antibodies present, and the plaque reduction neutralization test, for detecting and quantifying the presence of virus-neutralizing antibodies.
• This approach allowed them to identify the presence of antibodies related to two specific Arboviruses: Chikungunya and Japanese encephalitis virus (JEV).

Findings

• Results showed JEV antibodies detected through the HI test in 52% (58) horses, with only 10% (11) having antibodies related to Chikungunya.
• The study also found a disparity in JEV infection rates between the two stables. 66% of the horses at Pamulang tested positive for JEV, which was significantly higher than the 40% positive rate found amongst the horses at Pulo Mas.
• Further indication of the substantial presence of JEV infection was found when testing the neutralization antibodies – of the 58 horses with JEV antibodies, 90% (52 horses) were found to have specific neutralization antibodies to JEV.

Implications

• While the risk for alpha virus infections (which include Chikungunya) appeared relatively minimal in the horse population of Java, the incidence of JEV was considerably higher in the same population.
• These findings reflect the significant presence and risk of JEV infections among horses in this area and subsequently, important implications are raised for animal healthcare and disease control strategies.