Investigation of equine infectious anaemia in Queensland using gel diffusion.

This research conducted in Queensland investigates equine infectious anaemia (EIA) – a viral disease in horses – using gel diffusion tests. A specially prepared antigen was used for the tests, and it was found that a significant number out of 451 horses tested showed detectable levels of EIA antibody.

Research Method

• The researchers prepared an antigen for gel diffusion testing. This antigen was made from the spleen of a horse that was purposefully infected with the ‘CQ’ strain of EIA.
• The antigen was then tested against a variety of known positive serums. In this context, a ‘positive serum’ refers to a blood sample that has been tested and confirmed to contain the specific antigens or antibodies of interest – in this case, EIA.
• Serums that were taken before the horse was infected, and serums that are known to be negative for EIA, were also tested against the antigen as a comparison group.

Findings

• When the antigen was tested against the different serums, it produced a single, distinct line of precipitation if the serum was positive for EIA. This reaction did not occur when the antigen was tested against negative or pre-infection serums.
• The same reaction test was performed using extracts prepared from uninfected spleens, and these extracts displayed no reaction.
• The researchers tested 451 horses in Queensland for EIA using this antigen. Out of these, they found that 34 horses had detectable levels of EIA antibodies in their serums.
• The horses that tested positive were from various areas across the state, suggesting that EIA is not confined to a specific geographical area in Queensland.

Implications

• This research demonstrates the potential of gel diffusion tests as an effective method for testing EIA.
• The findings highlight the presence of EIA in broader regions in Queensland, rather than in limited, concentrated areas. This suggests that efforts to prevent and control EIA should be statewide, rather than targeted at specific locations.
• The preparation of an effective antigen from the spleens of infected horses may pave the way for similar research and testing strategies for other equine diseases.