Evaluation of antigen detection kits for diagnosis of equine influenza.

The research article presents a study examining the effectiveness of five rapid antigen detection kits, typically used for diagnosing human influenza, in diagnosing equine influenza. The article concludes that two specific kits show promising results and could be suitable for field diagnoses of equine influenza.

Understanding the study

• The study was undertaken to investigate the possible utility of five rapid antigen detection kits, originally designed for human influenza, for the diagnosis of equine influenza.
• Equine Influenza (EI) is a highly contagious respiratory disease in horses. Rapid and accurate diagnosis of this disease is crucial to prevent further spread.
• The two detection kits that showed the highest sensitivity to equine-2 influenza viruses (EIV) were the Directigen Flu A+B and ESPLINE INFLUENZA A&B-N. Sensitivity in the context of a diagnostic test refers to its ability to correctly identify those with the disease. High sensitivity is desirable as it makes false negatives (saying the disease is not there when it is) less likely.

Nasal Swabs and Diagnosis

• The study tested the efficacy of the two kits using nasal swabs derived from horses infected with EIV. Nasal swabs are commonly used for the instantaneous diagnosis of influenza.
• The results from the detection kits were then compared with those obtained by virus isolation and RT-PCR tests—commonly used and more comprehensive diagnostic methods.
• There was reasonable agreement between the results, suggesting that these kits could be a viable option for swift diagnosis of EI in the field setting. However, it is important to note that this is a preliminary outcome and further tests are required for conclusive results.

Specificity of the Kits

• The article also evaluated the kits from the viewpoint of specificity for EIV. Specificity in the medical testing context refers to the ability of a test to correctly identify those without the disease. High specificity ensures there are fewer false positives (saying the disease is there when it isn’t).
• The ESPLINE seems to be more specific to EIV, making it a superior choice over Directigen when considering this parameter. However, both sensitivity and specificity need to be factored in when considering the ideal diagnostic tool.