Diagnosis and prevention of equine infectious diseases: present status, potential, and challenges for the future.

This research article investigates current challenges, potentials, and the present status of diagnosing and preventing equine infectious diseases. It explores modern diagnostic methods and highlights the urgent need for standardization of these methods, the development and validation of more efficient vaccines, and the importance of management practices in controlling the diseases.

Diagnosis of Equine Infectious Diseases

• The extensive movements of horses, permanently or temporarily, necessitate rigorous control of infectious diseases. The control requires reliable and rapid tools for accurate disease diagnosis.
• Indirect diagnosis, based on antibody detection, is considered an effective method for managing epidemiologic surveillance of diseases on regional, national, or global scales. Direct diagnosis, however, is essential for identifying a new outbreak.
• New diagnostic methods resulting from advancements in biochemistry, molecular biology, and immunology are available. These methods use immunoassays, particularly ELISAs, for antibody detection.
• Identification of pathogens depends much on isolation. However, significant progress has been witnessed with immunocapture tests like capture ELISA based on monoclonal antibodies. DNA probes and amplification tests including PCR or RT-PCR are also marking noteworthy advancements.
• The main requirements of these diagnostic tests are specificity, sensitivity, rapid implementation, and quick results. However, many tests are still in the development stage and require multicentric evaluations for validation before broad usage.

Standardization of Diagnostic Reagents

• There is a critical need for standardization of the reagents used in these diagnostic tests. A false diagnosis, either positive or negative, can have significant technical and economic impacts, thereby justifying the need for harmonization.
• The Office International des Epizooties (OIE) can potentially play a critical role in standardizing these diagnostic tools and processes on a global scale.

Vaccines for Control of Equine Infectious Diseases

• Vaccines are essential in controlling equine infectious diseases. However, many vaccines, particularly those used against viral or bacterial diseases, are inactivated adjuvanted vaccines that could potentially lead to harmful side effects and questionable efficacy.
• Subunit vaccines offer significant advancements concerning safety. However, more developments are expected with the utilization of new technologies, such as recombinant DNA technology and immunomodulators.
• Substantial results have been obtained with subunit vaccines or with live vectored vaccines using recombinant DNA technology. The article also anticipates good results from naked-DNA or genetic vaccines.
• The availability of a new generation of safer, more efficacious vaccines that will also distinguish vaccinated animals from infected ones is expected in the short term. These vaccines will greatly aid in controlling the infection.

The Importance of Management Practices

• Regardless of future vaccine quality, vaccination alone will never fully control infectious diseases. It is therefore essential to continue educating animal owners and veterinarians about the importance of management and hygiene practices in controlling diseases.