Enhanced Rabies Surveillance Using a Direct Rapid Immunohistochemical Test

Area of Science:

• Veterinary Pathology
• Immunohistochemistry
• Public Health Virology

Background:

• Laboratory surveillance is crucial for rabies control.
• The direct fluorescent antibody test (DFA) is the gold standard but requires specialized equipment.
• Developing countries need accessible diagnostic techniques for rabies surveillance.

Purpose of the Study:

• To present a standard protocol for the direct rapid immunohistochemical test (DRIT) as an alternative diagnostic method for rabies.
• To evaluate the DRIT's performance compared to the DFA for rabies diagnosis.
• To highlight the DRIT's utility in laboratory and field-based rabies surveillance.

Main Methods:

• The DRIT protocol involves fixing touch impressions of brain tissue in formalin.
• Rabies virus-specific antibodies, a streptavidin-peroxidase enzyme, and a chromogen reporter are used for detection.
• Light microscopy is employed for sample interpretation, with results available in approximately one hour.

Main Results:

• The DRIT demonstrated high sensitivity and specificity, approaching 100%, when compared to the DFA.
• Evaluations across various animal species and continents confirmed the DRIT's accuracy.
• The USDA WS program has successfully used the DRIT to test over 94,000 wildlife samples since 2005.

Conclusions:

• The DRIT is a powerful, economical tool for rabies diagnosis.
• It can be utilized by both laboratorians and field biologists.
• The DRIT can significantly improve global rabies surveillance, prevention, and control programs.