Biotinylated Polyclonal vs Monoclonal Antibodies for Rapid Rabies Diagnosis in Southern Africa

What is it about?

This study compares the diagnostic efficacy of a direct rapid immunohistochemical test (dRIT) using a biotinylated polyclonal antibody (PAb) preparation with the currently recommended direct fluorescent antibody (DFA) test in detecting rabies virus (RABV) in resource-limited countries of Africa and Asia. The PAb dRIT showed 100% diagnostic sensitivity and specificity, marginally higher than the PAb DFA test. The classical dRIT using two-biotinylated monoclonal antibodies (MAbs) showed reduced diagnostic sensitivity for mongoose RABV variants. Antigenic typing of false-negative samples indicated all to be mongoose RABV variants. The study suggests that the dRIT with alternative antibody preparations conjugated to a biotin moiety has equal or improved diagnostic efficacy compared to the DFA, and the antibody preparation should be optimized for virus variants specific to the geographical area of focus.

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Why is it important?

The study highlights the importance of alternative diagnostic methods for rabies, particularly in resource-limited countries where the traditional diagnostic tests may have limited availability or effectiveness. The use of a polyclonal antibody (PAb) preparation in the direct rapid immunohistochemical test (dRIT) protocol offers a potentially more cost-effective and accessible alternative to monoclonal antibody (MAb) cocktails, while maintaining similar diagnostic sensitivity and specificity. The study emphasizes the need for optimizing antibody preparations for specific virus variants prevalent in a given geographical region, ensuring that diagnostic tests are as effective as possible in detecting rabies. Key Takeaways: 1. The study compares the use of a polyclonal antibody preparation with monoclonal antibody cocktails in the direct rapid immunohistochemical test (dRIT) for rabies diagnosis. 2. The PAb dRIT had a diagnostic sensitivity and specificity of 100%, which was slightly higher than the PAb DFA test, while the classical dRIT using two-biotinylated MAbs had reduced diagnostic sensitivity for mongoose RABV variants. 3. The study underscores the importance of optimizing antibody preparations for specific virus variants and the potential advantages of using polyclonal antibody preparations in diagnostic tests.