Investigating the Impact That Diagnostic Screening with Lateral Flow Devices Had on the Rabies Surveillance Program in Zanzibar, Tanzania

With the global impetus for the elimination of canine-mediated human rabies, the need for robust rabies surveillance systems has become ever more important. Many countries are working to improve their rabies surveillance programs and, as a result, the reported use of lateral flow devices (LFDs) is increasing. Despite their known diagnostic limitations, previous studies have hypothesised that the benefits associated with LFDs could make them potentially quite useful towards improving the overall robustness of surveillance programs. To test this, a best practice standard operating procedure was developed which was used to guide the implementation of the ADTEC LFD as a diagnostic screening tool in Zanzibar. Over the course of the first 22 months of this investigation, 83 samples were subjected to in-field diagnostic screening, coupled with subsequent laboratory confirmation, and only one false-negative result was detected. Furthermore, the findings of our investigation indicated that the routine use of LFDs as a diagnostic screening tool resulted in a four-fold increase in the number of samples subjected to rabies diagnosis per month and a three-fold increase in the number of wards where samples were collected per year. Our findings suggest that LFDs could play a noteworthy role in improving the robustness of surveillance systems by increasing the number of samples tested and promoting diagnostic screening in areas distant from laboratories. Their implementation would, however, need to be carefully controlled through standardised protocols that align with the international best practices to ensure their judicious use.