An inter- laboratory proficiency testing exercise for rabies diagnosis in Latin America and the Caribbean

The direct fluorescent antibody test (DFA), is performed in all rabies reference laboratories across Latin America and the Caribbean (LAC). Despite DFA being a critical capacity in the control of rabies, there is not a standardized protocol in the region. We describe the results of the first inter-laboratory proficiency exercise of national rabies laboratories in LAC countries as part of the regional efforts towards dog-maintained rabies elimination in the American region. Twenty three laboratories affiliated to the Ministries of Health and Ministries of Agriculture participated in this exercise. In addition, the laboratories completed an online questionnaire to assess laboratory practices. Answers to the online questionnaire indicated large variability in the laboratories throughput, equipment used, protocols availability, quality control standards and biosafety requirements. Our results will inform actions to improve and harmonize laboratory rabies capacities across LAC in support for the regional efforts towards elimination of dog-maintained rabies.
Author summary The incidence of dog-maintained rabies in Latin America has showed a significant reduction in the last 30 years. Although several countries have achieved its elimination there are still focalized areas in the region where rabies remain endemic. Many factors, including poverty, geographic and environmental features, as well as social, cultural, political and economic variables, have limited the effective implementation of canine rabies control programs in these endemic areas. Critical to the goal of control and elimination of rabies is a robust laboratory diagnostic capacity. This report presents the results of an Inter-laboratory proficiency testing exercise for rabies diagnosis by direct fluorescent antibody test among laboratories across Latin America and the Caribbean (LAC). Our results indicate that although all laboratories can perform the direct fluorescent antibody test, there are substantial differences in the overall results and test interpretation. This study identified important gaps in standardization and/or harmonization between laboratories which could be overcome and corrected with appropriate DFA protocols standardized across the LAC, including its broad distribution and proper training.