Evaluation of lateral flowdevices for postmortem rabies diagnosis in animals in the Philippines: a multicenter study

Abstract

Expansion of the use of lateral flowdevices (LFD) for animal rabies diagnosis can help mitigate the widespread underreporting of rabies. However, this has been hindered by the limited number and small sample size of previous studies. To overcome this limitation, we conducted a multicenter study with a larger sample size to assess the diagnostic accuracy of the ADTEC LFD for postmortem rabies diagnosis in animals. Thirteen governmental animal diagnostic laboratories in the Philippines were involved in this study, and 791 animals suspected of having rabies were tested using both the direct fluorescenceantibody test (DFAT) and ADTEC LFD between August 2021 and October 2022. The LFD demonstrated a sensitivity of 96.3% [95% confidenceinterval (CI): 94.1%-97.9%] and a specificityof 99.7% (95% CI: 98.4%-100%). Notably, false-negative results were more likely to occur in laboratories with lower annual processing volumes of rabies samples in the previous years (adjusted odds ratio 4.97, 95% CI: 1.49-16.53). Inthis multicenter study, the high sensitivity and specificityof the LFD for the diagnosis of animal rabies, compared to that of the DFAT, was demonstrated, yet concerns regarding false-negative results remain. In areas with limited experience in processing rabies samples, it is essential to provide comprehensive training and careful attention during implementation.