Evaluation of lateral flow devices for postmortem rabies diagnosis in animals in the Philippines: a multicenter study.

Expansion of the use of lateral flow devices (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 fluorescence antibody test (DFAT) and ADTEC LFD between August 2021 and October 2022. The LFD demonstrated a sensitivity of 96.3% [95% confidence interval (CI): 94.1%-97.9%] and a specificity of 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). In this multicenter study, the high sensitivity and specificity of 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.

Emerging Genomic Trends on Rabies Virus in Davao Region, Philippines, 2018-2021.

Rabies, caused by the rabies virus (RABV), remains a significant public health issue in the Philippines despite efforts to control it. To eliminate rabies by 2030, effective surveillance strategies are crucial. In this study, we examined RABV evolution and phylodynamics in the Davao Region using genome sequences from Davao City and nearby provinces. We adapted the RABV ARTIC Protocol for Oxford Nanopore High-Throughput Sequencing to optimize workflow efficiency under limited resources. Comparing new virus samples collected from June 2019 to June 2021 (n = 38) with baseline samples from June 2018 to May 2019 (n = 49), new sub-clades were observed in the phylogenetic tree, suggesting divergence from older variants that were previously undetected. Most of the new viruses belonged to the Asian SEA4_A1.1.1 lineage, but new (SEA4_B1 and SEA4_B1.1) and emerging (SEA4_B1.1_E1) lineages that have never been reported in the Philippines were also identified. The baseline study reported phylogeographic clustering of RABV isolates from the same areas. However, this pattern was disrupted in the current biosurveillance, with variants detected in areas outside the original cluster. Furthermore, our findings revealed significant transmission routes between Davao City and neighboring provinces, contrasting with the predominantly intra-city transmission observed in the baseline study. These results underscore the need for ongoing and timely genomic surveillance to monitor genetic diversity changes and the emergence of novel strains, as well as to track alterations in transmission pathways. Implementing cost-effective next-generation sequencing workflows will facilitate the integration of genomic surveillance into rabies control programs, particularly in resource-limited settings. Collaborations between different sectors can empower local laboratories and experts in genomic technologies and analysis.