Lateral flow devices for samples collected by straw sampling method for postmortem canine rabies diagnosis

Abstract

The direct fluorescent antibody test (dFAT) using brain sample after opening the skull is the standard rabies diagnostic test in animal rabies. However, it is not feasible in many resource-limited settings. Lateral flow devices (LFD) combined with a simple sampling methodology is quicker, simpler, and less hazardous than the standard test and can be a useful tool. We conducted a prospective on-site study to evaluate the diagnostic accuracy of the LFD with the straw sampling method compared with that of the dFAT with the skull opening procedure for post-mortem canine rabies diagnosis. We collected 97 rabies-suspected animals between December 1, 2020 and March 31, 2021. Among the 97 samples, 53 and 50 cases were positive tests for dFAT and LFD, respectively. The sensitivity and specificity of LFD with straw sampling method were 94.3% (95% confidence interval [CI], 84.3–98.8%) and 100% (95% CI, 92.0–100%), respectively. The performance of LFD by the straw sampling method showed relatively high sensitivity and 100% specificity compared with that of dFAT performed on samples collected after opening the skull. This methodology can be beneficial and is a strong tool to overcome limited animal surveillance in remote areas. However, because of our limited sample size, more data using fresh samples on-site and the optimizations are urgently needed for the further implementation in endemic areas.

Molecular Analysis of Rabies Virus Using RNA Extracted from Used Lateral Flow Devices

“…This analysis was implemented under an existing study to evaluate LFDs for postmortem rabies diagnosis in animals ( 13 , 14 , 18 ). This study was performed at the Regional Animal Diagnostic Laboratory in Central Luzon, Philippines.…”

“…This laboratory routinely receives decapitated animal heads for rabies confirmatory testing, namely, DFATs. When this laboratory received samples, brain specimens for LFD testing were collected by a simple sampling methodology using a drinking straw ( 14 , 15 , 19 , 20 ). The collected brain samples were homogenized in a BioMasher II instrument (Nippi, Tokyo, Japan) with approximately 400 to 500 μL of the assay buffer provided by the LFD kit manufacturer (rabies antigen test kits, lot no.…”

“…The collected brain samples were homogenized in a BioMasher II instrument (Nippi, Tokyo, Japan) with approximately 400 to 500 μL of the assay buffer provided by the LFD kit manufacturer (rabies antigen test kits, lot no. 1904; Adtec Co., Ltd., Oita, Japan) ( 14 ). Next, 100 μL of the suspension was added to the sample well of the test kit.…”

“…LFDs have the strong advantage of being used for point-of-care testing. The usefulness and accuracy of LFDs for the diagnosis of rabies in animals have been shown in recent studies in the Philippines ( 13 , 14 ). Rabies animal surveillance would be strengthened if LFDs were used not only for on-site diagnosis but also for subsequent molecular analysis.…”

The Impact of the First Year of the COVID-19 Pandemic on Canine Rabies Control Efforts: A Mixed-Methods Study of Observations About the Present and Lessons for the Future

“…In-country distribution challenges could, again, be minimized by the distribution of thermostable vaccines and shared supplies between countries in emergencies. Meanwhile, support from the OIE Vaccine Bank (37) and Gavi, the Vaccine Alliance (38), remains essential. Moreover, actions that are being taken to improve the inequities in vaccine supplies highlighted by COVID-19 should be co-opted in the longer term to benefit rabies control and prevention as well.…”