Investigating The Perfomance Of Lateral Flow Devices In Diagnosis And Genetic Characterization Of Foot And Mouth Disease Virus In Tanzania

ABSTRACT

A study on rapid detection and diagnosis of foot and mouth disease (FMD) field outbreaks was carried out in field settings using a Svanodip® foot and mouth disease virus (FMDV)- antigen (Ag) test lateral flow device (LFD) in Serengeti and Ngorongoro districts of Tanzania. Epithelial tissues from cattle (n=80) were collected from different villages and tested at penside using Svanodip® FMDV-antigen test to evaluate the sensitivity and specificity of LFDs relative to gold standard reverse transcription polymerase chain reaction (RT-PCR) molecular technique for FMDV. The duplicates of same epithelial tissues were stored in liquid nitrogen and transported to the laboratory for confirmation using gold standard RT-PCR technique targeting conserved region (3D) region of the FMDVgenome. Seventy eight samples showed positive reaction to LFDs antigen test and two samples were negative. All eighty samples collected during this study were positive to RT-PCR gold standard. LFDs and RT-PCR showed sensitivity and specificity of 97.5% and 100% respectively. There was no significant difference on the results of LFDs and RT-PCR in relation to the age of the lesions and type of epithelial tissues used (P>0.05). Tested LFDs were kept at-20°C and at room temperature for six and eight months respectively and possibility of FMDV RNA recovery was done. LFDs kept at room temperature for eight months were shown to be good vehicle for recovery, storage and transportation of FMDV RNA, than those kept at -20°C for six months. Antigen ELISA serotyping revealed that serotype A and O were associated with the current FMD outbreaks in the studied villages. Although, the lateral flow devices are panserotypic and provide point of care results for the rapid detection and the diagnosis of FMDV field outbreaks, their use must go in parallel with (OIE) gold standard technique for confirmation of FMDV outbreaks. Further studies are required to validate and deploy the LFDs for a wider application for FMDV outbreak investigations in Tanzania.