Molecular Surveillance as a Monitoring Tool to Detect FMDV Among Asymptomatic Cattle Populations in Uganda

Foot and mouth disease (FMD) is a highly contagious viral disease that primarily affects cloven hooved livestock and wildlife. The disease was first confirmed in Uganda in1953 and is now endemic. Serotypes O, A and SAT2 have... [ view full abstract ]

Foot and mouth disease (FMD) is a highly contagious viral disease that primarily affects cloven hooved livestock and wildlife. The disease was first confirmed in Uganda in1953 and is now endemic. Serotypes O, A and SAT2 have been identified in most outbreaks. Although passive surveillance exists, there continues to be several incursions every year. Sero surveillance using NSP ELISA has its limitations based on purity of vaccines used. Molecular surveillance provides timely and easily interpretable information that can be used to quickly enhance disease control.

This work is part of an ongoing project supported the United States Department of Agriculture (USDA) aimed at research and development of countermeasures to support the control of FMDV in Uganda.

Four endemic districts were identified and 100 cattle randomly selected. Probang samples are taken from cattle every four months. Probangs are collected in 50 ml falcon tubes and preserved in an equal volume of VTM and immediately stored in liquid nitrogen.RNA is extracted using QIAamp RNA Mini kit and detection of FMDV is done using the superscript III platinum one step qrt-PCR kit. Aliquots of the Probangs are shipped to Plum Island Animal Disease Center (PIADC) for virus isolation, sequencing and interlaboratory comparison for Real time PCR.

Molecular results indicate presence of FMDV with varying prevalence on each visit. FMD virus has been successfully isolated from these non clinical probangs. Sequencing results indicate serotype O circulating among these non clinical cases. Molecular surveillance can be a useful tool in determining non clinical FMDV among cattle. The relationship between non clinical FMDV and Outbreak FMDV needs to be established.

Keywords

Foot and Mouth Disease Virus, Uganda