Diagnosis of foot-and-mouth disease of clinically infected cattle using antigen-detection Elisa in South Eastern Nigeria

Abstract

Foot and mouth disease (FMD) viruses SAT1 and SAT2 were found concurrently causing disease in a dairy farm of 120 cattle and 19 calves in South Eastern Nigeria. Diagnosis was made using antigen detection ELISA (IZLER) a test with deviation from Liquid Phase Blocking ELISA (LPBE) and Solid Phase Competitive ELISA (SPCE). It provides information on presence of FMDV antigen in the specimen and tests for serotype A, Serotype O, Serotype SAT1, SAT2, and Pan FMD virus which are MAB for serotype C, SAT3 and Asia 1. Most common FMDV serotypes reported to cause infections in Nigeria have been consistently Types A, O, SAT1, SAT2. Affected animal were Friesian cattle crossbred with local N’dama breed of cattle. Clinical diagnosis was made using signs of oral and feet lesions causing severe anorexia and lameness respectively in affected animals and calves. Feet lesions were found to be similar to those in exotic animals with sloughing of hoof unlike in indigenous cattle that often are interdigital granulomatous lesions. Mortality among calves was about 60% (11 died out of 19). There was a striking lymphocytosis from haematology of affected animals; other blood parameters were within normal physiological range showing that there were no concurrent haemoparasitic or bacterial infections. Control of FMD in endemic area has to be adapted to local requirements. As such data on serotypes involved in outbreaks are required. To achieve this, clinical diagnosis has to be complemented with serological test and molecular techniques that requires primers, standard molecular laboratory equipment and well trained personnel. The primary challenge remains sample preservation and secure shipping for effective analysis and identification. The challenge of epileptic power supply remains obvious and most viral RNA is readily destroyed with constant freezing and thawing. Antigen ELISA is found as very good diagnostic alternative for FMD in endemic area.

Keywords: Antigen detection ELISA – Diagnosis – Foot-and-mouth disease – Nigeria