-DETECTION OF FOOT AND MOUTH DISEASEـVIRUS INFECTION ASSOCIATED ANTIBODIES IN SHEEP SERA IN BASRA BY AGID TEST

Abstract

Foot and mouth Disease (FMD) is the most contagious disease of the clovenhoofed animals and has a great potential for causing severe economic losses in susceptible cloven-hoofed animals, of the domestic species, cattle, pigs, sheep, goats and buffalo are susceptible to FMD, in addition many species of cloven- hoofed wildlife such as deer, antelope and wild pigs may became infected (1).Infection of susceptible animals with FMD virus lead to the appearance of vesicles on the feet, in and around the oral cavity and on the mammary gland in females, the severity of the clinical signs varies with the strain of virus, the exposure dose, the age and breed of animal, the host species and its degree of immunity (2).There are seven serotypes of FMD virus namely O, A, C, SAT1, SAT2, SAT3, and Asia1, infection with any serotype dose not confer immunity against other (3). In Iraq, the serotypes A, O, and Asia1 were recorded in years 1952, 1957, and 1975 respectively (4). In the period between the end of 1998 to the beginning of 1999 an sever outbreak of FMD occurred in Iraq, it affected cows, buffalos, sheep and goats and may be other animals, the virus isolated from cow, buffalo, and sheep, the disease is still endemic in Iraq (5). FMD is still prevalent in many parts of the world as emphasized by the 2001 epidemics in the European Union, southern Africa, Asia and South America (6).(7) reported the finding of third antigenic component associated with infection with Foot and Mouth Disease Virus, called virus infection associated antigen (VIA), which reacted with the sera from convalescent animals but not with sera from vaccinated animals, VIA antigen is specific for FMD but is not virus type-specific, as antiserum to six of the seven virus types gave positive agar gel diffusion precipitin (AGID) reaction with VIA antigen prepared from type A infected tissue culture fluids.Antibody against VIA was originally demonstrated only in sera from animals infect with FMDV and not in sera from animals immunized with inactivated vaccines (8).VIA antibodies in sera from animals convalescent with FMD have been detected by Immunodiffusion in agar gel (AGID) test (9).The antibodies against the VIA antigen were detected between the second week and 13thor 14thweek after infection (10).The detection of antibodies to virus infection associated antigen was done in Iraq by (11), the survey was done on Iraqi cow sera, collected from Mosul slaughter house in Mosul Government. By the Agar Gel Immuno-Diffusion, samples were examined.