AN ANTIVIRAL AGENT, T-1105 PREVENTS FROM VIRUS EXCRETION FROM PIGS INFECTED WITH PORCINOPHILIC FOOT-AND-MOUTH DISEASE VIRUS

Introduction It is a great challenge to control the spread of foot-and-mouth disease virus (FMDV) from the infected animal, especially pigs. We evaluated effectiveness of T-1105, one of pyrazinecarboxamide derivatives, in the virus excretion from the pigs infected with O/TAW/97, known as porcinophilic strain. Materials and methods One hour before the virus inoculation of 106.2 TCID50 of FMDV O/TAW/97, 200 mg/kg of T-1105 was orally administered to four pigs. The same dose of T-1105 was administered twice a day for 7 days. Two control pigs were all done without administration. Virus excretion in nasal swab and virus contents in plasma were examined by real-time PCR. Antibody to FMDV was measured by virus neutralization test and liquid phase blocking (LPB) ELISA. Results The control pigs showed the typical clinical signs. In the administered group two pigs showed no clinical sign but other two pigs formed vesicles at the limited site of the injection and the viral RNA was detected from nasal swab samples. Viremia was detected three of the four pigs at early stage of infection. But amounts of viral RNA in plasma were ten times lower than non-administered group. Both antibodies titers of LPB ELISA and the virus neutralization test were lower than those of non-administered group. Discussion By the oral administration of T-1105, some pigs inoculated with porcinophilic FMDV created mild symptoms but the duration of viremia became shorter and the virus excretions from nasal route were nothing or minor than that in non-administered group. The antibody responses to FMDV were so low that it was considered there was no or low virus replication in the pigs. It was suggested that administration of T-1105 also controlled virus excretion from pigs infected with porcinophilic FMDV.