Monitor Of Swine Fmd Immunity Antibody And Disease In Yancheng District In Jiangsu Province

Foot-and-Mouth Disease (FMD) is an acute virus infectious animal disease which is characterized by rapid and long-distance spread. Because it can lead to enormous economic losses and social effects, FMD is the first one on OIE 15 A-type animal diseases list and also No.1 on China 14 A-type animal diseases list. How to prevent and control FMD is an urgent subject faced by governments at all levels. In order to evaluate the efficiency of the FMDV inactivated vaccine, the immunity antibody to FMDV and the disease were monitored in Yancheng district in Jiangsu province during period 2003-2005.I . Detection of FMD immunity antibody and vaccination programsTotal 2162 serum samples of pigs in 10 different counties, vaccinated with FMD vaccine were selected randomly and the antibodies level to O-type FMD were detected by HI tests. The results showed that 1010 were positive among 2162 samples. The positive rate was 47%. Among the 2162 samples, 1203 samples were collected from scale breeding herds, the results showed that 956 samples were positive to FMDV. The positive rate was 79.5%. Meanwhile, the positive rate in scatter pigs was 15.6% , and the antibodies level was comparatively lower than that in large herds.In order to study the immune effect and dynamic rule of antibody, 69 hybrid cross pigs were separated into three groups. Vaccination was given as follows: group 1 received O-type FMD vaccine by one time. Group 2 received the vaccine by two times at 30 days intervals. Group 3 served as an unvaccinated negative group. The animals were bled at 15, 30, 60 and 75 days post vaccination in group 1 and at 15, 30 days post the first vaccination and 15, 30 and 60 days post the second vaccination. The results showed that the level of antibodies of pigs at 15 days post the second vaccination can provide 100% protect against FMD and can last for 60 days. It indicated that the antibodies level of pigs in scale herds was comparatively high after vaccination with O-type FMD vaccine and it can provide protect against the disease. But the antibodies level of pigs in scatter herds was comparatively low and pigs were susceptible to FMD. Therefore, pigs must be vaccinated according to FMD vaccination program.Ⅱ. Monitor of FMD occurredNine suspected cases of pig FMD happened in Yancheng district. Among them, five cases were occurred in the pigs imported from other places. There were only 28 suspected cases of FMD at all in the last two years in that area. The results showed that the 28 samples were positive to O-type FMDV by reverse indirect HA test. It was indicated that O-type FMD has been effectively controlled in Yancheng district under current preventive measures against FMD, although there were sporadic cases in that area. Therefore, monitor and control of O-type FMD and attention to the prevalence and the change of virulence of O-type and AsianⅠ-type FMD and epidemic prevention of these different types FMD should be strengthened.