Using Synthetic Management Technique For Eradication Of Transmissible Gastroenteritis Virus Without Depopulation

Swine Transmissible Gastro-Enteritis disease (TGE) is a highly infection disease caused by the Swine Transmissible Gastroenteritis Virus. All piglets that were less than 2 weeks old at the start of the outbreak were affected. Piglets show the symptoms of vomiting, severe diarrhea and high death loss. It was first reported in USA in 1945. In China, there have been frequent reports of TGEV outbreaks since the early 1970's.In January 2005, a pure breeding farm in Jiangsu province determined that the diarrhea in its pigs was caused by TGE. Preliminary diagnosis was TGE based on epidemiology, clinic symptoms and pathology examination. Laboratory confirmation on blood samples was carried out using virus isolation, indirect fluorescence antibody check, and indirect ELISA.To maintain the good quality of breeding stock sales and good reputation of the company after outbreak of TGE, that farm decided to start TGEV eradication. The farm is located in a very good isolated area naturally; each production department has separated far enough; the production management system is based on all-in/all-out, weekly production control. These advantages allowed farm to try the Non-depopulating TGEV eradication technique. The eradication program was carried out between Feb 2005 - August 2005. The steps of the trial are: 1) Preparation, a) stopped all breeding pig sales to customers; b) stopped all TGE negative pigs entering the breeding herd; c) Exposed the entire population of pigs on the farm, breeding, nursery, grower/finisher, with a high virulent TGEV strain by feed-back oral vaccination; d) transferred sufficient boars and gilts into the breeding herd so no new replacements would need to be introduced into the breeding herd for a period of 6 months; e) Set up a TGEV eradication program. 2) Implementation, a) Strictly enforce complete bio-security system; b) Disinfecting the site, workers and tools and equipment; c) All farrowing, nursery and finishing building was "sterilized"; d) After each building was "sterilized" and started to be used again it was then completely isolated from all buildings had not yet been cleaned; e) When it was repopulated with pigs, the people looking after the pigs were kept entirely separate from other people working on the farm. 3) Follow up and Inspection, a) Serum sample collection from all categories of pigs for TGEV anti-body test; b) Follow up all the pigs that have clinical symptom; c) Follow up the production performance for one year; d) TGEV serum antibody inspection for pigs that had suffered diarrhea; e) Follow up any customer farms that show TGE clinical symptoms. All the result from follow up and inspection showed that TGEV eradication has succeeded and achieved the target. Also it has the advantage of low cost, shorter time period, no interruption of regular production and can be put into practice.