Teschen disease (Teschovirus encephalomyelitis) eradication in Czechoslovakia: a historical report

摘要

Teschen disease (previously also known as Klobouk's disease), actually called Teschovirus encephalomyelitis, is a virulent fatal viral disease of swine, characterized by severe neurological disorders of encephalomyelitis. It was initially discovered in the Teschen district of North-Eastern Moravia. During the 1940s and 1950s it caused serious losses to the pig production industry in Europe. The most critical situation at that time, however, was in the former Czechoslovakia. A nationally organized eradication programme started in 1952. That year the reported number of new cases of Teschen disease reached 137 396, i.e., an incidence rate of 2 794 per 100 000 pigs, in 14 801 villages with 65 597 affected farms, i.e., 4.43 affected farms per village and2.10 diseased pigs per affected farm. The average territorial density of new cases was 1.07 per km2. For etiological diagnosis histological investigation of the central nervous system, isolation of virus and seroneutralization were used. Preventive measures consisted in feeding pigs with sterilized waste food and in ring vaccination. Eradication measures took the form of the timely detection and reporting of new cases, isolating outbreak areas, and the slaughter of intrafocal pigs followed by sanitation measures. Diseased pigs were usually destroyed in rendering facilities. The carcasses of other intrafocal pigs were treated as conditionally comestible, i.e., only after sterilization. During the years 1952-1965 from a reported 537 480 specifically diseased pigs 36 558 died; i.e., Teschen disease mortality rate was 6.80% while other intrafocal pigs (88.12%) were urgently slaughtered. During the whole eradication programme there were a reported 542 971 Teschen disease cases. The disease was found mainly in small private farms where domestic refuse was used for pig feeding without proper sterilization. During 1959-1972 there were a reported 16 981 529 vaccinations using a vaccine of national origin. The ratio of vaccination to national pig population was reduced from 0.4904 in 1959 to 0.0786 in 1972. During 1959-1965 the ratio of reported vaccinations to reported new diseased pigs was 521:1 and during 1960-1965 the ratio of reported vaccinations to reported intrafocal pigs was 85 :1. After eradicationthe vaccination was stopped. The last cases were detected in 1973 and from that time Czech and Slovak territories have been free from this dangerous infection.