A sero‐epizootiological study of porcine respiratory coronavirus in belgian swine

Abstract

SUMMARYA porcine respiratory coronavirus (PRCV), antigenically closely related to transmissible gastroenteritis virus (TGEV), appeared in the European swine population in 1984. The present serological study was performed to obtain insight into the epizootiology of PRCV and of TGEV PRCV-induced neutralizing antibodies were found in 90.6 per cent of the 160 sera collected from sows at slaughter, demonstrating the enzootic appearance of PRCV in the Belgian swine population. A serological study of fattening swine on 33 farms revealed that 11 farms situated in an area with a high farm density (all farms within 4 km2) and I I on 22 closed breedingfattening farms situated in areas with a low farm density (only one to four farms per 12 km2) were infected with PRCV throughout the year, whereas the other 11 closed breedingfattening farms were temporarily free of PRCV PRCV disappeared from the farms mainly in spring and summer. All the 11 farms became reinfected in autumn or winter, indicating that PRCV is regularly reintroduced in farms in the colder seasons.There was no correlation between the herd size and the temporary disappearance of PRCV from farms. It was observed on some farms that PRCV could infect pigs shortly after weaning in the presence of declining maternal antibodies, indicating that PRCV can persist on a farm by regularly infecting newly weaned pigs.TGEV-specific antibodies were found in 7.6 per cent of the 160 sera from the slaughterhouse sows. TGEV-specific antibodies were also detected in sera from fattening swine of 5 of the above mentioned 33 farms. TGEV-outbreaks were not observed on these farms. During the last years, TGEV-outbreaks have rarely been diagnosed in Belgium. The present results suggest that TGEV infections still regularly occur but that they are not clinically manifest.

Prevalence of Antibodies against Transmissible Gastroenteritis Virus and Porcine Respiratory Coronavirus among Pigs in Six Regions in Japan

“…Several experimental studies have reported that PRCV can induce a variable degree of protection against TGEV infection [1,3,9,18,19]. Taken together with our data, these findings suggest that the recent decrease in epidemic TGE outbreaks in Japan may have resulted from widespread infection of PRCV, as observed in European countries [10,12,13]. On the other hand, in our study, TGEV antibody-positive pigs were found at several PRCV antibody-positive farms; furthermore, a TGE outbreak occurred at one of these farms, although the reason for the outbreak was unclear.…”

“…The incidence and severity of TGE have decreased markedly since the widespread infection of PRCV in European swine herds in the late 1980s to early 1990s [10,12,13]. In the United States, a decrease in TGE incidence has been reported in one area having a high prevalence of PRCV antibody [20,21]; in other TGEV-and PRCV-seronegative herds, however, TGE remains a major cause of sickness and death in piglets [14,15].…”

Lung Cell Tropism and Inflammatory Cytokine-Profile of Porcine Respiratory Coronavirus Infection

“…PRCV has spread widely in the European swine population (reviewed in [4]). In 1989-1990 up to 90.6% of the pigs in Belgium were seropositive for PRCV [5]. At present, more than 95% of the Belgian swine herds are seropositive against PRCV (unpublished data).…”

A potential role for tumour necrosis factor-α in synergy between porcine respiratory coronavirus and bacterial lipopolysaccharide in the induction of respiratory disease in pigs

“…Porcine respiratory coronavirus (PRCV) is ubiquitous in Europe and appears to have become increasingly prevalent in swine herds in North America [1,2]. In Belgium, most pigs become infected between 6 and 15 weeks of age, and antibodies to PRCV are prevalent in c. 90% of pigs at slaughter.…”