Porcine reproductive and respiratory syndrome virus detection in Thailand during 2005–2010 in relation to clinical problems, pig types, regions, and seasons

Abstract

The objectives of the present study were to determine the prevalence of porcine reproductive and respiratory syndrome virus (PRRSV) in Thailand between 2005 and 2010. The study was conducted by retrospectively investigating the detection of PRRSV from different pig types including boars, sows, piglets, nursery pigs, and fattening pigs from six regions of Thailand, i.e., the northern, eastern, northeastern, central, western, and southern parts. The data were obtained from cases submitted to the Chulalongkorn University Veterinary Diagnostic Laboratory for PRRSV detection between 2005 and 2010. Frequency analyses and generalized linear models were used to evaluate the prevalence of PRRSV in relation to various factors. In total, 2,273 tissues (n = 636), semen (n = 210) and serum (n = 1,427) samples were included. PRRSV was detected in 32.6 % (740/2,273) of the pigs. The virus was found in 43.1 %, 15.7 %, and 30.3 % in the tissues, semen, and serum samples, respectively (P < 0.001). The prevalence of PRRSV was highest in 2005 (43.6 %) and lowest in 2009 (23.6 %) (P < 0.001). The prevalence of PRRSV was highest in nursery pigs (43.7 %) and lowest in boars (15.4 %) (P < 0.001). The prevalence of PRRSV in the hot season (34.9 %) was higher than that found in the cool season (28.1 %, P = 0.018) but did not differ significantly compared to rainy season (34.0 %, P = 0.486). The strain of PRRSV isolated in the present study was genotype 2 (54.5 %), genotype 1 (31.0 %), and mixed genotypes (14.5 %). It can be concluded that PRRSV was detected in the tissue samples more frequently than the semen and serum samples. The prevalence of PRRSV was high in the nursery pigs. A high prevalence of PRRSV was found in the hot season, indicating that climatic factors may also contribute to the prevalence of PRRSV in Thailand. Of all the PRRSV detected, 31.0 %, 54.5 %, and 14.5 % belonged to genotype 1, genotype 2, and mixed genotypes, respectively.

Sero-Prevalence of Porcine Reproductive and Respiratory Syndrome (PRRS) in Pigs of Different Developmental Regions of Nepal

“…However, in support of Sharma (2011) our study also confirms that PRRS virus is infecting pigs of Nepal and spreading to many regions. Regarding PRRS status in other countries, there was prevalence of 32.6% of PRRS antibody sero-positive samples in pigs of Thailand which is quite higher than this study (Tummaruk et al, 2013). According to Montagnaro et al,37.7% (129/342) sero-positive samples were found for PRRS in wild boars in Campania, southern Italy which is also very much higher than our finding (Montagnaro et al, 2010).…”

Prevalence of porcine reproductive and respiratory syndrome virus detection in aborted fetuses, mummified fetuses and stillborn piglets using quantitative polymerase chain reaction

“…Herd location and general management : The herds were located in the eastern (A and G), middle (B, D, E, I and J), northeastern (C and H) and southern (F) parts of Thailand. All herds were breeding herds with 900 to 5,000 sows per herd and were defined as PRRS virus-positive herds according to the results of a commercial ELISA test (HerdChek ® PRRSV antibody test kit 2XR ® , IDEXX Laboratories, Inc., Westbrook, ME, U.S.A.) and a reverse transcription polymerase chain reaction (RT-PCR) of the herd’s monitoring data [ 26 ]. Gilts and sows were housed in a conventional open housing system with equipment, e.g., water sprinklers, fans and roofs with heat reflecting material, to reduce the impact of high temperatures.…”

A Cross-Sectional Study of Porcine Reproductive and Respiratory Syndrome Virus and Mycoplasma hyopneumoniae in Wild Boars Reared in Different Types of Captive Setting in Thailand

“…The identical viruses were present in different provinces [5]. The PRRSV infected pigs are often co-infected with M. hyopneumoniae and other agents causing porcine respiratory disease complex (PRDC) [2,3]. The prevalence M. hyopneumoniae was previously reported at 2.08-45.00% in domestic pigs in Thaiand [6].…”

“…Both genotype 1 and genotype 2 of PRRSV were detected in domestic pig farms in all regions of Thailand. Prevalence of PRRSV in domestic pigs in the country varied from 24.6-53.6% and the prevalence was 32.7% in the central region [3] where the density of domestic pig population is high. The recorded pig density in this region according to previous study was between 0.00 and 777.56 heads per square kilometer [4].…”