Characterization of Porcine Circovirus Type 2 in Taiwan

Abstract

ABSTRACT. In an effort to understand the genetic diversity of porcine circovirus type 2 (PCV2) and the prevalence of PCV2 infection in Taiwanese herds, we have sequenced the complete genomes from PCV2-infected specimens and individually measured the antibody tite r against PCV2 from pigs reared in Taiwan between the years 2000 and 2002. A total of 623 specimens originating from pigs display ing varied clinical signs were screened with the polymerase chain reaction (PCR). Results showed that 309 pigs (49.6%) tested positive for PCV2. Eight of the positive specimens were used for the amplification of the complete viral genome. Sequence comparison of the complete genomes indicated that the 8 Taiwanese PCV2 isolates shared 95-99% similarity. Phylogenetic analysis of all 40 PCV2 isolates from North America, Europe, Asia and Taiwan revealed that those isolates were grouped together in one large group containing two minor subgroups. The Taiwanese PCV2 isolates were classified into the two minor subgroups. The prevalence of serum antibodies to PCV2 in pigs was investigated, and results showed that approximately 83.5% of the pigs in Taiwan were seropositive. Finishing pigs possess the highest titers of antibodies, while 9-week-old pigs contained the lowest titers for specific antibodies. Our result s suggest that PCV2 infections have become common in Taiwanese pig farms. KEY WORDS: phylogenetic analysis, polymerase chain reaction, porcine circovirus type 2, seropositive.

Epidemiological Investigation of the Prevalence and Features of Postweaning Multisystemic Wasting Syndrome in Japan

“…19 Similar high prevalence rates of PCV2 infection have been reported in other countries. 9,27,46 In the present study, PCV2 DNA was detected in 75.1% of pigs without histological lesions of PMWS. porcine reproductive and respiratory syndrome, M.hyopneumoniae, or bacterial infections were major factors in the poor growth of these PMWS-negative pigs, as shown in Table 3.…”

Genetic Diversity of Porcine Circovirus Type 2 in Korean Pigs with Postweaning Multisystemic Wasting Syndrome during 2005-2007

“…Since PMWS was initially described in Western Canada, incidences of PMWS and PCV2 infection have been reported in many countries of Europe, America and Asia, and PMWS is nowadays considered a very significant disease in swine industry [3,4,7,13,18,24,30]. In Korea, first PCV2 infection was diagnosed in weaned pigs with PMWS by immunohistochemistry and PCR [10].…”

Exploratory Epidemiological Study on Porcine Circovirus Type 2 Infection and Postweaning Multisystemic Wasting Syndrome in the Czech Republic

“…PMWS was first described in Canada in mid 1990s (Clark 1997). The disease was subsequently confirmed in many countries in Europe (Segales et al 1997;Kennedy et al 1998;Wallgren et al 2004;Madec et al 2000;Allan et al 1998), North America , Asia (Wang et al 2004) and Japan (Onuki et al 1999).…”