PCR Detection of Porcine circovirus type 2 DNA in Whole Blood, Serum, Oropharyngeal Swab, Nasal Swab, and Feces from Experimentally Infected Pigs and Field Cases.

Abstract

ABSTRACT. Porcine circovirus type 2 (PCV2) shedding patterns were investigated by polymerase chain reaction (PCR) for the detection of PCV2 DNA, and the diagnostic suitability of a sample for the PCR was examined by using different types of samples. In the e xperimental infection, sixteen pigs were inoculated intranasally with PCV2. The samples, including oropharyngeal and nasal swabs, feces, whole blood and serum became positive for PCV2 DNA by PCR immediately after the inoculation, and almost all samples remained positive during the observation period, post-inoculation-day 70. Field samples were collected from 313 pigs in five different a ge groups. The overall percentages of positive samples in the whole blood, nasal swabs, and feces detected by PCR were 30.4%, 19.2%, and 20 .4%, respectively. The frequency of positive samples increased after the nursery stages and reached a peak in the 3 to 4-month-old pigs. These results indicate that PCV2 infection may occur after weaning, that PCV2 DNA may be present in whole blood for a long period after infection, and that whole blood and serum are the most suitable sample types for the PCR analysis of PCV2.

Shedding Pattern and Serological Profile of Porcine Circovirus Type 2 Infection in Cesarean-Derived, Colostrum-Deprived and Farm-Raised Pigs

“…This experimental finding is similar to that obtained by a Japanese animal trial that found that PCV2 shedding increases following nursery stages and peaks at 3-4 months of age [22]. The duration of PCV2 shedding in this study among pigs and between herds differed slightly.…”

“…In a previous in vivo study, 2-week-old pigs challenged with PCV2 had PCV2 DNA in nasal, oropharyngeal and fecal samples on day 1 postinoculation [3]. Another in vivo study demonstrated the PCV2 shedding lasted for at minimum 70 days after viral challenge in weaned pigs [22]. In this study, the onset and duration patterns of PCV2 shedding differed from these findings.…”

“…Two-week-old pigs challenged with PCV2 had PCV2 DNA in nasal, oropharyngeal and fecal samples on day 1 postinoculation [3]. PCV2 exists in nasal and oropharyngeal swabs and in feces of pigs at minimum 70 days after PCV2 inoculation [22]. A recent field study identified PCV2 viremia in commercial pigs at 11-15 weeks of age [11].…”

Nested Polymerase Chain Reaction Detection and Duration of Porcine Circovirus Type 2 in Semen with Sperm Morphological Analysis from Naturally Infected Boars

“…8,11 Although the pathogenesis and primary mode of transmission of PCV2 are not known, there is evidence to support horizontal and vertical transmission. Porcine circovirus type 2 was detected in ocular, nasal, and fecal secretions from experimentally infected swine 13 and field cases 18 suggesting horizontal transmission. Recently, PCV2 has been cultured from the feces of naturally infected swine suggesting a potential for fecal-oral transmission.…”

Circovirose suína

“…O circovírus resiste à inativação quando exposto a ambiente ácido (pH 3), a clorofór-mio, a temperaturas entre 56ºC e 70ºC (Allan et al 1994c), ao congelamento, à luz ultra-violeta e a desinfetantes (Shibata et al 2003). O agente permanece estável em fezes e secreções respiratórias (Shibata et al 2003).…”