INVESTIGATION OF PORCINE CIRCOVIRUS‐ASSOCIATED DISEASE (PCVAD) IN GOVERNMENT PIG BREEDING FARMS IN BHUTAN

Abstract

Porcine circovirus type 2 (PCV2) belonging to genus Circovirus is the primary causative agent of several syndromes collectively known as porcine circovirus‐associated disease (PCVAD). An investigative study was conducted on the prevalence of PCVAD following a report of various degrees of morbidity and mortality in targeted government pig farms (NNPBC, Yusipang, NPBC, Wangchutaba & RPPBC, Lingmethang). Screening of sera samples conducted during September 2021 detected seroprevalence of PCV2 of 28/29 (96.5%) at RPPBC Lingmethang, 11/11(100%) at NNPBC Yusipang and 5/5 (100%) at NPBC Wangchutaba. From the same serum samples screened also detected seroprevalence of PRRSV as 7/29(24.1%) at RPBC Lingmethang, 1/11(9%) at NNPBC Yusipang indicating co-infection.  However, from the clinical samples of NNPBC, Yusipang 5/10 (50%) tested positive to PCV2 through rtPCR during September 2021, whereas from the clinical samples of outbreak at RRPBC, Lingmethang during September 2022, 11/11(100%) sera tested positive in ELISA to PCV2 antibodies; 11/11(100%) of vaginal swab samples and 5/5(100%) of organ samples tested positive to PCV2 in PCR. All the clinical samples from RRPBC, Lingmethang tested positive to PCV2. As the prevalence of disease is quite evident, a strict biosecurity control measures at the farms should be implemented to stop further spread of the virus. Besides, vaccination of pigs like in other countries may have to be explored and adopted in these government farms if found feasible. Furthermore, a detailed study needs to be conducted in all the government and private pig farms with larger sample size to clearly understand the real status of the disease in the country for devising an appropriate intervention.