An outbreak of classical swine fever in pigs in Bangladesh, 2015

Abstract

In a group of 22 healthy pigs aged between 4 and 6 months, 2 pigs became ill with high fever, complete anorexia, cough and abnormal swaying movements on 22 June 2015. One of them died on June 24 and the second died on July 3. Shortly after, the remaining pigs also fell ill and died from the same illness by 10 August 2015. We investigated the aetiology, epidemiological and clinical features of the outbreak. We recorded the clinical signs and symptoms for each pig with the date of onset of illness. Veterinarians conducted post‐mortem examinations on the 12 dead pigs, they collected tissue samples from the dead pigs and placed them in a tube containing 1 mL of nucleic acid extraction buffer (lysis buffer). We tested all the tissue samples by real‐time reverse transcription polymerase chain reaction (rRT‐PCR) to detect classical swine fever virus (CSFV) because the animals’ symptoms matched those of this disease. We also conducted a phylogentic analysis of the nucleotide sequence of the E2 gene segment of CSFV detected in a lung tissue sample. The attack rate (22/22) and the case fatality were 100%. The predominant symptoms of the disease included high fever, cough, diarrhoea and swaying movements of the hind legs prior to death. Of the 12 pigs tissue samples tested, all had evidence of the presence of CSFV RNA by rRT‐PCR. The phylogenetic analysis indicated that the virus belongs to genotype 2.2, which is closely related to CSFV genotype 2.2 reported in India. Our investigation suggests that CSF is circulating in pigs, posing a risk for communities in Bangladesh that rely on pigs for economic income and dietary protein. Future research could focus on estimating the disease and economic burden of CSFV in pig rearing areas to determine if interventions might be warranted or cost‐effective.

Pathology and molecular characterization of classical swine fever virus from piggery units in Haryana

“…The typical clinical signs of CSF exhibited by the affected pigs were also reported by various workers in India as well as abroad (Saini et al 2000, Freitas et al 2012, Malswamkima et al 2015, Sarkar et al 2018, Borca et al 2019. The clinical signs generally depend upon the virulence of the strain, host responses and secondary bacterial infections (Blome et al 2017).…”

“…CSF is endemic in swine population of Eastern Europe, South America, Africa and Asia (Brown and Bevins 2018) and it remains a major threat to pigs in South Asia, including India (Sarkar et al 2018). The disease has been reported from most of the Indian states where pig rearing is practiced (Patil et al 2010, Nandi et al 2011, Singh et al 2018.…”

A further outbreak of classical swine fever in indigenous pigs in Kurigram district, Bangladesh

“…In the TaqMan (Sarkar et al, 2018). Our investigated strain belonged to CSF genotype 2.2 on phylogenetic analysis (Figure 4).…”

“…Depending on the virulence of the virus strain, host (age and breed) and environmental factors, the course of the disease in affected pigs can be classified as per-acute, acute, sub-acute, chronic or atypical (Moennig, Floegel-Niesmann, & Greiser-Wilke, 2003). A single outbreak of CSF was recently reported for the first time in Naogaon district in 2015, Bangladesh (Sarker, Hossain, Gurley, Hasan, & Rahman, 2018). We report another outbreak of CSF, which occurred during November-December 2015 in Nageshwari sub-district of Kurigram district in Bangladesh.…”