Validation of a Real Time PCR for Classical Swine Fever Diagnosis

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.

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“…We tested all the tissue samples by real-time onestep reverse transcription polymerase chain reaction (rRT-PCR) to detect CSFV (Dias et al 2014).…”

Section: Laboratory Investigationsmentioning

confidence: 99%

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

Sarkar

Hossain

Gurley

et al. 2017

Veterinary Medicine & Sci

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“…Brazil, in a broader way, considering the OVS, has been investing in training, data analysis and staff training with a scientific basis, including themes related to the inspection of products of animal origin (Rodrigues et al, 2017(Rodrigues et al, , 2018(Rodrigues et al, , 2021, international agricultural surveillance (Melo et al, 2014a(Melo et al, , 2014b(Melo et al, , 2015Sá et al, 2018), agricultural defence (Moraes et al, 2017;Oliveira et al, 2021) and diagnosis and official laboratory structure (Dias et al, 2014;Oliveira et al, 2018Oliveira et al, , 2021. This shows that the country has been preparing for the new sanitary challenges in livestock and in this sense, the DF continues to adapt to international requirements, as demonstrated in this paper, especially considering the stage Brazil is at in the National Programme for the Eradication of FMD, in which the intention is to gradually remove vaccination against FMD from cattle and buffalo herds in Brazilian states, in accordance with the proposal approved by the OIE (Brasil, 2019).…”

Section: /11mentioning

confidence: 99%

Challenges to and advancements of the official veterinary service of the Federal District, Brazil

Taques¹,

Coelho

Barbosa-Júnior

et al. 2021

Braz. J. Vet. Med.

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Animal diseases can be both a precursor to social instability and a result of social instability. For disease outbreaks to be prevented or even quickly controlled, an efficient and well-structured veterinary service is fundamental. The monitoring of the efficiency of an official veterinary service (OVS) by official audits is a sine qua non condition for the progress of an efficient way to control and eradicate diseases. In this sense, the present work aims to study the advances and challenges of the OVS of the Federal District (DF), Brazil, from a study of the scores obtained by the evaluation of the Programme of Quality Evaluation and Improvement of Official Veterinary Services which is based on the World Organisation for Animal Health -Performance of Veterinary Services Pathway (Quali-SV/OIE-PVS), which was used to officially assess the quality and improvement of the OVS of the DF. In Brazil, the official evaluation was conducted by the Coordination of Evaluation and Improvement of Veterinary Services, Ministry of Agriculture, Livestock and Food Supply, considering manpower, infrastructure and financial resources. Five possible scoring levels were audited: authority, technical and operational capacity, interaction with stakeholders and access to markets. These components were described and assessed as critical competencies in the OVS assessment. Strengths and weaknesses observed during the audit were listed, and levels of OVS progress were rated and assessed. Despite the predominance of strengths in the OVS audit, the weaknesses detected require urgent corrective action, especially with regard to the autonomy of the OVS.

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“…The RNA from tissue samples (lung, liver and spleen) and nasal swabs were used to synthesize complementary DNA (cDNA) by one-step reverse transcription using Invitrogen SuperScript III First Strand cDNA Synthesis Kit. These synthesized cDNA were tested by TaqMan probe-based real-time polymerase chain reaction (qPCR) F I G U R E 1 The Bangladesh map showing the location of classical swine fever outbreak in 2015 [Colour figure can be viewed at wileyonlinelibrary.com] using CSF virus (CSFV)-specific primers and probe to detect the presence of CSFV E2 gene in the test samples (Dias et al, 2014).…”

Section: Real-time Reverse Transcriptase Pcrmentioning

confidence: 99%

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

Chowdhuary¹,

Islam²,

Khair³

et al. 2020

Transbound Emerg Dis

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Deaths of native scavenging pigs were reported in mid‐November 2015 at Nageswari sub‐district, Kurigram district of Bangladesh. The investigation for a suspected classical swine fever (CSF) outbreak was accomplished via a joint outbreak investigation team from Department of Livestock Services (DLS) and Food and Agriculture Organization, Emergency Center for Transboundary Animal Disease (FAO‐ECTAD), Bangladesh. Out of 592 pigs, 396 were infected and among them 263 died. The attack rate and case fatality rate were 66.9% and 66.4%, respectively. The epidemic curve constructed using the data captured from the CSF outbreak site was nearly bell‐shaped, indicating a point source epidemic. The basic reproduction numbers (R0) were estimated to be 1.6 (95% Confidence interval [CI]: 1.5–1.7) and 1.5 (95% CI: 1.3–1.7) based on attack rate and exponential growth rate methods, respectively. Adult pigs showed signs of high fever, staggering gait and depression, whereas piglets either died without any premonitory signs or purulent exudates in the eyes were observed. Post‐mortem examination was carried out on a 6‐month‐old piglet. The necropsy findings included were swollen lymph nodes deep red in colour, and haemorrhages on serous and mucous membranes of the intestinal organs together with button‐like ulceration in the intestines. Nasal swabs and tissue samples (spleen, lung and liver) were tested using real‐time reverse transcriptase polymerase chain reaction (RT‐qPCR) and found to be positive for CSF virus. One‐step RT‐PCR was used to amplify 1,148 base pair of E2 gene in extracted RNA and was sequenced using standard Sanger's sequencing. Phylogenetic analysis revealed the virus as genotype 2.2 that clustered with CSF virus sequences from Bangladesh and India. This is only the second report of a CSF outbreak in Bangladesh. CSF appears to be an emerging transboundary disease in this country. A special programme for controlling swine diseases is needed since pigs are being reared by marginalized communities of Bangladesh to provide livelihoods and food security.

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Validation of a Real Time PCR for Classical Swine Fever Diagnosis

Cited by 13 publications

References 14 publications

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

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

Challenges to and advancements of the official veterinary service of the Federal District, Brazil

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

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