African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5233

Full Length Research Paper

Comparative detection of African swine fever virus by loop-mediated isothermal amplification assay and polymerase chain reaction in domestic pigs in Uganda

David Kalenzi Atuhaire*
  • David Kalenzi Atuhaire*
  • 1. College of Veterinary Medicine, Animal resources and Biosecurity, Makerere University, P. O. BOX 7062 Kampala, Uganda; 2. National Agricultural Research Organization, National Livestock Resources Research Institute, P. O. BOX 96, Tororo, Uganda
  • Google Scholar
Mathias Afayoa
  • Mathias Afayoa
  • College of Veterinary Medicine, Animal resources and Biosecurity, Makerere University, P. O. BOX 7062 Kampala, Uganda
  • Google Scholar
Sylvester Ochwo
  • Sylvester Ochwo
  • College of Veterinary Medicine, Animal resources and Biosecurity, Makerere University, P. O. BOX 7062 Kampala, Uganda
  • Google Scholar
Dianah Katiti
  • Dianah Katiti
  • College of Veterinary Medicine, Animal resources and Biosecurity, Makerere University, P. O. BOX 7062 Kampala, Uganda
  • Google Scholar
Frank Norbert Mwiine
  • Frank Norbert Mwiine
  • College of Veterinary Medicine, Animal resources and Biosecurity, Makerere University, P. O. BOX 7062 Kampala, Uganda
  • Google Scholar
Ann Nanteza
  • Ann Nanteza
  • College of Veterinary Medicine, Animal resources and Biosecurity, Makerere University, P. O. BOX 7062 Kampala, Uganda
  • Google Scholar
Claire Mack Mugasa
  • Claire Mack Mugasa
  • College of Veterinary Medicine, Animal resources and Biosecurity, Makerere University, P. O. BOX 7062 Kampala, Uganda
  • Google Scholar
Enock Matovu
  • Enock Matovu
  • College of Veterinary Medicine, Animal resources and Biosecurity, Makerere University, P. O. BOX 7062 Kampala, Uganda
  • Google Scholar
Julius Boniface Okuni
  • Julius Boniface Okuni
  • College of Veterinary Medicine, Animal resources and Biosecurity, Makerere University, P. O. BOX 7062 Kampala, Uganda
  • Google Scholar
William Olaho-Mukani
  • William Olaho-Mukani
  • African Union-Interafrican Bureau of Animal Resources, P. O. BOX 30786, Nairobi, Kenya
  • Google Scholar
Lonzy Ojok*
  • Lonzy Ojok*
  • College of Veterinary Medicine, Animal resources and Biosecurity, Makerere University, P. O. BOX 7062 Kampala, Uganda
  • Google Scholar


  •  Received: 22 April 2014
  •  Accepted: 19 May 2014
  •  Published: 04 June 2014

Abstract

African swine fever (ASF) is a contagious viral disease, which can cause up to 100% mortality among domestic pigs. Pig production is growing rapidly in Uganda among East African countries and is not only a source of food but also an important income for many people living in the rural areas. Field diagnosis of ASF depends only on clinical signs and has to be confirmed in the laboratory since the clinical signs are not pathognomonic. Diagnostic techniques for ASF are focused on serological tests for detection of antigen and antibody, genomic DNA detection by polymerase chain reaction (PCR), and on virus isolation and localization in clinical samples. There have been many recent reports of ASF outbreaks in Uganda yet laboratory diagnosis is limited due to the high cost and expertise required. This work reports the evaluation and application of a loop-mediated isothermal amplification (LAMP) test for detecting African swine fever virus (ASFV) DNA based on the topoisomerase II gene. Thirty (30) tissue samples obtained from suspected ASF outbreaks were collected from different regions of Uganda. The tissue samples were found to have lesions consistent with ASF. One hundred and eighty eight (188) additional blood samples were obtained from the abattoir and field surveillance. Six primers targeting the topoisomerase II gene were used. The sensitivity and specificity of LAMP and OIE recommended diagnostic PCR were compared. The LAMP assay is rapid with results obtained within 1 h (45-60 min). The sensitivity of LAMP for the detection of ASFV was 100% (95% CI: 91.78-100) while the specificity was 44% (95% CI: 36.52-51.69). The Kappa statistic for level of agreement between PCR and LAMP test in the detection of ASFV was 23.7% (95% CI: 16.42-30.91). This Kappa value indicated a fair agreement between the two assays. No cross reaction was observed with Porcine circovirus type 2 virus and E. coli isolated from pigs in Uganda. This is the first study evaluating and applying the LAMP assay in the detection of ASF in domestic pigs in Uganda. The LAMP assay was found to be more sensitive than PCR. Due to its simplicity, sensitivity and specificity, the LAMP assay has the potential for use in the diagnosis and routine surveillance of ASF in Uganda.

 

Key words: African swine fever virus, loop-mediated isothermal amplification (LAMP), polymerase chain reaction (PCR), sensitivity, specificity, topoisomerase II gene.