Pathogen of the Month
October pathogen of the month:
African swine fever
What is it?
African swine fever is a highly contagious hemorrhagic disease of domestic pigs and wild boar. It is characterized by high fever, loss of appetite, hemorrhages in the skin and internal organs, and death in 2-10 days with most isolates. Mortality rates may be as high as 100%.
The organism which causes ASF is a DNA virus of the Asfarviridae family. Due to the high mortality rate and absence of any vaccine, it can have a tremendous economic consequence for the pork production industry. However, humans are not susceptible to ASF.
What is the current status?
The disease has been endemic across sub-Saharan Africa and eastern Europe, and a few months ago found its way eastward into China and westward into Belgium. Those facts concerned those involved in the pork industry due to the fact that China produces nearly half the world’s pork.
Apart from the outbreaks in China and Belgium, ongoing ASF outbreaks have also been reported during September in the following countries: Poland, Hungary, Ukraine, Romania, Moldova, Latvia, Russia and Bulgaria.
How serious can it be?
Due to its potential impact on the world’s food supply, ASF is considered to be a serious economic threat. That threat is intensified by the ease with which ASF appears to spread, apparently being cared by populations of wild boars that obviously have the ability to cross even closely monitored international borders.
What is CEEZAD doing about African swine fever?
The efforts to enhance general knowledge about the ASF threat, to improve diagnostic tools and to develop a vaccine are each major focal points of CEEZAD’s research program.
Dr. Juergen Richt, CEEZAD’s director and an internationally recognized expert on transboundary animal diseases, was in the Far East on a series of presentations when the outbreak occurred in China. Dr. Richt spoke with veterinary medicine faculty and students at Konkuk University in Seoul, and also with members of the media and swine associations in South Korea to update them on the potential threat in their country.
Dr. Richt was Principal Investigator of a CEEZAD-based research project that worked on an ASF vaccine approach based on prime-boost vaccination. In parallel, gene-deleted ASF viruses to be used as modified live virus vaccines have been developed using CRISP-Cas9 knock-out approaches. Both projects were in collaboration with Dr. Yolanda Revilla at Centro de Biologia Molecular Severo Ochoa in Madrid.
CEEZAD also co-sponsored a June presentation on ASF by Dr. Armanda Bastos, a professor of veterinary microbiology and conservation genetics at the Mammal Research Institute of the Department of Zoology and Entomology at the University of Pretoria in South Africa. Dr. Bastos reported on her research into the prevalence of the species of tick that is responsible for the distribution of ASF, in the northern regions of South Africa, notably the Kruger National Park and the Mkuze Reserve. Based on the new research, Dr. Bastos said she believes eradication of the virus is “doable,” but will require intense and ongoing surveillance.
With respect to diagnostics, Dr. Richt leads CEEZAD efforts to develop tests for the detection of nucleic acid markers of ASFV and anti-ASFV antibodies in different samples like oral fluids and meat juice. Work is also being done on point-of-care detection of ASFV using a portable detection device.
Sources: Centers for Disease Control, oie.int, www.ceezad.org, http://www.cvmbs.colostate.edu/aphi/feralswine/PDFs/Rassow_paper.pdf