ASF, CSF Very Different Viruses; Both Deadly

It’s important to understand the differences between Classical Swine Fever, which was reported in Japan last week, African Swine Fever, which is spreading across a wide swath of China.  But controlling these diseases is proving difficult.

To get a handle on the differences, a Veterinary Research article published online on Nov. 28, 2017, by BioMed Central, the open access publisher, was studied and is cited here.

Both diseases are feared in the worldwide swine industry, and the similar names and the same susceptible species suggest a similarity of the two viral diseases.  ASF, at one time, was even thought to be caused by the same virus as CSF, yet, despite the similar clinical signs and some shared pathogenic characteristics, the two are caused by completely different viruses.

Lots of questions remain unanswered about these two diseases and how to eradicate each.  Most central and eastern European countries mainly had experience with CSF, and control strategies for ASF often were copied from CSF contingency plans.

However, ASF epidemics in the Baltic EU member states and in Poland showed that the disease did not follow the expected pattern.  It neither died out nor spread with high speed as predicted.




ASF is a large enveloped double-stranded DNA virus.  It is the only DNA virus known to be carried by arthropods (ticks, in this case).  There are at least two genotypes known and four described levels of virulence, at least in wild swine species, suggesting that some virulence and mortality differences may show up in domestic swine as well.

Wild swine mortality ranges from high to low.

Wild swine species recovering from ASF usually have an immunity to the disease they had, but cross protection against other strains may be lacking, and there have been reports that survivors can become long-term carriers.

Safe and effective vaccines against ASF do not exist at present, although several approaches have been pursued to develop immunization protocols.




The CSF virus is a small single-stranded enveloped RNA virus.  The various strains can be assigned to three genotypes with three to four subtypes.  Different subtypes show a particular geographical distribution.  Some European strains are moderately virulent.

Three different courses of infection are known with the acute form causing fever, respiratory and gastro-intestinal problems, lethargy and lack of appetite.

The acute form can be accompanied by severe hemorrhagic or neurological symptoms.  Piglet mortality can be very high, but older animals can survive with immunity.

The chronic form has a lower virulence with unspecific symptoms.  Some animals can show an initial recovery, but all succumb eventually to infection and die but not before shedding large amounts of virus.

Unborn piglets also can catch the disease, live for a time, shedding virus all the time before finally dying.

Vaccines exist for domestic and wild swine.




No fed cattle sold last Wednesday on the Livestock Exchange Video Auction, compared with 280 that traded two weeks previous at $109.50 per cwt.

Light cash cattle trading was reported in Nebraska Tuesday at a steady $107 per cwt on a live basis and $170 dressed.

Cash cattle traded last week at $107 to $108 per cwt on a live basis, unchanged from the previous week, and at $168 to $170 on a dressed basis, also unchanged.

The USDA choice cutout Tuesday was down $0.23 per cwt at $206.07, while select was off $0.62 at $198.31.  The choice/select spread widened to $7.76 from $7.37 with 97 loads of fabricated product sold into the spot market.

The CME Feeder Cattle index for the seven days ended Monday, was $152.09 per cwt, down $0.55.  This compares with Tuesday’s Sep settlement of $152.12, down $0.40.