ROME — African Swine Fever (A.S.F.), a deadly pig disease, has traveled 1,243 miles from southern Russia to St. Petersburg in northwestern Russia, according to the Food and Agriculture Organization of the United Nations (F.A.O.). On Oct. 20, the latest outbreak was found near the Baltic city confirming the worst fears of F.A.O. experts who have been tracking the virus in Georgia and neighboring countries for several years.
African swine fever is caused by a virus and is not related to the H1N1 virus that is responsible for the current human influenza pandemic. Although A.S.F. can not be transmitted to humans, it could spread to other regions, F.A.O. said.
"Although we have known that the virus has been circulating in the Caucasus — in Georgia, Armenia and Azerbaijan — for several years now, eventually spreading to southern Russia, it is its sudden appearance far away near the Baltic coast that is worrying," said Juan Lubroth, F.A.O.’s chief veterinary officer.
The virus shows both progressive local spread and also that it can be transported over wider geographic areas through the movement of infected swine or contaminated pork products.
"The Baltic Republics, together with the Ukraine, Belarus, Moldavia, Romania and Bulgaria, are directly threatened," Mr. Lubroth said. "That means there could be possible incursions into the E.U. and also it could spread across Russia, including eastwards into Siberia and perhaps eventually China."
Iran, Turkey and central Asia could form a transit point for the virus because of relatively large numbers of wild boar in these areas. Clinical signs of A.S.F. are similar to classical swine fever virus and the two diseases have to be differentiated by specialized diagnostic laboratories.
According to F.A.O., A.S.F. is believed to have entered into the Caucasus through the Black Sea port of Poti, Georgia, where garbage from a ship was taken to a local dump where pigs would come to feed. Contaminated pig swill — remainders of food, including a pork scrap that is then fed to swine — has also been implicated as a conduit for outbreaks in swine populations in the past.
In a sub-Saharan context, the virus is spread through transmission in warthogs and other wild pig species and can be transmitted by a particular type of tick. Local spread can occur from direct contact between pigs, and direct transmission is a growing problem. A.S.F. existed for decades in the Iberian Peninsula until it was eliminated in the late 1990s.
Because no vaccine exists against A.S.F., F.A.O. is calling for a renewed effort by U.S., European and Russian Federation laboratories to develop an effective vaccine against A.S.F. The disease is usually eradicated by the culling of infected animals and strict movement control.