The rise of the deadly Nebraska pig virus is alarming health officials worldwide. Although the so-called Nebraska pig virus, aka Porcine epidemic diarrhea virus (PEDv), has now made an appearance in Nebraska, this marks the latest U.S. state out of 20 to be affected, Reuters reported on Dec. 13.
There have been at least 1,500 document cases of the pig virus in Iowa, North Carolina, Minnesota and Oklahoma. Furthermore, this number is projected to dramatically increase, according to health officials.
Officials say that the Nebraska pig virus will have a negative impact on U.S. hog supplies and they fear it will cause a spike in pork prices during the spring and summer of 2014.
The spread of the Nebraska pig virus has increased scrutiny of the U.S. trucking industry, and livestock transportation vehicles are believed to play a major role in the spread of the pig virus. The Inquistr reports that officials are asking farmers to clean and disinfect their vehicles in order to prevent further spread of the virus.
The Nebraska pig virus causes vomiting, diarrhea and severe dehydration, Wikipedia writes. The virus affects pigs of all ages, with a markedly higher mortality rate in infants and weaned piglets.
Over the past 40 years, the prevalence of these viruses has undergone considerable changes in Europe, Asia and North America, with a marked increase in the 1970s and 1980s, followed by a significant reduction in the 90's. The apparent reduction in the prevalence of the pig virus in the 90s is attributed to the emergence of new strains of porcine respiratory coronavirus field with a natural ability to generate immunity in their hosts. However, the ability of this virus to protect against PEDv seems to have disappeared in recent outbreaks.
Large outbreaks of the pig virus appeared in Korea in the 90s and were followed by outbreaks associated throughout East Asia. From 2005 to the present, pig virus outbreaks due to these "Korean" strains have become a problem for the pig industry in East Asia, especially the Philippines.
Since 2008, there has been a new wave of outbreaks throughout East Asia, attributed to new strains of the pig virus that appeared in China, causing more disruption in pig production in the area. These current PEDv outbreaks have spread throughout China, also reaching to Vietnam and Thailand. The swine industry in these countries has been consolidating and expanding, so it has been a movement of pigs and staff between the countries of the region during this period.
There are few local vaccines that have been used widely to combat both original strains and new strains of the pig virus. However, the utilitization of such vaccines in problem farms was probably very limited. Although this practice has been shown to be effective for a long time in previous outbreaks, scientists have achieved only temporary immunity on new growth. Farmers reported recurrent outbreaks every 6 months, each as bad as the last. In recent months, there have been numerous outbreaks of the pig virus throughout the USA.
Currently there is a high prevalence of the pig virus in Chinese farms and other countries in Asia. Such infections usually happen more often on larger farms. Symptoms of new strains in both Asia and the U.S. are indistinguishable from those that appeared previously in the field or in trials. The results of several studies suggest that recent Asian strains have a genetic relationship and the worldwide scientific community is still searching for a useful vaccine to combat the pig virus.