Porcine Epidemic Diarrhea(PED) is one of the most important viral causes of diarrhea in the Philippines. It is caused by a coronavirus, a genus of animal virus belonging to the family Coronaviridae. Coronaviruses are enveloped viruses with a positive-sense single stranded ribonucleic acid (RNA) genome and a helical symmetry. The name “coronavirus” is derived from the Latin corona, meaning crown, as the virus envelope appears under electron microscope to be crowned by a characteristic ring of small bulbous structures.
The porcine epidemic diarrhea virus (PEDV) damages the gut villi (small fingerlike projections protruding from the wall of the small intestine) thus reducing the absorptive surface, with loss of fluid and dehydration. After introduction of the virus into a susceptible breeding herd, a strong immunity develops over two to three weeks. The colostral immunity then protects the piglets. The virus usually disappears spontaneously from breeding herds particularly small ones.
Fecal-oral transmission is probably the main or only route of infection. Most commonly, the introduction of infected pigs into susceptible farms causes outbreaks of PED within 4 to 5 days. Virus may also be introduced through contaminated equipment and other fomites (i.e., inanimate objects that carry disease causing germs that spread infections) or personnel. After disease outbreak, PEDV may disappear, or it may become enzootic (endemic or prevalent) on farms where there are sufficient litters of pigs to allow the virus to be maintained through infection of consecutive litters that have lost their lactogenic immunity at weaning.
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Posted on November 13th, 2008 under Livestock. Tags: Disease, Livestock, PED. Comments: None
