Epidemiology and vaccine of porcine epidemic diarrhea virus in China: a mini-review

Abstract

Porcine epidemic diarrhea (PED) is an intestinal infectious disease caused by porcine epidemic diarrhea virus (PEDV); manifestations of the disease are diarrhea, vomiting and dehydration. Starting from the end of 2010, a PED outbreak occurred in several pig-producing provinces in southern China. Subsequently, the disease spread throughout the country and caused enormous economic losses to the pork industry. Accumulating studies demonstrated that new PEDV variants that appeared in China were responsible for the PED outbreak. In the current mini-review, we summarize PEDV epidemiology and vaccination in China.

Fig. 1.

Circulation of PEDV in China. A, Distribution of PEDV infection in China from February 2011 to March 2014; B, The positive rate of PEDV infection of the samples and pig farms.

Fig. 2.

Phylogenetic analysis of selected PEDV strains among Europe, North America, South America and Asia from 1988 to 2015 based on the S1 gene. The phylogenetic trees were generated from the ClustalX-generated alignments by MEGA6.06 software using the neighbor-joining method, respectively. The reliability of the generated phylogenetic tree was assessed by bootstrapping, using 1,000 bootstrap replications. ● China.

Fig. 3.

Confirmation of the potential recombination events occurred between the 65 PEDV strains from China. A, The recombination event between the minor parent strain CH-ZWBZb-01-2015 (KR296681) and the major parent strain CH/JL/2011 (JQ638924), which led to the recombinant CH-ZWBZa-01-2015 strain (KR296680); B, The recombination event between the minor parent strain ZJ-2011-1 (JN825710) and the major parent strain PJ1407 (KM406184), which led to the recombinant JS-2004-2 strain (AY653204); C, The recombination event between the minor parent strain MX1405 (KM406182) and the major parent strain JY7C (KF177256), which led to the recombinant GDS01 strain (AB857233); D, The recombination event between the minor parent strain MX1405 (KM406182) and the major parent strain JY7C (KF177256), which led to the recombinant FJ-YX 2013 strain (KJ646590). (a), Bootscan evidence for each potential recombinant event on the basis of pairwise distance, modeled with a window size 200, step size 20 and 100 bootstrap replicates; (b) Fast neighbor-joining (NJ) tree (1,000 replicates, Kimura two-parameter distance) constructed using the recombinant region of each potential recombinant event; (c) Fast neighbor-joining (NJ) tree (1,000 replicates, Kimura two-parameter distance) constructed using the non-recombinant region of each potential recombinant event.