A descriptive survey of porcine epidemic diarrhea in pig populations in northern Vietnam

Abstract

Porcine epidemic diarrhea (PED) virus (PEDV) is a globally emerging and re-emerging epizootic swine virus that causes massive economic losses in the swine industry, with high mortality in piglets. In Vietnam, PED first emerged in 2009 and has now developed to an endemic stage. This is the first cross-sectional survey performed to evaluate the proportion of PEDV-positive swine farms in Vietnam from January 2018 to February 2019. Fecal samples from 327 pig farms in northern Vietnam were collected and tested for PEDV infection by reverse transcription-loop-mediated isothermal amplification (RT-LAMP) method. The proportion of PEDV-positive farms was 30.9% and PEDV-positive farms were distributed throughout the study area. The highest proportion of PEDV-positive farms was 70% (7/10) among nucleus production type farms (P < 0.05). Higher proportions of PEDV-positive farms were found in the Northeast and Red River Delta areas, which are the major areas of pig production (P < 0.05). The proportion of PEDV-positive farms was higher among larger farms (P < 0.05). Our findings illustrate the high proportion of PEDV-positive farms in the Vietnamese pig population and will help to better understand the epidemiological dynamics of PED infection, to estimate impact, and establish and improve prevention and control measures.

A persistent epidemic of porcine epidemic diarrhoea virus infection by serological survey of commercial pig farms in northern Vietnam

“…These data again indicated that PEDV infection was naturally widespread in the pig populations in these 3 provinces. In other report, 30.89 % of pig farms were found as PED positive in northern Vietnam which was detected by LAMP method and these farms at northern Vietnam may be the source of transmission in countrywide [ 21 ].…”

“…PEDV infection can also cause subclinical infections with no clinical signs in finishing pigs, and these asymptomatic pigs could therefore represent an important risk factor for spreading the disease [ 23 ]. It was reported that 70 % of PED positive farms were subclinically infected in Northern Vietnam and this may be the risk of cross-contamination in pigs in Vietnam [ 21 ]. In the present study, symptoms such as diarrhoea were not observed at most of the pig farms.…”

Dynamic Models of Within-Herd Transmission and Recommendation for Vaccination Coverage Requirement in the Case of African Swine Fever in Vietnam

“…The other three farms are located in Ninh Binh and Ha Nam provinces. All provinces in this study are located in northern Vietnam, where the largest populations of pigs are found [26].…”

Molecular analysis reveals a distinct subgenogroup of porcine epidemic diarrhea virus in northern Vietnam in 2018–2019

“…PEDV was detected in Vietnam in 2008 and rapidly spread throughout the country, causing severe economic loss [ 25 ]. It is now persistent and circulating in the swine populations [ 26 , 27 ]. Studies on the S gene sequences of PEDV strains isolated during 2012–2016 showed that these strains had undergone substantial changes [ 11 , 28 , 29 ], which might explain the decrease in vaccine efficiency.…”

“…Studies on the S gene sequences of PEDV strains isolated during 2012–2016 showed that these strains had undergone substantial changes [ 11 , 28 , 29 ], which might explain the decrease in vaccine efficiency. Moreover, PEDV continues to predominate in pig populations, even in vaccinated herds, and has become a persistent endemic nationwide [ 26 , 27 ]. In Vietnam, imported attenuated PEDV and locally produced inactivated vaccines have been used to immunize pigs and sows.…”