Evaluation of humoral immune status in porcine epidemic diarrhea virus (PEDV) infected sows under field conditions

Abstract

Porcine epidemic diarrhea virus (PEDV) is an economically devastating enteric disease in the swine industry. The virus infects pigs of all ages, but it cause severe clinical disease in neonatal suckling pigs with up to 100% mortality. Currently, available vaccines are not completely effective and feedback methods utilizing PEDV infected material has variable success in preventing reinfection. Comprehensive information on the levels and duration of effector/memory IgA and IgG antibody secreting B cell response in the intestines and lymphoid organs of PEDV-infected sows, and their association with specific antibody levels in clinical samples such as plasma, oral fluid, and feces is important. Therefore, our goal in this study was to quantify PEDV specific IgA and IgG B cell responses in sows at approximately 1 and 6 months post-infection in commercial swine herds, including parity one and higher sows. Our data indicated that evaluation of both PEDV specific IgA and IgG antibody levels in the plasma and oral fluid (but not feces) samples is beneficial in disease diagnosis. PEDV specific B cell response in the intestine and spleen of infected sows decline by 6 months, and this associates with specific antibody levels in the plasma and oral fluid samples; but the virus neutralization titers in plasma remains high beyond 6 months post-infection. In conclusion, in sows infected with PEDV the presence of effector/memory B cell response and strong virus neutralization titers in plasma up to 6 months post-infection, suggests their potential to protect sows from reinfection and provide maternal immunity to neonates, but challenge studies are required to confirm such responses.

Lactogenic immunity and vaccines for porcine epidemic diarrhea virus (PEDV): Historical and current concepts

“…In gestating sows that were exposed to PEDV in the field, IgA and IgG PEDV-specific ASC were detected in the intestine of sows at 1 month post-PEDV exposure. The numbers of ASC waned but were still detectable in the sow intestines at 6 months post-PEDV exposure (Ouyang et al, 2015). However, this latter study did not investigate PEDV-specific ASC trafficking in blood.…”

Characterization of anti-porcine epidemic diarrhea virus neutralizing activity in mammary secretions

“…to suckling neonates via colostrum and milk are pivotal for early passive protection (Chattha et al, 2015;Wesley and Lager, 2003). Inoculations with PEDV virulent isolates, killed or attenuated strains induce specific mucosal and systemic immune responses in sows (Goede et al, 2015;Ouyang et al, 2015). The specific neutralizing antibodies (NA) were presented in colostrum, milk and serum after attenuated PEDV was orally or intramuscularly administered to late-term pregnant sows (Kweon et al, 1999;Ouyang et al, 2015).…”

“…Inoculations with PEDV virulent isolates, killed or attenuated strains induce specific mucosal and systemic immune responses in sows (Goede et al, 2015;Ouyang et al, 2015). The specific neutralizing antibodies (NA) were presented in colostrum, milk and serum after attenuated PEDV was orally or intramuscularly administered to late-term pregnant sows (Kweon et al, 1999;Ouyang et al, 2015). Lactogenic immunity, based on the presence of specific NA, can decrease the mortality of neonatal piglets or prevent death after challenge with wild-type PEDV (Goede et al, 2015;Kweon et al, 1999;Song et al, 2007).…”

Diagnostic evaluation of assays for detection of antibodies against porcine epidemic diarrhea virus (PEDV) in pigs exposed to different PEDV strains

“…As the farms classified as negative were excluded from the sensitivity analysis, this did not affect the estimated sensitivity. Previous studies have shown that PEDV antibodies in serum samples can be detected up to 7 months after initial exposure (Goede et al, 2015;Ouyang et al, 2015). Basing a negative farm classification on testing fecal samples by RT-PCR at a single time point could easily lead to a misclassification if the farm had experienced Table 4 Detection rates of anti-PEDV antibodies in field serum samples (n = 96) with discordant results, defined as a sample that exhibited a positive result in one or more ELISA and a negative result in another ELISA(s).…”