scholarly journals Experimental Porcine Reproductive and Respiratory Syndrome Virus Infection in One-, Four-, and 10-Week-Old Pigs

1994 ◽  
Vol 6 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Kurt D. Rossow ◽  
Elida M. Bautista ◽  
Sagar M. Goyal ◽  
Thomas W. Molitor ◽  
Michael P. Murtaugh ◽  
...  

One-, 4-, and lo-week-old pigs were exposed to porcine reproductive and respiratory syndrome virus (PRRSV) to determine the effect of age on clinical signs, hematologic alterations, the onset and duration of viremia, routes of virus shedding, antibody production, and microscopic lesions produced by PRRSV isolate ATCC VR-2332. The response to PRRSV infection was similar among age groups. Fever, usually prolonged, and a marked dyspnea with cutaneous erythema when restrained for sample collection were the most consistent clinical signs. Prolonged periocular edema was unique to the 1-week-old pigs. The white blood cell count was decreased on day 4 postexposure (PE) due to decreases in neutrophils and lymphocytes. The virus was isolated from buffy coats at day 1 PE and was isolated from serum, buffy coat, or plasma at each sample collection period through the end of the trial (day 28 PE). Virus was most consistently isolated from lung, lymph node, spleen, and tonsil on day 7 PE and exclusively from lymph node, spleen, and tonsil on day 28 PE. Virus was infrequently isolated from urine and fecal and nasal swabs. Consistent microscopic changes in all age groups included interstitial pneumonia and lymph node hypertrophy and hyperplasia on days 7 and 28 PE, lymph node necrosis on day 7 PE, and subacute mononuclear myocarditis on day 28 PE. Findings presented here indicate that interstitial pneumonia, lymphoid necrosis, and mononuclear myocarditis are characteristic lesions of PRRSV isolate ATCC VR-2332 infection in 1-, 4-, and lo-week-old pigs.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yuan Zhao ◽  
Junbin Wang ◽  
Dexuan Kuang ◽  
Jingwen Xu ◽  
Mengli Yang ◽  
...  

Abstract Since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became a pandemic event in the world, it has not only caused huge economic losses, but also a serious threat to global public health. Many scientific questions about SARS-CoV-2 and Coronavirus disease (COVID-19) were raised and urgently need to be answered, including the susceptibility of animals to SARS-CoV-2 infection. Here we tested whether tree shrew, an emerging experimental animal domesticated from wild animal, is susceptible to SARS-CoV-2 infection. No clinical signs were observed in SARS-CoV-2 inoculated tree shrews during this experiment except the increasing body temperature particularly in female animals. Low levels of virus shedding and replication in tissues occurred in all three age groups. Notably, young tree shrews (6 months to 12 months) showed virus shedding at the earlier stage of infection than adult (2 years to 4 years) and old (5 years to 7 years) animals that had longer duration of virus shedding comparatively. Histopathological examine revealed that pulmonary abnormalities were the main changes but mild although slight lesions were also observed in other tissues. In summary, tree shrew is less susceptible to SARS-CoV-2 infection compared with the reported animal models and may not be a suitable animal for COVID-19 related researches. However, tree shrew may be a potential intermediate host of SARS-CoV-2 as an asymptomatic carrier.


Viruses ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 148
Author(s):  
Aleksandra Woźniak ◽  
Piotr Cybulski ◽  
Lilla Denes ◽  
Gyula Balka ◽  
Tomasz Stadejek

Porcine respirovirus 1 (PRV1) is also known as porcine parainfluenza virus 1 (PPIV1). The prevalence and the role of PRV1 infections for pig health is largely unknown. In order to assess the PRV1 prevalence in Poland, nasal swabs and oral fluids collected from pigs from 30 farms were examined with RT real-time PCR. Additionally, IAV and PRRSV infection statuses of PRV1-positive samples were examined. The results showed that the virus is highly prevalent (76.7% farms positive) and different patterns of PRV1 circulation in herds with mild–moderate respiratory disease were observed. Co-infections with IAV and PRRSV were infrequent and detected in 8 (23.5%) and 4 (11.8%) out of 34 PRV1-positive nasal swab pools from diseased pens, respectively. In one pen PRV1, IAV, and PRRSV were detected at the same time. Interestingly, PRV1 mean Ct value in samples with co-infections was significantly lower (29.8 ± 3.1) than in samples with a single PRV1 infection (32.5 ± 3.6) (p < 0.05), which suggested higher virus replication in these populations. On the other hand, the virus detection in pig populations exhibiting respiratory clinical signs, negative for PRRSV and IAV, suggests that PRV1 should be involved in differential diagnosis of respiratory problems.


2021 ◽  
Author(s):  
Adthakorn Madapong ◽  
Kepalee Saeng-chuto ◽  
Angkana Tantituvanont ◽  
Dachrit Nilubol

Abstract Two separated experiments (Exp) were conducted to evaluate the shedding and efficacy of 2 modified live porcine reproductive and respiratory syndrome virus (PRRSV) type 2 vaccines (MLV) when administered intramuscularly (IM) or intradermally (ID) (Exp A), and the potential of PRRSV transmission using a needle-free device (Exp B). 154, castrated-male, pigs were procured from a PRRSV-free herd. In Exp A, 112 pigs were randomly allocated into 4 groups of 21 pigs including IM/Ingelvac MLV (G1), IM/Prime Pac (G2), ID/Prime Pac (G3), and non-vaccination (G4). G1 was IM vaccinated once with Ingelvac PRRS MLV (Ing) (Boehringer Ingelheim, Germany). G2 and G3 were IM and ID vaccinated once with Prime Pac PRRS (PP) (MSD Animal Health, The Netherlands), respectively. Following vaccination, an antibody response, IFN-γ-SC, and IL-10 were monitored. Sera, tonsils, nasal swabs, bronchoalveolar lavage (BAL), urines, and feces were collected from 3 vaccinated pigs each week to 42 days post-vaccination (DPV) and assayed for the presence of PRRSV using virus isolation and PCR. Age-matched sentinels were introduced weekly into vaccinated groups from 0 to 42 DPV and monitored for seroconversion. In Exp B, pigs were randomly allocated into 5 groups of 3 pigs each including IM/High (T1), ID/High (T2), IM/Low (T3), ID/Low (T4), and NoChal. The T1 and T2, and T3 and T4 groups were intranasally challenged with HP-PRRSV-2 at high (106) and low (103 TCID50/ml) doses, respectively. At 7 days post-challenge (DPC), T1 and T2, and T3 and T4 groups were IM and ID injected with Diluvac Forte using needles and a needless device (IDAL 3G, MSD Animal Health, The Netherlands), respectively. Same needles or devices were used to inject the same volume of Diluvac Forte into sentinel pigs. Seroconversion of sentinels was evaluated. The results demonstrated that PP vaccinated groups (G2 and G3), regardless of the route of vaccination, had ELISA response significantly lower than G1 at 7 and 14 DPV. PP-vaccinated groups (G2 and G3) had significantly higher IFN-γ-SC and lower IL-10 compared to the Ing-vaccinated group (G1). Based on IM, 2 different MLV had different virus distribution and shedding patterns. PP-vaccinated pigs had significantly shortened viremia than the Ing-vaccinated pigs. However, ID-vaccinated pigs had lower virus distribution in organs without virus shedding to sentinel pigs. In Exp B, ID-injected sentinel pigs had no seroconversion compared to IM-injected sentinel pigs regardless of the challenge dose. In conclusion, our results demonstrated that ID vaccination might represent an alternative to improve vaccine efficacy and safety, and may be able to reduce the shedding of vaccine viruses and reduce the iatrogenic transfer of pathogens between animals with shared needles.


Author(s):  
Yuan Zhao ◽  
Junbin Wang ◽  
Dexuan Kuang ◽  
Jingwen Xu ◽  
Mengli Yang ◽  
...  

ABSTRACTSince SARS-CoV-2 became a pandemic event in the world, it has not only caused huge economic losses, but also a serious threat to global public health. Many scientific questions about SARS-CoV-2 and COVID-19 were raised and urgently need to be answered, including the susceptibility of animals to SARS-CoV-2 infection. Here we tested whether tree shrew, an emerging experimental animal domesticated from wild animal, is susceptible to SARS-CoV-2 infection. No clinical signs were observed in SARS-CoV-2 inoculated tree shrews during this experiment except the increasing body temperature (above 39° C) particular in female animals during infection. Low levels of virus shedding and replication in tissues occurred in all three age groups, each of which showed his own characteristics. Histopathological examine revealed that pulmonary abnormalities were mild but the main changes although slight lesions were also observed in other tissues. In summary, tree shrew is not susceptible to SARS-CoV-2 infection and may not be a suitable animal for COVID-19 related researches.


2007 ◽  
Vol 14 (3) ◽  
pp. 269-275 ◽  
Author(s):  
O. J. Lopez ◽  
M. F. Oliveira ◽  
E. Alvarez Garcia ◽  
B. J. Kwon ◽  
A. Doster ◽  
...  

ABSTRACT Previous work in our laboratory demonstrated that passive transfer of porcine reproductive and respiratory syndrome virus (PRRSV)-neutralizing antibodies (NA) protected pregnant sows against reproductive failure and conferred sterilizing immunity in sows and offspring. We report here on the dose requirement for protection by passive transfer with NA in young weaned pigs. The presence of a 1:8 titer of PRRSV-NA in serum consistently protected pigs against viremia. Nevertheless, their lungs, tonsils, buffy coat cells, and peripheral lymph nodes contained replicating PRRSV similar to the infected control group. Likewise, these animals excreted infectious virus to sentinels similar to the infectivity control animals. In an attempt to reach complete protective immunity equivalent to that previously observed in sows, the pigs were transferred with a higher titer of PRRSV-NA (1:32), and even then apparent sterilizing immunity was attained in only 50% of the animals. In conclusion, the presence of anti-PRRSV-NA in serum with a titer of 1:8 is enough to block viremia but not peripheral tissue seeding and transmission to contact animals. While a relatively low level of NA in blood is capable of conferring sterilizing immunity against PRRSV in sows, the amount of NA necessary to obtain full protection of a young weaned pig would be significantly higher, suggesting that differences exist in the PRRSV pathogenesis between both age groups. In addition, the titer of NA could be a helpful parameter of protection in the assessment of PRRSV vaccines.


2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 18-18
Author(s):  
Leticia P Sanglard ◽  
Felipe Hickmann ◽  
Yijian Huang ◽  
Kent A Gray ◽  
Daniel Linhares ◽  
...  

Abstract Immunoglobulin G antibody response, measured as sample-to-positive (S/P) ratio, to Porcine Reproductive and Respiratory Syndrome virus (PRRSV) has been proposed as an indicator trait for improved reproductive performance in PRRSV-infected purebred sows and PRRSV-vaccinated crossbred gilts. In this study, we investigated the genetic correlations (rg) of S/P ratio following a PRRSV outbreak and PRRSV-vaccination with performance in non-exposed and PRRSV-exposed sows. PRRSV outbreak phase was defined based on previously described methodologies after the detection of typical clinical signs of PRRSV infection. 541 Landrace sows had S/P ratio measured at ~54 days after the beginning of the PRRSV outbreak (S/Poutbreak), and 906 Landrace x Large White naïve F1 gilts had S/P ratio measured at ~50 days after vaccination with a commercial modified live PRRSV vaccine (S/PVx). 711 and 428 Landrace sows had reproductive performance recorded before and during the PRRSV outbreak, respectively. 811 vaccinated F1 animals had farrowing performance for up to 3 parities. All animals were genotyped for ~28K SNPs. The estimate of rg of S/Poutbreakwith S/PVx was high (rg±SE = 0.72±0.18). Estimates of rg of S/Poutbreak with reproductive performance in F1 sows were low to moderate, ranging from 0.05±0.23 (number stillborn) to 0.30±0.20 (total number born). Estimates of rg of S/PVxwith reproductive performance in non-infected purebred sows were moderate and favorable with number born alive (0.50±0.23), but low (0 to -0.11±0.23) with litter mortality traits. Estimates of rg of S/PVx were moderate and negative (-0.47±0.18) with the number of mummies in PRRSV-infected purebred sows and low with other traits (-0.29±0.18 for total number born to 0.05±0.18 for number stillborn). These results indicate that selection for antibody response following a PRRSV outbreak collected in purebred sows and to PRRSV vaccination collected in commercial crossbred gilts may increase litter size of non-infected and PRRSV-exposed purebred and commercial crossbred sows.


Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 784
Author(s):  
Sylvia Reemers ◽  
Sander van Bommel ◽  
Qi Cao ◽  
David Sutton ◽  
Saskia van de Zande

Equine influenza virus (EIV) is a major cause of respiratory disease in horses. Vaccination is an effective tool for infection control. Although various EIV vaccines are widely available, major outbreaks occurred in Europe in 2018 involving a new EIV H3N8 FC1 strain. In France, it was reported that both unvaccinated and vaccinated horses were affected despite >80% vaccination coverage and most horses being vaccinated with a vaccine expressing FC1 antigen. This study assessed whether vaccine type, next to antigenic difference between vaccine and field strain, plays a role. Horses were vaccinated with an ISCOMatrix-adjuvanted, whole inactivated virus vaccine (Equilis Prequenza) and experimentally infected with the new FC1 outbreak strain. Serology (HI), clinical signs, and virus shedding were evaluated in vaccinated compared to unvaccinated horses. Results showed a significant reduction in clinical signs and a lack of virus shedding in vaccinated horses compared to unvaccinated controls. From these results, it can be concluded that Equilis Prequenza provides a high level of protection to challenge with the new FC1 outbreak strain. This suggests that, apart from antigenic differences between vaccine and field strain, other aspects of the vaccine may also play an important role in determining field efficacy.


Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 417
Author(s):  
Lise K. Kvisgaard ◽  
Lars E. Larsen ◽  
Charlotte S. Kristensen ◽  
Frédéric Paboeuf ◽  
Patricia Renson ◽  
...  

In July 2019, a vaccine-derived recombinant Porcine reproductive and respiratory syndrome virus 1 strain (PRRSV-1) (Horsens strain) infected more than 40 Danish sow herds, resulting in severe losses. In the present study, the pathogenicity of the recombinant Horsens strain was assessed and compared to a reference PRRSV-1 strain using a well-characterized experimental model in young SPF pigs. Furthermore, the efficacies of three different PRRSV-1 MLV vaccines to protect pigs against challenge with the recombinant strain were assessed. Following challenge, the unvaccinated pigs challenged with the Horsens strain had significant increased viral load in serum compared to all other groups. No macroscopic changes were observed at necropsy, but tissue from the lungs and tonsils from almost all pigs were PRRSV-positive. The viral load in serum was lower in all vaccinated groups compared to the unvaccinated group challenged with the Horsens strain, and only small differences were seen among the vaccinated groups. The findings in the present study, combined with two other recent reports, indicate that this recombinant “Horsens” strain indeed is capable of inducing infection in growing pigs as well as in pregnant sows that is comparable to or even exceeding those induced by typical PRRSV-1, subtype 1 strains. However, absence of notable clinical signs and lack of significant macroscopic changes indicate that this strain is less virulent than previously characterized highly virulent PRRSV-1 strains.


2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Kaoruko Funakoshi ◽  
Yuji Ishibashi ◽  
Shuntaro Yoshimura ◽  
Ryoto Yamazaki ◽  
Fumihiko Hatao ◽  
...  

Abstract Background Ruptured pseudoaneurysms are a rare complication of gastrectomy, but when they do develop, they are often fatal. We presented herein the first report of a case of pseudoaneurysm arising from the right inferior phrenic artery (RIPA) after a laparoscopic gastrectomy. Case presentation A 61-year-old male patient underwent a laparoscopic distal gastrectomy and D1+ lymph node dissection with Roux-en-Y reconstruction for early gastric cancer. He was discharged on postoperative day (POD) 9 without any complications, such as anastomotic or pancreatic leakage. On POD 19, he was referred to the emergency room for upper abdominal pain. Enhanced abdominal computed tomography revealed a 60 × 70 mm hematoma, indicating intra-abdominal bleeding and a 10-mm pseudoaneurysm in the RIPA. Selective digital subtraction angiography confirmed the presence of a pseudoaneurysm in the RIPA, which was embolized using multiple microcoils. Thereafter, no clinical signs were observed, and the patient was discharged from the hospital 15 days after angiography without any recurrence of bleeding. We hypothesized that the cause of the pseudoaneurysm was mechanical vascular injury due to the thermal spread of the ultrasonically activated devices (USADs) during lymphatic node dissection. Conclusion Given the thermal spread of USADs, safe and appropriate lymph node dissection based on precise anatomical knowledge is crucial to preventing postoperative pseudoaneurysms.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1670
Author(s):  
Gerald Reiner ◽  
Josef Kuehling ◽  
Frederik Loewenstein ◽  
Mirjam Lechner ◽  
Sabrina Becker

Tail biting is a prevalent and undesirable behaviour in pigs and a major source of significant reduction in well-being. However, focusing on biting considers only one part of the solution, because tail damage can be found with a high prevalence without any action by other pigs. The lesions are not limited to the tail but can also be found in the ears, heels, soles, claw coronary bands, teats, navel, vulva, and face. Environmental improvement alone often fails to overcome the problem. This review addresses a new inflammation and necrosis syndrome in swine (SINS). It shows the clinical signs and the frequencies of occurrence in different age groups. It compiles scientific evidence from clinical and histopathological studies in newborn piglets that argue for a primary endogenous aetiology of the disease. Bringing together the findings of a broad body of research, the possible mechanisms leading to the disease are identified and then discussed. This part will especially focus on microbe-associated molecular patterns in the circulation and their role in activating defence mechanisms and inflammation. Finally, the methods are identified to ameliorate the problem by optimizing husbandry and selecting a suitable breeding stock.


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