scholarly journals Superficial Inguinal Lymph Nodes for Screening Dead Pigs for African Swine Fever

Viruses ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 83
Author(s):  
Kalhari Bandara Goonewardene ◽  
Chukwunonso Onyilagha ◽  
Melissa Goolia ◽  
Van Phan Le ◽  
Sandra Blome ◽  
...  

African swine fever (ASF) has spread across the globe and has reached closer to North America since being reported in the Dominican Republic and Haiti. As a result, surveillance measures have been heightened and the utility of alternative samples for herd-level monitoring and dead pig sampling have been investigated. Passive surveillance based on the investigation of dead pigs, both domestic and wild, plays a pivotal role in the early detection of an ASF incursion. The World Organization for Animal Health (OIE)-recommended samples for dead pigs are spleen, lymph nodes, bone marrow, lung, tonsil and kidney. However, obtaining these samples requires opening up the carcasses, which is time-consuming, requires skilled labour and often leads to contamination of the premises. As a result, we investigated the suitability of superficial inguinal lymph nodes (SILNs) for surveillance of dead animals. SILNs can be collected in minutes with no to minimum environmental contamination. Here, we demonstrate that the ASF virus (ASFV) genome copy numbers in SILNs highly correlate with those in the spleen and, by sampling SILN, we can detect all pigs that succumb to highly virulent and moderately virulent ASFV strains (100% sensitivity). ASFV was isolated from all positive SILN samples. Thus, sampling SILNs could be useful for routine surveillance of dead pigs on commercial and backyard farms, holding pens and dead on arrival at slaughter houses, as well as during massive die-offs of pigs due to unknown causes.

2021 ◽  
Author(s):  
Gustavo Machado ◽  
Trevor Farthing ◽  
Mathieu Andraud ◽  
Francisco Paulo Nunes Lopes ◽  
Cristina Lanzas

African swine fever (ASF) is considered the most impactful transboundary swine disease. In the absence of effective vaccines, control strategies are heavily dependent on mass depopulation and movement restrictions. Here we developed a nested multiscale model for the transmission of ASF, combining spatially explicit network model of animal movements with a deterministic compartmental model for the dynamics of two ASF strains within-pixels of 3 km x 3 km, amongst the pig population in one Brazilian state. The model outcomes are epidemic duration, number of secondary infected farms and pigs, and distance of ASF spread. The model also predicted the spatial distribution of ASF epidemics. We analyzed quarantine-based control interventions in the context of mortality trigger thresholds for the deployment of control strategies. The mean epidemic duration of a moderately virulent strain was 11.2 days assuming the first infection is detected (best-case scenario) and 15.9 days when detection is triggered at 10 % mortality. For a highly virulent strain, the epidemic duration was 6.5 days and 13.1 days, respectively. The distance from the source to infected locations and the spatial distribution was not dependent on strain virulence. Under the best-case scenario, we projected an average number of infected farms of 18.79 farms and 23.77 farms for the moderate and highly virulent strains, respectively. At 10% mortality-trigger, the predicted number of infected farms was on average 48.28 farms and 42.97 farms, respectively. We also demonstrated that the establishment of ring quarantine zones regardless of size (i.e., 5 km, 15 km) was outperformed by backward animal movement tracking. The proposed modeling framework provides an evaluation of ASF epidemic potential, providing a ranking of quarantine-based control strategies that could assist animal health authorities in planning the national preparedness and response plan.


Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 531
Author(s):  
Keke Wu ◽  
Jiameng Liu ◽  
Lianxiang Wang ◽  
Shuangqi Fan ◽  
Zhaoyao Li ◽  
...  

African swine fever (ASF) is a highly lethal contagious disease of swine caused by African swine fever virus (ASFV). At present, it is listed as a notifiable disease reported to the World Organization for Animal Health (OIE) and a class one animal disease ruled by Chinese government. ASF has brought significant economic losses to the pig industry since its outbreak in China in August 2018. In this review, we recapitulated the epidemic situation of ASF in China as of July 2020 and analyzed the influencing factors during its transmission. Since the situation facing the prevention, control, and eradication of ASF in China is not optimistic, safe and effective vaccines are urgently needed. In light of the continuous development of ASF vaccines in the world, the current scenarios and evolving trends of ASF vaccines are emphatically analyzed in the latter part of the review. The latest research outcomes showed that attempts on ASF gene-deleted vaccines and virus-vectored vaccines have proven to provide complete homologous protection with promising efficacy. Moreover, gaps and future research directions of ASF vaccine are also discussed.


1936 ◽  
Vol 64 (1) ◽  
pp. 131-147 ◽  
Author(s):  
D. Murray Angevine

1. Hemolytic streptococci, highly virulent for rabbits, when injected into the skin of normal animals increased greatly in number at the site of injection during the first 12 hours, diminished somewhat after 24 hours but still persisted after 21 days. They produced large abscesses within 24 hours, there was ulceration, and healing occurred after about 5 weeks. Histological observations confirmed the bacteriological evidence that the streptococci underwent great multiplication at the site of their injection. 2. Virulent hemolytic streptococci injected into the skin of normal rabbits appeared in small numbers within 1 hour in the lymph nodes. As multiplication proceeded in the skin, hemolytic streptococci were found in large numbers from 1 hour to 7 days after inoculation in the inguinal lymph nodes. 3. Hemolytic streptococci were recovered from deeper lymph nodes, that is, from the iliac nodes, but only in animals of which the inguinal lymph nodes contained bacteria in relatively large numbers. 4. Virulent hemolytic streptococci injected into the skin of normal rabbits in some instances entered the blood stream in considerable number, and occasionally caused death with bacteremia. Streptococci were recovered more frequently from the spleen and were present in this organ only when they had been recovered from the deep (iliac) lymph nodes. 5. When virulent hemolytic streptococci were injected into the skin of immunized rabbits, in a few instances they increased in number for a short time, but usually diminished rapidly and had entirely disappeared in 48 hours. The gross lesions were smaller than in normal rabbits. There was more phagocytosis, and redness and edema had disappeared after 48 hours. 6. When virulent streptococci were injected into the skin of immune rabbits they passed to the regional lymph nodes in relatively smaller numbers than in the previously normal controls and appeared in these nodes in considerable numbers only in animals in which there had been conspicuous multiplication at the site of inoculation. No streptococci could be found in the iliac lymph node, blood or spleen. 7. Virulent streptococci injected into the skin of normal animals multiply actively, resist phagocytosis, invade the tissues widely, enter adjacent and distant lymph nodes and in some instances are distributed by the blood stream to internal organs. After immunization associated with some sensitization, virulent streptococci are more readily ingested by phagocytes, remain sharply localized, are rapidly destroyed, fail to pass the nearest lymph nodes and do not enter the blood stream.


2021 ◽  
Author(s):  
Yong Yang ◽  
Changjie Lv ◽  
Junqing Fan ◽  
Ya Zhao ◽  
Lili Jiang ◽  
...  

AbstractThe outbreak of African swine fever (ASF) has caused significant economic losses to animal husbandry worldwide. Currently, there is no effective vaccine or treatment available to control the disease, and therefore, efficient disease control is dependent on early detection and diagnosis of ASF virus (ASFV). In this study, a chemiluminescent immunoassay (CLIA) was developed using the ASFV protein p54 as a serum diagnostic antigen and an anti-p54 monoclonal antibody. After optimizing the working parameters of the CLIA, the sensitivity of the established CLIA was 1:128, ASFV-specific serum antibody was identified, and there was no cross-reaction with other swine virus antibodies. After testing 49 clinical serum samples, the consistency rate between the CLIA and the World Organization for Animal Health (OIE) recommended commercial kit was 100%. Thus, this CLIA had a high degree of specificity, sensitivity, and reliability, and could be used as a rapid detection method for epidemiological investigations of ASFV infection.


2006 ◽  
Vol 45 (01) ◽  
pp. 57-61
Author(s):  
M. Puille ◽  
D. Steiner ◽  
R. Bauer ◽  
R. Klett

Summary Aim: Multiple procedures for the quantification of activity leakage in radiation synovectomy of the knee joint have been described in the literature. We compared these procedures considering the real conditions of dispersion and absorption using a corpse phantom. Methods: We simulated different distributions of the activity in the knee joint and a different extra-articular spread into the inguinal lymph nodes. The activity was measured with a gammacamera. Activity leakage was calculated by measuring the retention in the knee joint only using an anterior view, using the geometric mean of anterior and posterior views, or using the sum of anterior and posterior views. The same procedures were used to quantify the activity leakage by measuring the activity spread into the inguinal lymph nodes. In addition, the influence of scattered rays was evaluated. Results: For several procedures we found an excellent association with the real activity leakage, shown by an r² between 0.97 and 0.98. When the real value of the leakage is needed, e. g. in dosimetric studies, simultaneously measuring of knee activity and activity in the inguinal lymph nodes in anterior and posterior views and calculation of the geometric mean with exclusion of the scatter rays was found to be the procedure of choice. Conclusion: When measuring of activity leakage is used for dosimetric calculations, the above-described procedure should be used. When the real value of the leakage is not necessary, e. g. for comparing different therapeutic modalities, several of the procedures can be considered as being equivalent.


2021 ◽  
Vol 9 (4) ◽  
pp. 765
Author(s):  
Janika Wolff ◽  
Martin Beer ◽  
Bernd Hoffmann

Outbreaks of the three capripox virus species, namely lumpy skin disease virus, sheeppox virus, and goatpox virus, severely affect animal health and both national and international economies. Therefore, the World Organization for Animal Health (OIE) classified them as notifiable diseases. Until now, discrimination of capripox virus species was possible by using different conventional PCR protocols. However, more sophisticated probe-based real-time qPCR systems addressing this issue are, to our knowledge, still missing. In the present study, we developed several duplex qPCR assays consisting of different types of fluorescence-labelled probes that are highly sensitive and show a high analytical specificity. Finally, our assays were combined with already published diagnostic methods to a diagnostic workflow that enables time-saving, reliable, and robust detection, differentiation, and characterization of capripox virus isolates.


1991 ◽  
Vol 214 (5) ◽  
pp. 627-636 ◽  
Author(s):  
DANIEL G. COIT ◽  
ANDRE ROGATKO ◽  
MURRAY F. BRENNAN

1988 ◽  
Vol 68 (3) ◽  
pp. 474-477 ◽  
Author(s):  
G. W. P. M. Kramer ◽  
E. Rutten ◽  
J. Sloof

✓ A patient with a subcutaneous sacrococcygeal ependymoma and metastasis to the inguinal lymph nodes is presented and his treatment is described. Previous reports on sacrococcygeal ependymoma are reviewed.


Reproduction ◽  
2021 ◽  
Author(s):  
Amir Salek Farrokhi ◽  
Amir-Hassan Zarnani ◽  
Fatemeh Rezaei kahmini ◽  
Seyed Mohammad Moazzeni

Recurrent pregnancy loss (RPL) is one of the most common complications of early pregnancy associated in most cases with local or systemic immune abnormalities such as the diminished proportion of regulatory T cells (Tregs). Mesenchymal stem cells (MSCs) have been shown to modulate immune responses by de novo induction and expansion of Tregs. In this study, we analyzed the molecular and cellular mechanisms involved in Treg-associated pregnancy protection following MSCs administration in an abortion-prone mouse mating. In a case-control study, syngeneic abdominal fat-derived MSCs were administered intraperitoneally (i.p) to the DBA/2-mated CBA/J female mice on day 4.5 of pregnancy. Abortion rate, Tregs proportion in spleen and inguinal lymph nodes, and Ho1, Foxp3, Pd1, and Ctla4 genes expression at the feto-maternal interface were then measured on day 13.5 of pregnancy using flow cytometry and quantitative RT- PCR, respectively. The abortion rate in MSCs-treated mice was significantly reduced and normalized to the level observed in normal pregnant animals. We demonstrated a significant induction of Tregs in inguinal lymph nodes but not in the spleen following MSCs administration. Administration of MSCs remarkably upregulated the expression of HO1, Foxp3, Pd1, and Ctla4 genes in both placenta and decidua. Here, we show that MSCs therapy could protect the fetus in the abortion-prone mice through Tregs expansion and up-regulation of Treg-related genes. These events could establish an immune-privileged microenvironment, which participates in regulation of detrimental maternal immune responses against the semi-allogeneic fetus.


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