Marek Walczak

National Veterinary Research Institute

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Grzegorz Woźniakowski

Nicolaus Copernicus University

Małgorzata Juszkiewicz

National Veterinary Research Institute

Krzesimir Szymankiewicz

National Veterinary Research Institute

Anna Szczotka-Bochniarz

National Veterinary Research Institute

Natalia Mazur-Panasiuk

Jagiellonian University

Katarzyna Podgórska

National Veterinary Research Institute

Maciej Frant

National Veterinary Research Institute

JŻ

J. Żmudzki

National Veterinary Research Institute

Krzysztof Niemczuk

Polish Academy of Sciences

K. Kwiatek

Cooperative Institutions

National Veterinary Research Institute

Institute of Food Science

National Research Council

Institute of Protein Biochemistry

Centro de Biología Molecular Severo Ochoa

Universidad Autónoma de Madrid

Centre de Recerca en Sanitat Animal

Universitat Autònoma de Barcelona

Polish Academy of Sciences

Institute of Atmospheric Sciences and Climate

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Non-Invasive Sampling in the Aspect of African Swine Fever Detection—A Risk to Accurate Diagnosis

Viruses (2022)

Marek Walczak Anna Szczotka-Bochniarz J. Żmudzki Małgorzata Juszkiewicz Krzesimir Szymankiewicz

African swine fever remains one of the most economically important and dangerous diseases of the Suidae family. Until now, neither a safe vaccine nor a treatment against ASF has been available, which is why prevention of the disease involves biosecurity measures and early recognition based on accurate diagnosis. Nowadays, different strategies for ASF detection are discussed to reduce both animal suffering and the costs of ASF surveillance. This article aims to indicate the risk, with regard to non-invasive sampling, for the detection of ASFV. In this study, we analyzed data from three independent animal trials, in the framework of the detection of positive samples in different matrices (blood, sera, oral and rectal swabs) collected from nineteen domestic pigs infected with similar doses but under different scenarios, including different ASFV strains or routes of infection. Genetic material of ASFV was found in all matrices, but detection occurred earlier in the blood samples than in the oral and the rectal swabs. Furthermore, analyses revealed that at relevant sampling timepoints, PCR-positive blood samples were detected more frequently and reached higher percentages (up to 100% during fever) than oral and rectal swabs. Moreover, mean Ct values in blood samples collected from animals infected with virulent strains were significantly lower than in oral and rectal swabs, ensuring a higher probability of ASFV detection. High Ct values and occasional shedding in all tested matrices, in the cases of animals infected by an attenuated ASFV-strain, showed that blood sampling may be necessary to confirm the presence of anti-ASFV antibodies in sera. This study showed that during veterinary surveillance, blood sampling (for both PCR and serological analyses) is essential for the accurate diagnosis of ASF and provides the highest probability of detection of the disease.

African Swine Fever

Biosecurity

Blood sampling

10.3390/v14081756

Cite

Citations (8)

Virucidal effect of chosen disinfectants against African swine fever virus (ASFV) – preliminary studies

Polish Journal of Veterinary Sciences (2019)

Małgorzata Juszkiewicz Marek Walczak Natalia Mazur-Panasiuk Grzegorz Woźniakowski

Four commercial disinfectants were chosen for being generally accepted as effective against ASFV. Only two of them, based on sodium hypochlorite and potassium peroxymonosulfate, confirmed their effectiveness in selected concentrations. Taken together, our data supports the effectivenes of chemical disinfectants containing sodium hypochlorite (1%, 0.5% in low level soiling) and potassium peroxymonosulfate (1% in high level soiling). Furthermore, these results highlight the importance of pre-cleaning steps to remove soiling before proper disinfection which improves the effectiveness of tested disinfectants.

Sodium hypochlorite

Disinfectant

10.24425/pjvs.2019.131407

Cite

Citations (19)

Analiza przebiegu epizootii afrykańskiego pomoru świń w zachodniej Polsce

Życie Weterynaryjne (2020)

B. Konopka M. Welz Łukasz Bocian Krzysztof Niemczuk Marek Walczak

Source

Cite

Citations (0)

Evaluation of β-Actin and Mitochondrial DNA Levels in Determining the Age of Suidae Remains

International Journal of Molecular Sciences (2024)

Krzesimir Szymankiewicz Marek Walczak Katarzyna Podgórska

African Swine Fever (ASF) is an infectious disease affecting pigs and wild boars, causing significant economic losses. Epidemiological surveillance plays an important role in minimizing its impact. The aim of this study was to evaluate the usefulness of β-actin DNA and mitochondrial DNA (mtDNA) levels in determining the age of animal remains from the Suidae family, which could be helpful in epidemiological investigations. The study included selected tissues and internal organs of Sus scrofa domesticus, exposed to natural environmental conditions or kept in stable 4 °C conditions, to assess the levels of β-actin and mtDNA over a period of 18 months. The levels of both tested parameters exhibited the expected decreasing trend over time. However, in most tissues, some discrepancies from this general pattern were observed. The results obtained for bone marrow showed a consistent downward trend and a strong correlation between mtDNA and β-actin, with long-term detectability (up to the 13th month of the study). Therefore, bone marrow could be considered a matrix of choice for age assessment. However, due to various influencing factors, further studies are required.

10.3390/ijms252111674

Cite

Citations (0)

Effectiveness of Chemical Compounds Used against African Swine Fever Virus in Commercial Available Disinfectants

Pathogens (2020)

Małgorzata Juszkiewicz Marek Walczak Natalia Mazur-Panasiuk Grzegorz Woźniakowski

African swine fever (ASF) causes huge economic losses and is one of most dangerous diseases of pigs. The disease is known for almost 100 years, an effective vaccine or treatment is still unavailable, only proper biosecurity measures, including disinfection, are being applied, in order to prevent disease outbreaks. Eight active substances, i.e., formaldehyde, sodium hypochlorite, caustic soda, glutaraldehyde, phenol, benzalkonium chloride, potassium peroxymonosulfate and acetic acid, were tested, in order to confirm their effectiveness against African swine fever virus (ASFV). This specific selection was done based on the World Organisation for Animal Health (OIE)’s recommendation and previous disinfectant studies on surfaces. The result of our study shows that most of them inactivate the virus, in recommended concentrations. In order to reduce the cytotoxicity of the four substances, Microspin S-400 HR columns were applied, therefore making it possible to demonstrate four logarithms virus titer reduction. Sodium hypochlorite, glutaraldehyde, caustic soda and potassium peroxymonosulfate showed the best ASFV inactivation rates, achieving titer reductions over 5 logs. Despite microfiltration, the virucidal activity of formaldehyde was not assessable, due to its high cytotoxicity. Our results showed that cleaning is particularly important, because removal of the soiling provides improved effectiveness of the tested chemical compounds.

Disinfectant

10.3390/pathogens9110878

Cite

Citations (45)

Seminarium - "Aquaculture company worker skill training in breeding and cultivation of new species of fish in the Lithuanian aquaculture ponds and closed circulation breeding systems"

Komunikaty Rybackie (2013)

Zdzisław Zakęś M. Szczepkowski Małgorzata Juchniewicz Marek Walczak

Lithuanian

Circulation (fluid dynamics)

Source

Cite

Citations (0)

The Influence of the Temperature on Effectiveness of Selected Disinfectants Against African Swine Fever Virus (ASFV)

Viruses (2025)

Małgorzata Juszkiewicz Marek Walczak Grzegorz Woźniakowski Z. Pejsak Katarzyna Podgórska

African swine fever (ASF) is one of the most economically significant diseases of pigs caused by African swine fever virus (ASFV). Due to the lack of effective and safe vaccines, one of the crucial measures to protect farms from the introduction of the ASFV is to apply a strict regime of biosecurity and disinfection. However, in field conditions, the activity of disinfectants may be influenced by temperature, resulting in reduced activity or biodegradation (i.e., freezing or evaporating). The aim of this study was to evaluate the effect of a wide range of temperatures on the virucidal activity of selected active substances commonly used against ASFV. Eight active substances were tested, namely: sodium hypochlorite (1.0%), glutaraldehyde (0.1%), potassium peroxysulfate (0.5%), caustic soda (1.0%), phenol (1.0%), acetic acid (3.0%), benzalkonium chloride (1.0%), and formaldehyde (0.4%). The virucidal activity of each compound was tested at different temperatures (21, −10, and −20 °C for 30 min) and compared to the initial virus titer under the same temperature conditions. Exposure to a range of temperatures did not significantly affect the virucidal efficacy of tested active substances against ASFV. Most of the evaluated substances had reduced virus titers ≥ 4 log10, regardless of the temperature. However, two of them (benzalkonium chloride and acetic acid) were sensitive to sub-zero temperatures, showing a lack of the required 4 log10 virus titer reduction. The conducted study showed that temperature could hamper the virucidal effect of selected substances (i.e., benzalkonium chloride and acetic acid), showing their moderate efficacy against ASFV −10 °C and −20 °C. The results suggest that extreme caution should be taken while applying these substances at sub-zero temperatures. The other substances had no significant sensitivity to the temperature range. Nevertheless, in the case of freezing the agent, insufficient penetration of the disinfected surface may occur, which may result in an ineffective disinfection process.

Benzalkonium chloride

Peracetic acid

Disinfectant

Sodium hypochlorite

10.3390/v17020156

Cite

Citations (0)

Sporysz jako źródło niebezpiecznych alkaloidów w zbożowych materiałach żywnościowych i paszowych

Życie Weterynaryjne (2015)

Marek Walczak K. Kwiatek

Source

Cite

Citations (1)

Wybrane aspekty uprawy i wykorzystania rzepaku w Polsce

Pasze Przemysłowe (2006)

Marek Walczak K. Kwiatek

Source

Cite

Citations (0)

Analysis of the Clinical Course of Experimental Infection with Highly Pathogenic African Swine Fever Strain, Isolated from an Outbreak in Poland. Aspects Related to the Disease Suspicion at the Farm Level

Pathogens (2020)

Marek Walczak J. Żmudzki Natalia Mazur-Panasiuk Małgorzata Juszkiewicz Grzegorz Woźniakowski

This paper was aimed to characterize clinical signs and pathomorphological lesions in twenty-two pigs, infected intranasally by different doses of African swine fever virus (Pol18_28298_O111), isolated during the outbreak in a pig farm that occurred in Eastern Poland throughout 2018. This article also attempts to indicate risk, related to virus load and shedding, and present possible difficulties with proper disease recognition at the farm level. The results revealed that even a very low dose (5 HAU) may initiate the infection. Various forms of the disease (acute, subacute, and chronic), mainly with prodromal clinical signs like fever, apathy, and reduced feed intake were observed. The most frequently observed lesions (82%) were: hyperemia and enlargement of lymph nodes and splenomegaly. The minimal incubation period was estimated at five days post-infection (dpi). Mortality ranged from 80–100%. Two pigs survived the infection. Some viremic animals presented delayed fever. In some cases, the fever was not detectable. Shortly after viremia, the virus was secreted ion the urine, feces, and saliva. The highest levels of virus were found in the internal organs and blood; however in the case of one pig (chronic form), viral DNA was not detected in the spleen, liver, bone marrow, and brain. Veterinary diagnosis may be difficult, and the final results should always be based on laboratory investigations.

Viremia

Viral Shedding

10.3390/pathogens9030237

Cite

Citations (35)