Microbiological analysis of skin lesions of cod (Gadus morhua) from the southern part of the Baltic Sea.

Introduction: Since the middle of the 1980s, severe skin disorders have been observed in Baltic cod (Gadus morhua) each year. Available data on the spectrum of bacteria isolated from the clinical cases being limited, and evaluation of the microbial background of fish skin lesions being useful, a bacteriological examination has been undertaken. Material and Methods: A total of 1,381 cod were caught during two voyages of the Baltica research vessel in the Polish exclusive economic zone of the southern Baltic Sea. After an examination which found lesions in 164 of the fish, a microbiological analysis was performed to isolate bacteria from them. The collected strains were phenotyped and genotyped, and their antimicrobial resistance was analysed by minimum inhibitory concentration (MIC) techniques. Results: Bacteriological examinations provided 850 isolates. The dominant microorganisms were mesophilic Aeromonas spp., Pseudomonas spp. and Shewanella baltica. Opportunistic bacteria potentially hazardous to human health were also isolated, e.g. Alcaligenes faecalis, Staphylococcus epidermidis, Stenotrophomonas maltophilia and Vibrio sp. The MIC analysis determined the highest number of bacteria to resist sulphamethoxazole and amoxicillin and clavulanic acid. Conclusion: Most of the collected bacteria were opportunistic pathogens for fish, widespread in the aquatic environment, and potentially threatening to humans.

Gelatin medium for preserving of Trichinella spp. for quality control in laboratories - estimation of larvae viability.

INTRODUCTION AND OBJECTIVE: Official food control laboratories ensure food safety using reliable, validated methods. Council Regulations (EC) No. 853/2004, 854/2004 and 882/2004 of the European Parliament established hygiene rules the production of food of animal origin, together with requirements for official controls. This leads to detailed requirements for Trichinella control set out in Commission Implementing Regulation (EU) 2015/1375 of 10 August 2015. These regulations require the laboratory to participate in proficiency testing (PT) to confirm their competence and improve the quality of testing, and require the PT Organizer to use methods for the preparation and preservation of parasite larvae in order to evaluate and improve detection. Traditional methods of preparing such larvae expose them to rapid degradation, making it necessary to simultaneously isolate the larvae and place them in meatballs to ensure quality. MATERIAL AND METHODS: We developed a technique for preserving of Trichinella spp. for quality control such as PT sample preparation. The procedure protects larvae against toxic oxygen activity and bacterial destruction via a gelatin barrier. To estimate the viability of larvae preserved by this method, gelatin capsules with 10 larvae of T. spiralis in each were stored (4-8 °C) during 45 days of an experiment. Samples were tested at 2 day intervals (3 samples each day of testing). RESULTS: In total, 75 samples were tested. Larvae remained alive up to 3 weeks. The number of living larvae diminished after 27 days through day 43, after which no living larvae were observed. CONCLUSIONS: The gelatin medium procedure facilitated easy, high-throughput sample preparation and supported 100% recovery for 3 weeks. The method allows fast, efficient and accurate PT sample preparation.

Molecular confirmation of the systemic toxoplasmosis in cat.

INTRODUCTION AND OBJECTIVE: Systemic toxoplasmosis with tissue-spread parasites occurring in intermediate hosts may also occur in immunocompromised cats (e.g., infected with FLV or FIV). To the best of our knowledge, no reports have been published on the detection and genotyping of T. gondii DNA in cats with extraintestinal toxoplasmosis in Poland. The article describes the case of the sudden death of 3 out of 4 cats in a cattery, and the detection and molecular characterization of T. gondii DNA detected in the tissues of one of the dead cats. MATERIAL AND METHODS: Samples of brain, lungs, heart, and liver of the cat that died suddenly were examined for the presence of T. gondii DNA (B1 gene) by nested PCR and real-time PCR. DNA positive samples were also genotyped at 12 genetic markers using multiplex multilocus nested PCR-RFLP (Mn-PCR-RFLP) and multilocus sequence typing (MLST). RESULTS: A total of 9 out of the 20 DNA samples were successfully amplified with nested and/or Real-time PCR. DNA from 3 out of 5 types of tested samples were genotyped (brain, heart and muscle). Mn-PCR-RFLP and MLST results revealed type II (and II/III at SAG1) alleles at almost all loci, except a clonal type I allele at the APICO locus. This profile corresponds to the ToxoDB#3 genotype, commonly identified amongst cats in Central Europe. CONCLUSIONS: To the best of our knowledge, this is the first study describing the genetic characteristics of T. gondii population determined in a cat in Poland. These data confirm the importance of this host as a reservoir for this pathogen, and demonstrate the genotypic variation of this parasite. Veterinarians should take into account that cats may develop disseminated toxoplasmosis, and that it is a systemic disease which may lead to the death of the cat, and to transmission of the pathogen to other domestic animals and to humans.

Parasitological contamination of arable soil in selected regions of Poland - preliminary study.

INTRODUCTION AND OBJECTIVE: The hygienic status of arable soils in most developed countries has been unknown. In the presented study, a preliminary investigation was undertaken to determine the contamination with eggs of parasitic nematodes in the soil of arable fields in Poland. The aim of the study was to determine whether such contamination is common enough to constitute a significant problem and what factors may influence it. MATERIAL AND METHODS: The study was conducted in 5 Polish provinces from autumn 2021 to spring 2022. The provinces differed significantly in terms of the area of agricultural land, agricultural suitability, type of soil, scale of cattle and pig breeding, production of manure and slurry, and the use of manures and organic fertilizers for fertilization. A total of 133 soil samples were collected. Parasitological examination of soil samples was carried out using the PN-Z-19006 method [1], with confirmed high sensitivity. RESULTS: Parasite eggs were found in a total of 67 samples, of which 56 samples contained eggs of roundworms of the genus Ascaris (an average of 3.29 eggs/100 g of soil), 23 contained eggs of whipworms (an average of 1.22 eggs/100 g), and 3 contained eggs of Toxocara (1 egg/100 g). CONCLUSIONS: Differences in the percentage of positive samples were found depending on the period in which the samples were taken. The percentage of positive samples collected in autumn (53.57%) was higher than the percentage of positive samples collected in spring (48.05%). Similarly, the average number of eggs of in positive samples collected in autumn (3.43 eggs/100 g) was higher than the average number of eggs in samples collected in spring (2.90 eggs/100 g). Differences in the percentage of positive samples were also found depending on the region of origin of the samples.

Echinococcus multilocularis genetic diversity based on isolates from pigs confirmed the characteristic haplotype distribution and the presence of the Asian-like haplotype in Central Europe.

Introduction: The aim of the study was to determine the genetic diversity of Echinococcus multilocularis in pigs in highly endemic areas in Poland, as well as to attempt to confirm the occurrence and geographical distribution of haplotypes characteristic for these areas, which were previously described on the basis of examination of adult tapeworms isolated from foxes. Material and Methods: Twenty samples of E. multilocularis larval forms were obtained from pigs' livers in four provinces of Poland. Genetic analyses were conducted on sequences of two mitochondrial genes: cox1 and nad2. Results: Seven haplotypes were found for the cox1 gene (OQ874673-OQ874679) and four haplotypes for nad2 (OQ884981-OQ884984). They corresponded to the haplotypes described earlier in foxes in Poland (some of them differing only in one nucleotide). The analysis showed the presence of the Asian-like haplotype in both the cox1 and nad2 genes. The remaining haplotypes were grouped in the European clade. The geographical distribution of haplotypes identified in the pig samples was noticed to bear a similarity to the distribution of haplotypes previously isolated from foxes in the same regions. Conclusion: The characteristic geographical distribution of E. multilocularis haplotypes in Central Europe (including the presence of the Asian-like haplotype) previously described in the population of definitive hosts (foxes) has now been confirmed by the analysis of samples from non-specific intermediate hosts (pigs).

Comparison of the effectiveness of various parasitological methods in detecting nematode eggs in different types of soil.

INTRODUCTION AND OBJECTIVE: Natural fertilizers, sewage sludge, digestates, as well as organic fertilizers produced on their basis, can become a source of parasitological contamination of cultivated land. High concentration of invasive forms of parasites in the soil may pose a threat to human and animal health. Therefore, it is necessary to control the hygienic condition of fertilizers and fertilized soils with particular emphasis on parasites. The aim of the study was to compare the effectiveness of methods commonly used for parasitological examination of soil with own methods which were used to develop the standards. MATERIAL AND METHODS: The study was carried out using samples of sandy soil (SS), horticultural mix soil (HS) and peat-based substrate (PS). Each sample was spiked with 100 dyed Ascaris suum eggs and examined with the use of 6 methods: Vasilkova, Dada, Quinn, and 3 methods according to the Polish Standards (PN-19000, PN- 19005, PN-19006). For each variant, 8 repetitions were made. RESULTS: The largest number of A. suum eggs were found with PN-19006 (mean number of detected eggs was 21.25, 46.50, 23.00 for HS, SS, PS, respectively. Slightly lower results were obtained using PN-19005 - the mean number eggs was 21.25, 36.00, 16.75, respectively. On the other hand, the mean number of A. suum eggs found with the Dada method was about 2-3 times lower than with the PN-19006 - 15.75, 22.50, 6.50 for HS, SS, PS soil, respectively. Other methods were much less effective. CONCLUSIONS: PN-19006 method turned out to be the most effective in detecting A. suum eggs. This method can be used for parasitological examination of soils and can be the basis for developing a system of methods dedicated to testing different types of soils for the presence of nematode eggs.

Investigating Cryptosporidium spp. Using Genomic, Proteomic and Transcriptomic Techniques: Current Progress and Future Directions.

Cryptosporidiosis is a widespread disease caused by the parasitic protozoan Cryptosporidium spp., which infects various vertebrate species, including humans. Once unknown as a gastroenteritis-causing agent, Cryptosporidium spp. is now recognized as a pathogen causing life-threatening disease, especially in immunocompromised individuals such as AIDS patients. Advances in diagnostic methods and increased awareness have led to a significant shift in the perception of Cryptosporidium spp. as a pathogen. Currently, genomic and proteomic studies play a main role in understanding the molecular biology of this complex-life-cycle parasite. Genomics has enabled the identification of numerous genes involved in the parasite's development and interaction with hosts. Proteomics has allowed for the identification of protein interactions, their function, structure, and cellular activity. The combination of these two approaches has significantly contributed to the development of new diagnostic tools, vaccines, and drugs for cryptosporidiosis. This review presents an overview of the significant achievements in Cryptosporidium research by utilizing genomics, proteomics, and transcriptomics approaches.

Occurrence of Eucoleus aerophilus in wild and domestic animals: a systematic review and meta-analysis.

BACKGROUND: Eucoleus aerophilus (syn. Capillaria aerophila) is a nematode with a worldwide geographical distribution. It causes a disease called lung capillariosis by affecting the respiratory tract of wild and domestic animals, and has also occasionally been described in humans. Despite steady increases in knowledge of the morphology of this neglected parasite, many aspects are still poorly understood. Epidemiological data regarding, for example, geographic distribution, range of hosts, clinical relevance and the actual zoonotic potential of this nematode are scarce and incomplete. METHODS: This article is a systematic review based on the screening of three databases (PubMed, Web of Science and Science Direct) to identify eligible studies published from 1973 to the end of 2022. RESULTS: From a total of 606 studies describing the occurrence of E. aerophilus, 141 articles from 38 countries worldwide were included in this meta-analysis, all of which presented results obtained mainly with flotation and necropsy. Due to the occurrence of E. aerophilus in many different species and different matrices (lungs and faeces), we decided to conduct the meta-analysis separately for each species with a given matrix. This systematic review confirmed the status of the Red fox as the main reservoir and main transmitter of E. aerophilus (average prevalence of 43% in faeces and 49% in lungs) and provided evidence of a higher prevalence of E. aerophilus in wild animals in comparison to domestic animals, such as dogs (3% in faeces) and cats (2% in faeces and 8% in lungs). Previous studies have investigated many host-related factors (age, sex, environmental/living conditions) in relation to the prevalence of E. aerophilus, but they show wide variations and no simple relationship has been demonstrates. Furthermore, mixed infections with other pulmonary nematodes, such as Crenosoma vulpis and/or Angiostrongylus vasorum, are reported very frequently, which greatly complicates the diagnosis. CONCLUSIONS: This systematic review focused on identifying data gaps and promoting future research directions in this area. To the best of our knowledge, this is the first systematic review that evaluates and summarizes existing knowledge on the occurrence and prevalence of E. aerophilus in wild and domestic animals originating from different geographical locations worldwide.

Scheme of Effective Epidemiological Investigations in Trichinella Outbreaks on Pig Farms.

Trichinellosis is a parasitic, zoonotic disease caused by larvae of the genus Trichinella. Infection occurs via the consumption of raw or undercooked meat containing this parasite. Symptoms of the disease manifest as intestinal disorders, followed by facial swelling, fever, muscle pain and other symptoms, eventually leading to neurological and cardiac complications and even death. In Europe, trichinellosis is most often associated with the consumption of meat from wild boars, pigs and horses. In recent years, wild boars that are hunted illegally and not tested for Trichinella spp. have been the most common cause of trichinellosis in humans; however, there have also been cases where infected pigs have been the source of infection. When trichinellosis is suspected in humans, epidemiological measures are taken to identify the source. Similarly, an epidemiological investigation should be initiated whenever Trichinella spp. has been detected in pigs. However, commonly used actions do not provide sufficient data to determine the source of infection for pigs and to prevent further transmission. Therefore, in this article, we propose a scheme for effective epidemiological investigations into Trichinella outbreaks on pig farms that can help trace the transmission mechanisms of the parasite and that takes into account currently available testing tools. The proposed pathway can be easily adopted for epidemiological investigations in routine veterinary inspection work.

Validation Parameters of the Magnetic Stirrer Method for Pooled Sample Digestion for Trichinella spp. in Horse Meat Based on Proficiency Tests Results.

Meat of horses may be infested with nematodes of the genus Trichinella spp. and can cause serious disease in humans. Rules for the carcasses sampling of species susceptible to Trichinella spp. infection and examination are laid down in Commission Regulation 1375/2015, where the magnetic stirrer method for pooled-sample digestion is recommended (Commission Regulation 1478/2020). All personnel involved in the examination should be properly trained and participate in quality control programs. Proficiency tests (PTs) play a key role in the quality verification process. This paper presents the results of PTs organized for 68 Polish laboratories in 2014-2019. Results were assessed qualitatively at three levels of sample contamination (0, 3, 5 larvae) and quantitatively at one level (5 larvae). The laboratories have achieved the average correct qualitative results 100%, 96.2% and 96.8% for the samples contaminated with 0, 3 and 5 larvae, respectively. In the quantitative evaluation, an average 94.1% of the reported results were correct. The data from PTs enabled us to define, for the first time, validation parameters of the digestion method for the horse meat matrix in a large-scale experiment including: specificity (100%), sensitivity (95.6%), accuracy (97.1%), the limit of detection (LOD) (1.14 ≈ 1) and the limit of quantification (LOQ) (3.42 ≈ 3).

Molecular Confirmation of Taenia crassiceps Cysticercosis in a Captive Ring-Tailed Lemur (Lemur catta) in Poland.

(1) Background: Taenia crassiceps is a cosmopolitan tapeworm endemic to the northern hemisphere with an indirect lifecycle. Its definitive hosts are carnivores, and its intermediate hosts are rodents and rabbits. Nonhuman primates in zoos appear to be highly susceptible to T. crassiceps cysticercosis. The aim of this study was to confirm the presence and the molecular characterization of T. crassiceps cysts isolated from a captive ring-tailed lemur. (2) Methods: Surgery revealed multifocal, transparent saccules containing several thin-walled tapeworm cysticerci. In some of the metacestodes, single or multiple exogenous buds from daughter cysticerci were spotted. A molecular analysis was performed to confirm our morphological examinations, using two protocols to obtain the partial nad1 and cox1 genes of the Taenia sp. (3) Results: On the basis of morphological features and molecular analysis, the cysticerci were identified as T. crassiceps metacestodes, and products taken from the PCRs were sequenced. With respect to interpreting the sequencing results of the obtained amplicons, we compared them with data in the GenBank database, proving that, in this case, the causative agent was indeed T. crassiceps. (4) Conclusions: The received data can be used to supplement descriptions of this species. To the best of our knowledge, this is the first case of cysticercosis caused by T. crassiceps in a nonhuman primate in Poland.

Comparison Study of Four Extraction Methods Combined with PCR and LAMP for Feline Tritrichomonas foetus Detection in Fecal Samples.

Feline trichomonosis occurs worldwide, with gastrointestinal symptoms such as chronic large-bowel diarrhea and abdominal pain. The inclusion of molecular methods in diagnostic and epidemiological studies has necessitated an effective method for extracting DNA from feces. We tested four extraction commercial kits: ZR Fecal DNA MiniPrep (50 preps) (Zymo Research, Irvine, CA, USA), QIAamp® DNA Stool Mini Kit (Qiagen Inc., Valencia, CA, USA), UltraClean Fecal DNA Kit (50 preps) (MO BIO, San Diego, CA, USA), and Sherlock AX/100 isolations (A&A Biotechnology, Gdynia, Poland). We assessed the sensitivity of detection of Tritrichomonas foetus in spiked fecal samples for the four kits combined with two molecular assays: PCR and LAMP. The extraction efficacy was quantified using defined aliquots of fecal samples spiked with 5 µL of suspensions containing serial dilutions of trophozoites (0.1; 1; 10; 100; 1000; 10,000), with six replicates for each concentration. In our study, we proved that the ZR Fecal DNA MiniPrep (50 preps) kit combined with LAMP and PCR had the highest efficiency among all the compared methods for the detection of feline T. foetus from fecal samples.

Analysis of a Trichinellosis Outbreak in Poland after Consumption of Sausage Made of Wild Boar Meat.

An outbreak of trichinellosis due to the consumption of sausage made from wild boar meat unexamined for the presence of Trichinella spp. was reported in Poland in December 2020. The outbreak affected eight people. Examination of the sausages made of wild boar meat collected during epidemiological investigation indicated a high level of Trichinella spp. Larvae per gram (>30 lpg) and therefore the threat of an infection in humans after consumption of such product was significant. Over the years, the main source of trichinellosis in Poland has been wild boar meat, and the majority of trichinellosis cases were related to the consumption of traditional raw meat products such as Polish sausage. Taking this into account, there is the need for better education of consumers in the Trichinella spp. endemic regions and among cultures consuming traditional raw meat products.

Grass Snakes (Natrix natrix) as a Reservoir of Alaria alata and Other Parasites.

The aim of the study was to investigate the occurrence of Alaria alata (Goeze, 1782) in fifty-one grass snakes (Natrix natrix) collected in Gostyninsko-Wloclawski Landscape Park. Each snake was tested for the presence of A. alata mesocercariae using the AMT and MSM methods. 18S ribosomal RNA (18S rRNA), cytochrome C oxidase subunit I (COI) and 28S ribosomal RNA (28S rRNA) genes were amplified by PCR and sequenced for the purpose of species identification. Fifty grass snakes were infected with helminths. The molecular characterization of trematodes allowed us to identify A. alata in 30 snakes (58.8%), Conodiplostomum spathula (Dubois, 1937) in 16 snakes (31.3%), Strigea falconis (Szidat, 1928) in 12 snakes (23.5%), and Neodiplostomum attenuatum (Linstow, 1906) in 2 snakes (3.9%), while, in 4 snakes (7.8%), the trematodes species could not be identified. Based on the analysis of 18S and COI sequences, Crenosoma vulpis (Dujardin, 1845) was identified in four snakes (7.8%), while nematodes collected from three snakes remained unidentified. The tapeworm sample was identified as Ophiotaenia. The obtained results indicate that grass snakes are an excellent vector of A. alata and may be a potential source of infection for mammals, e.g., wild boars and foxes, which results in an increased risk of alariosis for consumers of raw or undercooked game meat.

Proteomic Profiling and In Silico Characterization of the Secretome of Anisakis simplex Sensu Stricto L3 Larvae.

Anisakis simplex sensu stricto (s.s.) L3 larvae are one of the major etiological factors of human anisakiasis, which is one of the most important foodborne parasitic diseases. Nevertheless, to date, Anisakis secretome proteins, with important functions in nematode pathogenicity and host-parasite interactions, have not been extensively explored. Therefore, the aim of this study was to identify and characterize the excretory-secretory (ES) proteins of A. simplex L3 larvae. ES proteins of A. simplex were subjected to liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, and the identified proteins were then analyzed using bioinformatics tools. A total of 158 proteins were detected. Detailed bioinformatic characterization of ES proteins was performed, including Gene Ontology (GO) analysis, identification of enzymes, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis, protein family classification, secretory pathway prediction, and detection of essential proteins. Furthermore, of all detected ES proteins, 1 was identified as an allergen, which was Ani s 4, and 18 were potential allergens, most of which were homologs of nematode and arthropod allergens. Nine potential pathogenicity-related proteins were predicted, which were predominantly homologs of chaperones. In addition, predicted host-parasite interactions between the Anisakis ES proteins and both human and fish proteins were identified. In conclusion, this study represents the first global analysis of Anisakis ES proteins. The findings provide a better understanding of survival and invasion strategies of A. simplex L3 larvae.

Parasitic threat in commercial organic fertilizers.

The use of fertilizers based on sewage sludge is common practice. Due to the possible presence of pathogens and eggs of intestinal parasites like Ascaris sp., Toxocara sp., and Trichuris sp. in these products, it is necessary to control them. The aim of the study was to determine the presence of parasite eggs in commercial organic fertilizers available on the market. Selected commercial products were tested using the Quinn flotation method and a method dedicated to the study of dewatered sewage sludge. Assessment of the viability of helminth eggs was carried out on the basis of staining with calcein and propidium iodide. In 57% of the tested samples, the presence of live eggs of the abovementioned parasites was detected, and in 21% of samples, the eggs with live larvae were detected. Eggs of Trichuris sp. (50%) and Ascaris sp. (36%) were the most common. The obtained results clearly indicate that the process of hygienization of the sewage sludge before the production of fertilizers was not effective enough and it is necessary to standardize the prophylaxis against the spread of parasitic nematodes in commercially available products.

Validation of the Magnetic Stirrer Method for the Detection of Trichinella Larvae in Muscle Samples Based on Proficiency Tests Results.

Trichinellosis is a zoonotic disease caused by the nematodes of the genus Trichinella. Infection takes place through the consumption of infected meat containing live larvae. The only way to prevent the disease is to break its epizootic chain. To ensure effective control of Trichinella spp., a range of preventive and control measures have been undertaken. These efforts have been focused on controlling Trichinella in domestic pigs, the main source of the disease. Artificial digestion is also the reference point for other methods for Trichinella risk control. Descriptive data validation of the digestion assay was presented in 1998 based on results published by scientific laboratories. Herein, we supplement those data by characterizing the method's performance in inter-laboratory comparisons. The source of data was the results of Proficiency Testing conducted in 2015-2019. Samples were contaminated by 0, 1, 3, and 5 larvae. In total, 7580 samples were examined by the laboratories. Based on Proficiency Testing results, the main parameters characterizing the method performance in field conditions were established as follows: specificity, 97.3%; sensitivity, 86.5%; accuracy, 89.2%; uncertainty, 0.3; limit of detection (LOD), 1 larva; and limit of quantification (LOQ), 3 larvae.

Trichinella Outbreaks on Pig Farms in Poland in 2012-2020.

Trichinella nematodes continue to circulate in various hosts both in the domestic and sylvatic cycles. In the majority of countries in Europe, wild boars have been noticed as a primary source of Trichinella spp. infections in humans. However, in some regions, the meat of pigs containing Trichinella spp. larvae can still be a cause of trichinellosis. Therefore, in the present study, we aimed to determine and present actual data on the occurrence of Trichinella spp. on pig farms (Sus scrofa f. domestica) in Poland. In this study, over 194 million pigs, slaughtered for commercial and personal purposes between 2012 and 2020, were tested with a digestion method according to the official rules for Trichinella control. Positive results were noticed in 172 pigs which gives an overall prevalence of 0.000088%. On seven farms, rats (Rattus norvegicus) infected with Trichinella spp. were also discovered. The species identification showed pigs were infected with Trichinella spiralis on 26 farms, and on four farms pigs with Trichinella britovi infections were found. Therefore, it is important to constantly monitor pigs for the presence of these parasites, especially in view of the growing interest in organic meat originated from ecological farms.

Results of Proficiency Testing for Trichinella in Poland, 2015-2019.

Trichinellosis is a zoonotic meat-borne disease caused by the nematodes of the genus Trichinella. Meat containing live Trichinella larvae is a source of infection. The examination of meat for Trichinella was introduced in 1869, but the digestion method for this did not appear in Poland until the late 1970s. Nowadays, the meat of all food animals susceptible to Trichinella spp. is examined in the frame of official post mortem control with the digestion method. The majority of laboratories in Poland meet the requirements of the ISO/IEC 17025 Standard (352 field laboratories). Laboratory personnel participate in quality control programs. This paper presents the results of proficiency tests (PTs) organized within 2015-2019 in Poland. Over this period, the laboratories examined 7580 samples (contamination levels: zero, one, three, and five larvae). Each laboratory was provided with a set of samples (one negative and three positive). Over 95% of the samples were considered correct in qualitative assessments, though the results of the quantitative evaluations were slightly lower, with 89% of samples being considered correct. Based on a sample evaluation, 88% of laboratories passed the PT comparison. A slight decrease was observed in the examination of samples spiked with five larvae, and great progress was achieved in samples containing three larvae. Low levels of sample contamination are sought after in laboratories but may make evaluations difficult. For this reason, we must consider increasing the number of larvae added to the samples in the next PTs.

Infection, genetics, and evolution of Trichinella: Historical insights and applications to molecular epidemiology.

Genetic variation in pathogen populations provides the means to answer questions in disease ecology and transmission, illuminating interactions between genetic traits, environmental exposures, and disease. Such studies elucidate the phylogeny, evolution, transmission and pathogenesis of viruses, bacteria and parasites. Here, we review how such studies have fostered understanding of the biology and epidemiology of zoonotic nematode parasites in the genus Trichinella spp., which impose considerable economic and health burdens by infecting wildlife, livestock, and people. To use such data to define ongoing chains of local transmission and source traceback, researchers first must understand the extent and distribution of genetic variation resident in regional parasite populations. Thus, genetic variability illuminates a population's past as well as its present. Here we review how such data have helped define population dynamics of Trichinella spp. in wild and domesticated hosts, creating opportunities to harness genetic variation in the quest to prevent, track, and contain future outbreaks.