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Blastocystis is an intestinal microeukaryote with ambiguous pathogenicity, commonly detected in human feces worldwide. It comprises at least 28 genetically diverse subtypes (STs), 12 of which also occur in a wide range of animal species, giving rise to suspicion of zoonotic transmission. To investigate this, we conducted a molecular study of 145 stool samples of pet animals, and 67 of their owners, living in an urban area in Poland. Blastocystis was detected in only three (2.1%) animal samples (of two bearded agamas and a leopard gecko), while all dogs, cats, and pet rodents were Blastocystis-negative. Blastocystis was also present in three (4.5%) owners of animals, but they were cat owners, not reptile owners, and the subtypes identified in them differed significantly from those of reptiles. Additionally, the frequency of Blastocystis in different groups of dogs (depending on how they were kept) was analyzed. This work is the first to find Blastocystis in pet reptiles, and we encourage further investigation of Blastocystis in this poorly examined group of animals, as well as continued study on the transmission of this microorganism between humans and animals.

Aim of the study To assess the clinical usefulness of serological tests in the diagnosis and monitoring of treatment of patients with alveolar echinococcosis (AE). Material and methods The results of serological tests, i.e. Echinococcus multilocularis ELISA (Bordier Affinity Products) and Echinococcus Western Blot IgG (LDBIO Diagnostic), of 66 patients were analysed. Duration of follow-up was two years after diagnosis. In the second phase of the study 11 sera obtained from the patients undergoing surgical treatment, in whom the results of Echinococcus Western Blot IgG assay were still positive, were additionally tested with Anti-Echinococcus EUROLINE-WB (IgG) assay. Results Statistically significant negativization of the Echinococcus multilocularis ELISA test was observed in the group of patients who underwent radical surgery or liver transplantation. Negativization of Echinococcus Western Blot IgG assay results was observed in some patients, among both those who received conservative treatment and those who underwent surgery, but no statistically significant differences were found between treatment groups. In 54.5% of cases the Anti-Echinococcus EUROLINE-WB (IgG) test result was negative when the results of the Echinococcus Western Blot IgG assay were still positive. Conclusions Echinococcus multilocularis ELISA proved to be useful in assessing the activity of AE in a group of patients who underwent radical surgery or liver transplantation. The results of our study suggest that Anti-Echinococcus EUROLINE-WB (IgG) is a more dynamic test, which at the time of disappearance of AE activity becomes negative earlier.

Cod (Gadus morhua), an important fish species in the Baltic Sea, is the paratenic host for many parasite species, including the zoonotic nematodes, Anisakis sp. and Contracaecum osculatum. We aimed to identify which invertebrate species (found in situ in the fish stomach) are responsible for infection of cod with zoonotic nematodes. We found that Crangon crangon and Gammarus sp., both invertebrate prey species of cod, were infected with Anisakis simplex and C. osculatum, respectively. These host–parasite systems are reported here for the first time, implicating C. crangon and Gammarus sp. as sources of infection of Baltic cod with zoonotic nematodes.

The consumption of raw or inadequately cooked marine fish can lead to several disorders caused by the ingestion of viable anisakid nematodes. Although anisakid larvae can be killed by subzero temperatures, making freezing an important control measure for this potential health hazard, these parasites can survive freezing under some conditions. Therefore, the aim of the present study was to experimentally evaluate the time-temperature conditions needed to kill Anisakis simplex and Pseudoterranova spp. The effectiveness of freezing was tested on two species of fish: cod, Gadus morhua from the North Atlantic, and herring, Clupea harengus membras from the southern Baltic Sea. Samples, which comprised skinless fillets of cod (n = 40) with visible parasites and whole herring (n = 240), were separately frozen at − 15, − 18, or − 20 °C for 24 h, or at − 20 °C for 48 h in the single-compressor freezer and at − 20, − 25, or − 35 °C for 24 h in the double-compressor freezer. After thawing, parasites were stained with malachite green and examined under the microscope for viability. All A. simplex and Pseudoterranova spp. larvae in cod fillets died at a temperature of − 15 °C or lower. However, freezing did not kill all the A. simplex larvae in whole herring: spontaneous movement of these parasites was observed in samples stored in the single-compressor freezer at − 15, − 18, and − 20 °C over 24 h. Our results demonstrate that the freezing procedure must consider both the capability of the freezing device and the nature of the fish product to ensure consumer safety.

Sprat is one of the most important fish in the food webs of the open part of the Baltic Sea. It is a crucial element in the diet of predators, which include salmonid and gadoid fish, marine mammals and sea birds. Sprat might also be a source of parasitic invasion for piscivorous organisms. We evaluated the level of sprat invasion with zoonotic nematodes in the southern Baltic Sea (Polish EEZ) from two sampling periods (1987–1989–1990: 3511 fish examined; and 2015–2016: 180 fish examined). While there was no evidence for zoonotic nematode parasites in sprats sampled during the first period, or in those from 2015, we found larvae of the liver worm Contracaecum osculatum in sprat sampled in 2016 from the central off-shore area of the Polish EEZ. Together with other recent reports, this suggests that sprat recently may play a role as a transmitter of this parasite to piscivorous organisms in several areas of the Baltic Sea.

Dirofilariasis is an emerging zoonosis caused by nematodes of the genus Dirofilaria, most often D. repens and D. immitis . The main final hosts and reservoirs of pathogens are dogs. The intermediate hosts and vectors of infection are female mosquitoes (Culicidae). Human is an accidental host in which the parasite does not usually mature. Over the past 20 years, the range of Dirofilaria spp. in Europe has expanded. We present an unusual case of multifocal dirofilariasis of mixed subcutaneous-ocular course caused by D. repens in a 52-year-old Polish patient who was probably infected in Spain or Croatia, where she stayed one year before the onset of symptoms. Surgical removal of the nematodes followed by treatment with Ivermectin in a single dose of 1200 μg and Doxycycline 200 mg daily for 7 days resulted in complete recovery. We believe that all cases of human dirofilariasis, especially in countries where the disease is not frequent at present, should be registered for epidemiological purposes. Moreover, due to the widening of the range of D. repens and D. immitis occurrence and the possibility of atypical courses of infection with both nematodes, diagnostics should include the species identification of the parasite.

Blastocystis is an enteric microorganism commonly found in humans and animals worldwide. Its pathogenic role in humans and transmission patterns has not been fully explained. However, nine subtypes (ST1&ndash, 8, ST12) are considered as potentially zoonotic. Studies from various regions of the world show that pigs are mainly infected with ST5. Although pigs are important farmed animals in Poland, the question of Blastocystis infection in these animals has not yet been investigated. Herein, 149 pig stool samples from 10 Polish pig farms were analyzed using sequence-tagged-site PCR and barcode region sequencing. The percentage of samples in which Blastocystis was identified using each method separately was similar: 38.25% and 37.58%, respectively. However, the percentage of positive results obtained by combining both methods was 46.97%, which means that, depending on the method used, the number of undetected samples varied between 8.72% and 9.39%. This shows the methodological limitations of up-to-date molecular approaches commonly used in Blastocystis research. A moderate infection rate (44.4&ndash, 50%) observed in different pig age groups with a vital predominance of ST5 (94.28%) in every age group shows that pigs are a likely natural host of ST5. A small percentage of mixed infections, namely ST5/ST1 (5.26%), ST5/ST3 (1.75%), and ST3/ST1 (1.75%), was observed only in animals of older age, suggesting that ST3 and ST1 can be acquired by pigs during contact with humans. This study provides the first data on the prevalence and Blastocystis subtypes (STs) distribution in pigs in Poland. The results also highlight the need for the development of new methods capable of detecting highly genetically diverse Blastocystis isolates and mixed infections.

Simple Summary Blastocystis is one of the most common microorganisms living in the intestines of humans and various animals worldwide. Although the presence of this microorganism does not cause any ailments in many people, in some others Blastocystis is a source of various gastrointestinal disorders, such as abdominal pain, nausea, diarrhea, constipation, flatulence, or lack of appetite, as well as extraintestinal complaints, such as itching and skin rash. Transmission of Blastocystis is possible by direct contact with contaminated individuals, and by consuming water or food contaminated with cysts. It has been suggested that contact between animals and humans may pose a risk of human Blastocystis infection. In our study, we compared Blastocystis isolated from zoo animals and their keepers. The detection of identical sequences of Blastocystis in three monkeys and the man who looked after them showed that transmission of this microorganism between non-human primates (NHPs) and humans is possible under favorable conditions. Our research has shown that further investigation of animals and their in-contact humans is needed to better understand the transmission of Blastocystis between animals and humans and to find out which animals pose a risk of human infection, and to what extent. Abstract Blastocystis is a highly genetically diverse gut protist commonly found in humans and various animals. The role of animals in human infection is only partly understood. The aim of this study was to determine the host specificity and possibility of zoonotic transmission of this microorganism. Subtypes of Blastocystis isolated from 201 zoo animals and their 35 caregivers were identified by sequencing of the SSU rRNA gene. Blastocystis was found in 26.86% of animal and 17.14% of human samples. Both mammalian (ST1–ST3, ST5, ST8, ST10, ST13, ST14) and non-mammalian subtypes were detected. Of the subtypes found in non-human primates (ST1, ST2, ST3, and ST13), two subtypes (ST1 and ST3) were also detected in humans. The presence of identical ST1 sequences in three monkeys and their caregiver indicates the possibility of direct transmission of Blastocystis between these animals and humans. Detection of ST5 only in wild boars and peccaries, ST8 only in Marsupial, ST10 and ST14 only in Bovidae, and non-mammalian subtypes in reptiles suggests higher host specificity for these subtypes, and indicates that their transmission between animals and humans is unlikely. Additionally, this was probably the first time that ST5 was found in peccaries, ST2 in patas monkeys, and ST8 in red kangaroos.

SUMMARYToxoplasma gondiiinfections are acquired through the ingestion of oocysts present in the environment. However, there is no data about their occurrence in the air or about airborne transmission of these infections. In the present paper, we report on the identification ofT. gondiiusing rapid molecular detection methods, supported by microscopic analysis, in environmental air samples. A total of 71 samples were collected, using gelatine filters, from kitchen gardens, recreational areas and sandpits located in northern and north-eastern Poland. Material recovered from the filters was analysed using real-time PCR and loop-mediated isothermal assays targeting theT. gondiiB1 gene.Toxoplasma gondiiDNA was found in two samples, as confirmed by both molecular assays. Genotyping at the SAG2 locus showedToxoplasmaSAG2 type I. Moreover, the presence ofT. gondiioocysts was confirmed in one of the positive samples with the use of microscopy. The results showed thatT. gondiimay be present in environmental air samples and that respiratory tract infections may play a role in the high prevalence of toxoplasmosis in humans and animals. To the best of our knowledge, this is the first epidemiological evidence that oro-fecal and foodborne toxoplasmosis may be traceable to an airborne respiratory origin and that this may represent a new, previously unknown transmission route for this disease.

In the Baltic Sea, the great sandeel (Hyperoplus lanceolatus), a common fish species that inhabits sandy substrates, is an important element in the diet of marine mammals, sea birds, and piscivorous fish. It can also act as a transmitter of parasites to its predators, but parasitological studies on this species are limited. We sampled great sandeels in April 2016 in two areas of the southern Baltic Sea (SB-south of Bornholm and GG-the Gulf of Gdansk) and found parasitic anisakid nematodes in both locations. The only one species of nematode parasites has been detected: liver worm (Contracaecum osculatum) with average prevalence of infection 8.96%. This is the first study to report on infection of H. lanceolatus with anisakid nematodes in the southern Baltic Sea and our results suggest that the great sandeel may play a role in the transmission of liver worm in the food web of this marine environment.

Cod (Gadus morhua), an important fish species in the Baltic Sea, is the paratenic host for many parasite species, including the zoonotic nematodes, Anisakis sp. and Contracaecum osculatum. We aimed to identify which invertebrate species (found in situ in the fish stomach) are responsible for infection of cod with zoonotic nematodes. We found that Crangon crangon and Gammarus sp., both invertebrate prey species of cod, were infected with Anisakis simplex and C. osculatum, respectively. These host-parasite systems are reported here for the first time, implicating C. crangon and Gammarus sp. as sources of infection of Baltic cod with zoonotic nematodes.

Water is one of the possible transmission routes for water- and foodborne parasites to humans. Echinococcus multilocularis is a parasite, which causes alveolar echinococcosis (AE). Nevertheless, no environmental studies have been performed as yet to confirm the occurrence of E. multilocularis in water supplies. Accordingly, 105 water samples of 50 L volume were collected from surface waters (lakes, rivers, canals) and wells in the Warmia-Masuria Province (Echinococcus endemic area) and Pomerania Province (Echinococcus non-endemic area), Poland. The water was filtered and subsequently analysed with nested PCR and real-time PCR. E. multilocularis DNA was found in two (1.9%) samples, which originated from two lakes localised in the Warmia-Masuria Province. Sequencing of the positive samples confirmed that the PCR products were fragments of the E. multilocularis mitochondrial 12S rRNA gene. This is the first investigation describing E. multilocularis detection in environmental water samples, using molecular diagnostic tools. The results indicate that water could be considered as a potential source of E. multilocularis infections in humans and animals, in endemic areas.

Our case report involves a 28-year-old man who was diagnosed with left elbow bursitis. After thorough macroscopic and microscopic examinations and serological and molecular tests, it was found that the inflammation had been caused by a Dirofilaria repens infection. This case report is the world’s first documented description.

Echinococcus multilocularis is a tapeworm that may cause alveolar echinococcosis (AE), one of the most dangerous parasitic zoonoses. As in the case of other foodborne diseases, unwashed fruits and vegetables, contaminated with dispersed forms of E. multilocularis, may serve as an important transmission route for this parasite. In this article, we reply to the incorrect interpretation of results of our study concerning the detection of E. multilocularis DNA in fresh fruit, vegetable and mushroom samples collected from the highly endemic areas of the Warmia-Masuria Province, Poland, to dispel any doubts. The accusations formulated by the commentators concerning our paper are unfounded; moreover, these commentators demand information which was beyond the purview of our study. Making generalisations and drawing far-reaching conclusions from our work is also unjustified. The majority of positive samples were found in only a few hyperendemic communities; this information corresponds with the highest number of both infected foxes and AE cases in humans recorded in this area. Our findings indicate that E. multilocularis is present in the environment and may create a potential risk for the inhabitants. These people should simply be informed to wash fruits and vegetables before eating. No additional far-reaching conclusions should be drawn from our data. We believe these commentators needlessly misinterpreted our results and disseminated misleading information. Nevertheless, we would like to encourage any readers simply to contact us if any aspects of our study are unclear.

Introduction Alveolar echinococcosis is a parasitic disease caused by the larval stage of tapeworm Echinococcus multilocularis . It usually involves the liver, but can spread to other organs. The treatment of choice is a surgical resection supported by antiparasitic drugs. In the advanced stages of the disease a liver transplantation is the only option. Aim This article presents the problems related to care of patients after liver transplantation for advanced alveolar echinococcosis. Material Sixty-seven patients with alveolar echinococcosis were hospitalized in our clinic in the years 2000–2015. Liver transplantation has been a therapeutic option for 9 patients. We retrospectively analyzed data of qualification for the liver transplantation and the postoperative treatment. Results Follow-up time after liver transplantation ranged from 7 months to 155 months (average, 6.4 years). One patient, with a history of advanced disease (P4N1M0), died due to liver failure. One patient was lost to follow-up. After liver transplantation all patients were receiving albendazole treatment. Two patients did not follow the medical recommendations. In 1 patient, who decided to stop therapy after 1 year, the relapse of alveolar echinococcosis in the left lobe of the transplanted liver passing through the diaphragm to the pericardium was detected. In another case we suspected a relapse of alveolar echinococcosis in transplanted liver due to positive serological tests. Conclusion The prognosis of patient after liver transplantation for alveolar echinococcosis is good. The main problem caused by immunosuppressive therapy is a recurrence of disease in the transplanted liver.

Background & objectives: Dengue is a mosquito-borne viral disease, incidences of which have increased rapidly in the past decade. About 400 million new infections are recorded annually worldwide, and 40% of the human population lives in the areas at risk of dengue transmission. In this study, the clinical and laboratory profile of dengue diagnosed patients returning to Poland from tropical areas has been analyzed. Methods: This is a retrospective study of 65 patients based on clinical symptoms and serological tests conducted in the Department of Tropical Parasitology of Institute of Maritime and Tropical Medicine (IMTM) in Gdynia, Poland during 2010-15. The diagnosis of dengue virus (DENV) infection was based on the detection of specific immunoglobulin M (IgM) and IgA antibodies performed by specific ELISA assays. The samples were considered as positive, if the absorbance was >10% above the cut-off value. Results: Among 65 persons with dengue selected for the analysis, 59 patients were admitted to the hospital because of clinical symptoms of the disease; the six persons initially asymptomatic were hospitalized due to routine control treatment returning from tropical regions. Patients reported various destinations, purpose and duration of their travels. All of them had returned from dengue endemic regions and were positive for IgM antibodies against DENV. Common clinical symptoms observed were fever (ranging from 38 to 40°C in 43% of patients), weakness, headache and rash. Laboratory tests revealed elevated levels of transaminase activity, leukopenia and thrombocytopenia in 35.3, 24.6 and 20% of patients, respectively. Interpretation & conclusion: The number of Polish travelers to subtropics and tropics increases every year. As cases of fever and other symptoms appear to be increasingly in Polish people returning from tropical regions of Asia, America and Africa, their screening and management should be taken seriously. The study also suggests that the disease might be more widespread than it was known previously.

Consumption of raw or inadequately processed marine fish may result in anisakidosis – a zoonotic disease caused by larvae of the parasitic nematodes of the family Anisakidae (anisakiasis when caused by members of the genus Anisakis (Nematoda: Anisakidae)), commonly found in a variety of marine fish species all over the world. Most cases of anisakidosis have been detected in the residents of Japan and South Korea, which results from the tradition of eating raw and semi-raw fish dishes. However, the disease is now increasingly often diagnosed in other parts of the world, including Europe (mainly in Spain and Italy). In Poland, no cases of human infection with anisakid nematodes have been detected so far. In this study, we report the first case of gastric anisakiasis in Poland, in a 59-year-old female patient, after eating raw Atlantic salmon (Salmo salar). The parasite was identified as the third-stage larva of Anisakis simplex sensu stricto on the basis of morphology and molecular analysis. The larva was still alive and causing pain until it was removed, which occurred more than 5 weeks after infection. The described case prove that anisakiasis should be considered as a potential cause of gastrointestinal tract ailments following the consumption of seafood in countries where no cases of this zoonosis have been reported to date.

Blastocystis is a common, enteric protist of humans and animals with a worldwide distribution and unclear clinical relevance. Nine out of 17 genetically diverse subtypes occur in humans. We analysed the distribution of Blastocystis subtypes and the intensity of invasion in relation to the gastrointestinal tract disorders and travels to different continents. 122 Blastocystis stool cultures were subtyped via polymerase chain reaction (PCR) with seven pairs of subtype-specific, sequence-tagged-site (STS) primers. Five subtypes of Blastocystis were detected: ST3 (59%), ST2 (19.7%), ST1 (13.1%), ST6 (3.3%), ST7 (3.3%), and two mixed infections with ST1/ST3 (1.6%). ST1 was detected exclusively in travelers to hot climate zones and ST2 was found more frequently in people visiting other continents compared to those who never left Poland. We found no correlation between gastrointestinal tract disorders, Blastocystis STs, and parasite load. There was no age predisposition to the Blastocystis infection. We established the distribution of Blastocystis STs among Poles traveling to different continents and never leaving Poland. Our study sheds more light on the problem of importing Blastocystis infection. It shows that certain subtypes detected in Europe can be imported due to travel or migration. Collecting data on the travel history of the surveyed persons is necessary to clarify this matter.

Purpose Hepatic alveolar echinococcosis (AE) is a parasitic disease caused by the larval stage of the tapeworm Echinococcus multilocularis. Ultrasonography is the method of choice in the initial diagnosis of AE. The aim of the study is to present the most frequent sonomorphological patterns of lesions in hepatic AE based on the analysis of ultrasound findings in patients treated for AE at the University Centre of Maritime and Tropical Medicine (UCMMiT; Gdynia, Poland), and to establish whether there is a relationship between the clinical stage of AE and the occurrence of a specific sonomorphological pattern of hepatic lesions. Patients and methods We analysed the results of ultrasound examinations of 58 patients hospitalized in the UCMMiT with probable or certain diagnosis of AE. Liver lesions were assessed according to the classification developed by researchers from the University Hospital in Ulm (Germany). Statistical analysis was based on the relationship between the occurrence of a specific sonomorphological pattern of hepatic lesions and the clinical stage of AE. Results The most frequently observed patterns of AE lesions in the liver were the hailstorm and the pseudocystic patterns. There was no correlation between the clinical stage of the disease and the ultrasonographic appearance of lesions. There was no statistically significant relationship between the more frequent occurrences of specific ultrasonographic patterns of lesions in the liver and radical or non-radical surgery. Conclusions The ultrasonographic appearance of the lesion in liver AE cannot determine the therapeutic management. Treatment plan should be established based on the PMN classification.

Malaria remains an important public health issue all over the world. Among 5 Plasmodium species invasive to humans, Plasmodium knowlesi has been identified most recently. It is sometimes difficult to differentiate this species from P. malariae with the use of microscopic examination. However, P. knowlesi infection may be associated with rapidly increasing parasitaemia and severe clinical course with the risk of death. Samples from Polish travellers returning from areas where simian malaria is endemic were examined with the use of polymerase chain reaction (PCR). The small subunit of ribosomal RNA (SSU rRNA) genes was subjected to analysis using nested PCR reaction. No positive results of P. knowlesi were obtained. Due to morphological similarities to P. malariae, potentially severe clinical course of infection and P. knowlesi endemic regions being a common tourist destination, diagnostic and clinical vigilance is necessary, including molecular methods use for precise parasite identification.

The aim of this study was to estimate the presence of Echinococcus multilocularis DNA in fruits, vegetables, and mushrooms in rural areas of Varmia-Masuria Province, Poland, which is the region with the highest number of human alveolar echinococcosis (AE) cases in this country. Recovery tests showed that E. multilocularis DNA is detectable in samples contaminated with at least 100 eggs of this tapeworm. In total, 103 environmental fruit, vegetable, and mushroom samples collected in forests, plantations, and kitchen gardens were analyzed using nested PCR assay based on the mitochondrial 12S ribosomal RNA (rRNA) gene. The parasite DNA was detected in 23.3 % of the samples. Sequencing confirmed that the obtained PCR products represented E. multilocularis. This study is the first environmental survey of the presence of E. multilocularis DNA in fruits, vegetables, and mushrooms intended for consumption. The results clearly demonstrate that it may be a direct source of human infections and shows the need to educate the public about the threat, especially people living in at-risk areas.

Background: Dengue viruses are the most widespread arboviruses (transmitted mainly by Aedes aegypti and Ae. albopictus mosquitoes), which have shown an unexpected geographic expansion. There are four dengue virus serotypes: DENV-1, DENV-2, DENV-3, and DENV-4. Subsequent infections increase the risk of developing severe dengue fever. Materials and methods: Samples from travellers returning from the endemic area of dengue fever were examined with the reverse transcription-polymerase chain reaction method. Primers amplified 743 bp fragment of the NS5 and 3’UTR genomic region of mosquito-borne flaviviruses of JEV group were used. Results: The sequences from the 10 examined patients were compared to available DENV sequences in GenBank database and the basic local alignment search tool (BLAST) results confirmed that the infective virus was DENV-1 (6 patients), DENV-2 (2 patients) and DENV-3 (2 patients). Conclusions: For the first time in Poland, dengue virus serotypes were determined in travellers returning from dengue-endemic areas.

Giardia intestinalis is a protozoan parasite, transmitted to humans and animals by the faecal–oral route, mainly through contaminated water and food. Knowledge about the distribution of this parasite in surface water in Poland is fragmentary and incomplete. Accordingly, 36 environmental water samples taken from surface water reservoirs and wells were collected in Pomerania and Warmia-Masuria provinces, Poland. The 50 L samples were filtered and subsequently analysed with three molecular detection methods: loop-mediated isothermal amplification (LAMP), real-time polymerase chain reaction (real-time PCR) and nested PCR. Of the samples examined, Giardia DNA was found in 15 (42%) samples with the use of LAMP; in 12 (33%) of these samples, Giardia DNA from this parasite was also detected using real-time PCR; and in 9 (25%) using nested PCR. Sequencing of selected positive samples confirmed that the PCR products were fragments of the Giardia intestinalis small subunit rRNA gene. Genotyping using multiplex real-time PCR indicated the presence of assemblages A and B, with the latter predominating. The results indicate that surface water in Poland, as well as water taken from surface wells, may be a source of Giardia strains which are potentially pathogenic for humans. It was also demonstrated that LAMP assay is more sensitive than the other two molecular assays.

The parasite fauna of cod (Gadus morhus) is well described, but the life cycles of Baltic cod parasites are known only in general terms. Invertebrates commonly found in the stomach of cod are recognized as intermediate hosts in the life cycles of nematodes or acanthocephalans. The aim of this study was to determine the source of infection of Baltic cod with parasites found in situ in invertebrates present in the cod stomach. Our results indicate that Saduria entomon is both a source of infection of Baltic cod with parasites and an intermediate host in the life cycle of Hysterothylacium aduncum in the Baltic Sea.

The aim of this study was to estimate the presence of Echinococcus multilocularis DNA in the soil in rural areas of Varmia-Masuria Province, Poland, which is the region with the highest recorded number of human alveolar echinococcosis (AE) cases in this country. In total, 62 soil samples were analyzed. Samples were collected in forests near the lairs of foxes, as well as from arable fields, kitchen gardens and farmyards. The parasite DNA was detected in 11.3% of the samples. This study is the first environmental survey of the presence of E. multilocularis DNA in soil. The results demonstrate that the soil can be a direct source of human infections. These results should motivate the appropriate institutions to introduce informative and educational campaigns about the risk of infection, as well as developing methods for protecting the population, especially those living in at-risk areas.

Cryptosporidium is an opportunistic protozoan parasite that can cause severe diarrhoea in immunocompromised patients. The transmission of this pathogen in humans and animals is not fully understood. C. meleagridis, originally described in birds, is the only Cryptosporidium species known to naturally infect mammalian and avian species. This study documents the first detection of C. meleagridis in an HIV-infected woman in Poland.

Echinococcus multilocularis is a tapeworm that may cause alveolar echinococcosis (AE), one of the most dangerous parasitic zoonoses. As in the case of some foodborne diseases, unwashed fruits and vegetables contaminated with eggs of E. multilocularis may serve as an important transmission route for this parasite. The aim of this study was to investigate the presence of E. multilocularis DNA in fruit, vegetables, and mushrooms in rural areas of the Pomerania province, Poland (non-endemic territory). In total, 104 environmental fruit, vegetable, and mushroom samples collected in forests, plantations, and kitchen gardens were analysed using nested PCR based on the mitochondrial 12S rRNA gene. E. multilocularis DNA was detected in 6.7 % of the samples tested, which indicated that the environment of the Pomerania province is contaminated with this parasite, creating a potential risk for humans. Therefore, fresh fruit, vegetables, and mushrooms should be washed before consumption. Additionally, the results showed that the level of contamination is significantly lower than in the highly endemic Warmia-Masuria province. The differences in the occurrence of E. multilocularis in the environment of these neighbouring provinces appears to be connected with the general epidemiological situation of these two regions, but further study is required for an exact explanation.

Parasites impair healthy life and development in hundreds of millions of individuals throughout the world. Various human populations are at serious risk of illness and even death from these pathogens. It should be taken into account that medically important parasites are not only those often infecting human hosts but also species that rarely colonize the human organism in the given region of the world. The latter can induce serious diseases or high mortality rates as they may be not correctly diagnosed or may be left untreated (e.g., dirofilariosis and malaria in Poland). Recently, reemerging parasites and newly emerging species (e.g., free living, facultative parasitic amoebae) have become an increasing worldwide public health problem connected with many mistakes and uncertainties in diagnosis; thus, there is a need for introduction of new diagnostic methods and successive advances in therapeutic management. The available evidence indicates that there are changes in natural and anthropogenic environments that affect the spread and emergence of these diseases in any given area, including climate change, population growth agricultural intensification, and human encroachment into wildlife habitats. Likewise, increasing environmental pollution and degradation and alterations in microbial and other ecosystems influence the spread, prevalence, and epidemiological dynamics of parasitic infections. This issue addresses the region-dependent, recurrent, and newly emerging health threats generated by the parasites and related pathogens in specific countries. Yet, while the focus of each article in this issue is on specific geopolitical entities, each of these national or regional cases provides a model that can be applied globally to parasitic threats to any country or region. Among different causes, these threats are due to rising numbers of people traveling greater distances, who undertake trips to endemic countries [1]. For example, dengue fever, an emerging vector-borne disease, currently is threatening human populations in different countries of Asia, the Pacific, the Americas, Africa, and Caribbean, some of which are the popular tourist destinations. The World Health Organization and Centers for Disease Control and Prevention reported that the pathogens occur in about 100 countries. Causative agent of the disease is RNA DENV that shows unexpected geographical expansion and an increase in number and severity of outbreaks in the last decades. Dengue infections are transmitted to vertebrate hosts by the external blood-sucking vectors, usually Aedes mosquitoes. The geographical range of dengue incidences is expanding; they are much more widespread than has been suggested previously. Climate changes and the human movement between population centers are, among others, important factors of dengue spread. The available data on spread of the viral disease using a novel approach indicates that dengue incidences occur in 128 countries including those previously classified as dengue-free [2]. At present, dengue is one of the most important mosquito-borne viral diseases in the world that additionally may be transmitted from an infected pregnant mother to her fetus. Although Aedes aegypti, the main vector of DENV feeding on human blood, do not remain alive in the winter in temperate zones, not only can some Aedes species be active throughout the year in tropical and subtropical zones but they remain alive throughout the winter in the egg stage in temperate climates. This may include invasive species such as Aedes albopictus, which has recently colonized vast temperate areas of Europe and North America [3], where it threatens broader transmission of dengue and other diseases such as emerging human dirofilariosis across many new regions of Europe [4]. No diagnostic tests were performed in Poland regarding dengue virus infections until 2005, although, in Europe, sporadic indigenous dengue transmission cases have been detected. The number of Polish travelers to subtropics and tropics, including endemic regions in which dengue fever occurs, increases every year. There was a need to examine and assess a risk of dengue infection during a travel as well as the imported dengue cases. The serological tests performed in the University Centre for Maritime and Tropical Medicine allowed diagnosing the dengue in 149 travelers (19.8% of the investigated group) and indicated a serious risk of dengue virus infection during stays in endemic regions [5]. While these high-profile pandemic and emerging diseases often gain considerable attention from researchers and the popular press, national health ministries, hospitals, and regionally affiliated universities must focus on the health situations and threats that are encountered in their specific areas. Many of these threats come from major neglected diseases that have posed threats to human health for centuries but may be emerging in certain regions or may be emerging within specific groups of patients (e.g., pregnant women), under specific healthcare contexts (e.g., as sequelae to previously treated or cured infections), or under newly emerging situations (e.g., emerging drug resistance). In this issue, some of the most devastating and widespread diseases are presented as they relate to these particular contexts in specific regions of concern. Examples of current health threats in diverse regions and socioeconomic contexts in Asia, North America, South America, and Europe, as well as threats from global migration, are included (e.g., cutaneous leishmaniosis, malaria, Chagas disease, echinococcosis (hydatid disease), and amoebic keratitis). Thus, the issue presents a broad view portraying the intersection of national, regional, and global health. Malaria is among the most prevalent diseases across the globe; its impact on a particular semiurban community in India and within a particular group—pregnant women—is presented; it thus addresses the global public health priority of maternal and child health. Leishmaniosis, which is endemic in many areas, is reported from a nonendemic area in Brazil; the impact of the health-seeking behavior is examined among patients with post-Kala-azar dermal leishmaniosis in Bangladesh. Besides diverse geographical and biotic situations that affect human health differently in various regions, specific healthcare practices in particular regions may impact the emergence or maintenance of infectious disease. The effective healthcare needs to establish criteria for designating a disease as cured following therapy; methods applied in Brazil and elsewhere and questions of whether it is time to adopt new concepts in dealing with posttherapeutic cure criterion for Chagas disease are critically examined. As a major disease endemic in Brazil and broadly throughout South and Central America, but experiencing a major emergence in both North America and southwestern Europe, this provides an example of how policy in an experienced endemic country might inform better practices in newly threatened regions. The occurrences of Echinococcus granulosus sensu stricto infection among Polish patients are studied and analyzed as the important molecular epidemiology question of whether these result from autochthonous transmission or importation from other countries. Emerging threats for human health in Poland due to drug-resistant Acanthamoeba keratitis are also studied, among others in terms of adaptive capability of pathogenic strains, causative agents of the serious, vision-threatening disease. This general theme of international dissemination of infectious diseases is also examined and analyzed in the review; it relates a wide range of viral, bacterial, and parasitic disease threats to the immigration of adoptees and refugees into the United States from countries around the world. Besides their medical and humanitarian importance, both of these raise significant issues regarding national health policies on both domestic and international issues within the respective countries. In conclusion, it is important to encourage scientists in extension of our knowledge of serious but poorly recognized national/regional health threats, generated by parasites and related pathogens, intensifying during the last decade. It may allow a new appreciation of the importance of the holistic approach that involves in vivo and in vitro diagnostic techniques and biomolecular detection including advances in control and prevention strategies and therapeutic procedures as well as practical implications for diagnostics, treatments, and prophylaxis for such parasitic infections and diseases. Lidia Chomicz David Bruce Conn Jacek P. Szaflik Beata Szostakowska

Although numerous genetically isolated entities within Contracaecum rudolphii sensu lato are presently defined, information on the distribution and ecology of these groups is nonetheless in demand. In the present study, information based upon DNA sequence data (restriction analysis and sequencing of rDNA) on the distribution of the species C. rudolphii A and C. rudolphii B in the cormorant Phalacrocorax carbo sinensis from the Baltic region (Poland and Finland) is provided. These data corroborate previous work that identified C. rudolphii A in brackish water regions and C. rudolphii B in fresh water sites, although mixed infections also occur. The 2 species may inhabit the same host specimen. One rare heterozygote of the species was recorded.

BACKGROUND Malaria is one of the three most dangerous infectious diseases in the world. According to official statistics, there are a few dozen cases in Poland annually while the number of Poles treated abroad or self-treating remains unknown. Poland has been declared to be malaria-free since 1963 and nowadays all cases are imported. The aim of the study is to determine the minimal number of malaria cases in Poles at home and abroad in the last decade. MATERIALS AND METHODS The medical records of 4,710 patients tested for malaria in the Department of Tropical Parasitology in the years 2003-2012 were analysed. Two spreadsheets were created, which only included people with a history of malaria diagnosed in the reference centre where indirect immunofluorescent-antibody assay (IFA) for Plasmodium falciparum antigen proved positive. The minimum number of Poles who have had malaria at home and abroad was calculated on the basis of positive IFA results; the rate of all treated malaria patients in Poland in relation to those treated in the reference centre and the actual number of Poles with malaria diagnosed at home was calculated. RESULTS A group of 376 people with positive serologic tests results in indirect immunofluorescent antibody assay with titre ≥ 1:20 were received, including 227 patients with positive serologic results with titre ≥ 1:80. The rate of the overall number of malaria cases in Poland compared to the number of malaria cases in the University Centre for Maritime and Tropical Medicine Hospital was determined as 3.47:1. It was demonstrated that every year at least 174 to 211 Poles staying abroad may suffer from malaria. CONCLUSIONS This is the first attempt to estimate the minimal number of Poles infected and treated for malaria in Poland and abroad. The estimated number is 8-10 times greater than the number of registered cases in Poland.

Toxoplasma gondii infections are prevalent in humans and animals all over the world. The aim of the study was to estimate the occurrence of T. gondii oocysts in fruits and vegetables and determine the genotype of the parasites. A total number of 216 fruits and vegetables samples were taken from shops and home gardens located in the area of northern Poland. Oocysts were recovered with the flocculation method. Then, real-time polymerase chain reaction (PCR) targeting the B1 gene was used for specific T. gondii detection and quantification. Toxoplasma DNA was found in 21 samples. Genotyping at the SAG2 locus showed SAG2 type I and SAG2 type II. This is the first investigation describing T. gondii DNA identification in a large number of fruits and vegetables samples with rapid molecular detection methods. The results showed that fruits and vegetables contaminated with T. gondii may play a role in the prevalence of toxoplasmosis in Poland.

Infections caused by Toxoplasma gondii are prevalent in humans and animals throughout the world. So far, there is no sufficient information concerning T. gondii oocysts prevalence in the environment, especially in soil. Therefore, the aim of this study was to estimate occurrence of T. gondii oocysts in soil and determine the genotype of detected parasites. A total of 101 soil samples were taken from different sites (sand-pits, "farming ground", areas around rubbish dumps) located in the Tri-City (Poland). Oocysts were recovered using the flotation method. Then, PCR reactions targeting the B1 gene were performed for specific T. gondii detection. The positive samples were further confirmed by PCR amplification of a repetitive element (REP) sequence [GenBank accession number AF146527]. Toxoplasma DNA was found in 18 samples. Among them, seven samples were successfully genotyped at the SAG2 locus. They were classified as SAG2 type I (5 samples) and SAG2 type II (2 samples). This is one of the first investigations describing T. gondii oocyst detection in environmental soil samples with rapid molecular detection methods and genotyping. The results of our findings showed that soil contaminated with T. gondii oocysts may play a role in the epidemiology of human toxoplasmosis in Poland.

Malaria is, along with tuberculosis and HIV/AIDS, one of the three most dangerous infectious diseases in the world. In the absence of native cases since 1963, malaria has remained in Poland an exclusively imported disease, mainly occurring in people travelling to tropical and subtropical areas for professional reasons. The aim of this study was the epidemiological and clinical analysis of 82 patients admitted to the University Center for Maritime and Tropical Medicine (UCMTM), Gdynia, Poland, with a diagnosis of malaria between 2002 and 2014. The “typical” patient with malaria was male, middle-aged, returned from Africa within the preceding 4 weeks, had not used appropriate chemoprophylaxis, and had not applied nonpharmacological methods of prophylaxis, except for window insect screens.P. falciparumwas the most frequent species. The most common symptoms included fever, shivers and intensive sweating, thrombocytopenia, elevated creatinine, LDH, D-dimers and CRP, hepatomegaly, and splenomegaly. Within the analyzed group, severe malaria according to WHO standards was diagnosed in 20.7% of patients. Our report presents analysis of the largest series of patients treated for imported malaria in Poland.

Infections of humans with Echinococcus multilocularis, the causative agent of alveolar echinococcosis (AE), a zoonosis, have been described with increasing frequency in Poland since 1994. In the attempt to verify these reports, we analyzed specimens obtained from a representative group of Polish patients. Liver lesions in patients with AE that was diagnosed on the basis of results of histological and serological tests contained E. multilocularis DNA, as shown by the presence of specific microsatellite sequences and mitochondrial 12S rDNA. The same tests clearly distinguished between AE and cystic echinococcosis, which is caused by Echinococcus granulosus. These data are unequivocal proof that human infections with E. multilocularis occur in Poland.

Fish is an important food source for an estimated 300,000 people inhabiting the shores of Lake Turkana, Kenya. Despite its large size (7560 km2) and importance, the lake remains one of the least studied in the Great Lakes Region of Africa. This study describes the parasite community of the elongate tigerfish Hydrocynus forskahlii (Cuvier, 1819) and the redbelly tilapia Tilapia zillii (Gervais, 1848). A total of 87 individuals (43 H. forskahlii and 44 T. zillii) were dissected and examined for parasites. Two taxa infected H. forskahlii, the dominant one being an anisakid nematode Contracaecum sp. (L3) (P = 83.7%, mean intensity (MI) = 46.0, abundance (A) = 38.5). Twelve parasite taxa were recovered from T. zillii, with metacestodes of the gryporhynchid cestode Amirthalingamia macracantha being dominant (P = 79.5, MI = 10.3, A = 8.2). This was the first report of a mixture of merocercoids and plerocercoids in the same host. Fish size was positively correlated with the major parasite infection levels, but, the prevalence of Contracaecum sp. in H. forskahlii was negatively correlated with size, probably reflecting ontogenetic shifts in habitats and diets with age. Fish sex was not a significant influencing factor, with the exception of Contracaecum sp. in H. forskahlii, where prevalence differed significantly between sexes (p

In the years 1994-1996, a total of 592 specimens of herring Clupea harengus membras L., caught in southern Baltic, were examined. The investigations revealed four species of trematodes: Hemiurus luhei, H. raabei, H. levinseni, Brachyphallus crenatus, two species of nematodes: Hysterothylacium auctum (syn. H. aduncum), and Anisakis simplex and three acanthocephalans: Echinorhynchus gadi, Metechinorhynchus salmonis and Pomphorhynchus sp. The finding of H. levinseni constitutes the first record of this species in Polish waters. The infection parameters of herring (prevalence, intensity and abundance) were compared in relation to different capture areas and seasons of the year. Possible affects of the feeding ground, fish body length and the spawning group of herring on the infection levels were also examined. No relation was observed between the place and the season of catch and the infection level of herring. The fish representing different feeding grounds (Baltic, Danish Straits) and sequential length classes showed variable parameters of infection.

Acetylcholinesterase (AChE) activity measurement is widely used as a specific biomarker of neurotoxic effects. The aim of this study was to evaluate AChE activity in a host fish (the cod) and its acanthocephalan parasite Echinorhynchus gadi from the southern Baltic. AChE activity in hosts and parasites was inversely related: the highest cod AChE activity corresponded to the lowest E. gadi enzymatic activity and vice versa (“mirror effect”). This is the first report on the simultaneous application of this biomarker in cod and its acanthocephalan parasites. Results obtained for the host–parasite system are complementary and provide comprehensive information about the response of this biomarker. Analysis of the system allows for detection of a greater number of factors influencing AChE activity in the marine environment than separate analysis of the host and parasites. Thus, AChE activity measurement in a host–parasite system may be considered to be a promising tool for biomonitoring.

Background Alveolar echinococcosis (AE) caused by Echinococcus multilocularis infections is a dangerous old disease in the Northern Hemisphere. The aim of the paper was to collect and analyze data on human AE in Poland in the last two decades. Methodology/Principal Findings The sources of data were both the cases officially registered and detected by an active field and laboratory surveillance. The cases were verified by clinical, epidemiological, and laboratory criteria. Altogether 121 human cases of AE were detected. Among these 83 (68,6%) cases were classified as confirmed, 16 as probable and 22 as possible. During the two decades a continuous increase in detection rate was noticed. The cases were 6–82 years old at the time of diagnosis (mean - 47.7 years). Sex ratio M/F was 0.86/1.0. The AE was fatal in 23 (19%) patients (mean age at death - 54.1 years). Family agglomeration of AE was found in 4 foci, involving 9 patients. Seventy six of the cases were diagnosed in an advanced stage of disease. In all cases the liver was the primary location of AE. In 30 (24.8%) patients a spread to other organs was observed. Ninety four of the patients were treated with albendazole. In 73 (60%) patients a surgical operation was performed, including 15 liver transplantations. Conclusions/Significance The studies confirmed that AE is an emerging disease in Poland, which is the fourth country in Europe with over 120 cases detected. The results also indicate the need of a wider national programme for implementation of screening in the highest AE risk areas (north-eastern Poland) with an effort to increase the public awareness of the possibility of contracting E. multilocularis, and above all, training of the primary care physicians in the recognition of the risk of AE to allow for an early detection of this dangerous disease., Author Summary Human alveolar echinococcosis (AE) is a consequence of accidental ingestion of the eggs of the tapeworm Echinococcus multilocularis. AE constitutes a serious and increasing medical and epidemiological problem in many countries including Poland. The natural environments with a high AE prevalence are the areas where the definitive hosts (foxes, raccoons) and the intermediate hosts (rodents) live. The increasing population of infected foxes that penetrate nearby the village and urban buildings and infected dogs poses a certain risk to human health. This report is a joint clinical and epidemiological analysis of 121 AE cases recorded in the years 1990–2011 in Poland. The highest percentage of E. multilocularis infected foxes in the north-eastern regions of Poland (about 40% of the examined population infected) bears a clear-cut relation to the highest incidence of detected AE human cases in those areas. An epidemiological and clinical survey of the local population conducted for over a dozen years has contributed to the discovery of several new AE cases. Alveolar echinococcosis in humans caused by Echinococcus multilocularis infection belongs to the emerging diseases in Poland where a continuous increase in the detection rate was noticed during the last two decades.

The myxosporean specimens were noted in grey gurnard Eutrigla gurnardus (L.) from the area near the Shetland Islands. The structure and dimensions of its vegetative stage differ from earlier descriptions. A sequence of small subunit ribosomal RNA gene obtained during the current study differs from other Ceratomyxa spp. available in GenBank. A phylogenetic position of parasite based on the 18S rDNA fragment was estimated. The proposed name for this myxosporean is Ceratomyxa gurnardi sp. n.

Leishmania parasites are the etiological agents of leishmaniosis, with severe course and often fatal prognosis, and the global number of cases has increased in recent decades. The gold standards for the diagnosis of leishmaniosis are microscopic examinations and culture in vitro of the different clinical specimens. The sensitivity of these methods is insufficient. Recent development in specific and sensitive molecular methods (PCR) allows for detection as well as identification of the parasite species (subspecies). The aim of the study was to estimate the usefulness of molecular methods (PCR) for detection of Leishmania species and consequently for the implementation of such methods in routine diagnostics of leishmaniosis in Polish patients returning from endemic areas of the disease. In our investigations we used 54 known Leishmania positive DNA templates (from culture and clinical specimens) received from the CDC (Atlanta, GA, USA). Moreover, 25 samples of bone marrow, blood or other tissues obtained from 18 Polish individuals suspected of leishmaniosis were also examined. In PCR we used two pairs of primers specific to the conserved region of Leishmania kinetoplast DNA (kDNA) minicircle (13A/13B and F/R). Using these primers we obtained amplicons in all DNA templates from the CDC and in three Polish patients suspected for Leishmania infection. In one sample from among these cases we also obtained positive results with DNA isolated from a blood specimen which was previously negative in microscopic examinations.

Trophozoites and cysts of free-living Acanthamoeba castellanii present a serious risk to human health as causative agents of human diseases such as fatal granulomatous amoebic encephalitis and Acanthamoeba keratitis that is reported from various part of the world, also in Poland, with increasing frequency, particularly in the contact lens wearers. The amphizoic amoebae are generally extremely resistant to different chemical agents, however, several strains/isolates within A. castellanii may differ in virulence. Among the features considered as associated with the amoeba pathogenicity, temperature tolerance and resistance to different environmental conditions are reported. In the present study, A. castellanii strain cultured in 26 °C after several year passages were tested for sensibility/tolerance to instant temperature changes as well as exposition to deuterium oxide, D2O. Significant decrease of number of viable amoebae during in vitro exposition to D2O occurred, but no changes in trophozoites/cysts ratio. The ability of the strain examined to develop in higher temperature may indicate a wide adaptation reserve and its pathogenic potential.

Contracaecum sp. larvae (L3) from fish were identified using nucleotide sequences of the internal transcribed spacers ITS-1 and ITS-2 of the ribosomal DNA. The nematode larvae originated from fish in a freshwater situation (crucian carp Carassius carassius, from Selment Wielki Lake in Mazury, northeastern Poland) and a brackish-water region (Caspian round goby Neogobius melanostomus from the Baltic Sea, Gdafisk Bay at the Polish coast). Two strains (Contracaecum rudolphii A and B) of Contracaecum rudolphii senso lato, a parasite common at the adult stage in fish-eating birds, were identified. In fish from the freshwater site, only the strain temporarily designated C. rudolphii B was identified; in the brackish-water region, both strains were found, suggesting that fish serve as paratenic host for both genotypes. Contracaecum rudolphii sensu lato has been recorded in several species of fish-eating birds in Poland, particularly in the great cormorant, Phalacrocorax carbo, in which the abundance is highest. The results, although based on a restricted number of larvae, suggest that the life cycles of both genotypes can be completed in the Polish region and that at least one of them, C. rudolphii B, can develop both in fresh and brackish water.