Chronic intestinal schistosomiasis caused by co-infection with Schistosoma intercalatum and Schistosoma mansoni

The Grand Round concerns a 24-year-old man from Zimbabwe who was studying and living in Poland. The patient had been complaining of abdominal pain, fatigue, alternating diarrhoea and constipation, and presence of blood in his stool for 3 years. The patient had the following diagnostic tests: colonoscopy, CT scan, histopathology, and parasitological and molecular tests. Results of the examinations showed that the cause of the patient's complaints was chronic intestinal schistosomiasis due to the co-infection with Schistosoma intercalatum and Schistosoma mansoni. The patient had two cycles of praziquantel therapy (Biltricide) and responded well to the treatment. In the Grand Round, we describe full diagnostics as well as clinical and therapeutic management in the patient with S intercalatum and S mansoni co-infection. This case allows us to draw attention to cases of forgotten chronic tropical diseases (including rare ones) in patients from regions with a high endemic index staying in non-endemic regions of the world for a long time. Co-infection with S intercalatum and S mansoni should be considered as a very rare clinical case.

Successive Acanthamoeba Corneal Isolates Identified in Poland Monitored in Terms of In Vitro Dynamics

BACKGROUND

Amoebae of the genus Acanthamoeba cause a sight-threatening infection called Acanthamoeba keratitis. It is considered a rare disease in humans but poses an increasing threat to public health worldwide, including in Poland. We present successive isolates from serious keratitis preliminary examined in terms of the identification and monitoring of, among others, the in vitro dynamics of the detected strains.

METHODS

Clinical and combined laboratory methods were applied; causative agents of the keratitis were identified at the cellular and molecular levels; isolates were cultivated in an axenic liquid medium and regularly monitored.

RESULTS

In a phase-contrast microscope, Acanthamoeba sp. cysts and live trophozoites from corneal samples and in vitro cultures were assessed on the cellular level. Some isolates that were tested at the molecular level were found to correspond to A. mauritanensis, A. culbertsoni, A. castellanii, genotype T4. There was variability in the amoebic strain dynamics; high viability was expressed as trofozoites' long duration ability to intense multiply.

CONCLUSIONS

Some strains from keratitis under diagnosis verification and dynamics assessment showed enough adaptive capability to grow in an axenic medium, allowing them to exhibit significant thermal tolerance. In vitro monitoring that was suitable for verifying in vivo examinations, in particular, was useful to detect the strong viability and pathogenic potential of successive Acanthamoeba strains with a long duration of high dynamics.

Misdiagnosis and inappropriate treatment of cutaneous leishmaniasis: a case report

Background

Leishmaniasis is a widespread disease in tropical and subtropical countries, except for Australia and Oceania. In Poland, tourists, migrants and travellers from leishmaniasis-endemic countries may carry Leishmania.

Case presentation

We present a case of undiagnosed cutaneous leishmaniasis in a patient who received many weeks of inadequate antibiotic treatment. Ulceration in the right submandibular region was thought to be a purulent complication after laser surgery. Six weeks before the ulcer developed, the patient had visited the jungle (Guatemala). Cutaneous leishmaniasis was finally diagnosed after nine months based on a proper history and a polymerase chain reaction (PCR) assay. Treatment with antimony derivatives was administered. After three months, the ulcer healed but left a scar.

Conclusion

A lack of knowledge about tropical diseases among doctors and an incomplete medical history were the reasons for many weeks of erroneous treatment of cutaneous leishmaniasis with antibiotics. This is the first reported case of cutaneous leishmaniasis misdiagnosed as a complication after an aesthetic medical procedure.

Rare Occurrence of Blastocystis in Pet Animals and Their Owners in the Pomeranian Voivodeship in Poland in the Light of Literature Data

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.

Concurrent subcutaneous and ocular infections with Dirofilaria repens in a Polish patient: a case report in the light of epidemiological data

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.

Molecular Characterization of Blastocystis from Animals and Their Caregivers at the Gdańsk Zoo (Poland) and the Assessment of Zoonotic Transmission

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.

First Report on the Occurrence and Subtypes of Blastocystis in Pigs in Poland Using Sequence-Tagged-Site PCR and Barcode Region Sequencing

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 (ST1-8, 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 (44.4-50%) 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.

First case of human anisakiasis in Poland

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.

First detection of Echinococcus multilocularis in environmental water sources in endemic areas using capsule filtration and molecular detection methods

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.

Ultrasound images in hepatic alveolar echinococcosis and clinical stage of the disease

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.

Blastocystis subtypes isolated from travelers and non-travelers from the north of Poland - A single center study

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.

How effective is freezing at killing Anisakis simplex, Pseudoterranova krabbei, and P. decipiens larvae? An experimental evaluation of time-temperature conditions

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.

The First Case of Elbow Bursitis Caused by Dirofilaria repens in Humans

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.

Detection of Giardia intestinalis in water samples collected from natural water reservoirs and wells in northern and north-eastern Poland using LAMP, real-time PCR and nested PCR

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.

Detection of Echinococcus multilocularis DNA in fruit, vegetable, and mushroom samples collected in the non-endemic territory of the Pomerania province and comparison of the results with data from rural areas of the neighbouring highly endemic Warmia-Masuria province, 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.

An attempt to estimate the minimal number of Poles infected and treated for malaria in Poland and abroad

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.

Cryptosporidium meleagridis infection: the first report in Poland of its occurrence in an HIV-positive woman

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.

Fresh fruits, vegetables and mushrooms as transmission vehicles for Echinococcus multilocularis in highly endemic areas of Poland: reply to concerns

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.

Clinico-laboratory profile of dengue patients returning from tropical areas to Poland during 2010-15

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.

Investigations on the occurrence of Plasmodium knowlesi in travellers returning from the endemic areas of simian malaria

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.

Different serotypes of dengue virus (DENV) imported by Polish travellers from dengue endemic areas to Poland

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.

Studies on Immunogenicity and Antigenicity of Baculovirus-Expressed Binding Region of Plasmodium falciparum EBA-140 Merozoite Ligand

The erythrocyte binding ligand 140 (EBA-140) is a member of the Plasmodium falciparum erythrocyte binding antigens (EBA) family, which are considered as prospective candidates for malaria vaccine development. EBA proteins were identified as important targets for naturally acquired inhibitory antibodies. Natural antibody response against EBA-140 ligand was found in individuals living in malaria-endemic areas. The EBA-140 ligand is a paralogue of the well-characterized P. falciparum EBA-175 protein. They both share homology of domain structure, including the binding region (Region II), which consists of two homologous F1 and F2 domains and is responsible for ligand-erythrocyte receptor interaction during merozoite invasion. It was shown that the erythrocyte receptor for EBA-140 ligand is glycophorin C-a minor human erythrocyte sialoglycoprotein. In studies on the immunogenicity of P. falciparum EBA ligands, the recombinant proteins are of great importance. In this report, we have demonstrated that the recombinant baculovirus-obtained EBA-140 Region II is immunogenic and antigenic. It can raise specific antibodies in rabbits, and it is recognized by natural antibodies present in sera of patients with malaria, and thus, it may be considered for inclusion in multicomponent blood-stage vaccines.

The first detection of Echinococcus multilocularis DNA in environmental fruit, vegetable, and mushroom samples using nested PCR

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.

Parasite communities of the elongate tigerfish Hydrocynus forskahlii (Cuvier 1819) and redbelly tilapia Tilapia zillii (Gervais 1848) from Lake Turkana, Kenya: influence of host sex and size

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<0.05), with the females having a higher prevalence than the males. We conclude that H. forskahlii had a poor parasitic community but that the infection levels with Contracaecum sp. were high. T. zillii had a rich parasite fauna, although, most parasites occurred at low intensities.

Acetylcholinesterase activity in the host-parasite system of the cod Gadus morhua and acanthocephalan Echinorhynchus gadi from the southern Baltic Sea

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.

Human alveolar echinococcosis in Poland: 1990-2011

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.

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.

Morphological and molecular characterization of Ceratomyxa gurnardi sp. n. (Myxozoa: Ceratomyxidae) infecting the gallbladder of the grey gurnard Eutrigla gurnardus (L.) (Scorpaeniformes, Triglidae)

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.

The first detection of Toxoplasma gondii DNA in environmental fruits and vegetables samples

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.

Acanthamoeba castellanii: in vitro effects of selected biological, physical and chemical factors

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 degrees 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.

Usefulness of PCR method for detection of Leishmania in Poland

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.

Prevalence of anisakin nematodes in fish from Southern Baltic Sea

Nematodes from the superfamily Ascaridoidea (families Anisakidae and Raphidascarididae) are worldwide distributed parasites. Their live cycles include many species of water invertebrates and teleostean fish as intermediate hosts, and fish, sea mammals or fish-eating birds being definitive hosts. Humans can be infected with some of these parasites after consumption of raw or wrongly processed fish. The parasitological investigations of fish (herring, cod and flatfish) from southern Baltic (ICES 24-26) provided in the years 80 and 90 showed their infection with larvae of several anisakid species: Anisakis simplex s. str., Contracaecum osculatum C and Hysterothylacium auctum. Sporadically Pseudoterranova decipiens and Raphidascaris acus were also found. Larvae of Anisakis simplex were noted mainly in herrings, C. osculatum primarily in cods and H. auctum in flounders. Additionally, preserved herrings (marinated, smoked) were also investigated and sporadically live larvae of A. simplex were found. The main etiological agent of human anisakidosis worldwide is A. simplex. Although the live cycle of this nematode cannot be completed in the Baltic Sea--this nematode is brought to the Baltic by infected herring migrating from the North Sea for spawning in coastal waters of the Southern Baltic--the prevalence and intensity of infection with larvae of this nematode species were the highest in fish investigated by us. The results obtained suggest the possibility of the human infection with A. simplex larvae in Poland.

Cryptosporidium parvum and Giardia lamblia recovered from flies on a cattle farm and in a landfill

Filth flies associated with a cattle barn and a municipal landfill were tested positive by combined immunofluorescent antibody and fluorescent in situ hybridization for Cryptosporidium parvum and Giardia lamblia on their exoskeletons and in their guts. More pathogens were carried by flies from the cattle barn than from the landfill; 81% of C. parvum and 84% of G. lamblia pathogens were presumptively viable.

Assessment of clinical course and outcome of Plasmodium falciparum malaria in Angola diagnosed by microscopic and molecular methods

Malaria still remains the main infectious cause of morbidity and mortality in the world. The majority of cases occur in tropical Africa, including Angola. The study was performed in Angola, in the Health Centre of St. Lucas in Kifangondo, near Luanda during the dry season, from May to October 1999. 168 patients with symptoms of malaria were referred for study enrolment. In the study we assessed the efficacy of treatment in falciparum malaria based on clinical, microscopic and polymerase chain reaction (PCR) examination, and estimated the prevalence of mutations in the pfcrt gene in the P. falciparum isolates from chloroquine-treated patients. In 159 (95%) patients P. falciparum malaria was diagnosed using microscopic methods. This was confirmed by PCR. We admitted 68 patients to the hospital; 13 patients died from complicated malaria. We have analysed 59 cases of P. falciparum malaria known to be chloroquine-treated. In 58 (98%) cases we have found P. falciparum isolates that carried gene polymorphisms typical for chloroquine resistance. In the group with such P. falciparum isolates, 8 people were treated successfully. Reasons for this response are discussed.

Mechanical transmission of Cryptosporidium parvum oocysts by flies

Long term field studies and laboratory experiments demonstrated that synanthropic filth flies can mechanically transmit infectious oocysts of Cryptosporidium parvum, an anthropozoonotic protozoan parasite which significantly contributes to the mortality of immunocompromised or immunosuppressed people. C. parvum oocysts are acquired from unhygienic sources, and can pass trough fly gastrointestinal track without alteration of their infectivity and can be subsequently deposited on visited surfaces. Transmission of the oocysts by adult flies occurs via: (1) mechanical dislodgement from the exoskeleton; (2) fecal deposition; and (3) regurgitation, i.e., vomits. Filth flies can cause human or animal cryptosporidiosis via deposition of infectious oocysts on the visited foodstuf, and the biology and ecology of synanthropic filth flies indicate that their potential for mechanical transmission of C. parvum is high.

Molecular confirmation of human alveolar echinococcosis 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.

Identification of anisakid nematodes from the Southern Baltic Sea using PCR-based methods

Four common species of Baltic anisakids Anisakis simplex, Hysterothylacium auctum, Contracaecum osculatum from fish (the last one also from the grey seal) and C. rudolphii from cormorants were examined using PCR-RFLP technique for working out the method allowing their identification and differentiation. A fragment of nuclear DNA containing intergenic regions (ITS-1 and ITS-2) of ribosomal DNA together with adjacent sequences of genes coding 18S and 28S rRNA (in total; approximately 1500 bp) was amplified and the products were digested using three endonucleases Hin fI, Hae III and Pvu II. Digestion with Hin fI endonuclease enabled species identification and differentiation between all nematode species studied. Digestion with Hae III endonuclease enabled identification of A. simplex and H. auctum while electrophoretic patterns obtained for both Contracaecum species were similar (differentiation between A. simplex, H. auctum and the genus Contracaecum). Pvu II endonuclease was not suitable to this purpose. On the basis of nucleotide sequences obtained, the pairs of species-specific primers were designed for each species studied. By the use of these pairs of primers the species-specific PCR reactions were carried out. The sizes of specific products were: 486 bp for A. simplex, 491 bp for C. osculatum, 505 bp for C. rudolphii and 663 bp for H. auctum. The methods presented herein can be useful in diagnostics of human anisakidosis, especially when parasites are disrupted.