Parasitic infections among patients hospitalized in the Tropical and Parasitic Clinic of Poznan University of Medical Sciences, Poland between 2015 and 2018. Is there a relationship between protozoa infection and gastrointestinal symptoms?

Introduction: Diarrhoea is a common reason for hospitalization among travellers returning from the tropics. The aetiology is predominantly bacterial, but it can also be caused by parasites such as Giardia intestinalis, Cryptosporidium spp., and Blastocystis spp. Aim: We analysed patients from the Poznan Tropical and Parasitic Clinic to evaluate the presence of parasitic infections and to find correlations between infections, journeys, and gastrointestinal symptoms. Material and methods: In our study we examined 2561 stool samples obtained from patients hospitalized in the Tropical and Parasitic Department of Poznan Medical University, Poland. Microscopic examinations of samples were performed based on a direct thin smear in 0.9% NaCl, which allowed the assessment of the presence of protozoa life stages. Results: In 106 (4.14%) of the 2561 examined samples we detected parasites, mainly from people coming back from tropical areas (61.32%). Mostly we detected Blastocystis sp. and Giardia intestinalis. Fifty percent of patients suffered from gastrointestinal symptoms, so careful microscopic stool examination should be performed in every case in which intestinal pathology occurs, and certainly in travelling individuals. Conclusions: Traveling is a real risk factor for protozoa infection. The most common parasites detected in the stool are Blastocystis sp. and Giardia intestinalis. Parasitic coinfection should be taken into consideration as a pathologic agent in patients suffering from abdominal signs and persistent diarrhoea. Prolonged protozoa infection and its role in microbiota alterations requires further investigation.

Prevalence of Anti-SARS-CoV-2 Antibodies in Poznan, Poland, after the First Wave of the COVID-19 Pandemic.

In comparison to other European countries, during the first months of the COVID-19 pandemic, Poland reported a relatively low number of confirmed cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. To estimate the scale of the pandemic in Poland, a serosurvey of antibodies against SARS-CoV-2 was performed after the first wave of COVID-19 in Europe (March-May 2020). Within this study, we collected samples from 28 July to 24 September 2020 and, based on the ELISA results, we found that 1.67% (25/1500, 95% CI 1.13-2.45) of the Poznan (Poland) metropolitan area's population had antibodies against SARS-CoV-2 after the first wave of COVID-19. However, the presence of anti-SARS-CoV-2 IgG antibodies was confirmed with immunoblotting in 56% (14/25) samples, which finally resulted in a decrease in seroprevalence, i.e., 0.93% (14/1500, 95% CI 0.56-1.56). The positive anti-SARS-CoV-2 IgG results were associated with age, occupation involving constant contact with people, travelling abroad, non-compliance with epidemiological recommendations and direct contact with the novel coronavirus. Our findings confirm the low SARS-CoV-2 incidence in Poland and imply that the population had little herd immunity heading into the second and third wave of the pandemic, and therefore, that herd immunity contributed little to preventing the high numbers of SARS-CoV-2 infections and COVID-19-related deaths in Poland during these subsequent waves.

Immunoproteomic analysis of Trichinella spiralis and Trichinella britovi excretory-secretory muscle larvae proteins recognized by sera from humans infected with Trichinella.

The present study compares the immunogenic patterns of muscle larvae excretory-secretory proteins (ML E-S) from T. spiralis and T. britovi recognized by Trichinella-infected human sera. Samples were analyzed using two-dimensional electrophoresis (2-DE) coupled with 2D-immunoblot and liquid chromatography-tandem mass spectrometry LC-MS/MS analysis, two ELISA procedures and a confirmatory 1D-immunoblot test. Sera were obtained from nine patients with a history of ingestion of raw or undercooked meat who presented typical clinical manifestations of trichinellosis and from eleven healthy people. Specific anti-Trichinella IgG antibodies were detected in all samples tested with the Home-ELISA kits, but in only four samples for the commercially-available kit. The 1D-immunoblot results indicated that all nine serum samples were positive for T. spiralis ML E-S antigens, expressed as the presence of specific bands. In contrast, eight of the serum samples with T. britovi E-S ML antigens were positive, with one serum sample taken from a patient at 33dpi (days post infection) being negative. To identify immunoreactive proteins that are specifically recognized by host antibodies, both species of ML E-S proteins were subjected to 2D-immunoblotting with human serum taken at 49 dpi. The sera recognized 22 protein spots for T. spiralis and 18 for T. britovi in 2D-immunoblot analysis. Their molecular weights (MW) ranged from 50 to 60 kDa. LC-MS/MS analysis identified both common and specifically-recognized immunoreactive proteins: transmembrane serine protease 9, serine protease, antigen targeted by protective antibodies and Actin-1 partial were shared for both Trichinella species; hypothetical protein T01_7775 and P49 antigen, partial those specific to T. spiralis; deoxyribonuclease-2-alpha and hypothetical protein T03_17187/T12_7360 were specific to T. britovi. Our results demonstrate the value of 2-DE and 2D-immunblot as versatile tools for pinpointing factors contributing to the parasite-host relationship by comparing the secretomes of different Trichinella species.

Case of Plasmodium knowlesi Malaria in Poland Linked to Travel in Southeast Asia.

We report a case of Plasmodium knowlesi malaria imported to central Europe from Southeast Asia. Laboratory suspicion of P. knowlesi infection was based on the presence of atypical developmental forms of the parasite in Giemsa-stained microscopic smears. We confirmed and documented the clinical diagnosis by molecular biology techniques.

Massive Cryptosporidium infections and chronic diarrhea in HIV-negative patients.

Protozoa of the genus Cryptosporidium are common parasites of domestic and wild animals-mammals, birds, reptiles, and fishes. The invasive forms are thick-walled oocysts, which can be present in water supplies, on fruits, vegetables, or in the soil contaminated with feces. In this work, we describe three cases of middle-aged persons with massive Cryptosporidium hominis infection and chronic diarrhea with no immunological abnormalities and no history of previous travels to tropical countries. The lesions discovered during colonoscopy within the large intestine-cryptitis and the histopathological changes were related to massive cryptosporidiosis. All these statements indicate necessity of parasitological stool examination in cases with chronic diarrhea in which no etiological agents are detected, but not only in HIV positive individuals. Parasite's eradication leads to symptom disappearance as well as improvement of histopathological mucosa alterations.

Cerebral malaria and multi-organ dysfunction in an adult woman with Plasmodium falciparum infection imported from Cameroon: a case report

Malaria is one of the most life-threatening parasitic diseases caused by the protozoa of the genus Plasmodium, occurring in the tropical and subtropical regions. Misdiagnosed infection can progress to a wide range of life-threatening pathologies, including severe anemia and cerebral malaria which can lead to death even few days after first symptoms appearance. Cerebral malaria is rare in adults and most cases are connected to children under 5 years old living in malaria endemic areas. In this article we describe cerebral malaria caused by the Plasmodium falciparum in a 45-year-old Polish patient, who traveled to Cameroon without any malaria prophylaxis. The patient had been treated in an intensive care unit because of multi-organ dysfunction as a result of the delayed malaria diagnosis. The presence of thrombocytopenia, anemia, metabolic acidosis, acute respiratory distress syndrome and multi-organ dysfunction involving liver, kidneys, and brain created an image of advanced severe malaria. Loss of consciousness, GCS 6, and the presence of asexual Plasmodium falciparum forms in blood films are the evidence of cerebral malaria. To avoid development of cerebral malaria, the illness should be diagnosed immediately. The cerebral malaria can occur also in adult healthy individuals. Appropriate treatment with intravenous artemisine can protect the patient from lifethreatening complications. Prolonged anemia after treatment can be a consequence of artemisine usage as well as a severe malaria sequel.

Outcome of acute East African trypanosomiasis in a Polish traveller treated with pentamidine.

BACKGROUND: African trypanosomiasis is a parasitic infection sporadically imported to Europe by tourists or immigrants returning from endemic areas. We present the first and an unusual case of East African trypanosomiasis imported to Poland by a patient returning from a tourist trip to Uganda and Rwanda, which was successfully treated with pentamidine. CASE PRESENTATION: A 61-year-old Polish man was admitted to the Department because of high-grade fever and multi-organ dysfunction after a tourist trip to East Africa. He experienced a single tsetse fly bite during a safari trip to the Queen Elizabeth National Park in Uganda. On admission, his clinical status was severe, with high fever of 41ºC, preceded by chills, bleeding from the gums and oral mucosa, haemorrhages at the sites of venipuncture, numerous ecchymoses, fine-spotted skin rash, tachycardia, hepatosplenomegaly, dehydration, jaundice, dyspnoea, hypoxaemia, generalised oedema and oliguria. There was a typical non-painful trypanosomal chancre with central necrosis and peripheral erythema on his left arm. Laboratory investigations showed leucopenia, thrombocytopenia, haemolytic anaemia, hyperbilirubinaemia, hypoglycaemia, elevated creatinine and urea, high activity of aminotransferases, elevated levels of inflammatory markers, hypoproteinaemia, proteinuria, abnormal clotting and bleeding times, low fibrinogen level, metabolic acidosis, and electrolyte disturbances. A peripheral blood smear showed numerous Trypanosoma brucei trypomastigotes with a massive parasitaemia of 100,000/µl. T. brucei rhodesiense subspecies was finally identified on the basis of the characteristic serum resistance-associated gene using a polymerase chain reaction, and a seroconversion of specific immunoglobulin M and G antibodies in the peripheral blood by enzyme-linked immunosorbent assay. Serological tests for T. brucei gambiense subspecies were negative. A severe clinical course of acute rhodesiense trypanosomiasis with renal failure, respiratory distress, disseminated intravascular coagulation syndrome, haemolysis, liver insufficiency and myocarditis was confirmed. Intensive anti-parasitic and symptomatic treatment was immediately instituted, including intravenous pentamidine, plasmaphereses, oxygen therapy, blood transfusion, catecholamine administration, and fluid infusions, as well as haemostatic, hepatoprotective, anti-inflammatory, antipyretic and diuretic drugs. The final outcome was a full recovery with no late sequelae. CONCLUSION: Sleeping sickness should always be considered in the differential diagnosis of fever in people returning from safari trips to the national parks or nature reserves of sub-Saharan Africa.

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.

The co-occurrence of Toxocara ocular and visceral larva migrans syndrome: a case series.

INTRODUCTION: Ocular toxocarosis associated with high peripheral eosinophilia and together with systemic signs of visceral damage has been reported sporadically. Eye infections caused by numerous migrating larvae of Toxocara parasites, probably due to re-invasion or delayed reactivation, and leading to a progressive loss of vision is relatively rare. We report three atypical cases of toxocarosis with the co-existence of ocular larva migrans syndrome and generalized signs of Toxocara infection in schoolboys. CASE PRESENTATION: Two children aged 8 and 14 years respectively, with symptomatic ocular and visceral larva migrans syndromes, and one 16-year-old adolescent with chronic multifocal eye invasion, characterized by severe granulomatous retinochoroiditis with unilateral blindness, chronic abdominal pain and generalized synthesis of total immunoglobulin E antibody are described. The three patients, heavily infected with Toxocara species were boys of Polish origin. Ocular location of the parasite was confirmed by the detection of intraocular synthesis of specific anti-Toxocara immunoglobulin G antibody in aqueous humour samples from the affected eyes. Immunological parameters of tissue eosinophilia, allergy or hypersensitivity reactions to the presence of the migrating Toxocara parasites were analysed. Irreversible eye complications were observed in the patients with high level of exposure to Toxocara species in a contaminated environment, with a suggestion of possible re-activation or re-infection by different species or strains of the parasite. CONCLUSIONS: Wide promotion of sanitary education is strongly justified in children and adolescents in Toxocara endemic areas in order to reduce the potential risk of primary invasion or re-infection with the parasites, which can lead to a severe course or progression of the disease. A long-term clinical follow-up and more intensive anti-parasitic treatment is recommended in patients with subclinical and overt forms of toxocarosis to prevent later reactivation of the migrating larvae in tissues.

[Guidelines for diagnosis and treatment of liver alveococcosis caused by Echinococcus multilocularis]. / Zasady rozpoznawania i leczenia bablowicy watroby wywolywanej przez Echinococcus multilocularis.

UNLABELLED: Recent epidemiological reports have shown an increasing incidence of Echinococcus multilocularis infection among red foxes and inhabitants from Pomorskie, Warminsko-Mazurskie and Podkarpackie Districts of Poland. The study describes the actual recommendations for a proper diagnosis and optimal treatment in patients infected with E. multilocularis in order to standardize diagnostic and therapeutic procedures for this severe parasitic disease by reference centres. Liver lesions caused by the parasite were visualised by ultrasonography and computerized tomography scan. The clinical diagnosis based on typical imaging findings was completed by Em2plus ELISA and Em16 and Eml18 Western blot immunodiagnostic tests using specific antigens, and confirmed by positive histopathological and/or molecular examinations. Since 1992, forty-five cases of alveolar echinococcosis were registered in Poland. Professions related to forestry or picking-up mushrooms and blueberries were potential risk factors for an occurrence of the infection, especially in the northern region of the country. In the imaging techniques, the liver lesions were characterized by heterogenous, irregular masses with necrotic cavities, and clausters of calcifications located in the peripheral parts. The final diagnosis of alveococcosis was based on PAS-positive staining of lesions in histopathology and/or the detection of the parasite's DNA in liver sections by PCR. The patients were treated by radical surgery with concomitant long-term intensive chemotherapy with albendazole. CONCLUSIONS: Collaboration with physicians of various medical specialities is crucial for an early and more effective detection of alveococcosis in Poland. E. multilocularis infection should always be considered in the differential diagnosis of space-occupying lesions in the liver characterized by irregular heterogenous masses, suggesting slow tumor growth.

Neonatal Screening Programme for Increasing Early Postnatal Diagnosis of Congenital Cytomegalovirus Infection in the West Poland Province.

Congenital infection with cytomegalovirus (CMV) is the main cause of sensorineural hearing loss and psychomotor impairment which can develop at birth or later in infant's life. Because of a lack of nation-wide serological screening for pregnant women and accepted antiviral therapy during pregnancy in a high seroprevalence rate population of Poland, we introduced the regional screening programme for CMV infection in neonates from the Poznan Province to diminish a risk of the symptomatic disease. The aims of the study were: (i) to determine the prevalence of specific anti-CMV antibodies in populations of pregnant women and newborns from the Poznan area, (ii) to increase the early postnatal detection of congenital CMV infections, and (iii) to evaluate a risk of perinatal or early postnatal infections with CMV in newborns or infants born to seropositive mothers. Serological testing was performed in 4.192 live born neonates, using dried blood filter-paper specimens. The seropositivity rate in the studied population of neonates and pregnant women was 78.6%. The incidence of perinatal and early postnatal CMV infections was evaluated to be 3.1% or 1 per 25 neonates born to seropositive mothers. Congenital CMV infections confirmed by a presence of specific IgM antibodies were diagnosed in 5 newborns, which represent 1 case per 838 successive deliveries. In a clinical pattern of cytomegalovirus disease respiratory disorders and low birth weight were most frequently observed, and neurological signs, hepatitis, haemorrhagies or jaundice were sporadically diagnosed. Implementation of mass immunodiagnostic screening for congenital CMV infection, combined with other obligatory neonatal tests for metabolic errors, congenital malformations and endocrine disorders seems to be a valuable third line prophylactic strategy to prevent a late development of clinically overt cytomegalovirus disease.

The estimation of different ELISA procedures for serodiagnosis of human trichinellosis.

INTRODUCTION: The most important confirmative diagnostic test for trichinellosis is the presence of the muscle larvae in a tissue biopsy but this direct method has a low sensitivity of light and moderate infections. The aim of presented study was to compare the usefulness of the results obtained by three ELISA procedures for Trichinella spp. diagnosis in human outbreaks. MATERIALS AND METHODS: All sera (cases and controls) were tested for anti-Trichinella antibodies (immunoglobulin G) using commercially available Novatec KIT and two other ELISA procedures based on excretory-secretory (ES) antigens on Trichinella spiralis muscle larvae. The main differences in ELISA procedures were: the protein concentration in antigen, dilution of human serum samples, conjugate and the time of conjugate incubation. Additional differences were noticed in ES antigen preparation procedures as well as in T. spiralis isolates used in these procedures. Serum samples were obtained from 22 symptomatical patients from Poznafi region (West Poland), geographic area where human outbreak had occurred. Control serum samples were obtained from 20 patients from an open population from a non endemic trichinellosis area. RESULTS: The results were analyzed in terms of both: statistical and epidemiological point of view. Linear regression analysis and correlations coefficient r between OD values of total 22 patients obtained in three ELISA procedures were positive and high statistically significant. Three ELISA procedures revealed different cut-off values and positivity rates for outbreak. However, the majority of positive samples were found as positive in three procedures, but some of them were positive in two or one procedure only. These individual variability in sera reactivity observed in three ELISA procedures could be very important from epidemiological point of view.

[Clinical epidemiology and prevention of zoonotic parasitic infections in humans. A review]. / Epidemiologia kliniczna i prewencja odzwierzecych inwazji pasozytniczych czlowieka. Wklad badawczy i wdrozeniowy katedry i kliniki chorób tropikalnych i pasozytniczych akademii medycznej w poznaniu.

Multicentre and long standing (1964-2002) studies on clinical epidemiology of zoonotic parasitic invasions in humans and possibilities of its control in Poland are reviewed. The object of the studies were trichinellosis, taeniosis, giardiosis, toxoplasmosis, toxocarosis, as well as cystic and alveolar echinococcoses. In the control of these invasions very important was a close and long term cooperation of a clinical parasitological centre with veterinary scientific institutions and veterinary services in Poland as well as a collaboration between Polish parasitologists and leading parasitological centers in Europe and USA.

[Analysis of comparative immunological profiles of intraocular fluid and serum samples in patients suspected of ocular toxoplasmosis or toxocarosis]. / Ocena porównawczego profilu immunologicznego swoistych przeciwcial w plynie sródocznym i krwi obwodowej pacjentów podejrzanych o toksoplazmoze lub toksokaroze oczna.

High seroprevalence of Toxoplasma and Toxocara spp. in populations of children and adults in Poland constitutes a significant risk of supradiagnosed parasitic eye infections. We described the clinical characteristics in relation to the analysis of comparative immunological profiles of T. gondii-specific antibodies in aqueous humour and serum samples in patients with reactivated retinochoroiditis, and of Toxocara spp. ones in cases with posterior granuloma, fibrotic and calcified tumor-like masses simulating retinoblastoma, detected by ophthalmoscopy and echography. Intraocular synthesis of specific IgG antibodies was detected in anterior eye chamber fluid in 1/2 and 2/3 of patients respectively, strongly suspected of ocular toxoplasmosis or toxocarosis. The evidence of a local production of specific antibodies in intraocular fluid shown by the Western blot seems to be a valuable immunodiagnostic method for a final confirmation of eye lesions of parasitic origin and crucial in the choice of an appropriate treatment regimen.

[Evaluation of a risk of a cross-reactivity with Echinococcus multilocularis-specific Em2plus antigen in patients with liver cancer]. / Ocena ryzyka wystepowania niespecyficznych reakcji krzyzowych z antygenem Em2plus Echinococcus multilocularis u pacjentów z nowotworami watroby.

The incidence of non-specific reactions with E. multilocularis antigen in patients with liver malignancies, and the risk of a supradiagnosis of alveolar echinococcosis (AE) in space-occupying lesions in the liver due to neoplastic proliferative diseases were studied. Analysis of specific IgG serum antibody against Em2plus antigenic complex was performed in 11 AE patients in comparison to 76 individuals with malignant neoplasms of abdominal or extra-hepatic location, including some patients with primary hepatocellular cancer or distant metastases to liver, and 42 patients with benign hepatic lesions. Only one false borderline result was reported in a case with colorectal cancer, and dissemination to liver. Low risk of false positive results with E. multilocularis-specific Em2plus antigen in patients with liver malignancies makes the test valuable for practical reasons in a differential diagnosis of irregular tumor masses visualized by imaging techniques.

[Case definitions and clinical evaluation of patients infected with Echinococcus multilocularis treated in the Poznan centre]. / Kryteria rozpoznawania oraz oceny klinicznej pacjentów zarazonych Echinococcus multilocularis leczonych w osrodku poznanskim.

Recent epidemiological reports have shown an increasing risk of E. multilocularis infection among red foxes and humans in Poland. The aims of the study were: (i) to improve the early detection of alveolar echinococcosis (AE) in humans by implementation of clinical, imaging, immunodiagnostic, ultrastructural and molecular methods, (ii) to realize the parasitological verification of registered cases suspected of alveococcosis by the specialized, parasitological centres, and (iii) to standardize diagnostic and therapeutic procedures for this severe parasitic disease. Since 1993, eight cases of AE were registered in the Poznan centre. The final diagnosis was based on PAS-positive staining of lesions by histopathology or a detection of the parasite's DNA in liver sections. Collaboration with physicians of various medical specialities is crucial for an early and more effective recognition of AE. Alveococcosis should always be considered in the differential diagnosis of space-occupying lesions in the liver suggesting slow-growing cancer.