Intestinal protozoan and helminthic infections among hemodialysis and cancer patients

Intestinal parasitic infections (IPIs) can be a severe threat to immunocompromised patients. This is particularly true for those undergoing chemotherapy and hemodialysis. The present research is aimed at identifying intestinal parasites that might be present in immunocompromised patients. In this cross-sectional study 1040 stool samples were collected (279 samples from hemodialysis patients, 362 samples from chemotherapy patients and 399 samples from the control group) from March to September 2017. The samples were tested by direct, formalin-ether methods for protozoa and ova of intestinal parasites and Ziehl-Neelsen staining methods for coccidian parasites such as Cryptosporidium species. The overall parasitic infection rate was higher (15%) in hemodialysis patients and 11.3% in chemotherapy patients whereas the lowest rate was observed (7.3%) in the control group. The infectivity rates were statistically significant (P = 0.008) when compared with the control group. The most prevalent parasites present were Blastocystis hominis (8.9% of the cases), Entamoeba coli (1.6%), Iodamoeba butschlii (0.8%), Endolimax nana (0.6%), Chilomastix mesnili (0.5%), Strongyloides stercoralis (0.5%) and Taenia species (0.15%), whereas Giardia lamblia was found present only in the control group. Statistical analyses revealed a significant correlation between gastrointestinal symptoms (such as some abdominal pain, diarrhea) and the ratio of chemotherapy frequency to scheduled frequency and parasitic infections (P = 0.001). There was not a correlation between prevalence of parasites with age or education levels of the infected individuals. Results of the present study suggest that a periodic stool examinations in special parasitological laboratories should be included as part of routine and general medical care

Lymnaea schirazensis, an Overlooked Snail Distorting Fascioliasis Data: Genotype, Phenotype, Ecology, Worldwide Spread, Susceptibility, Applicability

BACKGROUND: Lymnaeid snails transmit medical and veterinary important trematodiases, mainly fascioliasis. Vector specificity of fasciolid parasites defines disease distribution and characteristics. Different lymnaeid species appear linked to different transmission and epidemiological patterns. Pronounced susceptibility differences to absolute resistance have been described among lymnaeid populations. When assessing disease characteristics in different endemic areas, unexpected results were obtained in studies on lymnaeid susceptibility to Fasciola. We undertook studies to understand this disease transmission heterogeneity. METHODOLOGY/PRINCIPAL FINDINGS: A ten-year study in Iran, Egypt, Spain, the Dominican Republic, Mexico, Venezuela, Ecuador and Peru, demonstrated that such heterogeneity is not due to susceptibility differences, but to a hitherto overlooked cryptic species, Lymnaea schirazensis, confused with the main vector Galba truncatula and/or other Galba/Fossaria vectors. Nuclear rDNA and mtDNA sequences and phylogenetic reconstruction highlighted an old evolutionary divergence from other Galba/Fossaria species, and a low intraspecific variability suggesting a recent spread from one geographical source. Morphometry, anatomy and egg cluster analyses allowed for phenotypic differentiation. Selfing, egg laying, and habitat characteristics indicated a migration capacity by passive transport. Studies showed that it is not a vector species (n = 8572 field collected, 20 populations): snail finding and penetration by F. hepatica miracidium occur but never lead to cercarial production (n = 338 experimentally infected). CONCLUSIONS/SIGNIFICANCE: This species has been distorting fasciolid specificity/susceptibility and fascioliasis geographical distribution data. Hence, a large body of literature on G. truncatula should be revised. Its existence has henceforth to be considered in research. Genetic data on livestock, archeology and history along the 10,000-year post-domestication period explain its wide spread from the Neolithic Fertile Crescent. It is an efficient biomarker for the follow-up of livestock movements, a crucial aspect in fascioliasis emergence. It offers an outstanding laboratory model for genetic studies on susceptibility/resistance in F. hepatica/lymnaeid interaction, a field of applied research with disease control perspectives

The Status of Human and Animal Fascioliasis in Iran: A Narrative Review Article

Background: The public health importance of human fascioliasis has increased during last few decades due to the appearance of new emerging and re-emerging foci in many countries. Iran, as the most important focus of human disease in Asia, has been included among six countries known to have a serious problem with fascio­liasis by WHO. Various aspects of the disease in Iran are discussed in this review. Methods: This narrative review covers all information about human and animal fascioliasis in Iran, which has been published in local and international journals from 1960 to 2014 using various databases including PubMed, SID, Google Scholar, Scopus, Science Direct. Results: During the period of the study the infection rates of 0.1% to 91.4% was noted in various livestock. Despite the higher infection rates of livestock in south­ern areas in past decades, human disease has been mostly encountered in northern Provinces especially in Guilan. Recent studies indicate noticeable decrease in preva­lence rates of veterinary fascioliasis in Iran, however the prevalence rates of fascio­liasis in livestock in northern Provinces of Guilan and Mazandaran seem to remain at a higher level in comparison to other parts. New foci of the disease have also been reported recently.  Conclusion: While the prevalence of animal fascioliasis has decreased during last decades, human fascioliasis emerged as a public health problem in the country. The validity of new foci of human fascioliasis needs complementary standard studies

Migratory routes, domesticated birds and cercarial dermatitis: the distribution of

Background: One of the major migration routes for birds going between Europe and Asia is the Black Sea-Mediterranean route that converges on the Volga Delta, continuing into the area of the Caspian Sea. Cercarial dermatitis is a disorder in humans caused by schistosome trematodes that use aquatic birds and snails as hosts and is prevalent in areas of aquaculture in Northern Iran. Before the disorder can be addressed, it is necessary to determine the etiological agents and their host species. This study aimed to document whether domestic mallards are reservoir hosts and if so, to characterize the species of schistosomes. Previous work has shown that domestic mallards are reservoir hosts for a nasal schistosome. Results: In 32 of 45 domestic mallards (Anas platyrhynchos domesticus) (71.1%), the schistosome Trichobilharzia franki, previously reported only from Europe, was found in visceral veins. Morphological and molecular phylogenetic analysis confirmed the species designation. These findings extend the range of T. franki from Europe to Eurasia. Conclusion: The occurrence of cercarial dermatitis in Iran is high in areas of aquaculture. Previous studies in the area have shown that domestic mallards are reservoir hosts of T. regenti, a nasal schistosome and T. franki, as shown in this study. The genetic results support the conclusion that populations of T. franki from Iran are not differentiated from populations in Europe. Therefore, the schistosomes are distributed with their migratory duck hosts, maintaining the gene flow across populations with compatible snail hosts in Iran

An Analysis of Clinical Characteristics of Strongyloides stercoralis in 70 indigenous patients in Iran

Background: Clinical manifestations of Strongyloides stercoralis are variable from asymptomatic to hyperinfection and devastating disseminated infections. Hereby, clinical characteristics of a large series of Iranian strongyloidiasis indigenous cases are described. Methods: The records of people referred to the Helminthological Diagnostic La-boratory of School of Public Health, Tehran University of Medical Sciences and School of Medicine, Gilan University of Medical Sciences, during 2009-2013 were reviewed. For those patients that were infected with S. stercoralis and their clinical manifestations and demographic data were available (70 cases) a checklist was pre-pared and data analyzed. Results: Forty-three patients (61.4%) were male and 27 (38.6%) female. Gastroin-testinal, cutaneous and pulmonary symptoms were present in 71.4%, 25.7%, and 15.7% of patients, respectively. None of them had larva currens eruption. Eosino-philia was the most prevalent reason for suspicious on S. stercoralis, but the mean was lower in elderly patients. Hyperinfection were recorded in 8 patients (11.4%), and 2 cases had disseminated infection. Conclusion: Eosinophilia is common both in asymptomatic and symptomatic cas-es of strongyloidiasis, but the mean tend to lower with increase in age

Prevalence of Strongyloides stercoralis and Other Intestinal Parasites among Institutionalized Mentally Disabled Individuals in Rasht, Northern Iran

Background: We aimed to determine the status of strongyloidiasis in mentally disabled population in the institutional places in Rasht City, the capital of Guilan Province, northern Iran. Methods: This cross-sectional study was conducted in 8 institutions for mentally retarded population in Rasht in 2013. Before collecting the samples, a questionnaire was filled out for each participant by an expert person. A single  stool sample was obtained from each of the 173 subjects and examined using direct wet mount, formalin-ether concentration technique and agar plate culture method.  Results: A total of 173 mentally disabled individuals aged 2-57 (25.69±11.56) yr old were studied. Stool examination showed that 51 (29.5%) cases were infected with at least one parasite. Of 173 studied cases only 10 (5.8%) individuals were infected with pathogenic parasites, of which 2 (1.2%) cases were infected with Strongyloides stercoralis and 8 (4.6%) with Giardia lamblia. On the other hand, 42 (24.3%) of the studied population were infected with non-pathogenic intestinal protozoa such as Blastocystis hominis (n=29, 16.8%), Entamoeba coli (n=16, 9.2%) and Endolimax nana (n=4, 2.3%). Mixed protozoal infections were observed in 8 (4.6%) individuals. Conclusion: The prevalence rate of S. stercoralis in mentally disabled individuals in Rasht was somewhat higher than those of normal population of the province. The same picture was seen when the prevalence of G. lamblia and non-pathogenic protozoa in normal and mentally disabled populations were compared

Seroprevalence of Human Fasciolosis in Lorestan Province, Western Iran, in 2015-16

Background: The aim of this study was the seroepidemiological survey for detecting the status of human fasciolosis in Lorestan Province, western Iran. Methods: This cross-sectional study was conducted in 2015-16. Based on statistical estimations, 1256 serum samples were collected from different parts of Lorestan Province, western Iran, and stored at -20 °C until use. The collected serum samples were analyzed at Tehran University of Medical Sciences, Tehran, Iran using indirect ELISA method. Results: Anti-Fasciola antibodies were detected in 16 (1.3%) individuals. Regarding the seropositivity to fasciolosis, no significant differences were found between age groups, sex, level of education and occupation; however significant differences were observed regarding location, consuming local freshwater plants and water resources (P<0.02.) Conclusion: Local freshwater plants and unfiltered water resources were probably the main sources of the infection. Health education by local health centers to elevate awareness of people, and providing facilities for safer drinking water, especially in rural areas may help decrease the risk of fasciolosis infection in this region

Emerging cases of fascioliasis in lorestan province, western iran: Case series report

Fascioliasis is a zoonotic disease caused by Fasciola spp. We report five serologically and molecularly confirmed cases in an emerging region in Iran. A retrospective, case series study, performed in Lorestan Province, west of Iran between January 2015 and June 2016. From 1256 patients examined, 16 patients had positive serum ELISA. Five cases were approved as infected with fasciolosis using stool exam and PCR. Age ranged from 24 to 80 yr with mean age of 45 years. All of patients were adults and four of them had abdominal and back pain. Other symptoms included fever and chills, coughing and sore throat, weight loss, cutaneous manifestations. All patients lived in the rural environment, and four reported the ingestion of raw aquatic plants such as watercress. In fecal examination for fluke eggs, four samples were positive for F. hepatica eggs. Conventional PCR analysis showed that five human stools were positive for F. hepatica. All of 5 patients were treated with the usual dose of triclabendazole. A history of recent consumption of raw aquatic plants (in 4 out of 5 patients) is an important finding, but in one patient the source of infection remained unclear. Lorestan should be considered as an emerging region for this disease and further research in this province should be carried out

Emerging Cases of Fascioliasis in Lorestan Province, Western Iran: Case Series Report

Fascioliasis is a zoonotic disease caused by Fasciola spp. We report five serologically and molecularly confirmed cases in an emerging region in Iran. A retrospective, case series study, performed in Lorestan Province, west of Iran between January 2015 and June 2016. From 1256 patients examined, 16 patients had positive serum ELISA. Five cases were approved as infected with fasciolosis using stool exam and PCR. Age ranged from 24 to 80 yr with mean age of 45 years. All of patients were adults and four of them had abdominal and back pain. Other symptoms included fever and chills, coughing and sore throat, weight loss, cutaneous manifestations. All patients lived in the rural environment, and four reported the ingestion of raw aquatic plants such as watercress. In fecal examination for fluke eggs, four samples were positive for F. hepatica eggs. Conventional PCR analysis showed that five human stools were positive for F. hepatica. All of 5 patients were treated with the usual dose of triclabendazole. A history of recent consumption of raw aquatic plants (in 4 out of 5 patients) is an important finding, but in one patient the source of infection remained unclear. Lorestan should be considered as an emerging region for this disease and further research in this province should be carried out