Current status of intestinal parasitic infections and associated risk factors in rural population of Guilan province, northern Iran: trichostrongyliasis is the most prevalent helminthic infection.

Aim: This study aimed to determine the distribution of enteric parasitic infections and related risk factors among rural communities of Guilan province, Northern Iran, and to compare the results with the situation in the past. Background: Intestinal parasitic infections are still considered as a major public health concern, particularly in human communities with poor economy and sanitation. Methods: This cross-sectional study was performed in rural areas of Masal and Shanderman district from February to December 2020. A total of 917 stool samples were collected and examined for presence of intestinal helminthes and protozoa using direct, formalin-ether and Kato-Katz techniques. Results: A total of 156 (17%) out of 917 examined individuals were infected with intestinal parasites. The overall prevalence of protozoa, helminths and mixed infections were 11.8% (108/917), 4.5% (41/917) and 0.8% (7/917), respectively. Blastocystis was the most prevalent intestinal protozoa (9.6%) followed by Giardia lamblia (1.9%), Endolimax nana (1.1%), E. coli (0.8%) and Entamoeba hartmani (0.1%). The highest prevalence of intestinal helminths belonged to Trichostongylus spp. (3.5%) and Strongyloides stercoralis (1.3%). Statistical analysis showed significant association between giardiasis and sex (P<0.03). On the other hand, prevalence of enteric helminths was influenced by close contact with livestock, keeping herbivorous animals at home, job, education, and consumption of uncooked vegetables (P<0.05). Conclusion: The findings indicate a decreasing trend in the prevalence of intestinal parasitic infections in Guilan province in comparison to the past few decades. Hookworm infections, which was very prevalent in the area, are now rare, while trichostrongylosis showed a high prevalence in rural residents of the study area.

Design and expression of a chimeric recombinant antigen (SsIR-Ss1a) for the serodiagnosis of human strongyloidiasis: Evaluation of performance, sensitivity, and specificity.

BACKGROUND: The sensitivity of parasitological and molecular methods is unsatisfactory for the diagnosis of strongyloidiasis, and serological techniques are remaining as the most effective diagnostic approach. The present study aimed to design and produce a chimeric recombinant antigen from Strongyloides stercoralis immunoreactive antigen (SsIR) and Ss1a antigens, using immune-informatics approaches, and evaluated its diagnostic performance in an ELISA system for the diagnosis of human strongyloidiasis. METHODOLOGY/PRINCIPAL FINDINGS: The coding sequences for SsIR and Ss1a were selected from GenBank and were gene-optimized. Using bioinformatics analysis, the regions with the highest antigenicity that did not overlap with other parasite antigens were selected. The chimeric recombinant antigen SsIR- Ss1a, was constructed. The solubility and physicochemical properties of the designed construct were analyzed and its tertiary structures were built and evaluated. The construct was expressed into the pET-23a (+) expression vector and the optimized DNA sequences of SsIR-Ss1a (873 bp) were cloned into competent E. coli DH5α cells. Diagnostic performances of the produced recombinant antigen, along with a commercial kit were evaluated in an indirect ELISA system, using a panel of sera from strongyloidiasis patients and controls. The physicochemical and bioinformatics evaluations revealed that the designed chimeric construct is soluble, has a molecular with of 35 KDa, and is antigenic. Western blotting confirmed the immunoreactivity of the produced chimeric recombinant antigen with the sera of strongyloidiasis patients. The sensitivity and specificity of the indirect ELISA system, using the produced SsIR-Ss1a chimeric antigen, were found to be 93.94% (95% CI, 0.803 to 0.989) and 97.22% (95% CI, 0.921 to 0.992) respectively. CONCLUSIONS/SIGNIFICANCE: The preliminary findings of this study suggest that the produced SsIR-Ss1a chimeric antigen shows promise in the diagnosis of human strongyloidiasis. However, these results are based on a limited panel of samples, and further research with a larger sample size is necessary to confirm its accuracy. The construct has potential as an antigen in the ELISA system for the serological diagnosis of this neglected parasitic infection, but additional validation is required.

Seroepidemiological study on coinfection of toxoplasmosis and active tuberculosis in Northern Iran: a case control study.

Coinfection of tuberculosis (TB) and human parasitic infections is common in developing countries. There is little information about the prevalence of Toxoplasma gondii (T. gondii) infection among TB patients in Iran. In this case-control study, anti-toxoplasma antibodies were measured by ELISA method in 100 patients with active tuberculosis and 100 healthy individuals who were matched in terms of sex, age, and place of residence. Anti-T. gondii IgG antibodies were diagnosed in 62% of TB patients (95% CI 53-71%) and 70% of control subjects (95% CI 62-78%). Anti-T. gondii IgM antibodies were found in 1% of both TB patients and control group. The seroprevalence of T. gondii infection was not significantly different between TB patients and healthy individuals (P > 0.05). None of the assessed sociodemographic and behavioral factors was recognized as a risk factor for toxoplasmosis in TB infected patients. Moreover, the level of anti-T. gondii IgG antibodies concentration in TB patients was significantly higher than in control subjects and revealed skewness towards humoral immune response in TB patients. Coinfection of toxoplasmosis and tuberculosis was prevalent but T. gondii infection was independent of active TB in this co-endemic area.

Identification and genotyping of Echinococcus granulosus from human clinical samples in Guilan province, north of Iran.

Cystic echinococcosis (CE) is a significant health problem in both human and veterinary medicine. It is caused by the tapeworm Echinococcus granulosus (E. granulosus). The objective of this study was to investigate molecular diversity of E. granulosus from the paraffin-embedded human (FFPE) tissue samples using sequencing of mitochondrial genes. Thirty-five FFPE tissue samples were collected from different regions of Guilan province, north of Iran. Demographic data were recorded using a questionnaire. Five sections (1 mm) of the tissue were prepared and deparaffined using xylene and ethanol methods. Molecular analysis was performed using the Nad1 and Cox1 genes using PCR and DNA sequencing. Totally, 25 cases (71.43%) were women and 10 cases (28.57%) were men. The most affected age group was 21-30 yr old. The most of cysts were isolated from the liver (n = 19; 54.29%) and others in the lung (n = 16; 45.71%). The Cox1 and Nad1 genes were successfully amplified in 16 (45.71%) and 12 (34.28%) DNA samples from FFPE tissue. Sequencing analysis revealed that all samples were E. granulosus sensu stricto complex (G1 and G3). In this study, E. granulosus sensu stricto complex G1 and G3 were identified in human hydatid cysts and showed the presence of sheep/dog cycle in human infection. This finding confirmed and completed previous studies on the geospatial distribution of E. granulosus sensu stricto complex G1 and G3 in the southern and coastal areas of the Caspian Sea region.

Assessment of species distribution and virulence factors of oral fungal carriage among hospitalized patients with COVID-19: a case-control study.

Background: The COVID-19 pandemic highlighted the need to study oral fungal carriage and its potential impact. In oral fungal environments, factors like changes in respiratory epithelium, increased pathogen attachment, local inflammation, and virulence factors could influence COVID-19 severity. The authors conducted a study to explore oral fungal carriage in COVID-19 patients and compare it to a healthy control group. Methods: The authors executed a case-control investigation including 144 COVID-19 patients and an equivalent number of 144 healthy controls. The matching criteria encompassed age, sex, body mass index, and the history of antibiotic and antiviral medication intake. This research was performed over a span of 12 months from May 2021 to May 2022. The mouth area was sampled with a cotton-tipped swab. Subsequently, all the samples underwent fungal culture and PCR-sequencing procedures. Results: In COVID-19 patients, oral fungal carriage was three times higher compared to healthy controls. Candida was the exclusive genus found in both groups, with Candida albicans being the most frequently isolated species (90.79%). Among COVID-19 patients, Candida species showed significantly higher esterase, proteinase, and hemolysin activity compared to healthy individuals. Both groups exhibited elevated levels of C. albicans virulence factors compared to non-albicans species. Conclusions: It is crucial to understand the way that virulence factors of oral fungal carriage act in COVID-19 patients in order to come up with novel antifungal medications, identify the contributing factors to drug resistance, and manage clinical outcomes.

Corrigendum to "Molecular detection of Toxoplasma gondii in chicken hearts from markets and retail stores in Northern Iran" [Food and Waterborne Parasitology 27 (2022) e00166].

[This corrects the article DOI: 10.1016/j.fawpar.2022.e00166.].

Application of Nested-qPCR-High Resolution Melting (HRM) Technology on Strongyloides stercoralis Isolates from Iran.

PURPOSE: Strongyloides stercoralis is a parasite with special characteristics presenting it as a unique nematode. Iran is an endemic area for S. stercoralis. In this study, nested-qPCR-high resolution melting (HRM) technology was applied on some human isolates of S. stercoralis from this country by focusing on evolutionary genetics analysis. METHODS: Twelve human isolates of S. stercoralis were collected from four endemic provinces of Iran. Genomic DNA was extracted from a single filariform larva for every isolate. Using specific primers targeting partial regions in cox1 gene, nested-qPCR-HRM was performed and melting-curve profiles were analyzed alongside the evaluation of genetic proximity and phylogenetic analysis using MEGA7 and DnaSP5 software. RESULTS: The melting temperature (Tm) values of the isolates were 77.9 °C-78.3 °C. All isolates from Guilan, Mazandaran, and Khouzestan Provinces shared Tm values of 78.2 °C to 78.3 °C, while the isolates from Hormozgan Province showed Tm values of 77.9 °C, 78.0 °C, and 78.1 °C. The phylogenetic tree illustrated that the sequences of the current study included nine haplotypes. Tajima's D index analyses showed that cox1 gene in S. stercoralis isolates was negative (Tajima's D = - 0.27). CONCLUSION: The isolates were divided into five temperature groups. Although HRM assay compared to PCR sequencing identified more limited genetic changes, it revealed that the mean of Tm of the isolates from Hormozgan Province was lower than those of other provinces and represented specific haplotypes for this geographical region on the phylogenetic tree.

First molecular description of Neorhadinorhynchus nudus (Acanthocephala: Cavisomidae) from fish in the pacific coast of Vietnam, with notes on biogeography.

Neorhadinorhynchus nudus (Harada, 1938) Yamaguti, 1939 (Cavisomidae) was morphologically described from the frigate tuna Auxis thazard (Lacépède) (Scombridae) in Nha Trang, Pacific south Vietnam. Females of N. nudus were fully described for the first time in the Pacific. Its original inadequate description as Rhadinorhynchus nudus (Harada, 1938) was corrected in material from Fiji Island, the Red Sea and Pacific Vietnam and errors in the text and line drawings of Harada were repeated in subsequent major publications where it underwent considerable nomenclature changes. New descriptive and biogeographical notes are included. We also provided here the molecular characterization of the nuclear gene (18S) and the mitochondrial cytochrome c oxidase subunit 1 (cox1) sequence data of N. nudus. Furthermore, to elucidate the phylogenetic relationship of N. nudus within the family Cavisomidae and with other isolates were performed incorporating nuclear (18S) and mitochondrial (cox1) sequence data using maximum likelihood (ML) and Bayesian inference (BI). The phylogenetic results showed that N. nudus has a relationship with other isolates of the same species and the median-joining network showed the pattern of haplotypes that reflected the structure of the populations.

Molecular Characterization of Spirometra erinaceieuropaei from Jungle Cat (Felis chaus) in North of Iran.

PURPOSE: The aim of this study is to conduct a molecular characterization of Spirometra tapeworm from jungle cat (Felis chaus) in Guilan Province, north of Iran using DNA sequence analysis of the mitochondrial cytochrome c oxidase subunit 1 (Cox1) and 12S rDNA sequences. METHODS: Morphological features of the adult tapeworm of Spirometra were evaluated using specific staining and light microscopy. The molecular characterization was performed using partial Cox1 and 12S rDNA regions. Genetic diversity was calculated and phylogenetic trees of the obtained sequences were constructed. RESULTS: Morphological features were compatible with previous description of adult Spirometra erinaceieuropaei. The Cox1 sequence of the specimen showed 100% similarity with S. erinaceieuropaei sequences in GenBank from Korea, China and Iran. Also, the 12S rDNA sequence revealed 99.7% similarity with S. erinaceieuropaei isolates from China and Japan. Intra-species variation within isolates of S. erinaceieuropaei was 0-1.4% and 0-4.6% for Cox1 and 12S rDNA genes, respectively. CONCLUSION: This is the first report of molecular characterization of S. erinaceieuropaei in jungle cat, F. chaus in Iran. Jungle cat probably plays a major role as reservoir host in maintaining of this parasite in this area with favorable climate condition. Needs for further assessment on the role of appropriate hosts, especially intermediate/paratenic hosts as well as the potential risk of human infectivity with sparganosis is emphasized.

Virtual spaced-learning method, during COVID-19 for Pharm D students.

BACKGROUND: The coronavirus (COVID-19) outbreak basically changed teaching methods across the world, and learning was almost replaced by virtual learning during the pandemic. Also, the spacing effect is one of the most well-established phenomena in the science of learning. Using temporal intervals for re-exposing learners to information over time (spaced learning) leads to more effective retention of knowledge compared to having information presented at a single time (massed learning). Hence, we designed a virtual spaced learning method to reap the benefits of virtual learning and spaced learning concomitantly. METHODS/APPROACH: An interventional semi- experimental survey among 66 Pharm D students was designed and implemented. Students were divided into two groups (spaced vs mass learning) in the national integrated virtual education platform (NAVID) as the matrix for teaching as well as evaluation. Classes were conducted in the following sequence: 1- answering the pre-test, 2- watching and listening to the educational content (separately for each group), 3- answering the post-test (n = 1). The pre/post-test consisted of 10 four-choice questions based on the Kirkpatrick Model extracted from the educational content. RESULTS/OUTCOMES: Findings revealed that the average score was not significantly different between the post-tests of the spaced learning and mass learning (7.26 ± 2.26 vs 6.5 ± 2.5) methods utilizing the independent t- test (p ≥ 0.05). CONCLUSIONS: Since no statistically significant improvement was observed in the virtual spaced learning group compared to the control group, it seems that clarifying the significant influence of the spaced learning strategy in pharmacy education requires longer period of study, or study on less complex or skill-based topics for further evaluation.

Characterisation of extracellular vesicles isolated from hydatid cyst fluid and evaluation of immunomodulatory effects on human monocytes.

Hydatidosis is a disease caused by the larval stage of Echinococcus granulosus, which involves several organs of intermediate hosts. Evidence suggests a communication between hydatid cyst (HC) and hosts via extracellular vesicles. However, a little is known about the communication between EVs derived from HC fluid (HCF) and host cells. In the current study, EVs were isolated using differential centrifugation from sheep HCF and characterized by western blot, electron microscope and size distribution analysis. The uptake of EVs by human monocyte cell line (THP-1) was evaluated. The effects of EVs on the expression levels of pro- and anti-inflammatory cytokines were investigated using quantitative real-time PCR (RT-PCR), 3 and 24 h after incubation. Moreover, the cytokine level of IL-10 was evaluated in supernatant of THP-1 cell line at 3 and 24 h. EVs were successfully isolated and showed spherical shape with size distribution at 130.6 nm. After 3 h, the expression levels of pro-inflammatory cytokine genes (IL1Β, IL15 and IL8) were upregulated, while after 24 h, the expression levels of pro-inflammatory cytokines were decreased and IL13 gene expression showed upregulation. A statistically significant increase was seen in the levels of IL-10 after 24 h. The main mechanism of the communication between EVs derived from HCF and their host remains unclear; however, time-dependent anti-inflammatory effects in our study suggest that HC may modulate the immune responses via EVs.

Molecular Characterization of Mitochondrial Cytochrome c oxidase subunit 1 (Cox1) gene from Trichostrongylus Species (Nematoda: Trichostrongylidae) in Northern Iran

Objective: The objective of the present study was to identify Trichostrongylus species by molecular analysis and also phylogenetic relationships of Trichostrongylus species by mitochondrial Cytochrome c oxidase subunit 1 (Cox1) gene in Guilan province, northern Iran. Methods: Abomasum and duodenum contents of 144 livestock were collected from sheep, goats, and cattle in Guilan province. Morphological survey was performed for initial screening. Total DNA was extracted, and the partial region of Cox1 gene was amplified and sequenced. Genetic diversity was calculated and phylogenetic analysis of the data on nucleotide sequence was conducted by MEGA7 software. Results: Three species of Trichostrongylus including T. colubriformis, T. vitrinus, and T. axei were identified by morphological characteristics. The genetic divergence within the species in the present study was observed for T. axei (0-2.5%), T. colubriformis (0.77%), and T. vitrinus (0%). The mean inter-species difference between the three species of Trichostrongylus obtained in this study was 14.4-15.4%. Conclusion: The Cox1 sequences of the members of Trichostrongylus spp. were highly variable and this could be used as a valuable measure to achieve a proper assessment on biodiversity. Sequence data generation from other species of Trichostrongylus will be needed to reconstruct the phylogenetic relationships of this genus of nematodes.

Molecular Characterization of Mesocestoides litteratus (Cestoda: Cyclophyllidea: Mesocestoididae) Tetrathyridium Isolated from Two Species of Rodents from Iran.

PURPOSE: Mesocestoides spp. are Cyclophyllidean tapeworms with zoonotic importance. The current study aimed to investigate the molecular characteristics of Mesocestoides larvae (tetrathyridium) isolated from the abdominal cavity of persion jird, Meriones persicus, and from the liver of grey hamster, Cricetulus migratorius, in Ardabil Province, northwest Iran. METHODS: Genomic DNA of the isolates of Mesocestoides tetrathyridium were extracted, and mitochondrial gene of cytochrome-c oxidase subunit1 (cox1) was amplified. Sequencing of PCR products were performed and phylogenic analysis was run using MEGA 6.0 software. RESULTS: Both isolates were identified as Mesocestoides litteratus, showing high identity with M. litteratus sequences available in GenBank. Also, they had 100% homology to each other. Intra-species variation within isolates of M. litteratus were 0-2.4%. The phylogenetic reconstruction based on the partial sequence of the cox1 gene showed that our sequences of M. litteratus were clustered with M. litteratus isolates from Slovakia, Netherlands, Germany and Italy. CONCLUSION: This is the first molecular description of M. litteratus from M. persicus and C. migratorius. Phylogenetic analysis illustrated that M. litteratus isolates of the current study had very high identities with the isolates of this species from other countries.

Hymenolepis diminuta Infection in a Rural Child from North of Iran.

We report a case of Hymenolepis diminuta infection in a two years old boy living in Guilan Province, northern Iran diagnosed in 2019. The patient was complained of anorexia, weight loss, weakness and disturbed sleep. Stool examination revealed numerous eggs of H. diminuta. After treatment with a single dose of oral praziquantel, the patient recovered without evidence of the egg shedding in follow-up stool samples. Moreover, we performed detailed phylogenetic analysis of the H. diminuta comparing with other isolates deposited in GenBank database based on Cox1 gene. Based on BLAST analysis of Cox1 gene our sequence showed 97.4-99.2% similarity with those of H. diminuta available in GenBank. The present study recommends the importance of reporting the infection cases, in order to improve knowledge on epidemiology and control of the neglected disease.

Molecular detection of Toxoplasma gondii in chicken hearts from markets and retail stores in Northern Iran.

Detection of Toxoplasma gondii in chicken products indicates risk of transmission to consumers. The objective of the current study was to investigate the molecular prevalence of T. gondii in free-ranging and industrial chickens in Guilan province, Northern Iran. A total of 150 chicken heart samples including 75 free-range and 75 industrial chickens were collected from farmers' markets and chicken retailers in Guilan, Northern Iran, between October 2017 and August 2018. Genomic DNA were extracted from samples and examined for evidence of T. gondii using polymerase chain reaction (PCR) targeting the B1 gene. The B1-positive samples were further analyzed by nested-PCR for SAG1 gene. Of the 150 samples, T. gondii DNA fragments were detected in 59 (39.3%), including 30 (40%) free-range and 29 (38.7%) industrial chicken. No significant differences of T. gondii DNA detection was observed between the free-range and industrial chicken samples (p = 0.73). Four selected positive samples were used for amplifying and sequencing of the SAG1 gene. The results revealed that all four sequences of SAG1 had 100% similarity with T. gondii sequences previously isolated from an AIDS/HIV patient in Mazandaran province, Northern Iran. Furthermore, the phylogenetic analysis demonstrated that all four sequences were closely related to Type I of T. gondii. However, our Type I identification is preliminary and needs to be confirmed by further multilocus sequence typing (MLST) analysis. The findings of the present study provide new data about the presence of T. gondii DNA in chicken hearts in the study area. These results confirm that chicken can be used as sentinels for environment contamination; however, further studies are needed to determine the viability of T. gondii in chicken hearts from Iran for risk assessment.

Formulation of Neem oil-loaded solid lipid nanoparticles and evaluation of its anti-Toxoplasma activity.

BACKGROUND: Toxoplasmosis is caused by an intracellular zoonotic protozoan, Toxoplasma gondii, which could be lethal in immunocompromised patients. This study aimed to synthesize Neem oil-loaded solid lipid nanoparticles (NeO-SLNs) and to evaluate the anti-Toxoplasma activity of this component. METHODS: The NeO-SLNs were constructed using double emulsification method, and their shape and size distribution were evaluated using transmission electron microscope (TEM) and dynamic light scattering (DLS), respectively. An MTT assay was employed to evaluate the cell toxicity of the component. The anti-Toxoplasma activity of NeO-SLNs was investigated using vital (trypan-blue) staining. Anti-intracellular Toxoplasma activity of NeO-SLNs was evaluated in T. gondii-infected Vero cells. RESULTS: The TEM analysis represented round shape NeO-SLNs with clear and stable margins. DLS analysis showed a mean particle size 337.6 nm for SLNs, and most of nanoparticles were in range 30 to 120 nm. The cell toxicity of NeO-SLNs was directly correlated with the concentration of the component (P-value = 0.0013). The concentration of NeO-SLNs, which was toxic for at least 50% of alive T. gondii (cytotoxic concentration (CC50)), was > 10 mg/mL. The ability of NeO-SLNs to kill Toxoplasma was concentration-dependent (P-value < 0.0001), and all concentrations killed at least 70% of alive tachyzoites. Furthermore, the viability of T. gondii- infected Vero cells was inversely correlated with NeO-SLNs concentrations (P-value = 0.0317), and in the concentration 100 µg/mL at least 75% of T. gondii- infected Vero cells remained alive. CONCLUSIONS: Overall, our findings demonstrated that the NeO-SLNs was able to kill T. gondii tachyzoites in concentration 100 µg/mL with a cell toxicity lower than 20%. Such results suggest that employing SLNs as carrier for NeO can effectively kill T. gondii tachyzoites with acceptable cell toxicity. Our findings also showed that SLNs capsulation of the NeO can lead to prolonged release of the extract, suggesting that NeO-SLNs could be also employed to clear cyst stages, which should be further investigated in animal models.

Prevalence and molecular characterization of Dirofilaria immitis in road killed canids of northern Iran.

BACKGROUND: Dirofilaria immitis is a mosquito-borne filarial nematode, which infects primarily wild and domestic canids, causing cardiopulmonary dirofilariasis. The aim of the present study was to determine the prevalence and characterize molecular features of D. immitis in road killed canids, northern Iran. METHODS: The carcasses of 53 road killed canids including 18 dogs (Canis familiaris), and 35 golden jackals (C. aureus) were necropsied in both Mazanderan and Guilan provinces, northern Iran. The molecular analyses were conducted based on the cytochrome oxidase (Cox) 1 and 18S ribosomal RNA (rRNA) genes. RESULTS: The heartworm infection was found in 55.6% of dogs and 22.9% of jackals. Our study revealed significantly higher prevalence of D. immitis in dogs compared to jackals (P = 0.031). The prevalence of D. immitis was no statistically significant between males and females in both dogs and jackal (P > 0.05). Comparison of the Cox1 gene sequences with available data in the GenBank illustrated 100% similarity with D. immitis isolates from different hosts in European, Asian, and South American continents. Moreover, the 18S rRNA gene sequences showed 100% identity with dog isolates from Japan and French Guiana. CONCLUSIONS: This study confirms the high prevalence of D. immitis in dogs and jackals of northern Iran. Developing control programs to prevent transmission of the disease is necessary for dogs and humans in the study areas.

Indirect immunofluorescence assay using embryonated eggs of Toxocara in human toxocariasis diagnosis is unreliable due to autofluorescence nature.

Toxocariasis is caused by infection with the nematode species Toxocara canis and Toxocara cati. Serological methods using eggs, larvae and adult worms of Toxocara spp. as antigen have been used for the diagnosis of human toxocariasis. The current study aimed to evaluate indirect immunofluorescence assay (IFA) using embryonated eggs of Toxocara for diagnosis of human toxocariasis. A total of 58 sera including twenty sera from patients with toxocariasis, 20 from healthy persons and 18 from patients with other parasitic infections were collected and used for the study. The embryonated eggs of Toxocara were prepared as antigen. Indirect immunofluorescence assay was performed using the frozen section of uterus containing embryonated T. canis eggs and unembryonated T. cati eggs. All serum samples had a positive reaction using IFA. The eggs of Toxocara as antigen exposed to the serum samples of toxocariasis, other parasitic infections and healthy persons, followed by IFA gave a bright greenish-yellow fluorescence. A number of samples such as eggs of Toxocara, Toxascaris, Trichuris and strongyloides larvae, and adult worm of Ancylostoma exhibited the bright greenish-yellow autofluorescence under fluorescent microscope. IFA using cryocut of embryonated eggs of Toxocara cannot be used for the diagnosis of human toxocariasis due to the existence of autofluorescence of the unembryonated and embryonated eggs, the second stage larva and adult worms of Toxocara spp.

A survey on the seroprevalence of toxocariasis and related risk factors in Eosinophilic children of Northwest Iran.

Background: Toxocariasis is a serious zoonotic helminthic disease caused by the nematodes; Toxocara species. Aim: A cross-sectional study was conducted to determine the seroprevalence of toxocariasis and related risk factors in eosinophilic children referred to the pediatrics hospital of Qazvin province northwest Iran during 2019-2020. Methods: A total of 200 blood samples were collected from eosinophilic children referred to the Qods Pediatrics Hospital. Demographic data, clinical symptoms, and dogs- and soil-contact history were collected. The presence of anti-Toxocara IgG antibody was evaluated by T. canis IgG ELISA kit. Results: Anti-Toxocara IgG antibodies were detected in 14 (7%) of the total eosinophilic children. The seropositive rate of toxocariasis in hyper-eosinophilic children (>1000/mm3) was 15.1%, while the seropositivity was 4.1% in children with eosinophilia status (500-999/mm3). There was a significant association between the eosinophilia rate and seropositivity (P<0.05). Also, seroprevalence in asymptomatic eosinophilic children was 4.4%, while in children with clinical symptoms it was 17.1%. Accordingly, a statistically significant difference was found between clinical symptoms and Toxocara infection (P<0.05). Conclusion: The prevalence of toxocariasis in eosinophilic children is a serious health problem in the study area. Therefore, serologic evaluation for the diagnosis of Toxocara infection is recommended for eosinophilic children.

Phylogeny and Life Cycles of the Archiacanthocephala with a Note on the Validity of Mediorhynchus gallinarum.

PURPOSE: The molecular profile of specimens of Mediorhynchus gallinarum (Bhalero, 1937) collected from chickens, Gallus gallus L. in Indonesia was analysed. The aim of this study was to assess the phylogenetic position of species of Mediorhynchus within the order Giganthorhynchida. METHODS: We used one mitochondrial gene (cytochrome oxidase 1) and one nuclear gene (18S ribosomal RNA) to infer phylogenetic relationships of class Archiacanthocephala. RESULTS: The COI and 18S rDNA genes sequences showed that M. gallinarum had low genetic variation and that this species is sister to Mediorhynchus africanus Amin, Evans, Heckmann, El-Naggar, 2013. The phylogenetic relationships of the Class Archiacanthocephala showed that it is not resolved but, however, were mostly congruent using both genes. A review of host-parasite life cycles and geographic distributions of Archiacanthocephala indicates that mainly small mammals and birds are definitive hosts, while termites, cockroaches, and millipedes are intermediate hosts. CONCLUSIONS: While the intermediate hosts have wide geographic distributions, the narrow distribution of the definitive hosts limit the access of archiacanthocephalans to a wider range of prospective hosts. Additional analyses, to increase taxonomic and character sampling will improve the development of a robust phylogeny and provide more stable classification. The results presented here contribute to better understanding of the ecological and evolutionary relationships that allow the host-parasite co-existence within the class Archiacanthocephala.