Cestode Research Articles

Intractable headaches secondary to a solitary lateral ventricle lesion of neurocysticercosis

Abstract Taenia solium is a parasitic tape worm that causes neurocysticercosis (NCC), which is classically characterized by scattered, intraparenchymal brain lesions. However, in very rare cases, a solitary, lateral ventricle lesion may be all that is present, which can make diagnosis difficult. Herein, we report the case of a 34-year-old female from Western Europe who presented with 12 days of intractable headaches. Magnetic resonance imaging revealed a single, heterogeneous appearing intraventricular mass with mild enhancement located in the left lateral ventricle near the foramen of Monro. Using a minimally invasive image-guided tubular retractor system for surgical biopsy and resection, NCC was identified on histological analysis. The patient tolerated the procedure well, and her headaches improved. Although NCC is associated with exposure to raw pork and/or prior residence in an endemic location, these are not always present. This case highlights the unusual radiographic findings and benign clinical history providers may encounter with NCC.

Metabolomic analyses uncover an inhibitory effect of niclosamide on mitochondrial membrane potential in cholangiocarcinoma cells.

Niclosamide is an oral anthelminthic drug that has been used for treating tapeworm infections. Its mechanism involves the disturbance of mitochondrial membrane potential that in turn inhibits oxidative phosphorylation leading to ATP depletion. To date, niclosamide has been validated as the potent anti-cancer agent against several cancers. However, the molecular mechanisms underlying the effects of niclosamide on the liver fluke Opisthorchis viverrini (Ov)-associated cholangiocarcinoma (CCA) cell functions remain to be elucidated. The aims of this study were to investigate the effects of niclosamide on CCA cell proliferation and on metabolic phenoconversion through the alteration of metabolites associated with mitochondrial function in CCA cell lines. The inhibitory effect of niclosamide on CCA cells was determined using SRB assay. A mitochondrial membrane potential using tetramethylrhodamine, ethyl ester-mitochondrial membrane potential (TMRE-MMP) assay was conducted. Liquid chromatography-mass spectrometry-based metabolomics was employed to investigate the global metabolic changes upon niclosamide treatment. ATP levels were measured using CellTiter-Glo® luminescent cell viability assay. NAD metabolism was examined by the NAD+/NADH ratio. Niclosamide strongly inhibited CCA cell growth and reduced the MMP of CCA cells. An orthogonal partial-least square regression analysis revealed that the effects of niclosamide on suppressing cell viability and MMP of CCA cells were significantly associated with an increase in niacinamide, a precursor in NAD synthesis that may disrupt the electron transport system leading to suppression of NAD+/NADH ratio and ATP depletion. Our findings unravel the mode of action of niclosamide in the energy depletion that could potentially serve as the promising therapeutic strategy for CCA treatment.

Epidemiological Situation on Animal Echinococcosis in Azerbaijan

The spread of echinococcosis is possible if the pathogen circulates between animals. A study was carried out of the epidemiological and epizootic situation regarding echinococcosis among animals on the territory of Azerbaijan. Fecal samples from dogs were collected individually and examined using standard methods. Nematode infections were tested using the Kotelnikov-Khrenov method, and cestode infections were tested using the Shcherbovich method. A total of 128 dogs were examined. It has been established that the highest level of infection of animals with echinococcosis is registered in the Guba, Gusar, Gabala, and Gakh districts. This situation requires a more in-depth study and development of appropriate anti-epidemiological measures.

Equine tapeworm (Anoplocephala spp.) infection: evaluation of saliva- and serum-based antibody detection methods and risk factor analysis in Slovak horse populations

A lack of accurate information on the prevalence and distribution of Anoplocephala spp. infections on horse farms has led to insufficient attention to tapeworm control and increasing horse anoplocephaloses in Europe. Our study aimed to examine the occurrence of Anoplocephala spp. infection using coprological, serum- and saliva-based antibody detection methods and to analyze the risk factors associated with tapeworm infection in domestic horses in Slovakia. Fecal, serum, and saliva samples were collected from 427 horses from 31 farms in Slovakia. Additionally, a questionnaire study was conducted to collect information on tapeworm distribution on horse farms and analyze risk factors associated with infection. Fecal samples were examined by the mini-FLOTAC and the double centrifugation/combined sedimentation-flotation techniques. Serum and saliva samples were analyzed by ELISA to determine antibody levels against Anoplocephala spp. The effects of variables associated with an individual horse were tested for the positive result of the saliva ELISA test on Anoplocephala spp. Cestode eggs were detected in 1.99% of fecal samples (farm prevalence 12.90%), with no differences between the two coprological methods. Serum-based tapeworm ELISA results revealed that 39.39% of horses tested positive (farm prevalence 83.87%); while saliva-based tapeworm ELISA results revealed 56.95% positive horses (farm prevalence 96.77%). Binary logistic regression analysis revealed four meaningful predictors that significantly impacted the likelihood of detecting tapeworm infection in horses: horse age, pasture size, anthelmintic treatment scheme, and access to pasture. The influences of other variables associated with an individual horse were not significantly associated with detecting tapeworm infection.

SAR study of niclosamide derivatives for neuroprotective function in SH-SY5Y neuroblastoma

Neurodegenerative disease is a debilitating and incurable condition that affects millions of people around the world. The loss of functions or malfunctions of neural cells are the causes of mortality. A proteosome inhibitor, MG132, is well known to cause neurodegeneration in vitro when model neuronal-derived cell lines are exposed to it. Niclosamide, an anthelmintic drug, which has been used to treat tapeworm infections for more than 50 years, has recently attracted renewed attention in drug repurposing because it has been found to be a good candidate in many drug development screenings. We recently found that all markers of MG132-induced neuronal cell toxicity, including the accumulation of ubiquitinated proteins, were prevented by the presence of niclosamide. In addition, niclosamide was shown to enhance autophagy induced by MG132. There results suggested that niclosamide could act as a neuroprotective agent. In the present study, niclosamide derivatives were synthesized, and the structure–activity relationship (SAR) were determined with respect to protein ubiquitination induced by MG132 and effect on cell survival signaling pathways for neuroprotective function. Our results indicate that phenol OH plays a significant role in neuroprotective activity while the niclosamide derivatives without Cl (5- or 2′-Cl) showed almost the same neuroprotective effect. 4′-NO2 can be replaced by N3 or CF3 whereas NH2 significantly decreased activity. These findings provide guidance for the development of new niclosamide analogues against neurodegenerative diseases including Parkinson’s disease.

Isolated Renal Hydatid Cysts in Children: A Systematic Review of Case Reports

Background: Echinococcosis is a zoonotic tapeworm infection caused by Echinococcus granulosus, occasionally affecting humans. The larval infection most commonly affects the liver and lungs and very rarely the kidneys. Objective: The present systematic review compiles data regarding clinical presentations, diagnostic modalities, management strategies and recurrences in children with isolated renal hydatid cysts. Methods: A comprehensive search was done in major databases PubMed and Google Scholar using defined search terms encompassing case reports or case series on isolated renal hydatid cysts in children. The identified reports underwent screening by three different authors for inclusion and exclusion criteria. Results: The median (range) age at presentation of isolated renal hydatid disease was 10 (6) years with female preponderance (52.7%). Most common presenting symptom and sign were abdominal pain (64.8%) and palpable abdominal mass (56.7%), respectively. Ultrasonography (94.5%) was most common diagnostic method. Patients were primarily managed with surgical interventions (95.5%) and only 2/37 were managed solely by medical management for a median duration of 3.5 weeks. Laparoscopic cystectomy was the most commonly used surgical procedure (45.9%). Recurrence was observed to be rare, seen in only 3 cases. Conclusion: Hydatid cysts need to be considered in the differential diagnosis of renal cysts. Radiological evaluation with pathological confirmation enables diagnosis. Surgery combined with adjuvant anti-parasitic chemotherapy is used to treat the condition.

Studies on some aspects of the fish Endoparasites (Cestodes)

Parasitic diseases are the major cause of morbidity and mortality in man, domesticated animals and wild life. Cestodes are multicellular, bilaterally symmetrical and parasites of great importance to human health. Intestinal infections of cestodes are very common in country and areas with poor socio-economic status are endemic unhygienic living and food habits promote the spread of infection causing high morbidity and complications. Mixed intestinal infection due to cestodes and nematodes is quite common and therefore, there is a need to study the cestode parasites whose prevalence is high. Cestodes infect almost all vertebrates. The freshwater fish species found in Nagapur Reservoir, Parli-Vaijnath, Dist. Beed (M.S.) were observed for the infection of cestode parasites. It was found that the freshwater fishes like Mystus seenghala and Mastacembelus armatus were infected by the cestode parasites. After detail study they were identified as Gangesia senghali (Hiware, 1999), Circumoncobothrium yamaguti (Jadhav et al., 1990). The cestode parasites were found in the small intestine of the host fishes.

18FDG-PET/CT-Scans and Biomarker Levels Predicting Clinical Outcome in Patients with Alveolar Echinococcosis-A Single-Center Cohort Study with 179 Patients.

Background: Alveolar echinococcosis (AE) is a severe larval tapeworm infection with a variable clinical course of the disease. Reliable imaging techniques and biomarkers are needed to predict the course of the disease. Methods: 179 AE patients that received PET/CT scans between 2008 and 2012 were retrospectively included. From stored blood samples taken on the day of the scan, levels of IgE, parasite-specific serology, amyloid A, C-reactive protein, soluble interleukin 2 receptor, cytokeratin fragments, eosinophilic cell count, and eosinophil cationic protein were measured. Additionally, the current clinical outcome (cured, stable, or progressive disease) after a median duration of 8 years after baseline examination was assessed. Ultimately, an ordinal logistic regression was conducted to evaluate which imaging parameters and biomarkers independently influence the clinical outcome. Results: In general, patients in need of medical treatment or with progressive disease, advanced PNM stages, and positive PET/CT scans exhibited higher levels of the respective biomarkers. However, only the parasite-specific serological markers and total IgE levels differed significantly between clinical groups, WHO PNM stages, and the results of the PET/CT scan. In the multivariate analysis, PET/CT results were a strong predictor of the clinical outcome (OR 8.908, 95%CI 3.019-26.285; p < 0.001), and age at baseline was a moderate predictor (OR 1.031, 95%CI 1.003-1.060; p = 0.029). Conclusions: The PET/CT scan is, preferably in combination with parasite-specific serology and IgE levels, a valuable tool in the clinical management of AE and is able to predict the course of the disease.

Praziquantel inhibits Caenorhabditis elegans development and species-wide differences might be cct-8-dependent.

Anthelmintic drugs are used to treat parasitic roundworm and flatworm infections in humans and other animals. Caenorhabditis elegans is an established model to investigate anthelmintics used to treat roundworms. In this study, we use C. elegans to examine the mode of action and the mechanisms of resistance against the flatworm anthelmintic drug praziquantel (PZQ), used to treat trematode and cestode infections. We found that PZQ inhibited development and that this developmental delay varies by genetic background. Interestingly, both enantiomers of PZQ are equally effective against C. elegans, but the right-handed PZQ (R-PZQ) is most effective against schistosome infections. We conducted a genome-wide association mapping with 74 wild C. elegans strains to identify a region on chromosome IV that is correlated with differential PZQ susceptibility. Five candidate genes in this region: cct-8, znf-782, Y104H12D.4, Y104H12D.2, and cox-18, might underlie this variation. The gene cct-8, a subunit of the protein folding complex TRiC, has variation that causes a putative protein coding change (G226V), which is correlated with reduced developmental delay. Gene expression analysis suggests that this variant correlates with slightly increased expression of both cct-8 and hsp-70. Acute exposure to PZQ caused increased expression of hsp-70, indicating that altered TRiC function might be involved in PZQ responses. To test if this variant affects development upon exposure to PZQ, we used CRISPR-Cas9 genome editing to introduce the V226 allele into the N2 genetic background (G226) and the G226 allele into the JU775 genetic background (V226). These experiments revealed that this variant was not sufficient to explain the effects of PZQ on development. Nevertheless, this study shows that C. elegans can be used to study PZQ mode of action and resistance mechanisms. Additionally, we show that the TRiC complex requires further evaluation for PZQ responses in C. elegans.

Gallic acid and Catechin induce morphological alterations on the zoonotic parasite Hymenolepis diminuta.

Tapeworm infections cause insidious and irreversible effects in the infected individuals and some of them have already shown resistance to available drugs. A search for alternative treatment is urgently required. Phenolic compounds are amongst the most researched natural substances for their medicinal use. The present study aims to determine anthelmintic efficacy of two polyphenols Gallic acid and Catechin against the zoonotic rat tapeworm Hymenolepis diminuta. Both compounds are potent anti-oxidants and play major roles in combating pathogens, while their anthelmintic property according to our knowledge is yet to be explored. The parasite model H. diminuta was procured from intestine of infected rats raised in our laboratory. Two sets of parasites were treated in vitro with 5, 10, 20 and 40mg/ml concentrations of each Gallic Acid and Catechin separately, another set of parasites were treated with standard dose of Praziquantel in RPMI 1640, while still another set of worms were kept in RPMI 1640 at 37 ± 10C with 1% Dimethyl sulfoxide as control. Motility and structural alterations were the parameters assessed for anthelmintic efficacy of the compounds. After paralysis the worms were processed for morphological, histological, and ultrastructural study and observed under light and electron microscope. Dose-dependent efficacy was observed in both compounds. Shrinkage of suckers, deformed proglottids and architectural alteration of the tegument were observed throughout the body of treated parasites compared to control. Although in terms of time taken for paralysis and mortality Gallic acid was more effective than Catechin, the degree of morphological aberrations caused were almost similar, except histological alteration was more in Catechin treated worms than in Gallic acid. Nevertheless, both Gallic acid and Catechin are suggested to possess anthelmintic efficacy besides other health benefits but extended studies are required to compare their efficacy.

The Lesser Mealworm Beetle (Alphitobius diaperinus) as an Intermediate Host for Poultry Tapeworm Raillietina cesticillus

Tapeworms are a widespread and recurrent problem in intensive chicken rearing and are transmitted by various types of invertebrate hosts dwelling in poultry litter. The mealworm beetle, Alphitobius diaperinus is the major pest in poultry litter and acts as an intermediate host for poultry tapeworms. Beetles collected from a poultry farm with suspected tapeworm infection were examined for the presence of the metacestode stage of the parasite. A total of 713 beetles were collected to study the vector potentiality. Out of these, 208 beetles (29.17%) were found to harbor cysticercoids of Railietina cesticillus. The percentage of cysticercoid infection in beetles was 33.42 and 24.78% respectively in two different surveys in a year. The beetles harboring the cysticercoids were identified as Alphitobius diaperinus, which may be a natural intermediate host for poultry tapeworm, Railietina cesticillus. The results of this study will help to formulate suitable control measures against the lesser mealworm beetles.

Optical microscopy and cross anatomy for the intestinal wall of sheep infected with Tap worm

Ten intestinal mucosa of sheep intestine were obtained for cross and microscopy examination, the specimens from those intestinal wall were taken at pieces half cm and washed well by running water, then processed by histological technique according to Bancoft &amp; Steven 1987 including fixation, dehydration, clearing and embedding with paraffin wax also sectioning at six micrometer by microtome, finally stained by Hematoxylin and Eosin after that mounted with D. P. X and after drying in dry cabinet for 24 hour examined by light microscope , The intestinal wall was congested and patches of blood hemorrhage were seen. The histological examination revealed to sloughing of the intestinal villi from the luminal surface with presence of hyper secretion of mucus from the goblet cells and intestinal glands in the lamina properia also infiltration of white blood cells in the lamina properia in between the intestinal glands. In conclusion; the intestinal wall was damages after infection with Tape worm due to its effect on the villi of mucosa which are vital structures for absorption of nutritional elements in a animals.

Dipylidiosis pada Pasien Kucing di Klinik RVet Bogor

Cats are one of the many pets kept in Indonesia. Dipylidiasis is a disease that often occurs in cats caused by infection with the Cestode worm Dipylidium caninum. The case study at the Rvet Bogor clinic aimed to find out Dipylidiosis cases as well as its diagnostic and treatment techniques. Medical record data for September 2020 to September 2021 showed fluctuations in Dipylidiosis cases in 35 cat patients at the Rvet Bogor clinic. The highest infection of Dipylidium caninum in cats occurred during the rainy season from November 2020 to March 2021. The lowest disease of D. caninum in cats happened in the dry season in August 2021 and September 2021. The patient is a cat named Nuna with a lethargy condition and of soft stools and a there is a gravid proglottid on her perianal. Groups of D.caninum eggs were seen around the gravid proglottids found in the perianal area of Nuna cat patients. Drontal® anthelmintic was given to cats infected with D. caninum at the Rvet Bogor clinic.

Amorphous Solid Dispersion of Niclosamide with Water‐Soluble β‐Cyclodextrins for Dissolution and Bioavailability Enhancement

AbstractCyclodextrins (CDs) are cyclic oligosaccharides widely employed for the solubility enhancement of poorly water‐soluble drugs. Niclosamide is a BCS class II drug for tapeworm infections and is currently under repurposing for various other indications, including COVID‐19. Due to its low aqueous solubility, a high daily dose (2 g) is required for clinical efficacy. Herein, we investigate the potential of beta‐cyclodextrin (β‐CD) and its sulfobutylether and hydroxypropyl derivatives for the dissolution enhancement of niclosamide. The solid dispersions were prepared by kneading the drug and cyclodextrins together by adding solvent, water: methanol (1 : 1 v/v). Among various CDs studied, 2‐Hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) in the 1: 2 molar ratio (SB‐IC‐N4 batch) shows the most significant improvement in water solubility of niclosamide (6.3 vs. 182 μg/ml), resulting in 2‐fold improved in‐vitro dissolution. The comparative oral pharmacokinetics in Wistar rats at 50 mg/kg produced 1.69‐fold higher plasma exposure of niclosamide. The spectral characterization provided molecular insights into interactions of niclosamide with HP‐β‐CD. These results suggest that the dispersion of niclosamide with HP‐β‐CD aid in faster dissolution and better drug bioavailability.

Molecular Screening of Echinococcus spp. and Other Cestodes in Wild Carnivores from Central Italy.

Tapeworm infections are among the most relevant parasitic diseases in humans and animals. Tapeworms from the Genus Echinococcus are particularly important as they can cause cystic or alveolar echinococcosis. A molecular screening was performed on 279 fecal samples collected from carcasses of wild carnivores from Central Italy using PCR targeting diagnostic fragments of nad1, rrnS, and nad5 genes. Samples positive for either Taenia spp. or Echinococcus granulosus were sequenced to taxonomically identify the parasitic DNA. Of the 279 samples, 134 (48.0%) gave positive results in the multiplex PCR. Only one (0.4%) sample from an Apennine wolf tested positive for Echinococcus granulosus sensu stricto (genotype G3), whereas no sample tested positive for E. multilocularis. The most frequently detected tapeworms were: Mesocestoides corti (syn M. vogae) (12.9%), M. litteratus (10.8%), Taenia serialis (9.3%), and T. hydatigena (6.5%), other tapeworms were rarely detected. The results suggest that Echinococcus infections in Central Italy do not seem to be sustained by sylvatic cycles, confirming the absence of E. multilocularis in Central Italy. The survey corroborates, yet again, the importance of passive surveillance of wild animals that can serve as reservoirs for zoonotic pathogens, especially on wild canids that in other areas are strongly implicated in the transmission of E. granulosus and E. multilocularis.

A 20 Years Retrospective Descriptive Study of Human Cystic Echinococcosis and the Role of Albendazole Concurrent with Surgical Treatment: 2001-2021.

Hydatid cyst, caused by the larvae of Echinococcus granulosus, is one of the most severe cestode infections occurring in Iran. The liver is the most commonly involved organ. The present study was carried out to review the demographic of 20 years surgically treated hydatic cysts. Ninety-eight patients were enrolled in the study. Demographic features, time of surgery, cyst size, and albendazole usage have been reviewed from the medical records of patients in Loghman Hakim Hospital, Tehran, Iran, from 2001 to 2021. Statistical analysis was performed to find any correlation between the uses of concurrent albendazole with surgical procedure. Of 98 patients with hydatid cyst, 57 (58.2%) were female. The mean age of patients was 39.4 ±18.7 yrs, and the mean surgery time was 217.5 ± 81.4 minutes. Regarding the infection site, the liver (60.2%) and lungs (22.4%) were the most affected organs, respectively. 56.1% of patients had one cyst, and 42.9 % had two or more cysts. 20.4% of them had taken albendazole before surgery, but 86.7 % took it after the operation. No recurrent cysts were seen among 91.8% of them, but 8.2% mentioned suffering from a recurrent cyst. 85.7% of those recurrent cases did not receive albendazole before surgery, and 75% of recurrent cases after surgery did not take albendazole (P<0.05). Administration of albendazole before and after the operation was significantly related to reduced recurrence, bleeding, morbidity, and even the time of surgery.

Experience of eradicating parasites of laboratory rats in conventional vivarium

The purpose of the research is to test different dehelminthization schemes of laboratory rats infected with cestodes Rodentolepis nana and nematodes Syphacia muris and evaluate the significance of combined environment disinfection measures. The practical experience of eradication (helminth eradication) in animals in a conventional vivarium was described.Materials and methods. Experiments were conducted to study the efficacy of anthelmintics and administration schemes against cestode and nematode infections in laboratory rats. In the first experiment, praziquantel was used at a dose of 10 mg/kg to treat rats infected with R. nana. In the second experiment, the comparative efficacy of fenbendazole, albendazole, and pyrantel was evaluated against syphaciosis at the recommended dosages of 20, 10, and 12.5 mg/kg, respectively. Each drug was given orally, individually, twice with an interval of 7 days. The third experiment tested different schemes for treating syphaciosis with fenbendazole. One group of rats was given the drug orally individually using an esophageal tube at a dose of 20 mg/kg once a day for 7 consecutive days. Other groups were given fenbendazole daily with food for 7 days (150 mg fenbendazole per 1 kg of food). In all three experiments, all animals were divided into groups, and their cells underwent a complex of additional disinfection measures, and those kept in cages without disinfection.Results and discussion. Praziquantel showed 100% efficacy at a single dose of 10 mg/kg in R. nana therapy. In animals without additional disinfection procedures, cestode eggs were again recorded starting from day 14 after the drug administration. In the group of animals with disinfection measures, pathogens were not detected during the experiment. Double administration of fenbendazole, albendazole and pyrantel in the recommended dosages against syphaciosis did not result in eradicated nematodes in the animals. The disinfection did not affect the obtained results. Fenbendazole administered daily for 7 days ensured helminth eradication in animals. However, on day 7 after the therapy, Syphacia sp. eggs were again found in the groups that received the drug individually intragastrically through a tube, regardless of whether their cells were disinfected. The animals that received fenbendazole with food and were regularly disinfested remained free from nematodes throughout the experiment until the additional disinfection measures were cancelled. In the absence of disinfection, released helminth eggs were recorded on day 14 after therapy.

An Initial Study on the Use of Machine Learning and Radio Frequency Identification Data for Predicting Health Outcomes in Free-Range Laying Hens.

Maintaining the health and welfare of laying hens is key to achieving peak productivity and has become significant for assuring consumer confidence in the industry. Free-range egg production systems represent diverse environments, with a range of challenges that undermine flock performance not experienced in more conventional production systems. These challenges can include increased exposure to parasites and bacterial or viral infection, along with injuries and plumage damage resulting from increased freedom of movement and interaction with flock-mates. The ability to forecast the incidence of these health challenges across the production lifecycle for individual laying hens could result in an opportunity to make significant economic savings. By delivering the opportunity to reduce mortality rates and increase egg laying rates, the implementation of flock monitoring systems can be a viable solution. This study investigates the use of Radio Frequency Identification technologies (RFID) and machine learning to identify production system usage patterns and to forecast the health status for individual hens. Analysis of the underpinning data is presented that focuses on identifying correlations and structure that are significant for explaining the performance of predictive models that are trained on these challenging, highly unbalanced, datasets. A machine learning workflow was developed that incorporates data resampling to overcome the dataset imbalance and the identification/refinement of important data features. The results demonstrate promising performance, with an average 28% of Spotty Liver Disease, 33% round worm, and 33% of tape worm infections correctly predicted at the end of production. The analysis showed that monitoring hens during the early stages of egg production shows similar performance to models trained with data obtained at later periods of egg production. Future work could improve on these initial predictions by incorporating additional data streams to create a more complete view of flock health.

Inhibition of mouse colon cancer growth following immunotherapy with a fraction of hydatid cyst fluid

BackgroundHydatid cyst is the larval stage of the tape worm Echinococcus granulosus which is located in human and livestock viscera. There are some scientific evidences indicating that parasitic infections induce antitumor activity against certain types of cancers. In this study, the effects of a fraction of hydatid cyst fluid on colon cancer tumor in BALB/c mice were investigated. Materials and methodsIn this experimental work six groups of mice were challenged with mouse colon cancer cells. 5 days later when the sign of tumor growth in mice was seen, group 1–4 were injected with hydatid cyst fluid, the 78 kDa fraction, live protoscolices and BCG respectively. Group five was injected with alum alone and the sixth group left intact without any injection. The size of the tumor was measured and compared in all groups. Then blood samples of mice were evaluated for serum cytokine levels. ResultIn mice injected with hydatid cyst antigens especially a fraction of hydatid cyst fluid, tumor size was smaller than the that of control groups and the difference of tumor size in cases and control groups was statistically significant. ConclusionThe results of this study showed that injection of mice with a fraction of hydatid cyst fluid significantly inhibits the growth of mouse colon cancer and this inhibition may be related to effect of immune response to these antigens.

Taenia solium: Socioeconomic changes and prevalence evolution in four endemic communities in northwestern Mexico.

In Mexico, for the past 30 years, a continuous decrease in the incidence of clinical taeniosis/cysticercosis has been documented. This work aimed to determine the influence of improvement in socioeconomic conditions on the prevalence of Taenia solium in four endemic communities in northwestern Mexico. This study was carried out in two phases. First, documentary information (1989-2018) was collected about the prevalence of Theridion solium in the federal entity of Sinaloa State. Second, a pilot study was performed in four communities of Sinaloa, which had an endemic history of Taenia transmission. In each community, a risk factor questionnaire was applied, and serum and stool samples were collected for convenience in a non-probabilistic way. Anti-cysticercus antibodies and adult worm coproantigen were determined. The documentary analysis showed the incidence of taeniosis and cysticercosis to have decreased by 98 and 53%, respectively, while the human development index increased by 5% (1992-2017). Our data suggest that the risk of parasitic transmission is low, although female sex was a risk factor for reporting tremors or seizures (prevalence rate 2.1336, CI: 1.1821-3.8508) and background of tapeworm infection (prevalence rate 1.2893, CI: 0.9795-1.6972). No tapeworms or eggs were found while examining stool samples, but protozoa cysts were observed in four samples. Unexpectedly, only one of the 79 stool samples was positive for coproantigens. This positive result was confirmed in a second sample. However, the evaluation of a third sample was negative. No antibodies were found in human (n=377) or pig (n=69) samples. These data suggest parasite transmission has been interrupted and could be possibly associated with improving socioeconomic conditions. Further studies are needed to determine the real prevalence of zoonoses in Mexico.