Parasitic Infections and Host Tissue Response in Histopathology: A Rare Retrospective Research Study from Rural India.

OBJECTIVE: Parasite are living organisms which survive on another living being for their nourishment and survival. When these parasites resides on human body, they bring about inflammatory response. This inflammatory response leads to tissue reaction. Tissue response on microscopy appear as an eosinophilia, abscess and granulomas. This study was planned with the objective to know the frequency of parasite infection, tissue response in parasite infection and its comparison in terms of variables like age, sex and the type of parasite. METHODS: This is a retrospective study, conducted in the department of pathology. A total of 26 cases of parasitic infections in human specimens reported in our department from January 2008 to December 2019 were included in this study. On all archived cases hematoxylin and eosin and where ever required periodic acid schiff was applied. These slides were thoroughly examined and clinicopathological correlation was studied. RESULTS: Age range of patients was 5 years to 70 years. Maximum number of patients were belonging to 11-20 year age group. Male to female ratio was 1:2. Among the 26 cases, there were 9 cases (34.62%) of hydatid cyst, six cases of Entamoeba histolytica (23.07%), four cases of Enterobious vermicularis (15.38%), and two cases (7.69%) each of Ascaris lumbricoides, filaria and cysticercosis respectively. A specific tissue response seen in cysticercosis having chronic inflammatory cells, palisaded epithelioid cells granuloma and giant cell reaction while other showed inflammatory cells infiltration. CONCLUSION: Clinically diagnosis of parasitic infection in each and every case is not possible, similarly radiological investigation is also suggestive only. Histopathology examination is the benchmark investigation to diagnose parasite infection and tissue reaction to the host. Histopathology examination must be implicated in every case to identify parasite and tissue reaction so that the patients can be managed accordingly before the complications rises.

Extracellular vesicles as biomarkers in parasitic disease diagnosis.

Parasitic diseases constitute a major global health problem, affecting millions of people worldwide. Recent advances in the study of extracellular vesicles (EVs) have opened up new strategies for biomarker discovery in protozoan and helminth infections. Analyses of EVs in cultures and biological fluids have identified numerous potential biomarkers that could be useful for early and differential diagnosis, monitoring therapeutic responses, and the overall management and control of these diseases. Despite the potential of these biomarkers, several challenges must be addressed, including limited research, the need for standardized protocols, and the reproducibility of results across studies. In many parasitic infections, EVs have been obtained from various sample types, including plasma from human patients and mouse models, as well as cultures of the parasites at different stages. EVs were isolated by various methods and predominantly characterized through proteomic analysis or RNA sequencing to assess their cargo and identify potential biomarkers. These biomarker candidates were investigated and validated using different assays such as ELISA, Western Blot, and ROC curves. Overall, the use of EVs is considered a promising new diagnostic strategy for parasite infections, but further research with larger cohorts, standardized methods, and additional validation tests are essential for effective diagnosis and management of these diseases.

[Advances in detection methods for fish-borne parasites in aquatic products].

Consumption of raw and semi-raw aquatic products is strongly associated with the development of fish-borne parasitic diseases. Detection of fish-borne parasites in aquatic products is of great significance for the prevention and control of fish-borne parasitic diseases. This review describes the advances in the application of etiological, molecular biological and immunological techniques alone and in combinations for detection of fish-borne parasites, so as to provide insights into detection of fish-borne parasites.

Parasitic and Fungal Triggers of Cytokine Storm Syndrome.

Infections caused by parasites and fungi can trigger the cytokine storm syndrome (CSS). These infections causing CSS can occur together with acquired immunodeficiencies, lymphomas, the use of immunosuppressive medications, transplant recipients, cancer, autoinflammatory, and autoimmune diseases or less frequently in healthy individuals. Histoplasma, Leishmania, Plasmodium, and Toxoplasma are the most frequent organisms associated with a CSS. It is very important to determine a previous travel history when evaluating a patient with a CSS triggered by these organisms as this may be the clue to the causal agent. Even though CSS is treated with specific therapies, an effort to find the causal organism should be carried out since the treatment of the infectious organism may stop the CSS. Diagnosing a CSS in the presence of parasitic or fungal sepsis should also lead to the study of an altered cytotoxic or hemophagocytic response in the susceptible host.

Can Parasites be Useful?

Parasites are commonly associated with harm, but they also have beneficial aspects that are still being discovered. It is important to acknowledge both the harmful and beneficial aspects of parasites. They have been found to have positive effects on non-healing wounds, surgical wounds, obesity, glucose metabolism disorders, nerve repair, cancer treatments, and fertility. Research has shown that helminths, protozoa, and arthropods have the ability to correct, prevent, and cure certain disorders through the use of the parasite itself, its molecules, or even its eggs. This article includes studies on the beneficial aspects of parasites. However, further research is needed to fully understand the mechanisms by which parasites stimulate or affect the immune system and how they can be used therapeutically.

Parasite prevalence is determined by infection state- and risk-dependent dispersal of the host.

The spread of parasites and the emergence of disease are currently threatening global biodiversity and human welfare. To address this threat, we need to better understand those factors that determine parasite persistence and prevalence. It is known that dispersal is central to the spatial dynamics of host-parasite systems. Yet past studies have typically assumed that dispersal is a species-level constant, despite a growing body of empirical evidence that dispersal varies with ecological context, including the risk of infection and aspects of host state such as infection status (parasite-dependent dispersal; PDD). Here, we develop a metapopulation model to understand how different forms of PDD shape the prevalence of a directly transmitted parasite. We show that increasing host dispersal rate can increase, decrease or cause a non-monotonic change in regional parasite prevalence, depending on the type of PDD and characteristics of the host-parasite system (transmission rate, virulence, and dispersal mortality). This result contrasts with previous studies with parasite-independent dispersal which concluded that prevalence increases with host dispersal rate. We argue that accounting for host dispersal responses to parasites is necessary for a complete understanding of host-parasite dynamics and for predicting how parasite prevalence will respond to changes such as human alteration of landscape connectivity. This article is part of the theme issue 'Diversity-dependence of dispersal: interspecific interactions determine spatial dynamics'.

Modern Strategies for Diagnosis and Treatment of Parasitic Diseases.

Parasites are very widely distributed in the environment and form complex relationships with their hosts, forming host-parasite systems [...].

Parasite infection in a cell population: role of the partitioning kernel.

We consider a cell population subject to a parasite infection. Cells divide at a constant rate and, at division, share the parasites they contain between their two daughter cells. The sharing may be asymmetric, and its law may depend on the number of parasites in the mother. Cells die at a rate which may depend on the number of parasites they carry, and are also killed when this number explodes. We study the survival of the cell population as well as the mean number of parasites in the cells, and focus on the role of the parasites partitioning kernel at division.

Molecular regulation of NLRP3 inflammasome activation during parasitic infection.

Parasitic diseases are a serious global health concern, causing many common and severe infections, including Chagas disease, leishmaniasis, and schistosomiasis. The NLRP3 inflammasome belongs to the NLR (nucleotide-binding domain leucine-rich-repeat-containing proteins) family, which are cytosolic proteins playing key roles in the detection of pathogens. NLRP3 inflammasomes are activated in immune responses to Plasmodium, Leishmania, Toxoplasma gondii, Entamoeba histolytica, Trypanosoma cruzi, and other parasites. The role of NLRP3 is not fully understood, but it is a crucial component of the innate immune response to parasitic infections and its functions as a sensor triggering the inflammatory response to the invasive parasites. However, while this response can limit the parasites' growth, it can also result in potentially catastrophic host pathology. This makes it essential to understand how NLRP3 interacts with parasites to initiate the inflammatory response. Plasmodium hemozoin, Leishmania glycoconjugate lipophosphoglycan (LPG) and E. histolytica Gal/GalNAc lectin can stimulate NLRP3 activation, while the dense granule protein 9 (GRA9) of T. gondii has been shown to suppress it. Several other parasitic products also have diverse effects on NLRP3 activation. Understanding the mechanism of NLRP3 interaction with these products will help to develop advanced therapeutic approaches to treat parasitic diseases. This review summarizes current knowledge of the NLRP3 inflammasome's action on the immune response to parasitic infections and aims to determine the mechanisms through which parasitic molecules either activate or inhibit its action.

The Parasitism and Tumors Carcinogenesis: A Review Subject.

BACKGROUND: Multi-factorial reasons are an induction to cause cancer. Different infections and infestations with viruses, bacteria, and parasites have been detected for many years to be related to human carcinogenesis. PURPOSE: The study aimed to review all ideas of tumor carcinogenesis and its associations with parasitic infections and infestations. METHODS: We reviewed several articles (published and imprinted) by selecting, extracting, and synthesizing data about the relationship between cancers and parasites. RESULTS: Several helminths infections as schistosomiasis, are highly carcinogenic agents for bladder cancer, whereas trypanosomiasis has a bi-model role in cancer development. Leishmaniasis may be a cause of hepatocarcinoma, skin cancer, and lymphomas. In addition, malaria appears to be causative in the carcinogenesis of some cancers; as Burkitt lymphoma. Also, data from previous studies suggested that Strongyloides stercoralis may be a relevant co-factor in lymphomas. CONCLUSION: There are different mechanisms of parasitic infection to be enhancing in carcinogenesis of cancer in human.

Extracellular vesicles in parasitic diseases - from pathogenesis to future diagnostic tools.

Parasitic diseases are still a major public health problem especially among individuals of low socioeconomic status in underdeveloped countries. In recent years it has been demonstrated that parasites can release extracellular vesicles that participate in the host-parasite communication, immune evasion, and in governing processes associated with host infection. Extracellular vesicles are membrane-bound structures released into the extracellular space that can carry several types of biomolecules, including proteins, lipids, nucleic acids, and metabolites, which directly impact the target cells. Extracellular vesicles have attracted wide attention due to their relevance in host-parasite communication and for their potential value in applications such as in the diagnostic biomarker discovery. This review of the literature aimed to join the current knowledge on the role of extracellular vesicles in host-parasite interaction and summarize its molecular content, providing information for the acquisition of new tools that can be used in the diagnosis of parasitic diseases. These findings shed light to the potential of extracellular vesicle cargo derived from protozoan parasites as novel diagnostic tools.

The postmortem diagnosis of an Armillifer infection case in a cynomolgus macaque (Macaca fascicularis).

Armillifer moniliformis belongs to the order Porocephalida and family Porocephalidae, and it can cause zoonotic pentastomiasis. A suspected parasitic infection was incidentally discovered in the abdominal cavity of a cynomolgus macaque that died of persistent diarrhea. 18S rDNA amplification and sequencing revealed a high similarity (99.83%) to the Armillifer moniliformis Guangxi isolate. The isolated parasite was named the Armillifer moniliformis Yunnan isolate (GenBank accession no. HM048870). Our report presents a case of Armillifer moniliformis infection in macaques. The results indicated that early quarantine and diagnosis should be employed for animal health.

Abdominal Calcifications in a Patient From the Congo Basin with History of Snake Meat Consumption: Radiographic Evidence of Prior Armillifer Infection.

We report a case of a 60-year-old asymptomatic male with history of consumption of uncooked snake meat while living in the Congo basin and prior imaging showing multiple abdominal calcifications. Patient had multiple subepithelial colonic lesions identified during screening colonoscopy and microscopic examination of the lesions demonstrated a calcified nodule in the submucosa with overlying normal mucosa. However, no parasite was identified within the calcified nodule. Given the history of consumption of uncooked snake meat and the typical radiographic feature of multiple abdominal calcifications, it is very likely that the patient's radiographic abnormalities are due to prior Armillifer armillatus infection, a parasitic infection acquired from consumption of uncooked snake meat. Patient was asymptomatic at the time of evaluation and was not given anti-parasitic treatment.

Vanadium compounds as antiparasitic agents: An approach to their mechanisms of action.

BACKGROUND: Parasitic infections are a public health problem since they have high morbidity and mortality worldwide. In parasitosis such as malaria, leishmaniasis and trypanosomiasis it is necessary to develop new compounds for their treatment since an increase in drug resistance and toxic effects have been observed. Therefore, the use of different compounds that couple vanadium in their structure and that have a broad spectrum against different parasites have been proposed experimentally. OBJECTIVE: Report the mechanisms of action exerted by vanadium in different parasites. CONCLUSION: In this review, some of the targets that vanadium compounds have were identified and it was observed that they have a broad spectrum against different parasites, which represents an advance to continue investigating therapeutic options.

Deciphering Diets and Lifestyles of Prehistoric Humans through Paleoparasitology: A Review.

Parasites have affected and coevolved with humans and animals throughout history. Evidence of ancient parasitic infections, particularly, reside in archeological remains originating from different sources dating to various periods of times. The study of ancient parasites preserved in archaeological remains is known as paleoparasitology, and it initially intended to interpret migration, evolution, and dispersion patterns of ancient parasites, along with their hosts. Recently, paleoparasitology has been used to better understand dietary habits and lifestyles of ancient human societies. Paleoparasitology is increasingly being recognized as an interdisciplinary field within paleopathology that integrates areas such as palynology, archaeobotany, and zooarchaeology. Paleoparasitology also incorporates techniques such as microscopy, immunoassays, PCR, targeted sequencing, and more recently, high-throughput sequencing or shotgun metagenomics to understand ancient parasitic infections and thus interpret migration and evolution patterns, as well as dietary habits and lifestyles. The present review covers the original theories developed in the field of paleoparasitology, as well as the biology of some parasites identified in pre-Columbian cultures. Conclusions, as well as assumptions made during the discovery of the parasites in ancient samples, and how their identification may aid in better understanding part of human history, ancient diet, and lifestyles are discussed.

Imaging as a (pre)clinical tool in parasitology.

Imaging of parasites is central to diagnosis of many parasitic diseases and has thus far played an important role in the development of antiparasitic strategies. The development of novel imaging technologies has revolutionized medicine in fields other than parasitology and has also opened up new avenues for the visualization of parasites. Here we review the role imaging technology has played so far in parasitology and how it may spur further advancement. We point out possibilities to improve current microscopy-based diagnostic methods and how to extend them with radiological imaging modalities. We also highlight in vivo tracking of parasites as a readout for efficacy of new antiparasitic strategies and as a source of fundamental insights for rational design.

[Anticancer effect of parasites and its underlying mechanisms: a review].

Both parasitic diseases and cancers are disorders that seriously threaten human health. A strong correlation has been recently found between parasitic infections and cancers, and multiple species of parasites and their derived products have shown effective to suppress cancer development, progression and metastasis. Therefore, deciphering the interaction among parasites, cancers and hosts not only provides new insights into the development of cancer therapy, but also provides the basis for screening of parasites-derived active anticancer molecules. This review summarizes the latest advances in the anticancer activity of parasites and underlying mechanisms.

Where Have All the Diagnostic Morphological Parasitologists Gone?

Advances in laboratory techniques have revolutionized parasitology diagnostics over the past several decades. Widespread implementation of rapid antigen detection tests has greatly expanded access to tests for global parasitic threats such as malaria, while next-generation amplification and sequencing methods allow for sensitive and specific detection of human and animal parasites in complex specimen matrices. Recently, the introduction of multiplex panels for human gastrointestinal infections has enhanced the identification of common intestinal protozoa in feces along with bacterial and viral pathogens. Despite the benefits provided by novel diagnostics, increased reliance on nonmicroscopy-based methods has contributed to the progressive, widespread loss of morphology expertise for parasite identification. Loss of microscopy and morphology skills has the potential to negatively impact patient care, public health, and epidemiology. Molecular- and antigen-based diagnostics are not available for all parasites and may not be suitable for all specimen types and clinical settings. Furthermore, inadequate morphology experience may lead to missed and inaccurate diagnoses and erroneous descriptions of new human parasitic diseases. This commentary highlights the need to maintain expert microscopy and morphological parasitology diagnostic skills within the medical and scientific community. We proposed that light microscopy remains an important part of training and practice in the diagnosis of parasitic diseases and that efforts should be made to train the next generation of morphological parasitologists before the requisite knowledge, skills, and capacity for this complex and important mode of diagnosis are lost. In summary, the widespread, progressive loss of morphology expertise for parasite identification negatively impacts patient care, public health, and epidemiology.