Neuroparasitic infections: cestodes, trematodes, and protozoans

Beyond the acute phase: a comprehensive literature review of long-term sequelae resulting from infectious diseases

Infectious diseases have consistently served as pivotal influences on numerous civilizations, inducing morbidity, mortality, and consequently redirecting the course of history. Their impact extends far beyond the acute phase, characterized by the majority of symptom presentations, to a multitude of adverse events and sequelae that follow viral, parasitic, fungal, or bacterial infections. In this context, myriad sequelae related to various infectious diseases have been identified, spanning short to long-term durations. Although these sequelae are known to affect thousands of individuals individually, a comprehensive evaluation of all potential long-term effects of infectious diseases has yet to be undertaken. We present a comprehensive literature review delineating the primary sequelae attributable to major infectious diseases, categorized by systems, symptoms, and duration. This compilation serves as a crucial resource, illuminating the long-term ramifications of infectious diseases for healthcare professionals worldwide. Moreover, this review highlights the substantial burden that these sequelae impose on global health and economies, a facet often overshadowed by the predominant focus on the acute phase. Patients are frequently discharged following the resolution of the acute phase, with minimal long-term follow-up to comprehend and address potential sequelae. This emphasizes the pressing need for sustained vigilance, thorough patient monitoring, strategic health management, and rigorous research to understand and mitigate the lasting economic and health impacts of infectious diseases more fully.

Hand palm sparganosis: morphologically and genetically confirmed Spirometra erinaceieuropaei in a fourteen-year-old girl, Egypt

Two spargana of 5 and 7 cm long were removed from the right-hand palm of 14-year-old girl at the General Hospital, Qalyubia, Egypt. Sparganum is the 2nd larval stage (pleurocercoid) of Diphyllobothrid cestode species develops in the vertebrate second intermediate host through ingestion of the crustacean first intermediate host.Dogs and cats are the final hosts get infected through predation of the second vertebrate host.Human attracts infection through drinking water contaminated with the infected crustacean host or consumption of the flesh of of vertebrate hosts such as frogs and reptilian species. The surgically removed specimens were parsitologically identified as a non-proliferative metacestodes of a spirometran species that then on molecular analysis proved to be Spirometra erinaceieuropaei. The present report has allocated Egypt on the world sparganosis map.Molecular characterization of 28 S rRNA of S. erinaceieuropae and correlation to other Spirometra spp. from the Nile countries, particularly Ethiopia and Lake Victoria countries where the Nile waters originate, and from China were dealt with. Drinking of contaminated fresh water is the only proposed mode of infection in Egypt.

Emerging and Re-Emerging Parasitic Infections of the Central Nervous System (CNS) in Europe

In a rapidly evolving global landscape characterized by increased international travel, migration, and ecological shifts, this study sheds light on the emergence of protozoal and helminthic infections targeting the central nervous system (CNS) within Europe. Despite being traditionally associated with tropical regions, these infections are progressively becoming more prevalent in non-endemic areas. By scrutinizing the inherent risks, potential outcomes, and attendant challenges, this study underscores the intricate interplay between diagnostic limitations, susceptibility of specific population subsets, and the profound influence of climate fluctuations. The contemporary interconnectedness of societies serves as a conduit for introducing and establishing these infections, warranting comprehensive assessment. This study emphasizes the pivotal role of heightened clinician vigilance, judicious public health interventions, and synergistic research collaborations to mitigate the potential consequences of these infections. Though rare, their profound impact on morbidity and mortality underscores the collective urgency required to safeguard the neurological well-being of the European populace. Through this multifaceted approach, Europe can effectively navigate the complex terrain posed with these emergent infections.

Discovery of N-methylbenzo[d]oxazol-2-amine as new anthelmintic agent through scalable protocol for the synthesis of N-alkylbenzo[d]oxazol-2-amine and N-alkylbenzo[d]thiazol-2-amine derivatives

We discovered a lead compound, N-methylbenzo[d]oxazol-2-amine (2a), which had comparable potency to albendazole, an orally administered anthelminticdrug, against Gnathostoma spinigerum, Caenorhabditis elegans and Trichinella spiralis. Compound 2a showed about 10 times lower cytotoxicity towards normal human cell line (HEK293) than albendazole. Moreover, we have developed new processes for the synthesis of N-alkylbenzo[d]oxazol-2-amine and N-alkylbenzo[d]thiazol-2-amine derivatives via metal-free conditions. This protocol could serve as a robust and scalable method, especially, to synthesize N-methylbenzo[d]oxazol-2-amine and N-methylbenzo[d]thiazol-2-amine derivatives which were difficult to prepare using other metal-free conditions. The method employed benzoxazole-2-thiol or benzothiazole-2-thiol as the substrate. The reaction was triggered by methylation of the thiol functional group to form the methyl sulfide intermediate, a crucial tactic, which facilitated in a smooth nucleophilic addition-elimination reaction with gaseous methylamine generated in situ from N-methylformamide. In addition, the proteomic analysis of compound 2a was also studied in this work.

Cerebral sparganosis masquerading brain neoplasm: A rare incidental case

Sparganosis is a parasitic infection caused by plerocercoid larvae of the genera Spirometra. Cerebral sparganosis is one of its most serious complications wherein clinical and imaging findings may pose diagnostic challenge. Here we present a case of cerebral sparganosis which mimicked as brain tumour on clinicoradiological examination. The case is reported in view of its rarity in India and the need for awareness of the entity.

Angiostrongilus cantonensis an Atypical Presenilin: Epitope Mapping, Characterization, and Development of an ELISA Peptide Assay for Specific Diagnostic of Angiostrongyliasis

Background: Angiostrongyliasis, the leading cause universal of eosinophilic meningitis, is an emergent disease due to Angiostrongylus cantonensis (rat lungworm) larvae, transmitted accidentally to humans. The diagnosis of human angiostrongyliasis is based on epidemiologic characteristics, clinical symptoms, medical history, and laboratory findings, particularly hypereosinophilia in blood and cerebrospinal fluid. Thus, the diagnosis is difficult and often confused with those produced by other parasitic diseases. Therefore, the development of a fast and specific diagnostic test for angiostrongyliasis is a challenge mainly due to the lack of specificity of the described tests, and therefore, the characterization of a new target is required. Material and Methods: Using bioinformatics tools, the putative presenilin (PS) protein C7BVX5-1 was characterized structurally and phylogenetically. A peptide microarray approach was employed to identify single and specific epitopes, and tetrameric epitope peptides were synthesized to evaluate their performance in an ELISA-peptide assay. Results: The data showed that the A. cantonensis PS protein presents nine transmembrane domains, the catalytic aspartyl domain [(XD (aa 241) and GLGD (aa 332–335)], between TM6 and TM7 and the absence of the PALP and other characteristics domains of the class A22 and homologous presenilin (PSH). These individualities make it an atypical sub-branch of the PS family, located in a separate subgroup along with the enzyme Haemogonchus contournus and separated from other worm subclasses. Twelve B-linear epitopes were identified by microarray of peptides and validated by ELISA using infected rat sera. In addition, their diagnostic performance was demonstrated by an ELISA-MAP4 peptide. Conclusions: Our data show that the putative AgPS is an atypical multi-pass transmembrane protein and indicate that the protein is an excellent immunological target with two (PsAg3 and PsAg9) A. costarisencis cross-reactive epitopes and eight (PsAg1, PsAg2, PsAg6, PsAg7, PsAg8, PsAg10, PsAg11, PsAg12) apparent unique A. cantonensis epitopes. These epitopes could be used in engineered receptacle proteins to develop a specific immunological diagnostic assay for angiostrongyliasis caused by A. cantonensis.

Emerging roles of IL-34 in neurodegenerative and neurological infectious disease

Neurological infections are often devastating in their clinical presentation. Although significant advances have made in neuroimaging techniques and molecular tools for diagnosis, as well as in anti-infective therapy, these diseases always difficult to diagnose and treat. Neuroparasitic infections and virus infections lead to neurological infections. In the nervous system, various cytokines and chemokines act as neuroinflammatory agents, neuromodulators, regulate neurodevelopment, and synaptic transmission. Among the most important cytokines, interleukins (ILs) are a large group of immunomodulatory proteins that elicit a wide variety of responses in cells and tissues. These ILs are involved in pro and anti-inflammatory effects, systemic inflammation, immune system modulation and play crucial roles in fighting cancer, infectious disease, and neurological disorders. Interleukin-34 (IL-34) identified by screening a comprehensive human protein library containing ∼3400 secreted and extracellular domain proteins in a human monocyte viability assay. Recent evidence has disclosed the crucial roles of IL-34 in the proliferation and differentiation of mononuclear phagocyte lineage cells, osteoclastogenesis, and inflammation. Additionally, IL-34 plays an important role in development, homeostasis, and disease. Dysregulation in IL-34 function can lead to various inflammatory and infectious diseases (e.g. Inflammatory bowel disease, liver fibrosis, Systemic Lupus erythematosus, rheumatoid arthritis), neurological disorders (e.g. Alzheimer disease) and neurological infectious disease (e.g. West Nile virus disease). In this review, we explore the biological role of IL-34 in addition to various impairments caused by dysregulation in IL-34 and discuss their potential links that may lead to important therapeutic and/or preventive strategies for these disorders.

Diagnostic Testing in Central Nervous System Infection

Patients with central nervous system (CNS) infection experience very high levels of morbidity and mortality, in part because of the many challenges inherent to the diagnosis of CNS infection and identification of a causative pathogen. The clinical presentation of CNS infection is nonspecific, so clinicians must often order and interpret many diagnostic tests in parallel. This can be a daunting task given the large number of potential pathogens and the availability of different testing modalities. Here, we review traditional diagnostic techniques including Gram stain and culture, serology, and polymerase chain reaction (PCR). We highlight which of these are recommended for the pathogens most commonly tested among U.S. patients with suspected CNS infection. Finally, we describe the newer broad-range diagnostic approaches, multiplex PCR and metagenomic sequencing, which are increasingly used in clinical practice.

Nematode eggs observed in cytology of cerebrospinal fluid diagnostic for intramedullary Spirocerca lupi spinal cord migration

Spinal spirocercosis due to aberrant Spirocerca lupi nematode migration is an emerging etiology for acute myelitis in dogs in Israel, causing severe, mostly nonsymmetrical hind limb paresis or paralysis, and sometimes tetraparesis or tetraparalysis. So far, incidental identification of parasites during spinal surgery or at necropsy provides the only definite diagnosis, while antemortem diagnosis of this condition has been uncertain. Specifically, antemortem diagnosis is based on the typical clinical presentation of acute, progressive, asymmetrical hind limb paresis or paralysis, with moderate to severe eosinophilic to mixed cerebrospinal fluid (CSF) pleocytosis and increased CSF protein concentration. Exclusion of other differential diagnoses also requires using spinal cord imaging. In this novel report, we document a case of an intradural spinal spirocercosis in a dog, diagnosed antemortem, by detecting S lupi eggs in the CSF, and subsequent treatment, resulting in the resolution of the clinical signs.

CSF in acute and chronic infectious diseases

Infections of the nervous system are an important and challenging aspect of clinical neurology. Immediate correct diagnosis enables to introduce effective therapy, in conditions that without diagnosis may leave the patient with severe neurological incapacitation and sometimes even death. The cerebrospinal fluid (CSF) is a mirror that reflects nervous system pathology and can promote early diagnosis and therapy. The present chapter focuses on the CSF findings in neuro-infections, mainly viral and bacterial. Opening pressure, protein and glucose levels, presence of cells and type of the cellular reaction should be monitored. Other tests can also shed light on the causative agent: serology, culture, staining, molecular techniques such as polymerase chain reaction. Specific examination such as panbacterial and panfungal examinations should be examined when relevant. Our chapter is a guide-text that combines clinical presentation and course with CSF findings as a usuaful tool in diagnosis of neuroinfections.

Fatal Liver and Lung Alveolar Echinococcosis with Newly Developed Neurologic Symptoms due to the Brain Involvement

The fox tapeworm Echinococcus multilocularis causes human alveolar echinococcosis, commonly affecting the liver. However, in ∼1% of cases, systematic spread of the disease involves the brain as well. A patient had a 6-year history of liver and lung alveolar echinococcosis that was considered not suitable for surgery, and treatment with albendazole was introduced. After the appearance of neurologic disturbances, an intracranial mass lesion was demonstrated by radiologic imaging. The lesion was surgically removed, and histologic analysis revealed metacestode tissue of E. multilocularis . Despite the surgical resection of the lesion, the patient died of progression of systemic alveolar echinococcosis. The authors highly recommend implementing neurologic monitoring to the follow-up algorithm for patients with systemically disseminated alveolar echinococcosis. When neurologic symptoms occur, radiologic imaging of the brain should be obtained immediately. Surgery should be considered for all intracranial echinococcal lesions, unless the lesion is located in the eloquent brain area.

Endoscopic resection of sparganosis presenting as colon submucosal tumor: A case report

Human sparganosis is a rare parasitic disease caused by infection with the tapeworm Sparganum, the migrating plerocercoid (second stage) larva of Spirometra species. Sparganosis usually involves subcutaneous tissues and/or muscles of various parts of the body, but involvement of other sites such as the brain, eye, peritoneopleural cavity, urinary track, scrotum, and abdominal viscera has also been documented. Infections caused by sparganum have a worldwide distribution but are most common in Southeast Asia such as China, Japan, and South Korea. Rectal sparganosis is an uncommon disease but should be considered in the differential diagnosis of unusual and suspicious rectal submucosal tumors. We report a case of rectal sparganosis presenting as rectal submucosal tumor. We performed endoscopic submucosal dissection of the rectal submucosal tumor. The sparganosis was confirmed based on the presence of calcospherules in the submucosal layer on histological examination. Moreover, the result of the immunoglobulin G antibody test for sparganosis was positive but became negative after endoscopic submucosal dissection. Though rare, rectal sparganosis should be considered in the differential diagnosis of rectal submucosal tumor-like lesions. This case suggests that physicians should make effort to exclude sparganosis through careful diagnostic approaches, including detailed history taking and serological tests for parasites. In this report, we aimed to highlight the clinical presentation of Sparganum infection as a rectal submucosal tumor.

Eosinophilic pleural effusion due to Spirometra mansoni spargana: a case report and review of the literature

A 36-year-old female presented with an eosinophilic pleural effusion. The eosinophilic pleural effusion was considered to have been caused by a parasitic infection. Spirometra mansoni spargana was confirmed by semi-rigid thoracoscopy. About 2 months after treatment with praziquantel for 3 days, the pleural effusion had disappeared on the chest roentgenogram.

Recurred sparganosis 1 year after surgical removal of a sparganum in a Korean woman

Sparganosis, an infection due to the plerocercoid of Spirometra erinacei, are found worldwide but the majority of cases occur in East Asia including Korea. This report is on a recurred case of sparganosis in the subcutaneous tissue of the right lower leg 1 year after a surgical removal of a worm from a similar region. At admission, ultrasonography (USG) of the lesion strongly suggested sparganosis, and a worm was successfully removed which turned out to be a sparganum with scolex. Since sparganum has a variable life span, and may develop into a life-threatening severe case, a patient once diagnosed as sparganosis should be properly followed-up for a certain period of time. Although imaging modalities were useful for the diagnosis of sparganosis as seen in this case, serological test such as ELISA should also be accompanied so as to support the preoperative diagnosis.

Subcutaneous sparganosis, a zoonotic cestodiasis, in two cats

Sparganosis is a zoonotic cestodiasis of human beings and animals caused by plerocercoid or second-stage larvae (sparganum) of pseudophyllidean tapeworms in host tissues. Cats are among definitive hosts in which the larva develops to adult stage in the intestines. Reports on larval infection involving various tissues and organs in cats are scarce. Rare single case reports of visceral sparganosis in cats are previously documented. The present report documents an unusual subcutaneous sparganosis in 2 Domestic Shorthair cats from southern Georgia. Veterinary clinicians should consider sparganosis as differential diagnosis for subcutaneous cyst-like masses in cats. As infected animals and animal tissues are sources of human infection, sparganosis warrants public awareness and due precaution to avoid human infection.

Two cases of pulmonary and pleural sparganosis confirmed by tissue biopsy and immunoserology

Sparganosis in humans is an incidental infection and is known to be associated with eating insufficiently cooked meat of frogs and snakes or drinking unboiled stream water. Although it can involve various internal organs, pulmonary and pleural involvement due to sparganum is rare. Because we recently experienced two cases involving lung parenchyma and pleura that were misdiagnosed as bacterial pneumonia and lung cancer, we herein intend to present them in detail.

Other cestodes: sparganosis, coenurosis and Taenia crassiceps cysticercosis

Many cestodes are capable of invading the central nervous system (CNS), and several are highly prevalent in the developing world. Neurocysticercosis due to Taenia solium and echinococcosis due to Echinoccocus granulosus are two of the most common parasitic infections affecting humans, but other less well-known parasites can also infect the nervous system. Coenurosis, caused by Taenia spp. such as T. multiceps, T. serialis, or T. brauni; sparganosis, caused by Spirometra spp., and neurocysticercosis caused by T. crassiceps are three less frequent zoonotic conditions that should be considered in the differential diagnosis of patients presenting with CNS infection - especially if they have lived in or traveled through areas where these infections are endemic. Diagnosis of these infections is typically made through a combination of serological testing, histopathology, and neuroimaging.

Platynosomum fastosum-induced chronic intrahepatic cholangitis and Spirometra spp. infections in feral cats from Grand Cayman

The occurrence of platynosomiasis and intestinal sparganosis is described in feral cats from Grand Cayman, Cayman Islands. Spirometra spp. was observed within the intestine of 18.18% (10/55) of cats; 1.18% (1/55) of cats demonstrated gross and histological manifestation of parasitism by Platynosomum fastosum, but 14.5% (8/55) of cats had the characteristic pathological manifestations of P. fastosum-induced intrahepatic cholangitis without the concomitant presence of the intraductal trematode. Combined parasitism (Spirometra spp. and P. fastosum) was observed in 9.09% (5/55) of feral cats. Significant pathological findings were only associated with the hepatic fluke, P. fastosum, and were grossly characterized by moderate hepatomegaly with enlarged and dilated bile ducts. Examples of cestodes with morphological features characteristic of Spirometra spp. were observed within the small intestine without any associated pathological lesion. The histopathological evaluation of liver fragments revealed chronic intrahepatic cholangitis with and without the associated intraductal trematode, and was characterized by marked periductal fibrosis, adenomatous proliferation of bile duct epithelium, dilation of intrahepatic bile ducts and portal accumulations of inflammatory cells. The occurrence of the cestode in feral cats coupled with factors that are unique to Grand Cayman makes this island the ideal location for sporadic cases of human sparganosis.

Two-dimensional immunoblot analysis of antigenic proteins of Spirometra plerocercoid recognized by human patient sera

Sparganosis is caused by invasion of Spirometra plerocercoid into various tissues/organs. Subcutaneous sparganosis can be diagnosed and treated by worm removal, while visceral/cerebral sparganosis is not easy to diagnose. The diagnosis depends largely on the detection of specific antibodies circulating in the patients' sera. Previous studies demonstrated that 31 and 36kDa proteins of the sparganum invoked specific and sensitive antibody responses, but also showed cross reactions with cysticercosis sera. We enriched protein fractions containing 31-36kDa through gel filtration and examined immune recognition pattern against the patient sera by 2-dimensional electrophoresis (2-DE) followed by immunoblotting. Serum samples from sparganosis patients recognized 8-10 protein spots of 31 and 36kDa with different isoelectric point (pI) values with variable combinations, in which four spots of 31kDa with pIs 3.4, 3.9, 4.0 and 4.1, and one 36kDa spot (pI 3.5) appeared to be specifically reactive. One 31kDa protein spot with pI 3.3 and two spots of 36kDa with pIs 3.3 and 3.5 reacted crossly with neurocysticercosis sera. Neither sera from patients with other parasitic infections nor those from healthy controls showed positive reaction. Two-DE/immunoblot analysis might be highly available in differential serodiagnosis of human sparganosis.