Review of Dancing Parasites in Lymphatic Filariasis

Musculoskeletal involvement in neglected tropical diseases: a comprehensive review

Neglected tropical diseases (NTDs) encompass a group of diseases predominantly found in tropical regions, with origins dating back to their inclusion in the United Nations Millennium Development Goals in 2000. This initiative aimed to raise awareness and global funding to combat these diseases, which thrive in areas with limited sanitation, healthcare, and education. NTDs are caused by various pathogens such as bacteria, fungi, parasites, and viruses and affect over two billion individuals in resource-poor communities, leading to preventable deaths and devastating consequences. While the musculoskeletal system is only occasionally affected, the resulting chronic disabilities prevent individuals from working, posing a significant socioeconomic burden in this region of the world. Some NTDs exhibit distinct imaging features, and radiologists need to be aware of these characteristics to facilitate early treatment. In this review, we delve into musculoskeletal NTDs, focusing on clinical features and imaging findings, differential diagnosis, and clinical management.

Isolated perinephric abscess as the initial manifestation of filariasis-an unusual presentation

Key Clinical Message

Filariasis may present as an isolated perinephric abscess. Hence, a high index of suspicion should be maintained in endemic settings.

Abstract

In cases with unexplained fever, eosinophilia and perinephric collection, it is necessary to do detailed infectious disease work up. High index of suspicion is required to diagnose filariasis due to its wide range of clinical presentation and laboratory findings. It may present as perinephric abscess, which can be diagnosed through ultrasonography.

Plasticity in the cell division processes of obligate intracellular bacteria

Most bacteria divide through a highly conserved process called binary fission, in which there is symmetric growth of daughter cells and the synthesis of peptidoglycan at the mid-cell to enable cytokinesis. During this process, the parental cell replicates its chromosomal DNA and segregates replicated chromosomes into the daughter cells. The mechanisms that regulate binary fission have been extensively studied in several model organisms, including Eschericia coli, Bacillus subtilis, and Caulobacter crescentus. These analyses have revealed that a multi-protein complex called the divisome forms at the mid-cell to enable peptidoglycan synthesis and septation during division. In addition, rod-shaped bacteria form a multi-protein complex called the elongasome that drives sidewall peptidoglycan synthesis necessary for the maintenance of rod shape and the lengthening of the cell prior to division. In adapting to their intracellular niche, the obligate intracellular bacteria discussed here have eliminated one to several of the divisome gene products essential for binary fission in E. coli. In addition, genes that encode components of the elongasome, which were mostly lost as rod-shaped bacteria evolved into coccoid organisms, have been retained during the reductive evolutionary process that some coccoid obligate intracellular bacteria have undergone. Although the precise molecular mechanisms that regulate the division of obligate intracellular bacteria remain undefined, the studies summarized here indicate that obligate intracellular bacteria exhibit remarkable plasticity in their cell division processes.

microRNAs: Critical Players during Helminth Infections

microRNAs (miRNAs) are a group of small non-coding RNAs that regulate gene expression post-transcriptionally through their interaction with the 3' untranslated regions (3' UTR) of target mRNAs, affecting their stability and/or translation. Therefore, miRNAs regulate biological processes such as signal transduction, cell death, autophagy, metabolism, development, cellular proliferation, and differentiation. Dysregulated expression of microRNAs is associated with infectious diseases, where miRNAs modulate important aspects of the parasite-host interaction. Helminths are parasitic worms that cause various neglected tropical diseases affecting millions worldwide. These parasites have sophisticated mechanisms that give them a surprising immunomodulatory capacity favoring parasite persistence and establishment of infection. In this review, we analyze miRNAs in infections caused by helminths, emphasizing their role in immune regulation and its implication in diagnosis, prognosis, and the development of therapeutic strategies.

Filariasis Diagnosed by Real-Time Ultrasound Scanning as Filarial Dance Sign - A Case Report

Introduction

Lymphatic filariasis (LF) is a vector-borne illness caused due to Wuchereria bancrofti. Genital abnormalities may result from chronic inflammation of the lymphatic vessels and obstruction of the afferent vessels in Bancroftian filariasis. Doxycycline, albendazole, diethylcarbamazine, and ivermectin are among the treatments available.

Case

A 16-year male presented to our OPD with a complaint of left inguinal swelling for the past 6 Months. Examination of the swelling revealed a left-sided inguinal swelling of 5 × 4 cm with intact overlying skin. A provisional diagnosis of inguinal lymph varix was made, and real-time ultrasound scanning along with FNAC was performed. Swelling resolved after conservative management.

Discussion

Ultrasonography can easily observe adult worms due to their size and fast movements. Using pulsed-wave doppler mode, the characteristic movement profile of adult worms in pulsed-wave doppler mode can be distinguished from other movements (e.g., blood in venous vessels).

Conclusion

Ultrasound is the imaging modality of choice to detect filarial worms/microfilaria in the lymphatic system, which produces the classic twirling of microfilaria in the lymphatic system, known as the "filarial dance sign".

An annotated checklist of the eukaryotic parasites of humans, exclusive of fungi and algae

The classification of "parasites" in the medical field is a challenging notion, a group which historically has included all eukaryotes exclusive of fungi that invade and derive resources from the human host. Since antiquity, humans have been identifying and documenting parasitic infections, and this collective catalog of parasitic agents has expanded considerably with technology. As our understanding of species boundaries and the use of molecular tools has evolved, so has our concept of the taxonomy of human parasites. Consequently, new species have been recognized while others have been relegated to synonyms. On the other hand, the decline of expertise in classical parasitology and limited curricula have led to a loss of awareness of many rarely encountered species. Here, we provide a comprehensive checklist of all reported eukaryotic organisms (excluding fungi and allied taxa) parasitizing humans resulting in 274 genus-group taxa and 848 species-group taxa. For each species, or genus where indicated, a concise summary of geographic distribution, natural hosts, route of transmission and site within human host, and vectored pathogens are presented. Ubiquitous, human-adapted species as well as very rare, incidental zoonotic organisms are discussed in this annotated checklist. We also provide a list of 79 excluded genera and species that have been previously reported as human parasites but are not believed to be true human parasites or represent misidentifications or taxonomic changes.

Substernal goitre presenting with upper and lower extremity oedema

Substernal goitre is characterised by compressive symptoms of the airway and oesophagus. Chronic, progressive symptoms usually result in surgical removal. We report a rare presentation of substernal goitre in a male in his early 70s who suffered from severe bilateral lower extremity (LE) lymphoedema, resulting in immobility and nursing home placement, and left upper extremity lymphoedema. Our initial assessment led to a filariasis work-up, which was negative, due to the patient's prior 2-year residence in India and service overseas. Chest CT scan revealed an incidental substernal goitre extending posterior to the left innominate vein and aortic arch to the level of the left mainstem bronchus. The patient underwent a left hemithyroidectomy via cervical excision and sternotomy and had an uneventful recovery with resolution of lymphoedema and mobility. Despite extensive literature regarding clinical presentations of substernal goitre, severe lymphoedema of the LE is not a well-established association.

An update on the mosquito fauna and mosquito-borne diseases distribution in Cameroon

The expansion of mosquito-borne diseases such as dengue, yellow fever, and chikungunya in the past 15 years has ignited the need for active surveillance of common and neglected mosquito-borne infectious diseases. The surveillance should be designed to detect diseases and to provide relevant field-based data for developing and implementing effective control measures to prevent outbreaks before significant public health consequences can occur. Mosquitoes are important vectors of human and animal pathogens, and knowledge on their biodiversity and distribution in the Afrotropical region is needed for the development of evidence-based vector control strategies. Following a comprehensive literature search, an inventory of the diversity and distribution of mosquitoes as well as the different mosquito-borne diseases found in Cameroon was made. A total of 290 publications/reports and the mosquito catalogue website were consulted for the review. To date, about 307 species, four subspecies and one putative new species of Culicidae, comprising 60 species and one putative new species of Anopheles, 67 species and two subspecies of Culex, 77 species and one subspecies of Aedes, 31 species and one subspecies of Eretmapodites, two Mansonia, eight Coquillettidia, and 62 species with unknown medical and veterinary importance (Toxorhynchites, Uranotaenia, Mimomyia, Malaya, Hodgesia, Ficalbia, Orthopodomyia, Aedeomyia, and Culiseta and Lutzia) have been collected in Cameroon. Multiple mosquito species implicated in the transmission of pathogens within Anopheles, Culex, Aedes, Eretmapodites, Mansonia, and Coquillettidia have been reported in Cameroon. Furthermore, the presence of 26 human and zoonotic arboviral diseases, one helminthic disease, and two protozoal diseases has been reported. Information on the bionomics, taxonomy, and distribution of mosquito species will be useful for the development of integrated vector management programmes for the surveillance and elimination of mosquito-borne diseases in Cameroon.

What does liver elastography measure? Technical aspects and methodology

Elastography can be thought as an extension of the ancient technique of palpation. After giving a short introduction to the history of elastography, the different technologies that are nowadays available and the physics behind them, the article focuses on the assessment of liver stiffness in patients with diffuse liver disease using shear wave elastography (SWE). Practical advices on how to perform the SWE techniques and on the factors that should be considered for a correct interpretation of the results are given. This paper aimed to provide a practical guide for beginners and advanced clinical users to better understand technical aspects, methodologies and terminology.

Generation of human scFv-IgG1Fc antibodies for detection of lymphatic filarial recombinant antigens, BmR1 and BmSXP

Lymphatic filariasis is a neglected parasitic disease that affects millions in tropical and subtropical countries and is caused by Wuchereria and Brugia species. Specific and sensitive detection methods are essential in mapping infected areas where rapid tests are needed to cover underdeveloped and remote regions, which facilitates eliminating the disease as a public health problem. A few commercialized rapid tests based on antigen or antibody detection are available, but the former only detects infection by Wuchereria species and cross-reacts with nonlymphatic filaria, whereas antibody detection might provide positive results of previous infection. Here, we report the production of three different recombinant immunoglobulin gamma (IgG)1 antibodies based on scFvs previously generated via human antibody phage display technology, that is, anti-BmR1 clone 4, anti-BmXSP clone 5B, and anti-BmXSP clone 2H2. The scFv sequences were cloned into a pCMV-IgG1 vector, then transfected into a HEK293F cell line. The generated antibodies were found to be able to bind to their respective targets even at relatively low concentration. Conjugation of Fc to scFv induces binder stability and provides multiple labeling sites for probes and signaling molecules that can be used in rapid tests.

Loop-Mediated Isothermal Amplification as Point-of-Care Diagnosis for Neglected Parasitic Infections

The World Health Organisation (WHO) has placed twenty diseases into a group known as neglected tropical diseases (NTDs), twelve of them being parasitic diseases: Chagas’ disease, cysticercosis/taeniasis, echinococcosis, food-borne trematodiasis, human African trypanosomiasis (sleeping sickness), leishmaniasis, lymphatic filariasis, onchocerciasis (river blindness), schistosomiasis, soil-transmitted helminthiasis (ascariasis, hookworm, trichuriasis), guinea-worm and scabies. Such diseases affect millions of people in developing countries where one of the main problems concerning the control of these diseases is diagnosis-based due to the most affected areas usually being far from laboratories having suitable infrastructure and/or being equipped with sophisticated equipment. Advances have been made during the last two decades regarding standardising and introducing techniques enabling diagnoses to be made in remote places, i.e., the loop-mediated isothermal amplification (LAMP) technique. This technique’s advantages include being able to perform it using simple equipment, diagnosis made directly in the field, low cost of each test and the technique’s high specificity. Using this technique could thus contribute toward neglected parasite infection (NPI) control and eradication programmes. This review describes the advances made to date regarding LAMP tests, as it has been found that even though several studies have been conducted concerning most NPI, information is scarce for others.

The immune response of inbred laboratory mice to Litomosoides sigmodontis: A route to discovery in myeloid cell biology

Litomosoides sigmodontis is the only filarial nematode where the full life cycle, from larval delivery to the skin through to circulating microfilaria, can be completed in immunocompetent laboratory mice. It is thus an invaluable tool for the study of filariasis. It has been used for the study of novel anti-helminthic therapeutics, the development of vaccines against filariasis, the development of immunomodulatory drugs for the treatment of inflammatory disease and the study of basic immune responses to filarial nematodes. This review will focus on the latter and aims to summarize how the L sigmodontis model has advanced our basic understanding of immune responses to helminths, led to major discoveries in macrophage biology and provided new insights into the immunological functions of the pleural cavity. Finally, and most importantly L sigmodontis represents a suitable platform to study how host genotype affects immune responses, with the potential for further discovery in myeloid cell biology and beyond.

The Epitome of Novel Techniques and Targeting Approaches in Drug Delivery for Treating Lymphatic Filariasis

BACKGROUND

Lymphatic filariasis is a pervasive and life-threatening disease for human beings. Currently, 893 million people in 49 countries worldwide affected by lymphatic filariasis as per WHO statistics. The concealed aspects of lymphatic diseases such as delayed disease detection, inappropriate disease imaging, the geographical outbreak of infection, and lack of preventive chemotherapy have brought this epidemic to the edge of Neglected Tropical Diseases. Many medications and natural bioactive substances have seen to promote filaricidal activity against the target parasitic species. However, the majority of failures have occurred in pharmaceutical and pharmacokinetic issues.

OBJECTIVE

The purpose of the study is to focus on the challenges and therapeutic issues in the treatment of filariasis. The review brings novel techniques and therapeutic approaches for combating lymphatic filariasis. It also offers significant developments and opportunities for such therapeutic interventions.

CONCLUSION

Through this review, an attempt has made to critically evaluate the avenues of innovative pharmaceuticals and molecular targeting approaches to bring an integrated solution to combat lymphatic filariasis.

Imaging of toxocariasis

Several imaging modalities have now been employed to visualize the manifestations of larval Toxocara infection in hepatic, neurologic, ocular, renal, and other anatomical sites. This report reviews the usefulness and value of these individual imaging methods in diagnosis and follow-up of the different cases causing eosinophilic (granulomatous) infiltrations the liver, lungs, brain, heart, and eyes. Imaging provides a means of assisting in diagnosis and management in this infection where diagnosis by biopsy is often unlikely to capture an actual larva for the purpose of making a definitive diagnosis on the basis of larval morphology or DNA detection.

Diagnosis of elephantiasis nostras verrucosa as a clinical mani-festation of Kaposi's sarcoma

Elephantiasis nostras verrucosa, a rare manifestation of Kaposis sarcoma, is a progressive cutaneous hypertrophy caused by chronic non-filarial lymphedema secondary to obstruction of the lymphatic system that can lead to severe disfigurement of parts of the body that have gravity-dependent blood flow, due to edema, fibrosis, and hyperkeratosis, especially lower extremities. Among the various conditions that can induce chronic lymphedema are tumors, trauma, radiotherapy, obesity, hypothyroidism, chronic venous stasis, and AIDS-related Kaposis sarcoma. Kaposis sarcoma is a vascular tumor associated with the presence of human gammaherpesvirus 8 that is predominantly cutaneous, locally aggressive, with metastasis, and is associated with the production of factors that favor inflammation, lymphatic obstruction, and lymphedema.