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Nature Reviews. Disease Primers May 2020Trichuriasis and ascariasis are neglected tropical diseases caused by the gastrointestinal dwelling nematodes Trichuris trichiura (a whipworm) and Ascaris lumbricoides... (Review)
Review
Trichuriasis and ascariasis are neglected tropical diseases caused by the gastrointestinal dwelling nematodes Trichuris trichiura (a whipworm) and Ascaris lumbricoides (a roundworm), respectively. Both parasites are staggeringly prevalent, particularly in tropical and subtropical areas, and are associated with substantial morbidity. Infection is initiated by ingestion of infective eggs, which hatch in the intestine. Thereafter, T. trichiura larvae moult within intestinal epithelial cells, with adult worms embedded in a partially intracellular niche in the large intestine, whereas A. lumbricoides larvae penetrate the gut mucosa and migrate through the liver and lungs before returning to the lumen of the small intestine, where adult worms dwell. Both species elicit type 2 anti-parasite immunity. Diagnosis is typically based on clinical presentation (gastrointestinal symptoms and inflammation) and the detection of eggs or parasite DNA in the faeces. Prevention and treatment strategies rely on periodic mass drug administration (generally with albendazole or mebendazole) to at-risk populations and improvements in water, sanitation and hygiene. The effectiveness of drug treatment is very high for A. lumbricoides infections, whereas cure rates for T. trichiura infections are low. Novel anthelminthic drugs are needed, together with vaccine development and tools for diagnosis and assessment of parasite control in the field.
Topics: Animals; Ascariasis; Ascaris lumbricoides; Humans; Prevalence; Trichuriasis; Trichuris
PubMed: 32467581
DOI: 10.1038/s41572-020-0171-3 -
Recent Patents on Inflammation &... 2020Ascaris lumbricoides is the most common helminthic infection. More than 1.2 billion people have ascariasis worldwide. (Review)
Review
BACKGROUND
Ascaris lumbricoides is the most common helminthic infection. More than 1.2 billion people have ascariasis worldwide.
OBJECTIVE
This article aimed to provide an update on the evaluation, diagnosis, and treatment of ascariasis.
METHODS
A PubMed search was conducted in February 2020 in Clinical Queries using the key terms "ascariasis" OR "Ascaris lumbricoides". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews published within the past 10 years. The search was restricted to English literature. The information retrieved from the above search was used in the compilation of the present article. Patents were searched using the key term "ascariasis" OR "Ascaris lumbricoides" in www.freepatentsonline.com.
RESULTS
Ascaris lumbricoides is transmitted through the ingestion of embryonated eggs from fecal- contaminated material. Ascariasis has high endemicity in tropical and subtropical areas. Predisposing factors include poverty, poor sanitation, inadequate sewage disposal, and poor personal hygiene. The prevalence is greatest in children younger than 5 years of age. The majority of patients with intestinal ascariasis are asymptomatic. For those with symptoms, anorexia, nausea, bloating, abdominal discomfort, recurrent abdominal pain, abdominal distension, and intermittent diarrhea are not uncommon. Other clinical manifestations vary widely, depending on the underlying complications. Complications include Löeffler syndrome, intestinal obstruction, biliary colic, recurrent pyogenic cholangitis, cholecystitis, acalculous cholecystitis, obstructive jaundice, cholelithiasis, pancreatitis, and malnutrition. The diagnosis is best established by microscopic examination of fecal smears or following concentration techniques for the characteristic ova. Patients with A. lumbricoides infection warrant anthelminthic treatment, even if they are asymptomatic, to prevent complications from migration of the parasite. Albendazole and mebendazole are the drugs of choice for children and nonpregnant individuals with ascariasis. Pregnant women with ascariasis should be treated with pyrantel pamoate. Recent patents related to the management of ascariasis are also discussed.
CONCLUSION
The average cure rate with anthelminthic treatment is over 95%. Unfortunately, most treated patients in endemic areas become re-infected within months. Health education, personal hygiene, improved sanitary conditions, proper disposal of human excreta, and discontinuing the use of human fecal matter as a fertilizer are effective long-term preventive measures. Targeting deworming treatment and mass anthelminthic treatment should be considered in regions where A. lumbricoides is prevalent.
Topics: Animals; Anthelmintics; Ascariasis; Ascaris lumbricoides; Humans; Patents as Topic
PubMed: 32628606
DOI: 10.2174/1872213X14666200705235757 -
The Korean Journal of Parasitology Jun 2021The use of albendazole and mebendazole, i.e., benzimidazole broad-spectrum anthelmintics, in treatment of parasitic infections, as well as cancers, is briefly reviewed.... (Review)
Review
The use of albendazole and mebendazole, i.e., benzimidazole broad-spectrum anthelmintics, in treatment of parasitic infections, as well as cancers, is briefly reviewed. These drugs are known to block the microtubule systems of parasites and mammalian cells leading to inhibition of glucose uptake and transport and finally cell death. Eventually they exhibit ovicidal, larvicidal, and vermicidal effects on parasites, and tumoricidal effects on hosts. Albendazole and mebendazole are most frequently prescribed for treatment of intestinal nematode infections (ascariasis, hookworm infections, trichuriasis, strongyloidiasis, and enterobiasis) and can also be used for intestinal tapeworm infections (taeniases and hymenolepiasis). However, these drugs also exhibit considerable therapeutic effects against tissue nematode/cestode infections (visceral, ocular, neural, and cutaneous larva migrans, anisakiasis, trichinosis, hepatic and intestinal capillariasis, angiostrongyliasis, gnathostomiasis, gongylonemiasis, thelaziasis, dracunculiasis, cerebral and subcutaneous cysticercosis, and echinococcosis). Albendazole is also used for treatment of filarial infections (lymphatic filariasis, onchocerciasis, loiasis, mansonellosis, and dirofilariasis) alone or in combination with other drugs, such as ivermectin or diethylcarbamazine. Albendazole was tried even for treatment of trematode (fascioliasis, clonorchiasis, opisthorchiasis, and intestinal fluke infections) and protozoan infections (giardiasis, vaginal trichomoniasis, cryptosporidiosis, and microsporidiosis). These drugs are generally safe with few side effects; however, when they are used for prolonged time (>14-28 days) or even only 1 time, liver toxicity and other side reactions may occur. In hookworms, Trichuris trichiura, possibly Ascaris lumbricoides, Wuchereria bancrofti, and Giardia sp., there are emerging issues of drug resistance. It is of particular note that albendazole and mebendazole have been repositioned as promising anti-cancer drugs. These drugs have been shown to be active in vitro and in vivo (animals) against liver, lung, ovary, prostate, colorectal, breast, head and neck cancers, and melanoma. Two clinical reports for albendazole and 2 case reports for mebendazole have revealed promising effects of these drugs in human patients having variable types of cancers. However, because of the toxicity of albendazole, for example, neutropenia due to myelosuppression, if high doses are used for a prolonged time, mebendazole is currently more popularly used than albendazole in anti-cancer clinical trials.
Topics: Albendazole; Animals; Anthelmintics; Antineoplastic Agents; Ascariasis; Female; Humans; Male; Mebendazole; Parasites; Trichuriasis
PubMed: 34218593
DOI: 10.3347/kjp.2021.59.3.189 -
Enfermedades Infecciosas Y... Jan 2020Infections causes by parasites of the gastrointestinal tract are a global public health problem. In industrialised countries, their particular epidemiological (low... (Review)
Review
Infections causes by parasites of the gastrointestinal tract are a global public health problem. In industrialised countries, their particular epidemiological (low general prevalence of enteroparasites), economic (high labour costs) and clinical characteristics (constant increase in the number of samples and diagnostic determinations to be performed) have led molecular techniques to progressively replace conventional microscopy as the first-line diagnostic method of these pathogens in modern clinical laboratories. PCR-based techniques, particularly those developed for the simultaneous detection of the various agents that can cause the same infectious disease (syndromic diagnosis), already represent a cost-effective option that allow process automisation, workflow optimisation, and comparison of results among different laboratories, and facilitate accreditation of diagnostic procedures. This review clearly and concisely discusses the current situation of the molecular diagnosis of the main species of intestinal parasites in humans, particularly the enteric protozoans causing diarrhoea (Cryptosporidium spp., Giardia duodenalis, Entamoeba histolytica), the most important members the Microsporidia phyla (Enterocytozoon bieneusi) and Stramenopiles phyla (Blastocystis sp.), as well as the helminths transmitted by soil (Ancylostoma spp., Ascaris lumbricoides, Necator americanus, Strongyloides stercoralis and Trichuris trichiura) and food (Anisakis spp., Clonorchis sinensis, Fasciola spp., Taenia solium, and Trichinella spiralis). Special attention is paid to the description of available techniques and formats, to their diagnostic benefits and the most widely used genetic markers for their detection, both in clinical laboratories and genotyping in referral and research centres.
Topics: Animals; Diarrhea; Feces; Helminthiasis; Humans; Intestinal Diseases, Parasitic; Molecular Diagnostic Techniques; Protozoan Infections; Real-Time Polymerase Chain Reaction
PubMed: 32111362
DOI: 10.1016/j.eimc.2020.02.005 -
Tropical Medicine and Infectious Disease Nov 2022Intestinal parasitic infections are common infectious diseases causing many health problems and impaired growth and physical development.. Children under five years old... (Review)
Review
Intestinal parasitic infections are common infectious diseases causing many health problems and impaired growth and physical development.. Children under five years old are the most vulnerable to infections, due to their immature immunity and feeding and exploratory behaviours. This systematic review aimed to assess the relationship between intestinal parasitic infections and undernutrition among children under 5 years old. Fifteen studies met the inclusion and exclusion criteria and were classified as high-quality studies. Twelve parasites were reported, including , spp., , , , hookworm, , , spp. and . Ascariasis is the most reported infection, with a prevalence ranging from 10.77% in Ethiopia to 57.14% in Malaysia, and is correlated with stunting (OR 2.17 (95% CI 1.14, 4.13), = 0.02). Giardiasis is the second most reported infection, with a prevalence ranging from 4.43% in Ethiopia to 66.33% in the Central African Republic, and is related to an increased risk of stunting (OR 2.34 (95% CI 1.07, 5.10), = 0.03)), wasting (OR 2.90 (95% CI 1.12, 7.49, = 0.03)), and being underweight (OR 1.53 (95% CI 1.02, 2.29, = 0.04)). The third and fourth most prevalent infections are and hookworm infections. Intestinal parasitic infections can occur very early in life and cause significant growth retardation. It is important to understand the prevalence and effects of infection based on the parasite species in order to implement therapeutic interventions and prevention controls.
PubMed: 36422922
DOI: 10.3390/tropicalmed7110371 -
Pediatric Clinics of North America Feb 2022Intestinal nematode infections caused by soil-transmitted helminths (STH), such as the roundworm Ascaris lumbricoides, the whipworm Trichuris trichiura, and the... (Review)
Review
Intestinal nematode infections caused by soil-transmitted helminths (STH), such as the roundworm Ascaris lumbricoides, the whipworm Trichuris trichiura, and the hookworms Ancylostoma duodenale, and Necator americanus, infect more than 1 billion people throughout the world. School-aged children tend to harbor the greatest numbers of intestinal worms, and as a result, experience more adverse health consequences, such as poor growth, anemia, and cognitive decline. Clinicians should maintain a high degree of suspicion in endemic areas when patients present with surgical abdomens, particularly children. Current antihelminthic drugs are moderately effective, but reinfection is possible. Global efforts are needed to eradicate STH infections.
Topics: Adolescent; Albendazole; Ancylostoma; Anemia; Animals; Anthelmintics; Ascariasis; Ascaris lumbricoides; Child; Child, Preschool; Female; Helminthiasis; Hookworm Infections; Humans; Hygiene; Infant; Intestinal Diseases, Parasitic; Male; Necator americanus; Nematode Infections; Soil; Trichuriasis; Trichuris
PubMed: 34794670
DOI: 10.1016/j.pcl.2021.08.005 -
Nucleic Acids Research Mar 2022Parasitic helminths infecting humans are highly prevalent infecting ∼2 billion people worldwide, causing inflammatory responses, malnutrition and anemia that are the...
Parasitic helminths infecting humans are highly prevalent infecting ∼2 billion people worldwide, causing inflammatory responses, malnutrition and anemia that are the primary cause of morbidity. In addition, helminth infections of cattle have a significant economic impact on livestock production, milk yield and fertility. The etiological agents of helminth infections are mainly Nematodes (roundworms) and Platyhelminths (flatworms). G-quadruplexes (G4) are unusual nucleic acid structures formed by G-rich sequences that can be recognized by specific G4 ligands. Here we used the G4Hunter Web Tool to identify and compare potential G4 sequences (PQS) in the nuclear and mitochondrial genomes of various helminths to identify G4 ligand targets. PQS are nonrandomly distributed in these genomes and often located in the proximity of genes. Unexpectedly, a Nematode, Ascaris lumbricoides, was found to be highly enriched in stable PQS. This species can tolerate high-stability G4 structures, which are not counter selected at all, in stark contrast to most other species. We experimentally confirmed G4 formation for sequences found in four different parasitic helminths. Small molecules able to selectively recognize G4 were found to bind to Schistosoma mansoni G4 motifs. Two of these ligands demonstrated potent activity both against larval and adult stages of this parasite.
Topics: Animals; Cattle; G-Quadruplexes; Genome; Helminths; Humans; Ligands; Nematoda; Parasites; Platyhelminths
PubMed: 35234933
DOI: 10.1093/nar/gkac129