Materiały źródłowe

• #1 Ascariasis – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/sites/books/n/statpearls/article-17878/

  Infection occurs when the host ingests eggs found in stool-contaminated soil. Once in the duodenum, larvae are released and enter the circulation via the enteric mucosa. Once in the capillaries (venous, arterial or lymphatic), it reaches the liver via the portal vein and then the lungs within the first week. In the lung, they damage the alveolar membrane and mature in the alveolus. Eventually, the larvae are expectorated and swallowed, reentering the gastrointestinal tract. Once in the small intestine lumen, the larvae mature into adult worms in about 20 days. When the adult female and male worms are present, they copulate, and the female can produce approximately 200,000 eggs per day. They are later eliminated in the feces of the soil. In the appropriate conditions of a moist, shady, and warm environment, the eggs mature to infective form in two to eight weeks and remain viable for up to 17 months. They can be ingested and restart the infective cycle.

• #2 Ascaris Lumbricoides: Background, Pathophysiology, Epidemiology

  https://emedicine.medscape.com/article/788398-overview

  A lumbricoides is the largest of the intestinal nematodes affecting humans, measuring 15-35 cm in length in adulthood. Infection begins with the ingestion of embryonated (infective) eggs in feces-contaminated soil or foodstuffs. Once ingested, eggs hatch, usually in the small intestine, releasing small larvae that penetrate the intestinal wall. Larvae migrate to the pulmonary vascular beds and then to the alveoli via the portal veins usually 1-2 weeks after infection, during which time they may cause pulmonary symptoms (eg, cough, wheezing). […] During the time frame of pulmonary symptoms, eggs are not being shed, and thus diagnosis via stool ovas and parasites is not possible. Eggs are not shed in stool until roughly 40 days after the development of pulmonary symptoms. […] After migrating up the respiratory tract and being swallowed, they mature, copulate, and lay eggs in the intestines. Adult worms may live in the gut for 6-24 months, where they can cause partial or complete bowel obstruction in large numbers, or they can migrate into the appendix, hepatobiliary system, or pancreatic ducts and rarely other organs such as kidneys or brain. From egg ingestion to new egg passage takes approximately 9 weeks, with an additional 3 weeks needed for egg molting before they are capable of infecting a new host. […] The roundworm Ascaris lumbricoides causes ascariasis. Worms can reach 10-30 cm in length. Clinical disease results from effects of pulmonary larval migration, intestinal obstruction, or migration through the biliary tree.

• #3 Ascariasis – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/ascariasis/symptoms-causes/syc-20369593

  Ascariasis (as-kuh-RIE-uh-sis) is a type of roundworm infection. These worms are parasites that use your body as a host to mature from larvae or eggs to adult worms. Adult worms, which reproduce, can be more than a foot (30 centimeters) long. […] Ascariasis occurs most often in children in tropical and subtropical regions of the world especially in areas with poor sanitation and hygiene. […] Ascariasis isn’t spread directly from person to person. Instead, a person has to come into contact with soil mixed with human or pig feces that contain ascariasis eggs or infected water. […] The tiny (microscopic) ascariasis eggs can’t become infective without coming into contact with soil. People can accidentally ingest (swallow) contaminated soil through hand-to-mouth contact or by eating uncooked fruits or vegetables that have been grown in contaminated soil.

• #4 Ascariasis: Background, Pathophysiology, Epidemiology

  https://emedicine.medscape.com/article/212510-overview

  Symptomatic ascariasis may manifest during the adult worm’s intestinal or larval migration phase, leading to complications such as pneumonitis, intestinal obstruction, or hepatobiliary and pancreatic injury. […] Larvae are released from the Ascaris eggs in the small intestine within 4 days of ingestion. These larvae migrate through cecum and proximal colon and penetrate the intestinal mucosa and reach the liver via the portal circulation. They enter the heart through the hepatic veins, infiltrate the lymphatics and end up in the lungs where they mature in about 2 weeks. The mature larvae cause symptoms of pneumonitis and ascend the trachea by the cough reflex. […] A significant exposure may produce subsequent pneumonia and eosinophilia. Symptoms of pneumonitis include wheezing, dyspnea, nonproductive cough, hemoptysis, and fever.

• #5 Ascariasis – Infectious Diseases – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/infectious-diseases/nematodes-roundworms/ascariasis

  Ingested A. lumbricoides eggs hatch in the duodenum, and the resulting larvae penetrate the wall of the small intestine and migrate via the portal circulation through the liver to the heart and lungs. Larvae lodge in the alveolar capillaries, penetrate alveolar walls, and ascend the bronchial tree into the oropharynx. They are swallowed and return to the small intestine, where they develop into adult worms, which mate and release eggs into the stool. […] A tangled mass of worms resulting from heavy infection can obstruct the bowel, particularly in children. Aberrantly migrating individual adult worms occasionally obstruct the biliary or pancreatic ducts, causing cholecystitis or pancreatitis; cholangitis, liver abscess, and peritonitis are less common. […] Even moderate infections can lead to undernutrition in children. The pathophysiology is unclear and may include competition for nutrients, impairment of absorption, and depression of appetite.

• #6 Ascariasis – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/ascariasis/symptoms-causes/syc-20369593

  Larvae hatch from the eggs in your small intestine and then go through the intestinal wall to travel to the heart and lungs via the bloodstream or lymphatic system. After maturing for about 10 to 14 days in your lungs, the larvae break into your airway and travel up the throat, where they’re coughed up and swallowed. […] Once they’re back in the intestines, the parasites grow into male or female worms. […] Female worms can produce 200,000 eggs a day if there are both female and male worms in the intestines, and the eggs leave your body in feces. The fertilized eggs must be in soil for at least two to four weeks before they become infective. […] The whole process from egg ingestion to egg deposits takes about two or three months. Ascariasis worms can live inside your body for a year or two.

• #7 Ascariasis: Background, Pathophysiology, Epidemiology

  https://emedicine.medscape.com/article/212510-overview

  When ingested, Ascaris lumbricoides eggs hatch in the duodenum, and the larvae penetrate the small bowel wall, migrating through the portal circulation to the liver, heart, and lungs. Once in the lungs, the larvae lodge in the alveolar capillaries, penetrate the alveolar walls, and ascend the bronchial tree to the oropharynx. They then are swallowed and return to the small intestine, where they mature into adult worms that mate and release eggs into the stool. This life cycle takes about 2 to 3 months, with adult worms living for 1 to 2 years. […] Heavy infections can lead to a tangled mass of worms that obstructs the bowel, particularly in children. Occasionally, individual adult worms may migrate aberrantly and obstruct the biliary or pancreatic ducts, resulting in conditions such as cholecystitis or pancreatitis, while cholangitis, liver abscess, and peritonitis are less common.

• #8 Ascaris lumbricoides- Life cycle, Pathogenicity, Clinical Manifestation

  https://microbenotes.com/ascaris-lumbricoides-life-cycle-pathogenicity-clinical-manifestation/

  They are more injurious than adults worm by causing hemorrhages. […] The migrating larvae cause pathological lesions. The severity of lesions depends upon the sensitivity of the host, the nutritional status of the host, and the number of migrating larvae. […] During migration and molding through lungs, larvae may cause acute pneumonia with fatal consequences. Frequently infection followed by low-grade fever, cough, anemia, leukocytosis, and eosinophilia. […] Adults usually cause enteritis and through their migration into the vermiform appendix, gall bladder, and common bile duct, may cause inflammation of these structures. […] The worm produces the toxin which irritates the mucous membrane of the gut or prevents digestion of proteins by the host or they may cause general nervousness, delirium, or convulsion.

• #9 Ascariasis – Helminthiases – Parasitic Diseases – Infectious Diseases – Diseases – McMaster Textbook of Internal Medicine

  https://empendium.com/mcmtextbook/chapter/B31.II.18.84.1.8.

  1. Larval migration: Symptoms are more likely to occur with higher numbers of migrating larvae and are caused by the immune reaction to larval migration through tissues. Migration of larvae through the lungs can cause pneumonitis with symptoms including dyspnea, dry or productive cough, wheezing, and fever. Transient eosinophilia may be present. Plain chest radiography may reveal migrating opacities (corresponding to inflammatory infiltrates). The combination of transient infiltrates and eosinophilia is termed Lffler syndrome. In some patients urticaria may be observed. Charcot-Leyden crystals and rare larvae may be found in sputum and bronchoalveolar lavage fluids during the period of larval migration. […] 3. Hepatobiliary ascariasis: Worms may migrate into the bile duct or pancreatic duct, causing cholangitis or acute pancreatitis. There are also reports of liver abscesses due to migration of adult worms into the liver, where they release eggs and die, invoking a granulomatous reaction.

• #10 Ascaris lumbricoides: Life cycle, Pathogenesis, Lab Diagnosis

  https://microbeonline.com/ascaris-lumbricoides-life-cycle-pathogenesis-and-lab-diagnosis/

  Reinfection and subsequent larval migration cause intense tissue reactions in some individuals. There may be pronounced tissue reaction around the larvae in the liver and lungs, with infiltration of eosinophils, macrophages, and epitheloid cells. This condition, also known as Ascaris pneumonitis is accompanied by an allergic reaction consisting of dyspnea, a dry or productive cough, wheezing or coarse rales, fever, transient eosinophilia, and a chest X-ray suggestive of viral pneumonia. Examinations of sputum or gastric washings may reveal larvae. […] The presence of adult worms in the intestine usually causes no difficulties (sometimes may cause colicky cramps and loss of appetite) unless the worm burden is very heavy. However, during migration and/or if heavy infections adult worms may result in intestinal blockage.

• #10 Ascaris lumbricoides: Life cycle, Pathogenesis, Lab Diagnosis

  https://microbeonline.com/ascaris-lumbricoides-life-cycle-pathogenesis-and-lab-diagnosis/

  People get an infection with Ascaris by swallowing embryonated eggs of Ascaris with raw vegetables cultivated on soil fertilized by human excreta or by drinking water contaminated with mature eggs of Ascaris. […] Pathogenesis caused by Ascaris infections is attributed to The host immune response, Effects of larval migration, Mechanical effects of the adult worms, and Nutritional deficiencies due to the presence of adult worms. […] Various allergic manifestations such as fever, urticaria, angioneurotic edema, wheezing, and conjunctivitis are seen when the host immune cells react with the toxic body fluid (ascaron) of the adult worms. […] The worms are restless wanderers. The migrating larvae may cause inflammatory and hypersensitivity reactions in the lungs. Allergic inflammatory reactions to migrating larvae may involve other organs such as liver and kidneys. Loefflers syndrome is caused by migrating larvae.

• #11 Ascariasis | PPT

  https://www.slideshare.net/slideshow/ascariasis-40623746/40623746

  Disease produced by A. lumbricoides is known as ascariasis and is caused by both adult worms and migrating larvae. There are two phases in ascariasis: 1. The blood-lung migration phase of the larvae 2. The intestinal phase of the adults […] In persons repeatedly infected with Ascaris and sensitised to the parasite antigens, the migrating larvae may lead to inflammatory and hypersensitivity reactions in the lungs. There is formation of granuloma and eosinophilic infiltrates. It leads to fever, cough, dyspnoea, urticarial rash and eosinophilia. The sputum may be blood-tinged, and may contain Ascaris larvae and Charcot-Leyden crystals. This condition is known as Loefflers syndrome. Allergic inflammatory reaction to migrating larvae may involve other organs such as liver and kidneys. Larvae and adult A. lumbricoides secrete allergens which cause hypersensitivity reactions in host

• #12 Pro-fibrinolytic potential of the third larval stage of Ascaris suum as a possible mechanism facilitating its migration through the host tissues | Parasites & Vectors | Full Text

  https://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-020-04067-5

  Cuticle and excretory/secretory antigens from infective larvae of A. suum were able to bind plasminogen and promote plasmin generation in the presence of plasminogen activators. […] To the best of our knowledge, the present results showed for the first time, the pro-fibrinolytic potential of infective larvae of Ascaris spp., which suggests a novel parasite survival mechanism by facilitating the migration through host tissues. […] The ability of AsL3 to enhance plasmin generation could be used by the parasite as a survival mechanism allowing it to degrade these components in order to facilitate its migration through the host tissues, as it has been postulated for other pathogens. […] The plasmin broad substrate specificity makes this enzyme susceptible to be used by parasites to complement their own protease repertoire, which could facilitate their migration through the host tissues. […] This suggests that plasminogen-binding proteins are exposed to the larval surface, which could allow them to interact with plasminogen at the host-parasite interface.

• #13 Ascariasis: Causes, Symptoms, and Diagnosis

  https://www.healthline.com/health/ascariasis

  Ascariasis is an infection of the small intestine caused by Ascaris lumbricoides, which is a species of roundworm. […] The infection usually causes no symptoms, but a high number of roundworms (heavier infestations) can lead to problems in the lungs or intestines. […] You can become infected with ascariasis after accidentally ingesting the eggs of the A. lumbricoides roundworm. […] After ingestion, the A. lumbricoides roundworm reproduces inside your intestine. […] The larvae then move through the bloodstream to your lungs. […] Once they’re back in your intestine, the worms will mate and lay more eggs. […] However, heavy infestations can spread to other parts of the body and lead to dangerous complications, including intestinal blockage. […] Intestinal blockage occurs when a mass of worms blocks your intestines, causing severe pain and vomiting. […] Infections that lead to loss of appetite and poor absorption of nutrients put children at risk of not getting enough nutrients, which can affect their growth. […] If you have an advanced case, you may need other treatment. Your doctor may recommend surgery to control a larger infestation.

• #14 Hepatobiliary and pancreatic ascariasis

  https://www.wjgnet.com/1007-9327/full/v22/i33/7507.htm

  Hepatobiliary and pancreatic ascariasis (HPA) is caused by invasion and migration of nematode, Ascaris lumbricoides, in to the biliary tract and pancreatic duct. […] HPA is initiated by proximal movement of the organisms in to duodenum (duodenal ascariasis). Heavy worm-load is the main factor for forward march of the ascarides. They have a propensity to explore the orifices and in duodenum, the organism repeatedly enters in to and out of the orifice of ampulla of Vater. The adult worm blocks the ampullary orifice and obstructs both the bile and the pancreatic duct. In addition, the writhing movements of the worm excites marked sphincter spasm and dysmotility. […] Ascarides make repeated traverses in to and out of the ductal lumen, as long as they are alive. Ascaris mobility within the ducts is maintained usually till 10 d on serial ultrasound examinations and have a chance to move out of ducts. Often, the ascarides get trapped inside the bile ducts, die and become the nidus and source of biliary sludge and brown pigment biliary calculi.

• #15 Ascaris lumbricoides: Life cycle, Pathogenesis, Lab Diagnosis

  https://microbeonline.com/ascaris-lumbricoides-life-cycle-pathogenesis-and-lab-diagnosis/

  Adult worms rob the host of its nutrition and may cause malnutrition and night blindness (due to vitamin A deficiency). In children, particularly those younger than 5 years, there may be severe nutritional impairment related to worm burden which may cause malnutrition, stunting, and impairment in cognitive ability among others.

• #16 Ascaris – Wikipedia

  https://en.wikipedia.org/wiki/Ascaris

  As part of the parasite defense strategy, Ascaris roundworms secrete a series of inhibitors to target digestive and immune-related host proteases, which include pepsin, trypsin, chymotrypsin/elastase, cathepsins, and metallocarboxypeptidases (MCPs). […] Ascaris species inhibit MCPs by releasing an enzyme known as Ascaris carboxypeptidase inhibitor (ACI). This enzyme binds to the active site of MCP and blocks the cleavage of its own proteins by the host MCP. […] Similarly, they inhibit trypsin by releasing the protein Ascaris Trypsin Inhibitor (pdb 1ATA).

• #17

  https://omim.org/entry/604291

  Sanglas et al. (2009) noted that Ascaris roundworms secrete a battery of selective inhibitors to protect themselves from host enzymes and the immune system. […] Sanglas et al. (2009) cloned the gene encoding an Ascaris metallocarboxypeptidase (MCP) inhibitor, ACI. […] Sanglas et al. (2009) proposed that ACI interaction with host MCPs in the intestine and intestinal mucosa mast cells may explain prolonged Ascaris survival in a hostile environment.

• #18 Ascaris lumbricoides- Life cycle, Pathogenicity, Clinical Manifestation

  https://microbenotes.com/ascaris-lumbricoides-life-cycle-pathogenicity-clinical-manifestation/

  A substance is produced by a worm combines with trypsin, thus interfering the protein digestion which leads to protein deficiency. […] The metabolites of living or dead worm are toxic and immunogenic. […] lumbricoides also produces various allergic toxin, which manifests fever, conjunctivitis, and irritation.

• #19 Roundworm Infection (Ascariasis) | Iowa State University

  https://vetmed.iastate.edu/vdpam/about/focus-areas/swine/swine-disease-manual/index-diseases/ascariasis

  Ascarids cause local inflammation in the intestine and compete with the host for nutrients. This adversely affects growth of pigs, especially those on marginal or poorly balanced diets. […] With heavy infections, the most significant effect of the disease is a result of the migrating larvae causing lesions in the liver and lungs, including scarring of liver and interstitial pneumonia. […] In the lungs, larvae break out of capillaries into alveoli. This results in small hemorrhages and an inflammatory reaction that interferes with the clearance mechanism of airways and favors secondary bacterial infections. […] Ascarids are known to produce immunosuppressive substances that affect the duration and severity of other swine diseases and also may influence the response of swine to vaccines. Although difficult to quantify, there is evidence that ascariasis increases the severity of acute erysipelas and mycoplasmal pneumonia.

• #20 Whipworm and roundworm infections | Nature Reviews Disease Primers

  https://www.nature.com/articles/s41572-020-0171-3

  Trichuriasis and ascariasis are neglected tropical diseases caused by the gastrointestinal dwelling nematodes Trichuris trichiura (a whipworm) and Ascaris lumbricoides (a roundworm), respectively. […] 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. […] 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.

• #21 Immune Responses on Humans — Ascaris | SpringerLink

  https://link.springer.com/chapter/10.1007/0-306-47383-6_6

  The human immune response against Ascaris parasites is characterised by prominent antibody and cellular responses that are directed primarily against the larval stages of infection. […] Ascaris infection stimulates the secretion of all antibody isotypes, although high circulating levels of total IgE and parasite-specific IgE are the most characteristic features. […] In endemic regions, the cellular response to A. lumbricoides infection is characterised by a polarized Th2 response with the prominent production of both IL-4 and IL-5. […] Evidence for the development of a protective immune response in human ascariasis is derived from observations of a decline in infection intensity with age in many endemic regions and by evidence for predisposition to either light or heavy infections. […] Protective immune responses may involve IgE-mediated mechanisms directed against invading larvae, although elevated IgE responses may merely be a marker of enhanced Th2 activation.

• #22 Gut bacteriome and metabolome of Ascaris lumbricoides in patients | Scientific Reports

  https://www.nature.com/articles/s41598-022-23608-9

  In our cohort, we found that both human and A. lumbricoides gut microbiomes were dominated by bacteria of the phylum Firmicutes. […] An imbalanced microbiome is frequently caused by a continuous increase in the abundance of the phylum Proteobacteria. […] When A. lumbricoides gut microbiomes in humans with different infection intensities were compared, we found Streptococcus to be the most common bacteria in the A. lumbricoides gut in high-intensity infections, whereas Lactococcus dominated in A. lumbricoides guts in low-intensity infections. […] Pathway analysis was performed to reveal the important mechanisms in A. lumbricoides gut in heavy and light infection intensities. […] This might indicate that A. lumbricoides in heavy infections obtain more amino acids, nucleotide precursors, lipids, and essential biomolecules by enhancing these metabolic processes, possibly leading to more egg production, which increases incidences of ascariasis. […] The discovery of the gut bacterial microbiota and metabolite profile of A. lumbricoides may be useful for development of novel and more effective approaches for parasitic disease therapy in the future.

• #23 SciELO Brazil – Abdominal complications of ascariasis in childhood Abdominal complications of ascariasis in childhood

  https://www.scielo.br/j/jped/a/vqhMMDBwsYGzjBnBjXcJb6R/

  The most common complication of ascariasis is intestinal obstruction, and the most common mechanism is mechanical obstruction due to occlusion of the intestinal lumen resulting from the entanglement of many worms, mainly in the distal ileum. Although the domain of these parasites extends from the stomach to the ileocecal valve, the vast majority inhabit the jejunum and the proximal ileum. Intestinal obstruction may also occur due to intestinal volvulus or intussusception and may cause gangrene in the small intestine. […] […] In addition to the mechanical factor itself, intestinal obstruction may be due to neurotoxins excreted by the Ascaris that die during their evolutionary cycle. These proteinaceous substances cause spasms in the muscles of the small intestine, mainly at the level of the distal ileum, facilitating the formation of intraluminal masses of Ascaris and obstruction. Other toxins, such as anaphylatoxins, hemolysins, and endocrinolysins, can also cause an inflammatory reaction in the intestinal segments affected by worms. These factors make the small intestine the most common site of surgical complications of ascariasis. […]

• #24 SciELO Brazil – Abdominal complications of ascariasis in childhood Abdominal complications of ascariasis in childhood

  https://www.scielo.br/j/jped/a/vqhMMDBwsYGzjBnBjXcJb6R/

  The cause of perforation of the small intestine remains controversial, with two main theories. During extreme conditions, such as inflammation, starvation, or worm bolus obstruction, some parasites are believed to migrate into the ulcers and cause perforations. Another possible explanation is that the large worm bolus can lead to pressure necrosis and gangrene. […] […] Complications of ascariasis in the hepatobiliary system are less frequent in children (5 %) than in adults (53 %), because of the small ductal caliber in childhood. They occur more frequently in the endemic areas of India and South Africa. A. lumbricoides tend to enter all orifices and carry the intestinal flora. If there is a massive worm burden in the duodenum, there is a greater likelihood of biliary ascariasis. Along with worm migration, bacterial migration can lead to inflammation and infection. In biliary ascariasis, one or two worms usually enter the biliary system, although there may be many of them. The irritation caused by the worm, or the result of its excretion causes biliary colic and spasm of the sphincter of Oddi with partial biliary obstruction. Both secretions from the worms and their breakdown in the extrahepatic biliary system can lead to an intense inflammatory response, resulting in cholangitis, stenosis, fibrosis, lithiasis, calcification, or ductal necrosis. […]

• #25

  https://www.tropicalgastro.com/articles/33/1/acute-jejunal-gangrene-with.html

  Infestation with Ascaris lumbricoides is a worldwide phenomenon. While most patients with Ascaris infection are asymptomatic, life threatening gastrointestinal conditions may develop that require immediate medical and surgical intervention. […] A final diagnosis of jejunal gangrene with perforation due to ascariasis was made. […] The commonest complication of ascariasis is intestinal obstruction due to a worm bolus. The obstruction may be acute or subacute. It can be complicated by intussusception, perforation and gangrene of the bowel. In ascariasis, the cause of perforation of the small intestine remains controversial, with two main theories. […] The mechanism of obstruction is occlusion of the intestinal lumen by worms packed in the distal ileum as well as localized volvulus of a segment of terminal ileum owing to the weight of the roundworms inside. The mechanism of gangrene may be due to pressure necrosis caused by the roundworms and the accompanying localized volvulus. In patients with ascariasis who present with acute surgical conditions, an urgent laparotomy is indicated to deal with intestinal perforation, to control peritonitis and to decompress the worm bolus that may be causing the acute intestinal obstruction.

• #26

  https://link.springer.com/article/10.1007/s40475-015-0058-7

  Ascariasis is still very prevalent; one billion people are infected all around the world. […] In rural areas, severe ascariasis impairs the immune responses to natural infections and vaccination programs. However, in urbanized areas, improved hygiene conditions and periodic anthelmintic treatments have led to light forms of ascariasis, where parasite-induced immunosuppressive effects are surpassed by the immunostimulating effects of the infection. […] This review focuses on the emerging evidence that supports the stimulatory effects of ascariasis on the allergic responses and its clinical importance. […] We show that ascariasis, beyond its known effects on human health, is able to modify the natural history of asthma, increasing Th2 responses and IgE synthesis to cross-reactive and species-specific mite allergens, being a risk factor for asthma and asthma severity.

• #27

  https://link.springer.com/article/10.1007/s40475-015-0058-7

  A. lumbricoides induces a Th2-biased immune response, similar to that observed in the allergic response but associated with parasite-induced immunomodulation, a condition that could be evolutionary related with the helminths ability of parasitic life. Therefore, ascariasis can influence allergic diseases by either stimulating or suppressing the allergic response, probably depending on the severity of the infection, which in turn is determined by host genetic susceptibility and the degree of exposure. […] During the last few years, it has become clear that ascariasis may influence several aspects of allergy, such as prevalence, diagnosis, severity, and prevention. […] In this review, we analyze the evidence supporting that, in the current relationship between ascariasis and allergy, the most important effect of ascariasis is increasing allergic symptoms.

• #28

  https://link.springer.com/article/10.1007/s40475-015-0058-7

  The immune response elicited by these infections differs depending on the type of parasite, lifecycle, host age, burden of co-infections (polyparasitism), and parasite loads. […] Ascariasis can boost the IgE/Th2 responses to bystander antigens. […] It is well known that ascariasis induces a polyclonal nonspecific stimulation of B cells; therefore, it can be hypothesized that the involved components also stimulate mite allergens-memory B cells that in the tropics are in permanent allergen-specific stimulation. […] Human ascariasis, in addition to its direct harmful effects, has other health impacts, among them boosting the Th2 allergic responses and increasing allergy symptoms.

• #29 A Role for Eosinophils in the Intestinal Immunity against Infective Ascaris suum Larvae | PLOS Neglected Tropical Diseases

  https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0002138

  The aim of this study was to explore the mechanisms of resistance against invading Ascaris suum larvae in pigs. […] Together, these results indicate an important role for eosinophils in the intestinal defense against invading A. suum larvae. […] Pigs build up a strong protective immunity after a prolonged exposure to Ascaris. This protective immunity develops at the level of the gut and prevents the incoming larvae to penetrate the intestinal tissue and start their hepato-tracheal migration. […] The purpose of this study was therefore to identify the key immunological elements involved in the formation of the pre-hepatic barrier in the caecum of pigs following Ascaris infections. […] We observed an almost 10-fold increase in mucosal eosinophils in immune animals. The recruitment of eosinophils to the caecum of immune animals was further supported by increased levels of IL-5, IL-13, CCL11 and eosinophil peroxidase (EPX) transcripts in the caecal mucosa.

• #30 A Role for Eosinophils in the Intestinal Immunity against Infective Ascaris suum Larvae | PLOS Neglected Tropical Diseases

  https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0002138

  Eosinophils had a toxic effect on the L3 larvae, which was enhanced when serum from naive animals was added and was highest when serum from immune animals was added. […] Our findings support this conclusion, as eosinophils only degranulated in response to the tissue dwelling L3 larvae, and not the lumen dwelling L4 larvae. […] In conclusion our results indicate that mast cells, eosinophils and goblet cells operate together to create an inhospitable environment that protects the host against invading Ascaris larvae.

• #31 The Intestinal Expulsion of the Roundworm Ascaris suum Is Associated with Eosinophils, Intra-Epithelial T Cells and Decreased Intestinal Transit Time | PLOS Neglected Tropical Diseases

  https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0002588

  Ascaris lumbricoides remains the most common endoparasite in humans, yet there is still very little information available about the immunological principles of protection, especially those directed against larval stages. […] In this study, we investigated the mucosal immune response leading to the expulsion of A. suum and the contribution of the hepato-tracheal migration. Self-cure was consistently associated with eosinophilia and intra-epithelial T cells in the jejunum. Furthermore, we identified increased gut movement as a possible mechanism of self-cure as the small intestinal transit time was markedly decreased at the time of expulsion of the worms. […] The aim of this study was to investigate in more detail the gastro-intestinal immune response leading to the elimination of L4 A. suum larvae from the small intestine and the contribution of the hepato-tracheal migration to the expulsion of the parasite.

• #32 Predisposition to ascariasis: patterns, mechanisms and implications | Parasitology | Cambridge Core

  https://www.cambridge.org/core/journals/parasitology/article/predisposition-to-ascariasis-patterns-mechanisms-and-implications/30A4F32A509626B4645B1AB3E961147F

  Ascaris lumbricoides, the human roundworm, is a remarkably infectious and persistent parasite. […] However, what has proved to be much more refractory to investigation has been the mechanisms that contribute to the observed epidemiological patterns. […] Parallel observations utilizing human subjects and appropriate animal model systems are essential to our understanding of the mechanisms underlying susceptibility/resistance to ascariasis. […] Furthermore, these patterns of Ascaris intensity and re-infection have broader implications with respect to helminth control and interactions with other important bystander infections.

• #33 Ascaris lumbricoides – Life Cycle, Pathogenesis, Pathology

  https://studymicrobio.com/ascaris-lumbricoides-life-cycle-pathogenesis-pathology/

  The pathogenicity of Ascaris lumbricoides is caused by both adult worms and migrating larvae. […] The severity of pathological lesions caused by migrating larvae in ascariasis depends on the sensitivity of the host, the nutritional status of the host, and the number of migrating larvae at any specific time. […] Individuals who are repeatedly infected by Ascaris lumbricoides are sensitized to the roundworm antigens. Thus the migrating larvae produce an inflammatory and hypersensitive reaction in the lung and liver. […] This hypersensitive reaction may cause pathological changes in the host such as granuloma and eosinophilic infiltrates. As a result pneumonitis, Loefflers syndrome may occur. […] The pathogenicity caused by adult Ascaris lumbricoides is due to mechanical action, sporiative action, and allergic reactions.

• #34 Discovering the Immunologic Mechanism of Ascaris-induced Allergic Airway Disease. – Jill Weatherhead

  https://grantome.com/grant/NIH/K08-AI143968-02

  Dr. Weatherhead’s research will evaluate the innate and adaptive immunologic mechanism by which Ascaris larval lung migration induces allergic airway disease. […] Questions outlined in this proposal are highly significant to the field of tropical medicine and parasitology having the potential to shift our understanding of the complex parasite-host relationship, lending support to the hypothesis that ascariasis is a leading cause of allergic airway disease in endemic regions. […] This proposal will advance the comprehension of the mechanistic pathways of Ascaris-induced allergic airway disease as well as provide therapeutic insight into asthma in general, suggesting novel interventional targets that are critically needed to prevent morbidity in children. […] The larval stage ascariasis can cause an asthma-like allergic airway disease. […] This proposal will identify the immunologic mechanisms of Ascaris-induced allergic airway disease in order to develop interventions that are urgently needed to prevent significant illness in children globally.

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