Gnathostoma
Gnathostomiasis
Cypriniformes
Angiostrongylus
Thelazioidea
Central Nervous System Parasitic Infections
Larva Migrans
Eye Infections, Parasitic
Larva
Otx expression during lamprey embryogenesis provides insights into the evolution of the vertebrate head and jaw. (1/64)
Agnathan or jawless vertebrates, such as lampreys, occupy a critical phylogenetic position between the gnathostome or jawed vertebrates and the cephalochordates, represented by amphioxus. In order to gain insight into the evolution of the vertebrate head, we have cloned and characterized a homolog of the head-specific gene Otx from the lamprey Petromyzon marinus. This lamprey Otx gene is a clear phylogenetic outgroup to both the gnathostome Otx1 and Otx2 genes. Like its gnathostome counterparts, lamprey Otx is expressed throughout the presumptive forebrain and midbrain. Together, these results indicate that the divergence of Otx1 and Otx2 took place after the gnathostome/agnathan divergence and does not correlate with the origin of the vertebrate brain. Intriguingly, Otx is also expressed in the cephalic neural crest cells as well as mesenchymal and endodermal components of the first pharyngeal arch in lampreys, providing molecular evidence of homology with the gnathostome mandibular arch and insights into the evolution of the gnathostome jaw. (+info)Gnathostomosis, an emerging foodborne zoonotic disease in Acapulco, Mexico. (2/64)
Between 1993 and 1997, 98 gnathostomosis cases were clinically identified in Acapulco, Mexico. Intermittent cutaneous migratory swellings were the commonest manifestation. Larvae were identified in 26 cases, while in 72, final diagnosis was made on the basis of epidemiologic data, food habits, and positive enzyme-linked immunosorbent assay and Western blot results. (+info)Intraocular gnathostomiasis. (3/64)
We report a rare case of intraocular Gnathostomiasis, where a live worm, intracameral in location, was successfully removed. Its identity was confirmed by microscopy. (+info)Medullary gnathostomiasis in a white patient: use of immunodiagnosis and magnetic resonance imaging. (4/64)
A 48-year-old French diplomat presented with a sensory-motor paraparesis of rapid onset, leading to paraplegia. Successive magnetic resonance image scans showed lesions of the thoracic spinal cord that were at different levels from one examination to the next. Specific anti-gnathostome antibodies were detected by means of enzyme-linked immunosorbent assay and Western blot test in both plasma and cerebrospinal fluid. Albendazole treatment prevented disease progression, but only partial regression of the neurologic symptoms was obtained. (+info)Ivermectin treatment of a traveler who returned from Peru with cutaneous gnathostomiasis. (5/64)
We describe a 21-year-old patient who experienced a relapse of cutaneous gnathostomiasis after receiving initial treatment with albendazole and who had a successful outcome after receiving a short course of ivermectin for the relapse. This is the first reported case of gnathostomiasis acquired by a human in Peru. (+info)Analysis of lamprey and hagfish genes reveals a complex history of gene duplications during early vertebrate evolution. (6/64)
It has been proposed that two events of duplication of the entire genome occurred early in vertebrate history (2R hypothesis). Several phylogenetic studies with a few gene families (mostly Hox genes and proteins from the MHC) have tried to confirm these polyploidization events. However, data from a single locus cannot explain the evolutionary history of a complete genome. To study this 2R hypothesis, we have taken advantage of the phylogenetic position of the lamprey to study the history of gene duplications in vertebrates. We selected most gene families that contain several paralogous genes in vertebrates and for which lamprey genes and an out-group are known in databases. In addition, we isolated members of the nuclear receptor superfamily in lamprey. Hagfish genes were also analyzed and found to confirm the lamprey gene analysis. Consistent with the 2R hypothesis, the phylogenetic analysis of 33 selected gene families, dispersed through the whole genome, revealed that one period of gene duplication arose before the lamprey-gnathostome split and this was followed by a second period of gene duplication after the lamprey-gnathostome split. Nevertheless, our analysis suggests that numerous gene losses and other gene-genome duplications occurred during the evolution of the vertebrate genomes. Thus, the complexity of all the paralogy groups present in vertebrates should be explained by the contribution of genome duplications (2R hypothesis), extra gene duplications, and gene losses. (+info)Case report: Ocular gnathostomiasis in northwestern Mexico. (7/64)
A 42-year-old woman from Culiacan in the Sinaloa State of Mexico presented with a four-year history of migratory, pruritic, painful swellings of the face. Palpebral edema with conjunctival erythema developed when lesions developed near the eye. Routine eye examination showed a mobile worm in the anterior chamber. Following surgical removal, the parasite was identified by light and electron microscopy as an advanced third-stage larva of Gnathostoma sp. This prevalence of this helminthiasis may be increasing in areas where eating freshwater raw fish ("cebiche") is customary. (+info)Antigenic components of Gnathostoma spinigerum recognized by infected human sera by two-dimensional polyacrylamide gel electrophoresis and immunoblotting. (8/64)
Antigenic components of Gnathostoma spinigerum larval extract were revealed by two-dimensional gel electrophoresis (2-DE) and immunoblot analysis using sera from patients with 6 proven cases of gnathostomiasis, 5 presumptive cases of gnathostomiasis, 3 proven cases of angiostrongyliasis, 3 proven cases of cysticercosis, and pooled sera from healthy adults. By the 2-DE, the larval extract was highly complex and consisted of more than 75 polypeptides. Immunoblotting analysis of this larval extract after reaction with each of 6 proven gnathostomiasis sera revealed various numbers of antigenic spots ranging from 30 to 70 spots at the approximate molecular masses of less than 14.4 to more than 94 kDa with isoelectric points (pI) of less than 4.65 to 9.6. Antigenic spots at the approximate molecular mass of more than 30 kDa were recognized with the proven angiostrongyliasis, proven cysticercosis and healthy control sera but these sera did not react with the spots at approximate molecular masses of 23-25 kDa with pI of 8.3-8.5. The reacted spots, which consisted of at least 1 to 2 spots, were unique for the recognition of gnathostomiasis sera. Five out of 6 (83.3%) proven and 4 out of 5 (80%) presumptive gnathostomiasis sera reacted with these specific spots. (+info)"Gnathostoma" is a genus of parasitic nematodes (roundworms) that are known to cause gnathostomiasis, a foodborne zoonotic disease. The adult worms typically infect the stomach of carnivorous animals such as cats and dogs, while the larvae can migrate through various tissues in humans and other animals, causing cutaneous and visceral lesions.
The term "Gnathostoma" itself is derived from the Greek words "gnathos" meaning jaw and "stoma" meaning mouth, which refers to the distinctive muscular mouthparts (called "hooks") that these parasites use to attach themselves to their host's tissues.
It's worth noting that there are several species of Gnathostoma that can infect humans, with Gnathostoma spinigerum being one of the most common and widely distributed species. Proper cooking and hygiene practices can help prevent gnathostomiasis infection in humans.
Gnathostomiasis is a parasitic infection caused by the third-stage larvae of nematodes (roundworms) in the genus Gnathostoma. The infection typically occurs through the consumption of raw or undercooked freshwater fish, amphibians, or birds that contain the parasite's larvae.
The third-stage larvae penetrate the gastrointestinal tract and migrate to various tissues, including the skin, subcutaneous tissue, eyes, and central nervous system, causing cutaneous, ocular, or visceral lesions. The clinical manifestations of gnathostomiasis depend on the migration pathway and the organs involved.
Symptoms can range from mild dermatological reactions to severe neurological complications, such as eosinophilic meningitis or encephalitis. Diagnosis is often challenging due to its nonspecific clinical presentation and requires a high index of suspicion in travelers returning from endemic areas.
The disease is prevalent in Southeast Asia, East Asia, and Central and South America. Preventive measures include avoiding the consumption of raw or undercooked fish, amphibians, or birds in endemic regions and practicing good hygiene.
Spirurida infections refer to parasitic diseases caused by roundworms belonging to the order Spirurida. These nematodes have a complex life cycle that involves an intermediate host, usually an arthropod (such as a beetle or a mosquito), and a definitive host, which is a vertebrate animal (including humans).
Humans can become accidentally infected with these parasites through the consumption of raw or undercooked infected meat or fish, or by ingesting contaminated water or soil that contains infective larvae. The most common Spirurida infections in humans are:
1. Gnathostomiasis: Caused by the nematode Gnathostoma spp., which is commonly found in Asia, Central and South America, and Africa. Humans can become infected after consuming raw or undercooked fish, snails, or amphibians that contain infective larvae. The parasite migrates through various tissues, causing symptoms such as skin lesions, abdominal pain, diarrhea, and neurological disorders.
2. Mansonellosis: Caused by the nematodes Mansonella perstans, M. streptocerca, and M. ozzardi, which are transmitted to humans through the bites of infected blackflies or midges. The parasites reside in the connective tissue, causing mild symptoms such as itching, rash, and joint pain.
3. Spirurid infection: Caused by various species of Spirurida nematodes, including Dirofilaria spp., which can infect humans through the bites of infected mosquitoes. The parasites typically reside in the subcutaneous tissue or lungs, causing symptoms such as cough, chest pain, and skin lesions.
Preventive measures for Spirurida infections include avoiding consumption of raw or undercooked meat or fish, practicing good hygiene and sanitation, using insect repellent to prevent mosquito bites, and treating domestic animals for parasitic infections. Treatment options for Spirurida infections depend on the specific species involved and may include anthelmintic drugs such as albendazole or ivermectin.
Cypriniformes is an order of freshwater fish that includes carps, minnows, and loaches. These fish are characterized by the presence of a single pair of barbels near their mouths and the absence of teeth on their jaws. They are found primarily in North America, Europe, and Asia. Some well-known examples of Cypriniformes include the common carp, goldfish, and zebrafish. These fish are often used as model organisms in scientific research due to their relatively small size, ease of breeding, and genetic similarity to humans.
Angiostrongylus is a genus of parasitic nematode roundworms that are known to cause serious diseases in humans and animals. The most common species that affects humans is Angiostrongylus cantonensis, also known as the rat lungworm. This parasite primarily infects rats but can accidentally infect humans through the consumption of raw or undercooked intermediate hosts, such as snails, slugs, or freshwater shrimp.
Infection with Angiostrongylus cantonensis can lead to a condition called angiostrongyliasis, which primarily affects the central nervous system. Symptoms of this disease may include severe headaches, neck stiffness, nausea, vomiting, and in some cases, temporary paralysis or long-term neurological damage.
Preventing Angiostrongylus infection involves avoiding the consumption of raw or undercooked intermediate hosts and practicing good hygiene when handling raw produce. In areas where the parasite is endemic, public health education campaigns are often implemented to raise awareness about the risks associated with this infection and promote preventative measures.
Thelazioidea is not a medical term, but a taxonomic category in the field of biology. It refers to a superfamily of nematodes (roundworms) that includes the genus Thelazia. Members of this superfamily are known as "eyeworms" because they can infect the eyes of various animals, including humans.
Thelazia species are transmitted by flying insects such as flies, which serve as intermediate hosts for the parasites. The adult worms live in the conjunctival sac of the eye and feed on tears, causing symptoms such as eye irritation, tearing, and discharge. In severe cases, they can cause corneal ulcers or blindness.
While it is important for medical professionals to be aware of the existence of Thelazia species and other eyeworms, a specific medical definition of Thelazioidea does not exist.
Central nervous system (CNS) parasitic infections refer to the invasion and infection of the brain and/or spinal cord by parasites. These infections can cause a range of symptoms depending on the type of parasite, the location of the infection within the CNS, and the severity of the infection.
Parasites that can infect the CNS include protozoa (such as Toxoplasma gondii, Naegleria fowleri, and Plasmodium falciparum), helminths (such as cysticercosis caused by Taenia solium tapeworm larvae), and arthropods (such as ticks that can transmit Lyme disease).
Symptoms of CNS parasitic infections can include headache, fever, seizures, confusion, weakness, numbness, loss of coordination, and changes in behavior or personality. Diagnosis typically involves a combination of clinical evaluation, imaging studies (such as MRI or CT scans), and laboratory tests (such as CSF analysis or PCR).
Treatment for CNS parasitic infections depends on the specific type of parasite involved and may include medications such as antiparasitics, antibiotics, or corticosteroids. In some cases, surgery may be necessary to remove parasites or cysts from the CNS. Prevention measures include avoiding contaminated food and water, practicing good hygiene, using insect repellent, and seeking prompt medical attention for any suspected infectious symptoms.
Larva migrans is a parasitic infection caused by the larval stage of certain nematode (roundworm) species. The term "larva migrans" is used to describe two distinct clinical syndromes: cutaneous larva migrans and visceral larva migrans.
1. Cutaneous Larva Migrans (CLM): Also known as creeping eruption, it is caused by the hookworm species that typically infect dogs and cats (Ancylostoma braziliense, Ancylostoma caninum). The larvae penetrate human skin, usually through bare feet in contact with contaminated soil or sand, and cause an intensely pruritic (itchy) serpiginous (snake-like) track as they migrate under the skin.
2. Visceral Larva Migrans (VLM): It is caused by the migration of larvae from certain roundworm species, such as Toxocara spp., which primarily infect canids (dogs and related animals). Humans become accidental hosts when they ingest embryonated eggs present in contaminated soil, water, or undercooked meat. The larvae then migrate through various organs, causing inflammation and damage to tissues. VLM often affects the liver, lungs, eyes, and less commonly the central nervous system. Symptoms can vary widely depending on the organs involved but may include fever, cough, abdominal pain, and eye inflammation.
It is important to note that these infections are not transmitted from person-to-person. Preventive measures include wearing shoes in areas with contaminated soil, washing hands thoroughly after contact with soil or pets, cooking meat properly, and avoiding the ingestion of dirt or sand by young children.
Parasitic eye infections are conditions characterized by the invasion and infestation of the eye or its surrounding structures by parasites. These can be protozoans, helminths, or ectoparasites. Examples of such infections include Acanthamoeba keratitis, which is caused by a free-living amoeba found in water and soil; Toxoplasmosis, which is caused by the protozoan Toxoplasma gondii; Loiasis, which is caused by the parasitic filarial worm Loa loa; and Demodicosis, which is caused by the mite Demodex folliculorum. Symptoms can vary depending on the type of parasite but often include redness, pain, discharge, and vision changes. Treatment typically involves antiparasitic medications and sometimes surgery to remove the parasites or damaged tissue. Prevention measures include good hygiene practices and avoiding contact with contaminated water or soil.
Nematode infections, also known as roundworm infections, are caused by various species of nematodes or roundworms. These parasitic worms can infect humans and animals, leading to a range of health problems depending on the specific type of nematode and the location of the infection within the body.
Common forms of nematode infections include:
1. Ascariasis: Caused by Ascaris lumbricoides, this infection occurs when people ingest the parasite's eggs through contaminated food or water. The larvae hatch in the small intestine, mature into adult worms, and can cause abdominal pain, nausea, vomiting, and diarrhea. In severe cases, the worms may obstruct the intestines or migrate to other organs, leading to potentially life-threatening complications.
2. Hookworm infections: These are caused by Ancylostoma duodenale and Necator americanus. The larvae penetrate the skin, usually through bare feet, and migrate to the small intestine, where they attach to the intestinal wall and feed on blood. Symptoms include abdominal pain, diarrhea, anemia, and protein loss.
3. Trichuriasis: Also known as whipworm infection, this is caused by Trichuris trichiura. The larvae hatch in the small intestine, mature into adult worms, and reside in the large intestine, causing abdominal pain, diarrhea, and rectal prolapse in severe cases.
4. Strongyloidiasis: Caused by Strongyloides stercoralis, this infection occurs when the larvae penetrate the skin, usually through contaminated soil, and migrate to the lungs and then the small intestine. Symptoms include abdominal pain, diarrhea, and skin rashes. In immunocompromised individuals, strongyloidiasis can lead to disseminated disease, which is potentially fatal.
5. Toxocariasis: This infection is caused by the roundworms Toxocara canis or Toxocara cati, found in dogs and cats, respectively. Humans become infected through ingestion of contaminated soil or undercooked meat. Symptoms include fever, cough, abdominal pain, and vision loss in severe cases.
6. Enterobiasis: Also known as pinworm infection, this is caused by Enterobius vermicularis. The larvae hatch in the small intestine, mature into adult worms, and reside in the large intestine, causing perianal itching and restlessness, especially at night.
Preventive measures include:
1. Proper hand hygiene: Wash hands with soap and water after using the toilet, changing diapers, handling pets or their feces, and before preparing or eating food.
2. Personal hygiene: Keep fingernails short and clean, avoid biting nails, and wear shoes in public areas, especially where soil may be contaminated with human or animal feces.
3. Food safety: Wash fruits and vegetables thoroughly, cook meat properly, and avoid consuming raw or undercooked meat, poultry, or fish.
4. Environmental cleanliness: Regularly clean surfaces that come into contact with food, such as countertops, cutting boards, and utensils. Dispose of trash properly and maintain a clean living environment.
5. Pet care: Keep pets healthy and regularly deworm them as recommended by a veterinarian. Pick up pet feces promptly to prevent contamination of the environment.
6. Public health measures: Implement public health interventions, such as regular waste disposal, sewage treatment, and vector control, to reduce the transmission of parasitic infections.
Antibodies are proteins produced by the immune system in response to the presence of a foreign substance, known as an antigen. They are capable of recognizing and binding to specific antigens, neutralizing or marking them for destruction by other immune cells.
Helminths are parasitic worms that can infect humans and animals. They include roundworms, tapeworms, and flukes, among others. Helminth infections can cause a range of symptoms, depending on the type of worm and the location of the infection.
Antibodies to helminths are produced by the immune system in response to an infection with one of these parasitic worms. These antibodies can be detected in the blood and serve as evidence of a current or past infection. They may also play a role in protecting against future infections with the same type of worm.
There are several different classes of antibodies, including IgA, IgD, IgE, IgG, and IgM. Antibodies to helminths are typically of the IgE class, which are associated with allergic reactions and the defense against parasites. IgE antibodies can bind to mast cells and basophils, triggering the release of histamine and other inflammatory mediators that help to protect against the worm.
In addition to IgE, other classes of antibodies may also be produced in response to a helminth infection. For example, IgG antibodies may be produced later in the course of the infection and can provide long-term immunity to reinfection. IgA antibodies may also be produced and can help to prevent the attachment and entry of the worm into the body.
Overall, the production of antibodies to helminths is an important part of the immune response to these parasitic worms. However, in some cases, the presence of these antibodies may also be associated with allergic reactions or other immunological disorders.
A larva is a distinct stage in the life cycle of various insects, mites, and other arthropods during which they undergo significant metamorphosis before becoming adults. In a medical context, larvae are known for their role in certain parasitic infections. Specifically, some helminth (parasitic worm) species use larval forms to infect human hosts. These invasions may lead to conditions such as cutaneous larva migrans, visceral larva migrans, or gnathostomiasis, depending on the specific parasite involved and the location of the infection within the body.
The larval stage is characterized by its markedly different morphology and behavior compared to the adult form. Larvae often have a distinct appearance, featuring unsegmented bodies, simple sense organs, and undeveloped digestive systems. They are typically adapted for a specific mode of life, such as free-living or parasitic existence, and rely on external sources of nutrition for their development.
In the context of helminth infections, larvae may be transmitted to humans through various routes, including ingestion of contaminated food or water, direct skin contact with infective stages, or transmission via an intermediate host (such as a vector). Once inside the human body, these parasitic larvae can cause tissue damage and provoke immune responses, leading to the clinical manifestations of disease.
It is essential to distinguish between the medical definition of 'larva' and its broader usage in biology and zoology. In those fields, 'larva' refers to any juvenile form that undergoes metamorphosis before reaching adulthood, regardless of whether it is parasitic or not.
Helminth antigens refer to the proteins or other molecules found on the surface or within helminth parasites that can stimulate an immune response in a host organism. Helminths are large, multicellular parasitic worms that can infect various tissues and organs in humans and animals, causing diseases such as schistosomiasis, lymphatic filariasis, and soil-transmitted helminthiases.
Helminth antigens can be recognized by the host's immune system as foreign invaders, leading to the activation of various immune cells and the production of antibodies. However, many helminths have evolved mechanisms to evade or suppress the host's immune response, allowing them to establish long-term infections.
Studying helminth antigens is important for understanding the immunology of helminth infections and developing new strategies for diagnosis, treatment, and prevention. Some researchers have also explored the potential therapeutic use of helminth antigens or whole helminths as a way to modulate the immune system and treat autoimmune diseases or allergies. However, more research is needed to determine the safety and efficacy of these approaches.