Ascariasis
Encyclopedia
Ascariasis is a human
disease
caused by the parasitic roundworm Ascaris lumbricoides
. Perhaps as many as one quarter of the world's people are infected, with rates of 45% in Latin America and 95% in parts of Africa. Ascariasis is particularly prevalent in tropical regions
and in areas of poor hygiene
. Other species
of the genus
Ascaris
are parasitic and can cause disease in domestic animals. Certain genes have been identified in human populations that may increase the susceptibility to infection.
Infection
occurs through ingestion of food contaminated with feces
containing Ascaris eggs
. The larva
e hatch, burrow through the intestine
, reach the lungs, and finally migrate up the respiratory tract
. From there they are then reswallowed and mature in the intestine, growing up to 30 cm (12 in.) in length and anchoring themselves to the intestinal wall.
Infections are usually asymptomatic, especially if the number of worms is small. They may however be accompanied by inflammation
, fever
, and diarrhea
, and serious problems may develop if the worms migrate to other parts of the body.
and inflammation
, enlargement of the liver
or spleen
, toxicity, and pneumonia
. A heavy worm infestation may cause nutritional deficiency; other complications, sometimes fatal, include obstruction of the bowel by a bolus of worms (observed particularly in children) and obstruction of the bile
or pancreatic
duct. More than 796 Ascaris lumbricoides worms weighing up to 550 g [19 ounces] were recovered at autopsy from a 2-year-old South African girl. The worms had caused torsion and gangrene of the ileum
, which was interpreted as the cause of death.
Ascaris takes most of its nutrients from the partially digested host food in the intestine
. There is limited evidence that it can also pierce the intestinal mucous membrane and feed on blood, but this is not its usual source of nutrition. As a result, Ascaris infection does not produce the anemia
associated with some other roundworm infections.
In Canada in 1970, a postgraduate student tainted his roommates' food with Ascaris lumbricoides
. Four of the victims became seriously ill; two of these suffered acute respiratory failure.
of worms may obstruct the intestine; migrating larvae may cause pneumonitis
and eosinophilia
.
Transmission also comes through municipal recycling of wastewater into crop fields. This is quite common in emerging industrial economies, and poses serious risks for not only local crop sales but also exports of contaminated vegetables. A 1986 outbreak of ascariasis in Italy
was traced to irresponsible wastewater recycling used to grow Balkan vegetable exports.
Transmission from human to human by direct contact is impossible.
. On X-ray
, 15–35 cm long filling defects, sometimes with whirled appearance (bolus of worms).
facilities; safe excreta disposal; protection of food from dirt and soil; thorough washing of produce; and hand washing.
Food dropped on the floor should never be eaten without washing or cooking, particularly in endemic areas. Fruits and vegetables should always be washed thoroughly before consumption.
s and include:
Also, corticosteroids can treat some of the symptoms, such as inflammation. In some cases with severe infestation, the sudden death of the worms may cause bowel obstruction
, requiring surgical intervention.
Native Americans
have traditionally used epazote
(Chenopodium ambrisioides) for treatment, which was not as powerful as pharmaceutical compounds, but spontaneous passage of Ascarids provided some proof of efficacy.
in the United States
including Gulf Coast; in Nigeria
and in Southeast Asia
. One study indicated that the prevalence of ascariasis in the United States at about 4 million (2%) [8]. In a survey of a rural Nova Scotia
community, 28.1% of 431 individuals tested were positive for Ascaris, all of them being under age 20, while all 276 tested in metropolitan Halifax were negative.
Deposition of ova
(eggs) in sewage
hints at the degree of ascariasis incidence. A 1978 study showed about 75% of all sewage sludge
samples sampled in United States urban catchments contained Ascaris ova, with rates as high as 5 to 100 eggs per litre . In Frankfort
, Indiana
, 87.5% of the sludge samples were positive with Ascaris, Toxocara, Trichuris
, and hookworm
. In Macon
, Georgia
, one of the 13 soil samples tested positive for Ascaris . Municipal wastewater in Riyadh
, Saudi Arabia
detected over 100 eggs per litre of wastewater and in Czechoslovakia
was as high as 240–1050 eggs per litre.
Ascariasis can often be measured by examining food for ova. In one field study in Marrakech
, Morocco
, where raw sewage is used to fertilize crop fields, Ascaris eggs were detected at the rate of 0.18 eggs/kg in potatoes, 0.27 eggs/kg in turnip, 4.63 eggs/kg in mint, 0.7 eggs/kg in carrots, and 1.64 eggs/kg in radish. A similar study in the same area showed that 73% of children working on these farms were infected with helminths, particularly Ascaris, probably as a result of exposure to the raw sewage.
Human
Humans are the only living species in the Homo genus...
disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
caused by the parasitic roundworm Ascaris lumbricoides
Ascaris lumbricoides
Ascaris lumbricoides is the giant roundworm of humans, belonging to the phylum Nematoda. An ascarid nematode, it is responsible for the disease ascariasis in humans, and it is the largest and most common parasitic worm in humans. One-sixth of the human population is estimated to be infected by this...
. Perhaps as many as one quarter of the world's people are infected, with rates of 45% in Latin America and 95% in parts of Africa. Ascariasis is particularly prevalent in tropical regions
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
and in areas of poor hygiene
Hygiene
Hygiene refers to the set of practices perceived by a community to be associated with the preservation of health and healthy living. While in modern medical sciences there is a set of standards of hygiene recommended for different situations, what is considered hygienic or not can vary between...
. Other species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Ascaris
Ascaris
Ascaris is a genus of parasitic nematode worms known as the "giant intestinal roundworms". One species, A. suum, typically infects pigs, while another, A. lumbricoides, affects human populations, typically in sub-tropical and tropical areas with poor sanitation. A...
are parasitic and can cause disease in domestic animals. Certain genes have been identified in human populations that may increase the susceptibility to infection.
Infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
occurs through ingestion of food contaminated with feces
Feces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
containing Ascaris eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
. The larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e hatch, burrow through the intestine
Intestine
In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
, reach the lungs, and finally migrate up the respiratory tract
Respiratory tract
In humans the respiratory tract is the part of the anatomy involved with the process of respiration.The respiratory tract is divided into 3 segments:*Upper respiratory tract: nose and nasal passages, paranasal sinuses, and throat or pharynx...
. From there they are then reswallowed and mature in the intestine, growing up to 30 cm (12 in.) in length and anchoring themselves to the intestinal wall.
Infections are usually asymptomatic, especially if the number of worms is small. They may however be accompanied by inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
, fever
Fever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
, and diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
, and serious problems may develop if the worms migrate to other parts of the body.
Signs and symptoms
Patients can remain asymptomatic for very long periods of time. As larval stages travel through the body, they may cause visceral damage, peritonitisPeritonitis
Peritonitis is an inflammation of the peritoneum, the serous membrane that lines part of the abdominal cavity and viscera. Peritonitis may be localised or generalised, and may result from infection or from a non-infectious process.-Abdominal pain and tenderness:The main manifestations of...
and inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
, enlargement of the liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
or spleen
Spleen
The spleen is an organ found in virtually all vertebrate animals with important roles in regard to red blood cells and the immune system. In humans, it is located in the left upper quadrant of the abdomen. It removes old red blood cells and holds a reserve of blood in case of hemorrhagic shock...
, toxicity, and pneumonia
Pneumonia
Pneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...
. A heavy worm infestation may cause nutritional deficiency; other complications, sometimes fatal, include obstruction of the bowel by a bolus of worms (observed particularly in children) and obstruction of the bile
Bile
Bile or gall is a bitter-tasting, dark green to yellowish brown fluid, produced by the liver of most vertebrates, that aids the process of digestion of lipids in the small intestine. In many species, bile is stored in the gallbladder and upon eating is discharged into the duodenum...
or pancreatic
Pancreas
The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...
duct. More than 796 Ascaris lumbricoides worms weighing up to 550 g [19 ounces] were recovered at autopsy from a 2-year-old South African girl. The worms had caused torsion and gangrene of the ileum
Ileum
The ileum is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may be used instead of ileum.The ileum follows the duodenum...
, which was interpreted as the cause of death.
Ascaris takes most of its nutrients from the partially digested host food in the intestine
Intestine
In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
. There is limited evidence that it can also pierce the intestinal mucous membrane and feed on blood, but this is not its usual source of nutrition. As a result, Ascaris infection does not produce the anemia
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...
associated with some other roundworm infections.
In Canada in 1970, a postgraduate student tainted his roommates' food with Ascaris lumbricoides
Ascaris lumbricoides
Ascaris lumbricoides is the giant roundworm of humans, belonging to the phylum Nematoda. An ascarid nematode, it is responsible for the disease ascariasis in humans, and it is the largest and most common parasitic worm in humans. One-sixth of the human population is estimated to be infected by this...
. Four of the victims became seriously ill; two of these suffered acute respiratory failure.
Life cycle
First appearance of eggs in stools is 60–70 days. In larval ascariasis, symptoms occur 4–16 days after infection. The final symptoms are gastrointestinal discomfort, colic and vomiting, fever, and observation of live worms in stools. Some patients may have pulmonary symptoms or neurological disorders during migration of the larvae. However there are generally few or no symptoms. A bolusBolus
-Medicine:* Bolus , the administration of a drug, medication or other substance in the form of a single, large dose* Bolus , a tissue equivalent substance used in radiation therapy...
of worms may obstruct the intestine; migrating larvae may cause pneumonitis
Pneumonitis
Pneumonitis or pulmonitis is a general term that refers to inflammation of lung tissue.Pneumonia is pneumonitis combined with consolidation and exudation...
and eosinophilia
Eosinophilia
Eosinophilia is a condition in which the eosinophil count in the peripheral blood exceeds 0.45×109/L . A marked increase in non-blood tissue eosinophil count noticed upon histopathologic examination is diagnostic for tissue eosinophilia. Several causes are known, with the most common being...
.
Source
The source of transmission is from soil and vegetation on which fecal matter containing eggs has been deposited. Ingestion of infective eggs from soil contaminated with human feces or transmission and contaminated vegetables and water is the primary route of infection. Intimate contact with pets which have been in contact with contaminated soil may result in infection, while pets which are infested themselves by a different type of roundworm can cause infection with that type of worm (Toxocara canis, etc.) as occasionally occurs with groomers.Transmission also comes through municipal recycling of wastewater into crop fields. This is quite common in emerging industrial economies, and poses serious risks for not only local crop sales but also exports of contaminated vegetables. A 1986 outbreak of ascariasis in Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
was traced to irresponsible wastewater recycling used to grow Balkan vegetable exports.
Transmission from human to human by direct contact is impossible.
Diagnosis
The diagnosis is usually incidental when the host passes a worm in the stool or vomit. Stool samples for ova and parasites will demonstrate Ascaris eggs. Larvae may be found in gastric or respiratory secretions in pulmonary disease. Blood counts may demonstrate peripheral eosinophiliaEosinophilia
Eosinophilia is a condition in which the eosinophil count in the peripheral blood exceeds 0.45×109/L . A marked increase in non-blood tissue eosinophil count noticed upon histopathologic examination is diagnostic for tissue eosinophilia. Several causes are known, with the most common being...
. On X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
, 15–35 cm long filling defects, sometimes with whirled appearance (bolus of worms).
Prevention
Prevention includes: use of toiletToilet
A toilet is a sanitation fixture used primarily for the disposal of human excrement, often found in a small room referred to as a toilet/bathroom/lavatory...
facilities; safe excreta disposal; protection of food from dirt and soil; thorough washing of produce; and hand washing.
Food dropped on the floor should never be eaten without washing or cooking, particularly in endemic areas. Fruits and vegetables should always be washed thoroughly before consumption.
Treatment
Pharmaceutical drugs that are used to kill roundworms are called ascaricideAscaricide
Ascaricides are drugs to treat ascariasis that is caused by infections with parasitic nematodes of the genus Ascaris...
s and include:
- MebendazoleMebendazoleMebendazole or MBZ is a benzimidazole drug developed by Janssen Pharmaceutica and marketed as Vermox, Ovex, Antiox, and Pripsen...
(Vermox) (C16H13N3O2). Causes slow immobilization and death of the worms by selectively and irreversibly blocking uptake of glucose and other nutrients in susceptible adult intestine where helminths dwell. Oral dosage is 100 mg 12 hourly for 3 days. - PiperazinePiperazinePiperazine is an organic compound that consists of a six-membered ring containing two opposing nitrogen atoms. Piperazine exists as small alkaline deliquescent crystals with a saline taste....
(C4H10N2.C6H10O4). A flaccid paralyzing agent that causes a blocking response of ascaris muscle to acetylcholine. The narcotizing effect immobilizes the worm, which prevents migration when treatment is accomplished with weak drugs such as thiabendazole. If used by itself it causes the worm to be passed out in the feces. Dosage is 75 mg/kg (max 3.5 g) as a single oral dose. - Pyrantel pamoatePyrantel pamoatePyrantel pamoate or Pyrantel Embonate , is used as a deworming agent in the treatment of hookworms and roundworms in domesticated animals such as horses, cattle, sheep, pigs, cats, dogs, and many other species. It is a combination of pyrantel and pamoic acid...
(Antiminth, Pin-Rid, Pin-X) (C11H14N2S.C23H16O6) Depolarizes ganglionic block of nicotinic neuromuscular transmission, resulting in spastic paralysis of the worm. Spastic (tetanic) paralyzing agents, in particular pyrantel pamoate, may induce complete intestinal obstruction in a heavy worm load. Dosage is 11 mg/kg not to exceed 1 g as a single dose. - AlbendazoleAlbendazoleAlbendazole, marketed as Albenza, Eskazole, Zentel and Andazol, is a member of the benzimidazole compounds used as a drug indicated for the treatment of a variety of worm infestations. Although this use is widespread in the United States, the U.S. Food and Drug Administration has not approved...
(C12H15N3O2S) A broad-spectrum antihelminthic agent that decreases ATPAdenosine triphosphateAdenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
production in the worm, causing energy depletion, immobilization, and finally death. Dosage is 400 mg given as single oral dose (contraindicated during pregnancy and children under 2 years). - ThiabendazoleThiabendazoleTiabendazole is a fungicide and parasiticide.-Fungicide:...
. This may cause migration of the worm into the esophagusEsophagusThe esophagus is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. During swallowing, food passes from the mouth through the pharynx into the esophagus and travels via peristalsis to the stomach...
, so it is usually combined with piperazine. - HexylresorcinolHexylresorcinolHexylresorcinol is a chemical compound with anaesthetic, antiseptic and antihelmintic properties.It can be used topically on small skin infections, or as an ingredient in throat lozenges....
effective in single dose, mentioned in : Holt, Jr Emmett L, McIntosh Rustin: Holt's Diseases of Infancy and Childhood: A Textbook for the Use of Students and Practitioners. Appleton and Co, New York,11th edition - SantoninSantoninSantonin is a drug which was widely used in the past as an anthelminthic, a drug that expels parasitic worms from the body, by either killing or stunning them. Santonin was formerly listed in U.S...
, more toxic than hexylresorcinolHexylresorcinolHexylresorcinol is a chemical compound with anaesthetic, antiseptic and antihelmintic properties.It can be used topically on small skin infections, or as an ingredient in throat lozenges....
, mentioned in : Holt, Jr Emmett L, McIntosh Rustin: Holt's Diseases of Infancy and Childhood: A Textbook for the Use of Students and Practitioners. Appleton and Co, New York,, 11th edition - Oil of chenopodium, more toxic than hexylresorcinolHexylresorcinolHexylresorcinol is a chemical compound with anaesthetic, antiseptic and antihelmintic properties.It can be used topically on small skin infections, or as an ingredient in throat lozenges....
, mentioned in : Holt, Jr Emmett L, McIntosh Rustin: Holt's Diseases of Infancy and Childhood: A Textbook for the Use of Students and Practitioners. Appleton and Co, New York, 11th edition
Also, corticosteroids can treat some of the symptoms, such as inflammation. In some cases with severe infestation, the sudden death of the worms may cause bowel obstruction
Bowel obstruction
Bowel obstruction is a mechanical or functional obstruction of the intestines, preventing the normal transit of the products of digestion. It can occur at any level distal to the duodenum of the small intestine and is a medical emergency...
, requiring surgical intervention.
Native Americans
Indigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
have traditionally used epazote
Epazote
Epazote, wormseed, Jesuit's tea, Mexican tea, Paico or Herba Sancti Mariæ is an herb native to Central America, South America, and southern Mexico....
(Chenopodium ambrisioides) for treatment, which was not as powerful as pharmaceutical compounds, but spontaneous passage of Ascarids provided some proof of efficacy.
Epidemiology
Roughly 1.5 billion individuals are infected with this worm, primarily in Africa and Asia. Ascariasis is endemicEndemic (epidemiology)
In epidemiology, an infection is said to be endemic in a population when that infection is maintained in the population without the need for external inputs. For example, chickenpox is endemic in the UK, but malaria is not...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
including Gulf Coast; in Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...
and in Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
. One study indicated that the prevalence of ascariasis in the United States at about 4 million (2%) [8]. In a survey of a rural Nova Scotia
Nova Scotia
Nova Scotia is one of Canada's three Maritime provinces and is the most populous province in Atlantic Canada. The name of the province is Latin for "New Scotland," but "Nova Scotia" is the recognized, English-language name of the province. The provincial capital is Halifax. Nova Scotia is the...
community, 28.1% of 431 individuals tested were positive for Ascaris, all of them being under age 20, while all 276 tested in metropolitan Halifax were negative.
Deposition of ova
Ovum
An ovum is a haploid female reproductive cell or gamete. Both animals and embryophytes have ova. The term ovule is used for the young ovum of an animal, as well as the plant structure that carries the female gametophyte and egg cell and develops into a seed after fertilization...
(eggs) in sewage
Sewage
Sewage is water-carried waste, in solution or suspension, that is intended to be removed from a community. Also known as wastewater, it is more than 99% water and is characterized by volume or rate of flow, physical condition, chemical constituents and the bacteriological organisms that it contains...
hints at the degree of ascariasis incidence. A 1978 study showed about 75% of all sewage sludge
Sludge
Sludge refers to the residual, semi-solid material left from industrial wastewater, or sewage treatment processes. It can also refer to the settled suspension obtained from conventional drinking water treatment, and numerous other industrial processes...
samples sampled in United States urban catchments contained Ascaris ova, with rates as high as 5 to 100 eggs per litre . In Frankfort
Frankfort, Indiana
As of the census of 2000, there were 16,662 people, 6,279 households, and 4,175 families residing in the city. The population density was 3,240.5 people per square mile . There were 6,682 housing units at an average density of 1,299.6 per square mile...
, Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...
, 87.5% of the sludge samples were positive with Ascaris, Toxocara, Trichuris
Trichinosis
Trichinosis, also called trichinellosis, or trichiniasis, is a parasitic disease caused by eating raw or undercooked pork or wild game infected with the larvae of a species of roundworm Trichinella spiralis, commonly called the trichina worm. There are eight Trichinella species; five are...
, and hookworm
Hookworm
The hookworm is a parasitic nematode that lives in the small intestine of its host, which may be a mammal such as a dog, cat, or human. Two species of hookworms commonly infect humans, Ancylostoma duodenale and Necator americanus. A. duodenale predominates in the Middle East, North Africa, India...
. In Macon
Macon, Georgia
Macon is a city located in central Georgia, US. Founded at the fall line of the Ocmulgee River, it is part of the Macon metropolitan area, and the county seat of Bibb County. A small portion of the city extends into Jones County. Macon is the biggest city in central Georgia...
, Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
, one of the 13 soil samples tested positive for Ascaris . Municipal wastewater in Riyadh
Riyadh
Riyadh is the capital and largest city of Saudi Arabia. It is also the capital of Riyadh Province, and belongs to the historical regions of Najd and Al-Yamama. It is situated in the center of the Arabian Peninsula on a large plateau, and is home to 5,254,560 people, and the urban center of a...
, Saudi Arabia
Saudi Arabia
The Kingdom of Saudi Arabia , commonly known in British English as Saudi Arabia and in Arabic as as-Sa‘ūdiyyah , is the largest state in Western Asia by land area, constituting the bulk of the Arabian Peninsula, and the second-largest in the Arab World...
detected over 100 eggs per litre of wastewater and in Czechoslovakia
Czechoslovakia
Czechoslovakia or Czecho-Slovakia was a sovereign state in Central Europe which existed from October 1918, when it declared its independence from the Austro-Hungarian Empire, until 1992...
was as high as 240–1050 eggs per litre.
Ascariasis can often be measured by examining food for ova. In one field study in Marrakech
Marrakech
Marrakech or Marrakesh , known as the "Ochre city", is the most important former imperial city in Morocco's history...
, Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...
, where raw sewage is used to fertilize crop fields, Ascaris eggs were detected at the rate of 0.18 eggs/kg in potatoes, 0.27 eggs/kg in turnip, 4.63 eggs/kg in mint, 0.7 eggs/kg in carrots, and 1.64 eggs/kg in radish. A similar study in the same area showed that 73% of children working on these farms were infected with helminths, particularly Ascaris, probably as a result of exposure to the raw sewage.
Trivia
- Ascariasis may result in allergiesAllergyAn Allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when a person's immune system reacts to normally harmless substances in the environment. A substance that causes a reaction is called an allergen. These reactions are acquired, predictable, and rapid...
to shrimpShrimpShrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
and dustmites due to the shared antigenAntigenAn antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...
, tropomyosinTropomyosinTropomyosin is an actin-binding protein that regulates actin mechanics. It is important, among other things, for muscle contraction. Tropomyosin, along with the troponin complex, associate with actin in muscle fibers and regulate muscle contraction by regulating the binding of myosin...
. - Ascaris have an aversion to some general anesthetics and may exit the body, sometimes through the mouth.
| Genus and Species | Ascaris lumbricoides |
|---|---|
| Common Name | Giant Intestinal Roundworm |
| Etiologic Agent of: | Ascariasis |
| Infective stage | Embryonated Egg |
| Definitive Host | Human |
| Point of Entry | Mouth |
| Mode of Transmission | Ingestion of Embryonated egg through contaminated food or water |
| Habitat | Small Intestine |
| Pathogenic Stage | Adult, Larva |
| Mode of Attachment | Retention in the mucosal folds using pressure |
| Mode of Nutrition | Feeding of Chyme Chyme Chyme is the semifluid mass of partly digested food expelled by the stomach into the duodenum.Also known as chymus, it is the liquid substance found in the stomach before passing through the pyloric valve and entering the duodenum... |
| Pathogenesis | Larva – pneumonitis, Loeffler’s Syndrome; Adult – Obstruction, Liver abscess, Appendicitis Appendicitis Appendicitis is a condition characterized by inflammation of the appendix. It is classified as a medical emergency and many cases require removal of the inflamed appendix, either by laparotomy or laparoscopy. Untreated, mortality is high, mainly because of the risk of rupture leading to... . With Blood-Lung Phase along with Hookworms and Strongyloides stercoralis. |
| Laboratory diagnosis | Concentration methods and Direct Fecal Smear: Kato-Katz |
| Treatment | Albendazole Albendazole Albendazole, marketed as Albenza, Eskazole, Zentel and Andazol, is a member of the benzimidazole compounds used as a drug indicated for the treatment of a variety of worm infestations. Although this use is widespread in the United States, the U.S. Food and Drug Administration has not approved... , Mebendazole Mebendazole Mebendazole or MBZ is a benzimidazole drug developed by Janssen Pharmaceutica and marketed as Vermox, Ovex, Antiox, and Pripsen... , or Pyrantel pamoate Pyrantel pamoate Pyrantel pamoate or Pyrantel Embonate , is used as a deworming agent in the treatment of hookworms and roundworms in domesticated animals such as horses, cattle, sheep, pigs, cats, dogs, and many other species. It is a combination of pyrantel and pamoic acid... |
| Diagnostic Feature – Adult | Female – prominent genital girdle |
| Diagnostic Feature – Egg | Coarse mammilated albuminous coating |
External links
- Video of removal of Ascari lumbricoides with an endoscope
- Images (warning, very graphic): http://www.sp01.com/micro/worms/imagepages/image1.htm, http://www.personal.psu.edu/users/n/c/ncj111/Human%20Impact.htm
- CDCCenters for Disease Control and PreventionThe Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...
DPDx Parasitology Diagnostic Web Site
- Ascariasis: Radiology and color pathology pictures from MedPix
- Discussion of Ascaris on the "This week in Parasitism" Podcast