Metagonimiasis
Encyclopedia
Metagonimiasis is a disease caused by an intestinal trematode, most commonly Metagonimus yokagawai, but sometimes by M. takashii or M. miyatai. The metagonimiasis causing flukes are one of two minute flukes called the heterophyids. Metagonimiasis was described by Katsurasa in 1911-1913 when he first observed eggs of M. yokagawai in feces (date is disputed in various studies). M. takahashii was described later first by Suzuki in 1930 and then M. Miyatai was describe in 1984 by Saito.
Stained Adult Fluke Causing Metagonimiasis
supports M. yokagawai and M. takahashii be placed in the same clade, and phylogenic tree analysis supports their genetic similarity. M. miyatai, however, was found to be more genetically distinct, and the authors concluded it should be nominated as a separate species. An additional study examining karyotype
data on the three disease-causing agents also supported the nomination of M. miyatai as a separate species.
Trematodes are one class of phylum Platyhelminthes from the order Digenia and are generally referred to as flukes. Metagonimiasis is of the family Herterophyidae.
s are diarrhea
and colicky abdominal pain
. Because symptoms are often mild, infections can often be easily overlooked but diagnosis is important. Flukes attach to the wall of the small intestine
, but are often asymptomatic unless in large numbers. Infection can occur from eating a single infected fish source. Peripheral eosinophilia
is associated especially in early phase. When present in large numbers, can cause chronic intermittent diarrhea
, nausea
, and vague abdominal pains. Clinical complaints can also include lethargy and anorexia
. In acute metagonimiasis, clinical manifestations are developed only 5–7 days after infection. Heavy infection has also been associated with epigastric distress, fatigue, and malaise
.
Occasionally, flukes invade the mucosa and eggs deposited in tissue may gain access to circulation. This can then lead to eggs embolizing in the brain
, spinal cord
, or heart
. Granulomas may form around eggs and can cause seizures, neurologic deficits, or cardiac insufficiency.
An interesting case in Japan found Diabetes Mellitus
(DM) to be a sign of chronic infection with intracerebral hemorrhages as the acute sign of aggravation. Two months after administering the appropriate drug, Praziquantel, the ICHs were gone, as was the man's Diabetes Mellitus. This unique case shows the potential of additional symptoms associated with metagonimiasis that are still unknown.
Semisucospira libertine, Scoreana, and Thiara granifera.
Semisulcospira Snail
Infection is acquired through the secondary intermediate host, fish
, that haven’t been thoroughly cooked. Metacercariae encyst under the scales or in the flesh of fish from fresh or brackish water. Sweetfish (Pecoglossus altevelis) is one of the most common fish species infected, but other include the golden carp (Carassius auratus), common carp
(Cyprinus carpio), Zacco temminckii, Protimus steindachneri, Acheilognathus lancedata, and Pseudorashora parva.
Definitive hosts include humans and various fish-eating mammals, primarily dogs, cats, and pigs
. Fish-eating birds may also be infected with metagonimiasis.
, as seen in the many non-human reservoirs for metagonimiasis. The many reservoirs also have negative implications on the efficacy of prevention and eradication efforts of the disease.
and yellow-brown with a more conventional, ovoid egg shape. They are about the same size as those of Heterophers and Clonorchis, usually measuring 26-28 μm length and 15-17μm width. The egg also has a very slight opercular shoulder, marking the line of cleavage
between the shell and operculum
, an “escape hatch” for the mircidium. The Clonorchis has more distinctive tapering and a seated operculum that help distinguish it more readily from Metagonimus species.
is anterior to the testes and the uterus
is filled with eggs. The uterus winds forward to the genital pore and is the largest organ
in the body. The size of the adult fluke does not exceed 2.5 mm length by .75 mm width.
Adult Fluke (from CDC)
. Only after antihelminthic treatment will adult worms be seen in the feces, and then can be used as part of a diagnostic procedure. A 1993 analysis of the efficacy of ELISA
tests to diagnose metagonimiasis implied that simultaneous screening of specific antibodies to several parasite agents are important in serological diagnosis of acute parasitic disease and more research should be done on the efficacy of these methods of diagnosis.
Diagnosis may be difficult because the egg-laying capacity of heterophyids is limited, and therefore sedimentation concentration procedures may be needed to demonstrate eggs in lighter infections. Accurate species identification is also difficult because eggs of most flukes are similar in size and morphology, especially those of Heterophyes heterophyes
, Clonorchis and Opisthorchis
. It is important to ask where the person may have contracted the disease, find out if they have been to en endemic area, and check for signs and symptoms that would lead to metagonimiasis.
is recommended in both adult and pediatric cases with dosages of 75 mg/kg/d in 3 doses for 1 day. Praziquantel is a Praziniozoquinoline derivative that alters the calcium flux through the parasite tectum and causes muscular paralysis and detachment of the fluke. Prizaquantel should be taken with liquids during a meal and as provided commercially as Biltricide. Praziquantel is not approved by the U.S. Food and Drug Administration (FDA) for treatment of metagonimiasis, but is approved for use on other parasitic infections.
Praziquantel has some side effects but they are generally relatively mild and transient and a review of evidence shows it overall a well-tolerated drug. Possible side effects include abdominal pain
, allergy
, diarrhea
, headache
, hepatic dysfunction/hepatitis, nausea
or vomiting
, exacerbation of porphyries, pruritis, rash
, somnolence
, vertigo
, or dizziness
. In fact, in 2002, the World Health Organization
recommended the use of Praziquantel in pregnant and lactating women, though controlled trials are still needed to verify this.
Another possible drug option is Tetrachloroethylene, a chlorinated hydrocarbon, but its use has been superseded by new antihelminthic drugs (like Praziquantel). A 1978 study also looked at the efficacy of several drugs on metagonimiasis infection, including bithionol, niclosamide, nicoflan, and Praziquantel. All drugs showed lower prevalence of eggs in feces, however only Praziquantel showed complete radical cure. Therefore the authors concluded Praziquantel was the most highly effective, was very well-tolerated, and was the most promising drug against metagonimiasis.
, called a miracidium. Development can’t proceed past this stage unless the eggs are ingested by the first intermediary host, snails. After the snail host ingests the eggs, miracidia emerge and penetrate the snail’s intestines. In the snail tissue, mircadia develop into sporocysts, then rediae, and finally emerge from the snail as cercariae. The cercariae then penetrate the skin or go under the scale of a fresh or brackish water fish and encyst as metacercariae in the tissue. The type of fish that serves as secondary host varies based on location. The host then becomes infected by consuming undercooked, raw, or pickled fish containing the infectious metacercariae. The metacercariae then excyst in the small intestine
of the host (human, mammal or bird), and develop into adults. In the small intestine, the adults attach to the walls and develop new eggs.
is unlikely.
Stained Adult Fluke Causing Metagonimiasis
Classification of metagoniasis
Metagonimiasis is most commonly caused by one of the two smallest flukes known to infect man, Metagonimus yokagawai, also called the Japanese fluke. More rarely, metagonimiasis can arise from infection with M. takahashii or M. miyatai. Recent studies analyzing the DNA of the three agents causing metagonimiasis found that DNA sequencingDNA sequencing
DNA sequencing includes several methods and technologies that are used for determining the order of the nucleotide bases—adenine, guanine, cytosine, and thymine—in a molecule of DNA....
supports M. yokagawai and M. takahashii be placed in the same clade, and phylogenic tree analysis supports their genetic similarity. M. miyatai, however, was found to be more genetically distinct, and the authors concluded it should be nominated as a separate species. An additional study examining karyotype
Karyotype
A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. The term is also used for the complete set of chromosomes in a species, or an individual organism.p28...
data on the three disease-causing agents also supported the nomination of M. miyatai as a separate species.
Trematodes are one class of phylum Platyhelminthes from the order Digenia and are generally referred to as flukes. Metagonimiasis is of the family Herterophyidae.
Clinical presentation
The main symptomSymptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...
s are 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 colicky abdominal pain
Abdominal pain
Abdominal pain can be one of the symptoms associated with transient disorders or serious disease. Making a definitive diagnosis of the cause of abdominal pain can be difficult, because many diseases can result in this symptom. Abdominal pain is a common problem...
. Because symptoms are often mild, infections can often be easily overlooked but diagnosis is important. Flukes attach to the wall of the small intestine
Small intestine
The small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large intestine" are often used to...
, but are often asymptomatic unless in large numbers. Infection can occur from eating a single infected fish source. Peripheral 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...
is associated especially in early phase. When present in large numbers, can cause chronic intermittent 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...
, nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
, and vague abdominal pains. Clinical complaints can also include lethargy and anorexia
Anorexia (symptom)
Anorexia is the decreased sensation of appetite...
. In acute metagonimiasis, clinical manifestations are developed only 5–7 days after infection. Heavy infection has also been associated with epigastric distress, fatigue, and malaise
Malaise
Malaise is a feeling of general discomfort or uneasiness, of being "out of sorts", often the first indication of an infection or other disease. Malaise is often defined in medicinal research as a "general feeling of being unwell"...
.
Occasionally, flukes invade the mucosa and eggs deposited in tissue may gain access to circulation. This can then lead to eggs embolizing in the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
, spinal cord
Spinal cord
The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...
, or heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
. Granulomas may form around eggs and can cause seizures, neurologic deficits, or cardiac insufficiency.
An interesting case in Japan found Diabetes Mellitus
Diabetes mellitus
Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
(DM) to be a sign of chronic infection with intracerebral hemorrhages as the acute sign of aggravation. Two months after administering the appropriate drug, Praziquantel, the ICHs were gone, as was the man's Diabetes Mellitus. This unique case shows the potential of additional symptoms associated with metagonimiasis that are still unknown.
Transmission
Transmission requires two intermediate hosts, the first of which is snails, most commonly of speciesSpecies
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...
Semisucospira libertine, Scoreana, and Thiara granifera.
Semisulcospira Snail
Infection is acquired through the secondary intermediate host, fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, that haven’t been thoroughly cooked. Metacercariae encyst under the scales or in the flesh of fish from fresh or brackish water. Sweetfish (Pecoglossus altevelis) is one of the most common fish species infected, but other include the golden carp (Carassius auratus), common carp
Common carp
The Common carp is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia. The wild populations are considered vulnerable to extinction, but the species has also been domesticated and introduced into environments worldwide, and is often considered an invasive...
(Cyprinus carpio), Zacco temminckii, Protimus steindachneri, Acheilognathus lancedata, and Pseudorashora parva.
Definitive hosts include humans and various fish-eating mammals, primarily dogs, cats, and pigs
PIGS
PIGS is a four letter acronym that can stand for:* PIGS , Phosphatidylinositol glycan anchor biosynthesis, class S, a human gene* PIGS , the economies of Portugal, Italy , Greece and Spain...
. Fish-eating birds may also be infected with metagonimiasis.
Reservoirs
Reservoirs include fish-eating mammals such as dogs, cats and pigs as well as fish-eating birds. The presence of heterophyid infection in humans is generally caused by a lack of host specificity by the parasitesParasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
, as seen in the many non-human reservoirs for metagonimiasis. The many reservoirs also have negative implications on the efficacy of prevention and eradication efforts of the disease.
Incubation period
The incubation period is around 14 days and infestation may persist for more than one year.Eggs
The morphology of the eggs is very important for diagnosis, but is difficult as eggs are very small. Eggs have a smooth, hard shell that is transparentTransparency and translucency
In the field of optics, transparency is the physical property of allowing light to pass through a material; translucency only allows light to pass through diffusely. The opposite property is opacity...
and yellow-brown with a more conventional, ovoid egg shape. They are about the same size as those of Heterophers and Clonorchis, usually measuring 26-28 μm length and 15-17μm width. The egg also has a very slight opercular shoulder, marking the line of cleavage
Cleavage
Cleavage may refer to:*Cleavage , partial exposure of the separation between a woman's breasts.**Cleavage enhancement, methods of making a person's breast cleavage look more substantial than it really is....
between the shell and operculum
Operculum
Operculum may refer to:*Operculum , a stiff structure resembling a lid or a small door that opens and closes**Operculum , a lid on the shell of some gastropods**Operculum , a lid on the orifice of some bryozoans...
, an “escape hatch” for the mircidium. The Clonorchis has more distinctive tapering and a seated operculum that help distinguish it more readily from Metagonimus species.
Adult flukes
The body of the adult disease-causing agent of metagonimiasis is often described as leaf-shaped, similar to most trematodes. It is one of the smallest intestinal flukes, and is only slightly larger than Heteropheres. The most prominent feature is that its ventral sucker is deflected to the right of its midline and is closely associated with the opening of the genital pore. The testes are large and diagonal to each other while the smaller ovaryOvary
The ovary is an ovum-producing reproductive organ, often found in pairs as part of the vertebrate female reproductive system. Ovaries in anatomically female individuals are analogous to testes in anatomically male individuals, in that they are both gonads and endocrine glands.-Human anatomy:Ovaries...
is anterior to the testes and the uterus
Uterus
The uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...
is filled with eggs. The uterus winds forward to the genital pore and is the largest organ
Organ (anatomy)
In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...
in the body. The size of the adult fluke does not exceed 2.5 mm length by .75 mm width.
Adult Fluke (from CDC)
Diagnosis
Metagonimiasis is diagnosed by eggs seen in fecesFeces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
. Only after antihelminthic treatment will adult worms be seen in the feces, and then can be used as part of a diagnostic procedure. A 1993 analysis of the efficacy of ELISA
ELISA
Enzyme-linked immunosorbent assay , is a popular format of a "wet-lab" type analytic biochemistry assay that uses one sub-type of heterogeneous, solid-phase enzyme immunoassay to detect the presence of a substance in a liquid sample."Wet lab" analytic biochemistry assays involves detection of an...
tests to diagnose metagonimiasis implied that simultaneous screening of specific antibodies to several parasite agents are important in serological diagnosis of acute parasitic disease and more research should be done on the efficacy of these methods of diagnosis.
Diagnosis may be difficult because the egg-laying capacity of heterophyids is limited, and therefore sedimentation concentration procedures may be needed to demonstrate eggs in lighter infections. Accurate species identification is also difficult because eggs of most flukes are similar in size and morphology, especially those of Heterophyes heterophyes
Heterophyes heterophyes
Heterophyes heterophyes is a human parasite.-Geography:Common in north Africa, Asia Minor, Korea, China, Japan, Taiwan, and the Philippines.-Morphology:...
, Clonorchis and Opisthorchis
Opisthorchis
Opisthorchis is a genus of flukes in the family Opisthorchiidae.-Species:Species in the genus Opisthorchis include:* Opisthorchis felineus * Opisthorchis gomtii Mehra, 1941* Opisthorchis parasiluri Long & Lee...
. It is important to ask where the person may have contracted the disease, find out if they have been to en endemic area, and check for signs and symptoms that would lead to metagonimiasis.
Treatment
PraziquantelPraziquantel
Praziquantel is an anthelmintic effective against flatworms. Praziquantel is not licensed for use in humans in the UK; it is, however, available as a veterinary anthelmintic, and is available for use in humans on a named-patient basis....
is recommended in both adult and pediatric cases with dosages of 75 mg/kg/d in 3 doses for 1 day. Praziquantel is a Praziniozoquinoline derivative that alters the calcium flux through the parasite tectum and causes muscular paralysis and detachment of the fluke. Prizaquantel should be taken with liquids during a meal and as provided commercially as Biltricide. Praziquantel is not approved by the U.S. Food and Drug Administration (FDA) for treatment of metagonimiasis, but is approved for use on other parasitic infections.
Praziquantel has some side effects but they are generally relatively mild and transient and a review of evidence shows it overall a well-tolerated drug. Possible side effects include abdominal pain
Abdominal pain
Abdominal pain can be one of the symptoms associated with transient disorders or serious disease. Making a definitive diagnosis of the cause of abdominal pain can be difficult, because many diseases can result in this symptom. Abdominal pain is a common problem...
, allergy
Allergy
An 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...
, 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...
, headache
Headache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
, hepatic dysfunction/hepatitis, nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
or vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
, exacerbation of porphyries, pruritis, rash
Rash
A rash is a change of the skin which affects its color, appearance or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracked or blistered, swell and may be painful. The causes, and...
, somnolence
Somnolence
Somnolence is a state of near-sleep, a strong desire for sleep, or sleeping for unusually long periods . It has two distinct meanings, referring both to the usual state preceding falling asleep, and the chronic condition referring to being in that state independent of a circadian rhythm...
, vertigo
Vertigo (medical)
Vertigo is a type of dizziness, where there is a feeling of motion when one is stationary. The symptoms are due to a dysfunction of the vestibular system in the inner ear...
, or dizziness
Dizziness
Dizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....
. In fact, in 2002, the World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
recommended the use of Praziquantel in pregnant and lactating women, though controlled trials are still needed to verify this.
Another possible drug option is Tetrachloroethylene, a chlorinated hydrocarbon, but its use has been superseded by new antihelminthic drugs (like Praziquantel). A 1978 study also looked at the efficacy of several drugs on metagonimiasis infection, including bithionol, niclosamide, nicoflan, and Praziquantel. All drugs showed lower prevalence of eggs in feces, however only Praziquantel showed complete radical cure. Therefore the authors concluded Praziquantel was the most highly effective, was very well-tolerated, and was the most promising drug against metagonimiasis.
Life cycle
Here, the life cycle of M. yokagawai will be examined, however, it should be noted M. takahashii and M. miyatai follow similar life cycle pattern. All three species are hermaphroditic and capable of self-fertilization. Embryonated eggs are passed into an aquatic environment (fresh or brackish water) each containing a fully developed larvaLarva
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...
, called a miracidium. Development can’t proceed past this stage unless the eggs are ingested by the first intermediary host, snails. After the snail host ingests the eggs, miracidia emerge and penetrate the snail’s intestines. In the snail tissue, mircadia develop into sporocysts, then rediae, and finally emerge from the snail as cercariae. The cercariae then penetrate the skin or go under the scale of a fresh or brackish water fish and encyst as metacercariae in the tissue. The type of fish that serves as secondary host varies based on location. The host then becomes infected by consuming undercooked, raw, or pickled fish containing the infectious metacercariae. The metacercariae then excyst in the small intestine
Small intestine
The small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large intestine" are often used to...
of the host (human, mammal or bird), and develop into adults. In the small intestine, the adults attach to the walls and develop new eggs.
Worldwide distribution
Metagonimiasis infections are endemic or potentially endemic in 19 countries including Japan, Korea, China, Taiwan, the Balkans, Spain, Indonesia, the Philippines and Russia. Human infections outside endemic areas may result from ingesting pickled fish or sushi made from fish imported from endemic areas.Korea
Food-borne trematodes are currently the most important parasitic infections in Korea and approximately 240,000 Koreans are believe to be currently infected. Of the 240,000 estimated to be infected, 120,000 are caused by M. yokagawai, 20,000 by M. takahashii, and 100,000 by M. miyatai. The national rate of infections among randomly selected people was 1.2% in 1981, 1.0% in 1986, and down to 0.5% in 2004. M. yokagawai infections are found mostly around the large and small streams where sweetfish live and have been identified as endemic foci. M. miyatai and M. takahashii are prevalent along the upper reaches of the big rivers where minnows and carps are caught for eating raw.Japan
Metagonimiasis is also common in Japan, with 10-15% prevalence rates in populations bordering major rivers and 150,000 estimated infected. Food-borne trematodes are most common in rural areas where traditional food habits are more preserved and raw freshwater fishes are incorporated into the diet. Interestingly, both clonorchiasis and metagonimiasis have become infections of higher social classes in Hong Kong and Japan, owing to their frequent consumption of raw fish.India
There have also recently been two reported cases in India, a location in which occurrence of infection is almost unknown. The second case, in 2005, was in a 6-year-old female patient presenting with loose watery stools for four days (however more details were not obtained as the patient was both deaf and dumb since birth). Upon examination, M. yokagawai eggs were found in stool, but the patient left and further analysis and treatment could not be completed.Prevention efforts and implications for public health
Several public health prevention strategies could help lower the incidence of metagonimiasis. One is to control the intermediate host (snails). This can be done through use of molluscidals. Another is to use education to ensure all people, especially in endemic areas, fully cook all fish. This could potentially be problematic and not as effective as hoped as many of the people affected by metagonimiasis eat raw or pickled fish as part of a traditional, long-seated dietary practice. Additionally, implementing more sanitary water conditions would reduce the continual reintroduction of eggs to water sources, thus restarting the lifecycle. Complete control of metagonimiasis presents several potential problems because it does have several reservoir hosts, thus eradicationPest control
Pest control refers to the regulation or management of a species defined as a pest, usually because it is perceived to be detrimental to a person's health, the ecology or the economy.-History:...
is unlikely.