Fasciolopsiasis results from
infectionAn infection is the detrimental colonization of a host organism by a foreign species. In an infection, the infecting organism seeks to utilize the host's resources to multiply, usually at the expense of the host. The infecting organism, or pathogen, interferes with the normal functioning of the...
by the trematode
Fasciolopsis buski (Lankester, 1857) Odhner, 1902, the largest intestinal
flukeThe Trematoda is a class within the phylum Platyhelminthes that contains two groups of parasitic worms, commonly referred to as flukes.-Taxonomy and biodiversity:...
of
humanHumans are bipedal primates belonging to the species Homo sapiens in Hominidae, the great ape family. They are the only surviving member of the genus Homo. Humans have a highly developed brain, capable of abstract reasoning, language, introspection, and problem solving...
s (up to 7.5 cm in length).
This
diseaseA disease or medical condition isan abnormal condition of an organism that impairs bodily functions, associated with specific symptoms and signs...
occurs in
AsiaAsia is the world's largest and most populous continent, located in the eastern and northern hemispheres. It covers 8.6% of the earth's total surface area and with approximately 4 billion people, it hosts 60% of the world's current human population.Asia is traditionally defined as part of the...
and the
IndiaIndia, officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the west, and the Bay of Bengal...
n
subcontinentA subcontinent is a large, relatively self-contained landmass forming a subdivision of a continent. By dictionary entries, the term subcontinent signifies "having a certain geographical or political independence" from the rest of the continent, or "a vast and more or less self-contained subdivision...
, especially in areas where humans raise
pigPigs are a genus of even-toed ungulates within the family Suidae. The name hog most commonly refers to the domestic pig in everyday parlance, but technically encompasses several distinct species, including the wild boar...
s and consume raw aquatic plants.
The parasite infects an amphibic
snailThe word snail is a common name for almost all members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word snail is used in a general sense, it includes sea snails, land snails and freshwater snails. Snails lacking a shell or having only a very small one are...
(
Segmentina nitidella, Segmentina hemisphaerula, Hippeutis schmackerie, GyraulusGyraulus is a genus of small, mostly air-breathing, freshwater snails, aquatic pulmonate gastropod mollusks in the family Planorbidae, the ram's horn snails.The genus Gyraulus is known from the Early Eocene to the recent periods....
, LymnaeaLymnaea is a genus of small to large-sized air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae, the pond snails.-Species:Species within the genus Lymnaea include:...
, Pila, PlanorbisPlanorbis is a genus of freshwater air-breathing snails, aquatic pulmonate gastropod mollusks in the family Planorbidae, the ram's horn snails, or planorbids. All species in this genus have sinistral or left-coiling shells.- Description :...
(Indoplanorbis)) after being released by infected feces; from this intermediate host metacercaria infest on
aquatic plantAquatic plants — also called hydrophytic plants or hydrophytes — are plants that have adapted to living in or on aquatic environments. Because living on or under water surface requires numerous special adaptations, aquatic plants can only grow in water or permanently saturated soil...
s, which are eaten (raw) by pigs and humans.
Fasciolopsiasis results from
infectionAn infection is the detrimental colonization of a host organism by a foreign species. In an infection, the infecting organism seeks to utilize the host's resources to multiply, usually at the expense of the host. The infecting organism, or pathogen, interferes with the normal functioning of the...
by the trematode
Fasciolopsis buski (Lankester, 1857) Odhner, 1902, the largest intestinal
flukeThe Trematoda is a class within the phylum Platyhelminthes that contains two groups of parasitic worms, commonly referred to as flukes.-Taxonomy and biodiversity:...
of
humanHumans are bipedal primates belonging to the species Homo sapiens in Hominidae, the great ape family. They are the only surviving member of the genus Homo. Humans have a highly developed brain, capable of abstract reasoning, language, introspection, and problem solving...
s (up to 7.5 cm in length).
Geographic distribution
This
diseaseA disease or medical condition isan abnormal condition of an organism that impairs bodily functions, associated with specific symptoms and signs...
occurs in
AsiaAsia is the world's largest and most populous continent, located in the eastern and northern hemispheres. It covers 8.6% of the earth's total surface area and with approximately 4 billion people, it hosts 60% of the world's current human population.Asia is traditionally defined as part of the...
and the
IndiaIndia, officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the west, and the Bay of Bengal...
n
subcontinentA subcontinent is a large, relatively self-contained landmass forming a subdivision of a continent. By dictionary entries, the term subcontinent signifies "having a certain geographical or political independence" from the rest of the continent, or "a vast and more or less self-contained subdivision...
, especially in areas where humans raise
pigPigs are a genus of even-toed ungulates within the family Suidae. The name hog most commonly refers to the domestic pig in everyday parlance, but technically encompasses several distinct species, including the wild boar...
s and consume raw aquatic plants.
Infection cycle
The parasite infects an amphibic
snailThe word snail is a common name for almost all members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word snail is used in a general sense, it includes sea snails, land snails and freshwater snails. Snails lacking a shell or having only a very small one are...
(
Segmentina nitidella, Segmentina hemisphaerula, Hippeutis schmackerie, GyraulusGyraulus is a genus of small, mostly air-breathing, freshwater snails, aquatic pulmonate gastropod mollusks in the family Planorbidae, the ram's horn snails.The genus Gyraulus is known from the Early Eocene to the recent periods....
, LymnaeaLymnaea is a genus of small to large-sized air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae, the pond snails.-Species:Species within the genus Lymnaea include:...
, Pila, PlanorbisPlanorbis is a genus of freshwater air-breathing snails, aquatic pulmonate gastropod mollusks in the family Planorbidae, the ram's horn snails, or planorbids. All species in this genus have sinistral or left-coiling shells.- Description :...
(Indoplanorbis)) after being released by infected feces; from this intermediate host metacercaria infest on
aquatic plantAquatic plants — also called hydrophytic plants or hydrophytes — are plants that have adapted to living in or on aquatic environments. Because living on or under water surface requires numerous special adaptations, aquatic plants can only grow in water or permanently saturated soil...
s, which are eaten (raw) by pigs and humans. Also the water is possibly infective when drunk unheated ("
Encysted cercariae exist not only on aquatic plantAquatic plants — also called hydrophytic plants or hydrophytes — are plants that have adapted to living in or on aquatic environments. Because living on or under water surface requires numerous special adaptations, aquatic plants can only grow in water or permanently saturated soil...
s, but also on the surface of the water.".)
Clinical features
Most infections are light and asymptomatic. In heavier infections,
symptomA symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...
s include
diarrheaIn medicine, diarrhea , also spelled diarrhoea , is the condition of having frequent loose or liquid bowel movements. Acute diarrhea is a common cause of death in developing countries and the second most common cause of infant deaths worldwide...
,
abdominal painAbdominal 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...
,
feverFever is a frequent medical sign that describes an increase in internal body temperature to levels above normal...
,
ascitesIn medicine , ascites is an accumulation of fluid in the peritoneal cavity. Although most commonly due to cirrhosis and severe liver disease, its presence can portend other significant medical problems...
,
anasarcaAnasarca, also known as "extreme generalized edema" is a medical condition characterised by widespread swelling of the skin due to effusion of fluid into the extracellular space...
, and intestinal obstruction.
Laboratory diagnosis
Microscopic identification of
eggsIn most birds and reptiles, an egg is the zygote, resulting from fertilization of the ovum. To enable incubation the egg is usually kept within a favourable temperature range as it nourishes and protects the growing embryo. When the embryo is adequately developed it breaks out of the egg in the...
, or more rarely of the adult
flukeFluke may refer to:* A fluke, the pair of horizontal tail fins of whales, dolphins, and porpoises* Flounder, type of flatfish* Trematoda, class of flatworms* Fluke , electronic dance music group* Fluke, 1995 film* Fluke , 1977 novel...
s, in the
stoolA stool can refer to:*A type of chair without back and arm rests** In West Africa, a throne** A bar stool ** A footstool* A flush toilet, in some dialects* Feces:* A living stump capable of producing sprouts or cuttings...
or vomitus is the basis of specific
diagnosisIn medicine, diagnosis is a label given for a medical condition or disease identified by its signs, symptoms, and from the results of various diagnostic procedures...
. The eggs are indistinguishable from those of
Fasciola hepaticaFasciola hepatica, also known as the common liver fluke or sheep liver fluke, is a parasitic flatworm of the class Trematoda, phylum Platyhelminthes that infects liver of various mammals, including humans. The disease caused by the fluke is called fascioliasis . F...
.
Treatment
TriclabendazoleTriclabendazole is a member of the Benzimidazole family of anthelmintics...
is the
drugA pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
of choice for treatment of fasciolopsiasis.
Incidence/prevalence
- "It has been estimated that there may be 10 million people in East Asia infected with this fluke, yet its radiological identification remains unreported."