Schistosoma indicum
Encyclopedia
Schistosoma spindale is a species of digenetic
trematode in the family Schistosomatidae
.
The parasite is widespread in India and other Asian countries.
The most important the first intermediate host
is a freshwater snail
Indoplanorbis exustus
that may be the sole natural intermediate host for Schistosoma nasale (and other two Schistosoma species) on the Indian sub-continent. Other snail has been impolicated in transmission
of Schistosoma indicum as its the first intermediate host and it include Lymnaea luteola
.
Schistosoma indicum was discovered by the British scientist R. E. Montgomery, in 1906, from a horse from Mukteswar, Uttar Pradesh
, India
. This blood-fluke causes hepato-intestinal schistosomiasis
in many domestic animals (sheep, goat, water buffalo, cattle, camel, horse, donkey, dog, but not pigs). It was responsible for an outbreak of pulmonary schistosomiasis, in 1981, in sheep in Rajasthan
, leading considerable mortality.
A variant of Schistosoma indicum, rather than Schistosoma haematobium
, was suggested to be responsible for human schistosomiasis in Gimvi village, Ratnagiri district, India. Terminal-spined Schistosoma indicum-like eggs have been detected in human stools, too. Dr M. C. Agrawal demonstrated cross-immunity against Schistosoma incognitum by immunising the host against Schistosoma indicum.
Digenea
Digenea is a subclass within the Platyhelminthes consisting of parasitic flatworms with a syncytial tegument and, usually, two suckers, one ventral and one oral. Adults are particularly common in the digestive tract, but occur throughout the organ systems of all classes of vertebrates...
trematode in the family Schistosomatidae
Schistosomatidae
Schistosomatidae is a family of digenetic trematodes with complex parasitic life cycles. Immature developmental stages of schistosomes are found in molluscs and adults occur in vertebrates. The best studied group, the blood flukes of the genus Schistosoma, infect and cause disease in humans...
.
The parasite is widespread in India and other Asian countries.
The most important the first intermediate host
Intermediate host
A secondary host or intermediate host is a host that harbors the parasite only for a short transition period, during which some developmental stage is completed. For trypanosomes, the cause of sleeping sickness, humans are the primary host, while the tsetse fly is the secondary host...
is a freshwater snail
Freshwater snail
A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....
Indoplanorbis exustus
Indoplanorbis exustus
Indoplanorbis exustus is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails. The species is the sole member of its genus and is widely distributed across the tropics. It serves as an important intermediate host for...
that may be the sole natural intermediate host for Schistosoma nasale (and other two Schistosoma species) on the Indian sub-continent. Other snail has been impolicated in transmission
Transmission (medicine)
In medicine and biology, transmission is the passing of a communicable disease from an infected host individual or group to a conspecific individual or group, regardless of whether the other individual was previously infected...
of Schistosoma indicum as its the first intermediate host and it include Lymnaea luteola
Lymnaea luteola
Radix luteola is a species of freshwater snail, an aquatic gastropod mollusc in the family Lymnaeidae.Placement of this species in the genus Radix have been confirmed by Correa et al. .There exist two forms:...
.
Schistosoma indicum was discovered by the British scientist R. E. Montgomery, in 1906, from a horse from Mukteswar, Uttar Pradesh
Uttar Pradesh
Uttar Pradesh abbreviation U.P. , is a state located in the northern part of India. With a population of over 200 million people, it is India's most populous state, as well as the world's most populous sub-national entity...
, India
India
India , 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 with over 1.2 billion people, and the most populous democracy in the world...
. This blood-fluke causes hepato-intestinal schistosomiasis
Schistosomiasis
Schistosomiasis is a parasitic disease caused by several species of trematodes , a parasitic worm of the genus Schistosoma. Snails often act as an intermediary agent for the infectious diseases until a new human host is found...
in many domestic animals (sheep, goat, water buffalo, cattle, camel, horse, donkey, dog, but not pigs). It was responsible for an outbreak of pulmonary schistosomiasis, in 1981, in sheep in Rajasthan
Rajasthan
Rājasthān the land of Rajasthanis, , is the largest state of the Republic of India by area. It is located in the northwest of India. It encompasses most of the area of the large, inhospitable Great Indian Desert , which has an edge paralleling the Sutlej-Indus river valley along its border with...
, leading considerable mortality.
A variant of Schistosoma indicum, rather than Schistosoma haematobium
Schistosoma haematobium
Schistosoma haematobium is an important digenetic trematode, and is found in the Middle East, India, Portugal and Africa. It is a major agent of schistosomiasis; more specifically, it is associated with urinary schistosomiasis....
, was suggested to be responsible for human schistosomiasis in Gimvi village, Ratnagiri district, India. Terminal-spined Schistosoma indicum-like eggs have been detected in human stools, too. Dr M. C. Agrawal demonstrated cross-immunity against Schistosoma incognitum by immunising the host against Schistosoma indicum.
Further reading
- Attwood S. W., Fatih F. A., Mondal M. M., Alim M. A., Fadjar S., Rajapakse R. P. & Rollinson D. (2007). "A DNA-sequence based study of the Schistosoma indicum (Trematoda: Digenea) group; population phylogeny, taxonomy and historical biogeography". Parasitology 134: 2009-2020. , doi:10.1017/S0031182007003411.