Jabalpur
There are only three trematode infections of our domestic animals which have attracted greatest attention of the scientists and a lot has been worked out and written on these subjects. However, it is also true that these fluke infections are mainly problem of African and Asian countries. Why it is so ? , As every one will appreciate there is a great climatic difference between these continents and mostly European continent is not conducive for development of these fluke infections in the snails. Other reason of this difference, beside climatic, is husbandry practices in these continents.. While animal husbandry is confined to large agriculture farms in European and American countries ,it is mostly dependent on agriculture reseduces in African and Asian countries and considered a poor man's way of extra earning. Here, grazing of the animals is a big phenomenon in maintaining the domestic animals; these animals are allowed to let free in marshy lands, barren areas for grazing . They fulfill their water requirements from local sources which are either in the form of lake, ponds, tanks, rivers , rivulets or even low laying areas filled with rainy water. And these are the great source of trematode infections in our domestic animals.
There are only three trematode infections of our domestic animals which have attracted greatest attention of the scientists and a lot has been worked out and written on these subjects. However, it is also true that these fluke infections are mainly problem of African and Asian countries. Why it is so ? , As every one will appreciate there is a great climatic difference between these continents and mostly European continent is not conducive for development of these fluke infections in the snails. Other reason of this difference, beside climatic, is husbandry practices in these continents.. While animal husbandry is confined to large agriculture farms in European and American countries ,it is mostly dependent on agriculture reseduces in African and Asian countries and considered a poor man's way of extra earning. Here, grazing of the animals is a big phenomenon in maintaining the domestic animals; these animals are allowed to let free in marshy lands, barren areas for grazing . They fulfill their water requirements from local sources which are either in the form of lake, ponds, tanks, rivers , rivulets or even low laying areas filled with rainy water. And these are the great source of trematode infections in our domestic animals.
In true sense , history of parasitic diseases is not very old and it is only in late nineteenth century where malaria disease was suspected to be caused by a protozoan parasite . It is not surprising that the old literature on fluke infections, contain great emphasis on fascioliasis , considering it as main problem of our animals with little attention on amphistomes and schistosomes. This is so in any important veterinary parasitology book including that of Soulsby or old monneign book. It is not very difficult to speculate over this; as we are aware Fasciola hepatica was discovered long back because of ease of its finding in our domestic animals hence this was the fluke first considered causing much harm to the animal industry . Also other reason for this emphasis was discovery of Lymnea truncatula, as intermediate host for Fasciola hepatica in Australia- a country with emphasis on sheep hasbandry ; therefore, the scientists claimed Fasciola hepatica as an important pathogen for sheep health. Moreover, this snail was amphibious in nature thus giving possibility of its survival on land as well as in water. However subsequent research found that is is mainly F.gigantica in Asian countries where an obligatory aquatic snail is intermediate host . Again this snail (lymnaea aurricularia or L.accuminata ) is mainly present in perineal water source . This is in contrast to the intermeidate hosts for amphistomes and schistosomes which are present not only in perineal water sources but also temporary water sources. The other reason is increase in number of species of the flukes and snails proportionately in these cases.
Therefore , we have advocated that along with fascioliasis , two other fluke infections are also problems in India or other Asian and African countries.
Till now , it is a simple story but further work becomes complicated since little attention has been paid on mysteries of amphistomiasis and schistosomiasis. We have written in details on schistosomiasis in a book form that has been published by Springer India in 2012.
Therefore, this write up desires our attention on amphistomiasis where following points are to be considered
Presently, there are three important publications on amphistomes from India
a. A review by BSW Chauhan on amphistomes published in ZSI in 1966 or so
b. Dr SC Dutt Monograph on Paramphistomes and Paramphistomiasis in domestic runinants- published by PAU in 1980
c.Dr NK Gupta ,1993 book on Amphistomes ;systematics and biology- published by Oxford university, New Delhi
If you vet any of these publications , you will observe they are written from a Biologist's view point and many questions and literature which is important to deal the disease has been left as such.
In recent years there are some chapters on aphistomes but again dealing mainly systematics while our view point is dealing the subject from a Veterinary point of view ,
Therefore, this write up desires our attention on amphistomiasis where following points are to be considered
Presently, there are three important publications on amphistomes from India
a. A review by BSW Chauhan on amphistomes published in ZSI in 1966 or so
b. Dr SC Dutt Monograph on Paramphistomes and Paramphistomiasis in domestic runinants- published by PAU in 1980
c.Dr NK Gupta ,1993 book on Amphistomes ;systematics and biology- published by Oxford university, New Delhi
If you vet any of these publications , you will observe they are written from a Biologist's view point and many questions and literature which is important to deal the disease has been left as such.
In recent years there are some chapters on aphistomes but again dealing mainly systematics while our view point is dealing the subject from a Veterinary point of view ,
1. Its very simple to see amphistomes in slaughter houses or while conducting postmortem of a animal. This is because opening of stomach or rumen, reticulum, abomasum of any animal ,witnesses presence of amphistomes in these animals.
2.Those who are not well versed with Parasitology, claim these adult amphistomes for death of the animal
3 But for a Parasitologist it is always difficult to ascribe these adult amphistoomes for any pathology of the animal though there is no doubt that these flukes suck nutrients for their host for survival and reciprocation. All the books of parasitology tell there is no harm or no much harm due to presence of adult flukes in the stomach and it is difficult to refute this opinion.
4. There are more than 20 species of amphistomes prevalent in India but only four have been incriminated for causing pathogenesis ( though persons like Dr SC Dutt have identified about 40 amphistome species and most of them have been synchronized ). But the main question remains why all amphistome species are not considered pathogenic ? Is it due to their low number in nature or little power of infecting animals ? or no production of any toxic material during its life cycle ?
5. Another problem is that amphistomiasis is considered a problem of young animals and intake of large number of metacercariae simultaneously else smaller doses of metacercariae may not cause any harm to the host. The main reason ascribed for pathology is lodging of a large number of immature amphistomes in duodenum at a time thereby causing sloughing and blockage
6. Do we have technology to identify cercariae of each amphistome species and to calculate which amphistome species is more prevalent in particular area. Is there any relation between prevalence and pathology of the infection
7.Diagnosis of amphistomiasis is again a complicated issue as detecting amphistome eggs in the faeces is not considered pathogenic hence persons have to demonstrate immature amphistomes in faeces of the animals.
8.As detecting immature amphistomes in faeces is more tedious , scientists have developed a method of antigen detection test in faeces which if positive shows animals being suffering from amphistomiasis.
9. However, arguably eggs in the faeces will also turn the test positive hence will it not affect ssensitivity of the test ?
10. In fact, in countries like India, there are multiple infections that occur in an animal in nature and it is very difficult to ascribe importance of each infection in every host species. Perhaps , there are many factors like species of the animal, age , sex and nutritional status which decide pathogenecity of the infection.
11. Though it is simple to control these coprological fluke infections by preventing them not coming in contact with water hence preventing hatching of the eggs , yet it is easy to say then to practice. The future Gobar Dhan yojna may play a great role in controlling these fluke infections .
Nevertheless, i am planning to write all about amphistomes and amphistomiasis with a perspective of a veterinarian point of view and will appreciate to receive any research paper, project report , etc on my mail < drmcagrawal@gmail.com> Like schistosomiasis, i will not hesitate to incorporate any new modern technique that may help in solving the problem provided it cost effective and simple , ; this may be confirmed by reading the chapter "technologies developed" in the referred book.Needless to say that each and every contribution will be thankfully acknowledged in the book .
10. In fact, in countries like India, there are multiple infections that occur in an animal in nature and it is very difficult to ascribe importance of each infection in every host species. Perhaps , there are many factors like species of the animal, age , sex and nutritional status which decide pathogenecity of the infection.
11. Though it is simple to control these coprological fluke infections by preventing them not coming in contact with water hence preventing hatching of the eggs , yet it is easy to say then to practice. The future Gobar Dhan yojna may play a great role in controlling these fluke infections .
Nevertheless, i am planning to write all about amphistomes and amphistomiasis with a perspective of a veterinarian point of view and will appreciate to receive any research paper, project report , etc on my mail < drmcagrawal@gmail.com> Like schistosomiasis, i will not hesitate to incorporate any new modern technique that may help in solving the problem provided it cost effective and simple , ; this may be confirmed by reading the chapter "technologies developed" in the referred book.Needless to say that each and every contribution will be thankfully acknowledged in the book .
