Dr. Murai Éva szerk.: Parasitologia Hungarica 24. (Budapest, 1991)

In India, outbreaks of paramphistomosis are frequently reported from ruminants (Fig. 1). Pande (1935) recorded 30 to 40% mortality amongst cattle in Assam due to immature Paramphistomum spp. Data on outbreaks of amphistomosis have been comprehensively reviewed by Dutt (1980). Panda and Mistra (1980) recorded fatal paramphistomosis among buffalo calvs in Orissa caused by Cotylophoron cotylophorum and Gastrothylax crumenifer. Immature amphistomosis is produced by 28 different species of flukes (Sharma 1987). Adult amphistomes of the rumen (Fig. 2a) cause inflammation of the mucosa with associated mucoid diarrhoea, while liver amphistomes produce haemorrhage, pronounced periductal fibrosis (Fig. 2b) and other hyperplastic changes (Kulasiri and Seneveratne 1956; Arora and Kalka 1971; Jha et al. 1977). On the other hand, during migration in the intestine immature amphistomes cause severe pathological disorders including acute catarrhal and haemorrhagic inflammation associated with anaemia, hypoproteinaemia, and oedema (see review by Horak 1971). Anthelmintic treatment for adult and immature paramphistomosis is rarely practised. The removal of adult infections is probably of little direct benefit to the animal, but may be prophylactic so far as it reduces the reservoir infection for intermediate hosts. Several anthelmintics have proved effective against immature stages in ruminants and occasionally have been used in the field (Boray 1986). However, as yet no treatment produces a consistently effective cure in cattle (Horak 1971). The literature available on various aspects of amphistomosis is mostly confined to cattle, sheep and goats, and there is a scarcity of data concerning buffaloes. Application of a single method for the control has some limitations and has its own problems. For this reason, an integrated approach is being preferred. For the development of an effective control programme it is mandatory to have the basic data about the ecological and epidemiological factors responsible for the prevalance and natural history of the diseases in a particular geographical locality. In the case of amphistomosis, data on prevalance alone are not sufficient, because these parasites complete their life cycle in varied physicochemical environments. The biology and behaviour of the intermediate and definitive hosts constitute an important and integral part of the life cycles of parasites. It is therefor essential that the physiography, hydrogeology, topography, agroclimatic and soil conditions, water logging and irrigation problems as well as the human activity of the surveyed areas be investigated in relation to the biology of intermediate and definitive hosts. A detailed study of the epidemiology and natural history of amphistomosis, including topographical and agroclimatic conditions of the Aligarh region, was undertaken. Various aspects of the epidemiology and physiology of two buffalo amphistomes (G. crumenifer and E. explanatum) as model parasites were investigated. Some of these results have already been published (Dunn et al. 1986; Hanna et al. 1988; Firasat and Nizami 1989; Khan et al. 1990). The present paper is an outcome of studies carried out in this laboratory during the last eight years. It provides guidelines for future research directed towards the development of a time-based control programme.