Division of Virology, Indian Veterinary Research Institute, Mukteswar-263138, Uttaranchal.
Abstracts of the papers presented at the 16th Annual Convention and International Symposium of Indian Virological Society on “Management of Vector-Borne Viruses” at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru-502324, Hyderabad, India, February 7–10, 2006.
PPR is a disease affecting small ruminants in developing countries and accounts for significant losses in terms of both morbidity and mortality and is one of the major health threats to the small ruminant population of sheep and goats. The disease is caused by members of the genus Morbillivirus. These viruses are of major importance both in human and veterinary medicine. In humans measles virus remains one of the most significant causes of death in young children in the less developed parts of the world. Rinderpest virus continues to cause major losses in cattle and buffalo in parts of Africa and Asia. Similarly peste des petits ruminants is currently circulating with devastating effect in sheep and goats across the Asian continent from Arabia through Pakistan, India and as far as Nepal and Bangladesh. Canine distemper, although largely controlled by vaccination in domestic dogs, is responsible for epizootics in wild carnivores and remains a threat to some endangered species. In the past decade two new species of the genus, Morbillivirus have been identified which were responsible for severe epizootic diseases in marine mammals. A morbillivirus of unknown pathogenicity was identified in American cattle by sequence analysis during the course of rinderpest cloning experiments using primary bovine lymphocytes and in 1995 an unusual pulmonary infection in man and horses in Australia was ascribed to a new “equine morbillivirus”. These epizootics illustrate how “new viruses” are constantly emerging and how species jumping has been taking place in this group of viruses. The key question is to understand the receptor fidelity of these viruses with regard to their pathogenesis potential. In this paper the behaviour of virulent and attenuated PPR virus, with regard to their receptor affinity using a fibroepithelial cell (Vero) and a lymphocyte derived cell (B-95a) is evaluated. The focus is on understanding the basis of receptor switch over and its implications in the pathogenesis and host tropism of these viruses.
