title: Chemotherapeutic control of bovine trypanosomiasis: the present position and prospects for the future
Creators: name: Guzman, Victor Hugo
Publisher: name: The University of Edinburgh
Year: 1979
Subjects: subject: Annexe MSc Digitisation Project 2022 Block 41

description: The literature on the chemotherapeutic control of bovine trypanosomiasis has been reviewed, in relation to the existing drugs and some of the new drug developments of potential use in veterinary medicine. Emphasis has been given particularly to the chemical control of the disease in cattle due to T. vivax, T. congolense and T. brucei infections. Brief mention is made of aspects of the disease in cattle which are relevant to the main subject under consideration in this dissertation. This section deals with basic information about the disease itself including its geographic distribution and economic importance, trypanosome species involved and their mode of transmission, pathogenic effects and current diagnostic procedures. It is concluded that pathogenesis and diagnosis play an important.role in the chemotherapeutic and chemoprophylactic control of cattle trypanosomiasis. Undoubtedly, some aspects of the pathogenesis of the disease are influencing the efficacy of antitrypanosomal drug action. In view of the known different body distribution of each trypanosome subgenus, comparative studies of the pharmacokinetics of the existing and new trypanocidal drugs are urgently needed. In relation to diagnosis a better identification of the disease condition and pathogenic trypanosomes in the field, could contribute to more effective drug treatment and possibly to the avoidance of drug resistance development. Description of the existing trypanocidal drugs is included with special reference to their historical development, drug characteristics, methods of application and use, costs and benefits, problems of drug resistance and drug use improvement. It is argued that the small number of trypanocides which have been available for the past forty years for the treatment of cattle trypanosomiasis could also have influenced the widespread development of drug resistance. In addition, the successful build up of immunity in already infected animals when using the available drugs could be exploited in the control of the disease in cattle while alternative drugs are being produced. With regard to drug residues, determination of the distribution and levels of drugs in animal products and carcases needs to be carried out on the commonly known and used trypanocidal drugs. With respect to new drug developments, a description is made of the economic implications, new approaches, new leads and prospects for the future. Some outstanding achievements in this complex area of research have particularly concerned, the T. brucei group of trypanosomes, considered, normally of low pathogenicity for cattle. Thus, the justification for continuing this tendency to research on T. brucei in seeking new drugs for animal trypanosomiasis requires reappraisal of the real significance and comparability of the disease in man and the disease in cattle. It might be better to place greater emphasis in drug development work on infections with T. vivax and T. congolense. Finally, it is important to emphasize in this review the reduced availability of some trypanocidal drugs such as Antrycide compounds and Samorin, which are not at present being manufactured. To face this problem a strong collaboration between the pharmaceutical- industry and the international bodies is needed to develop new drugs for the chemotherapeutic control of cattle trypanosomiasis.