Haemorrhagic Trypanosoma vivax Outbreak in Cattle in Mbale and Tororo Districts in Eastern Uganda

Abstract

Surveys were carried out between March and May, 1997 to rule out acute trypanosomosis, following reports from Farmers and field Veterinarians in Mbale and Tororo districts of an outbreak of strange disease causing considerable deaths of cattle, manifesting with anaemia, bleeding through the skin and ears, before death and, petechial haemorrhages on the tongue and enlarged spleen observed at postmortem. A total 808 cattle were examined by Buffy Coat Technique (BCT) for trypanosomosis and tsetse trapping was done in 5 subcounties in Mbale and Tororo districts. Bovine trypanosomosis was found to be prevalent in 8.7% to 26.5% of the cattle in Mbale district and in 27.8% to 34.8% of the cattle in Tororo district. Trypanosome infections found were largely due to Trypanosoma vivax. Cattle infected with trypanosomosis had a lower mean PCV (23.6±0.64) than those free (mean PCV of 26.9±0.25). Of the cattle examined, 43% had PCV (packed cell volume) below or equal to 24, hence manifested anaemia. According to the findings, clinical signs and high mortality, the outbreak was sue to haemorrhagic T. vivax. This is the first time an outbreak of haemorrhagic T. vivax is reported in Uganda. Tsetse flies caught were predominantly of the Glossina fuscipes fuscipes species (F/T/D/: 0.7-3.0) but few were of G. pallidipes (F/T/D/: 0.1). Immediate implementation of integrated control programme involving application of pour-on, chemotherapy and deployment of insecticide impregnated traps was recommended.