Article Text

Exposure of cattle immunised against redwater to tick challenge in the field: challenge by a homologous strain of B divergens
  1. SM Taylor,
  2. J Kenny,
  3. RE Purnell and
  4. D Lewis


A field trial was conducted in Northern Ireland to determine whether calves could be protected against babesiosis by the prior inoculation of irradiated blood infected with Babesia divergens; The trial involved 30 yearling calves. Ten were inoculated with infected blood from a donor calf after the blood had been irradiated at 25 kilorads, and 10 with blood irradiated at 30 kilorads. Their reactions to the inoculation were observed daily for a month. They were then released, along with a control group of 10 susceptible calves, into an area heavily infested with B divergens-infected Ixodes ricinus ticks for two months. Between 24 and 41 days after exposure all the control animals contracted babesiosis and six of them reacted severely. None of the immunised animals suffered clinical babesiosis although 14 had detectable low-level infections. The relative severity of the reactions of the groups of calves was reflected in their haematology.

Statistics from

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.