The prevalence of trypanosome infections among trade cattle in subhumid and humid zones of Nigeria
The prevaleace or trypanosome infections among trade cattle in the sub-humid and humid zones or Nigeria was investigated during a twelve-month period. The infections were prevalent throughout the year and a mean infection rate of 11.04% was recorded in both zones, among 1,775 selected cattle. In the more northern area of subhumid zone (Kaduna), mean prevalence was 12.16% in 989 cattle and monthly figures ranged from 2.10% to 19.62%. Trypanosoma vivax and T. congolense contributed almost equally to the infections being responsible for 36.6% and 35.0%, respectively of all positive cases. The importance of T. vivax, however. increased in Gboko (in the humid zone) where it was responsible for 50% of the parasitaemia encountered. Monthly prevalence in Gboko averaged 9.46% and ranged between 4.17% and 16.88%. Peak infections were common at the beginning of the dry season. The difference in PCV between infected and non-infected cattle was significant (P < 0.05) only in Kaduna where higher prevalence was also associated with increased differences in mean monthly PCV. T. brucei subspecies isolated from Gboko did not exhibit potentials for human infectivity: they were all T. brucei brucei, an animal pathogen.
Key Words: Trypanosome; Trade cattle, Humid, sub-humid