Seasonal Dynamics and Distribution of Ticks in Rwanda: Implications for Tick Control Strategy in Rwanda

The broad objective of this study was to examine the dynamics and seasonal distribution of tick species in Rwanda in three agro-ecological zones namely high altitude (Gishwati), the mid altitude (Huye) and the lower altitude zones (Nyagatare). Ten cows per zone were identified and used for collecting ticks monthly on a period covering the short dry season and long rainy season from December 2002 to June 2003. These animals were not treated and remained on pasture land. The results revealed that much of the variance in tick population is explained by the altitude and rainfall (p<0.05). Ticks were endemic in the mid altitude zone with counts ranging from 239 ticks to 1552 ticks per month and this region accounted for 69% of all collected ticks. Ticks collected in other areas vary from 146 to 271 for the lower altitude zone, and 35 to 275 for the high zone and this represents 18.7% and 12.3% per 100 of all collected ticks. The dominant species is Rhipicephalus appendicaltus (96%). Effective tick control programs need to take into account the altitude and rainfall variations in Rwanda.