Abstract:
Fleas associated with different rodent species are considered as the major vectors of bubonic
plague, which is still rampant in different parts of the world. The objective of this study was to investigate
the contribution of land use to rodent flea load distribution at fine scale in the plague endemic area of
north-eastern Tanzania. Data was collected in three case areas namely, Shume, Lukozi and Mwangoi,
differing in plague incidence levels. Data collection was carried out during both wet and dry seasons of
2012. Analysis of Variance and Boosted Regression Tree (BRT) statistical methods were used to clarify the
relationships between fleas and specific land use characteristics. There was a significant variation (P ≤ 0.05)
of flea indices in different land use types. Fallow and natural forest had higher flea indices whereas
plantation forest mono-crop and mixed annual crops had the lowest flea indices among the aggregated
land use types. The influence of individual land use types on flea indices was variable with fallow having a
positive effect and land tillage showing a negative effect. The results also demonstrated a seasonal effect,
part of which can be attributed to different land use practices such as application of pesticides, or the
presence of grass strips around fields. These findings suggest that land use factors have a major influence
on rodent flea abundance which can be taken as a proxy for plague infection risk. The results further point
to the need for a comprehensive package that includes land tillage and crop type considerations on one
hand and the associated human activities on the other, in planning and implementation of plague control
interventions.
