3.3.4 Rodent trapping and processing
A total of 120 Sherman traps baited with peanut butter and mixed with
maize flour were used to capture rodents in plague and non-plague foci
villages in farm land, bush land, peridomestic and forest buffer zone
habitats. Selection of trapping sites was made successfully with the
help of the residents and involved observation of rodent’s signs such as
rodent’s pathway, droppings, movements sign or observation of gnawed
seeds, and depending on the information from the residents about
presence of rodents in their surroundings. Information about this study
was clearly provided to the owner of trapping site for requesting
permission before trapping. 35 traps were set at a distance of 10 m
apart in seven transect lines containing five trapping station in all
habitats except in peridomestic areas were 35 Sherman traps were set at
2 to 5 m apart by targeting areas with rodent burrows or other rodent
signs around human houses and livestock shelters. Traps were usually
sets on the field in the evening at 5:00 pm and left overnight for at
least three consecutive days while inspecting the traps for captured
rodents every day during morning and afternoon.
Captured rodents were carefully removed from the trap using animal
handling bag and were anaesthetized using diethyl ether in a bottle
contained cotton wool. Blood sample were collected from anaesthetized
rodents for making blood smear for observation of Yersinia pestiscoccobacilli under light microscope; organ such as lugs and spleen were
collected from the euthanized rodent for confirmation of (pla )
gene of Y.pestis DNA under qPCR (results in another manuscript).
Fleas were collected from a euthanized rodent before dissection by
brushing their body thoroughly over a plastic basin (Makundi et
al ., 2008). Rodents were brushed from the head to the base of the tail
using small shoeshine brush until all fleas stop to fall in a basin.
Animal handling bag and anaesthetizing bottle were checked for presence
of fleas and were all collected with a fine forceps. Collected fleas
were counted, recorded and preserved in a well labeled eppendorf tubes
containing 70% ethanol and stored at room temperature until
morphological identification using dichotomous key in the laboratory.