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.