A device for restraining mice and confining tsetse flies during trypanosome infection transmission experiments

Abstract

Chemical (anaesthesia) and manual techniques are commonly used to restrain mice during vector-mediated parasite transmission experiments in the laboratory. Chemical restraint may interfere with natural fly vector–mouse interactions and therefore potentially affect the outcome of transmission experiments. Conversely, manual restraint is labour-intensive and exposes laboratory animals to excessive restraining-related discomfort. We report development of a mouse restraining device (Infectra®-kit) that allows essential transmission studies to be carried out with minimal human manipulation and without the need for anaesthesia. Infectra®-kit can be used as a single unit for restraining one mouse or as eight-assembled units, thus significantly improving efficiency of a single operator in comparison to manual restraint. The kit was validated by comparing feeding success in tsetse flies fed on mice restrained using Infectra®-kit (Group I) to those manually restrained (Group II). The mean ± SE % feeding success was 75.0 ± 8.2% and 82.1 ± 8.2% for tsetse flies in Groups I and II respectively. Statistical analysis using two sample t-test showed no significant difference between the two groups at p ≤ 0.05, indicating that Infectra®-kit as a restraining device was as good as the conventional manual restraint method. The main benefits of using Infectra®-kit for transmission studies therefore include reduction of man-hours and animal restraining-related discomfort. In addition, the risk of accidental injury to laboratory personnel by either mice or tsetse flies is minimized, which is an important consideration when working with zoonotic parasites.