Determination of true patient origin through motorcycle mapping: design and implementation of a community-defined geographic infrastructure surveillance tool in rural Sierra Leone.

Background: Village-level geographic infrastructure data are often insufficient in low-resource settings, despite accurate patient origin determination being essential for surveillance and outbreak management. We detail a novel and seemingly reliable method for the determination of true patient origin with proof of concept in rural Sierra Leone.

Methods: Potential villages (n=2263), identified within a 7800 km2 hospital catchment area from satellite imagery, were accessed by motorcycle and surveyed in person, capturing village name and community-defined section/chiefdom/district.

A regulatory code for neurogenic gene expression in the Drosophila embryo.

Bioinformatics methods have identified enhancers that mediate restricted expression in the Drosophila embryo. However, only a small fraction of the predicted enhancers actually work when tested in vivo. In the present study, co-regulated neurogenic enhancers that are activated by intermediate levels of the Dorsal regulatory gradient are shown to contain several shared sequence motifs.