The adverse reaction seemed most likely to occur in communities hardest hit by eyeworm infestation, it was noticed. Carried by flies Scientists know that Loa Loa is mainly transmitted by a particular type of fly. By pinpointing communities lying close to habitats preferred by that fly, those with the highest chance of infestation could be identified. Then the population could be screened for Loa Loa, and kept under close watch while the river blindness drug was administered. Dr Madeleine Thomson, a consultant and lecturer in tropical medicine, was part of the team which analysed the satellite data.
River blindness is caused when the worm involved burrows up under the skin and reaches the eyes.
It is still one of the world's leading causes of blindness. The worm can also cause severe itching under the skin, and it is hoped that cases can be reduced to only a fraction of previous levels. The research was published in the medical journal The Lancet.