In this photograph taken on January 24, 2017, a Sri Lankan health worker sprays a neighbourhood with a fog used to ward off mosquitos in Biyagama on the outskirts of Colombo. Mosquito-related dengue cases have risen sharply in and around the capital despite dry weather conditions, according to local officials, who have stepped up efforts to fog residential areas to tackle mosquito breeding areas. (Photo by Ishara S. Kodikara/AFP Photo)
