It exists in Senegal because Vietnamese wives of Senegalese colonial soldiers, sent home after France's 1954 defeat in Indochina, settled in Dakar and began selling them at Marché Kermel to get by.
Rice paper is rolled tight around glass noodles and seasoned ground meat or shrimp, then deep-fried until golden and shatteringly crisp. It's sold everywhere from Dakar's beaches to school gates, usually with a sweet-sour dipping sauce, and ranks among the city's most popular grab-and-go snacks.