Visceral leishmaniasis in a six-year-old patient – unexpected diagnosis: case study - Sierżęga-Staykov, Katarzyna; Węcławek-Tompol, Jadwiga; Kawecka, Ewa; Pela, Halina; Kazanowska, Bernarda (Pediatria Polska - Polish Journal of Paediatrics, 2019)