Detection of Neisseria gonorrhoeae and Chlamydia trachomatis by PCR in a sample pool (urine, rectum and pharynx) in asymptomatic patients at risk of sexually transmitted infections Sofía Narváez; Natalia Arnalda; Marisa López; Andrea Vergara; Vanessa Guilera; Iván Chivite; David García-Hernández; Ana González-Cordón; Josep Riera-Monroig; Irene Fuertes; Josep Mallolas; José Luis Blanco; Jordi Bosch;