Test sample TS: once the availability of users to participate had been corroborated, previously-trained undergraduate students made a visit to familiarise residents with how the samples would be collected and delivered; a plastic bag was thus given to them.
Muestra de prueba MP: una vez corroborada la disponibilidad de los usuarios a participar, estudiantes universitarios previamente capacitados realizaron una visita para familiarizar a los residentes con la forma de presentación y entrega de las muestras, para lo cual se entregó una bolsa plástica.