Sample collection technique is critical in RSV testing (respiratory syncytial virus testing). The best and most frequently used sample is a nasal aspirate or wash. A syringe is used to push a small amount of sterile saline into the nose, then gentle suction is applied (for the aspirate) or the resulting fluid is collected into a cup (for a wash).
Sometimes, a nasopharyngeal (NP) swab is used, although it is not preferred because the amount of virus obtained on a swab is usually low. The NP swab is collected by having a person tip his or her head back, then a Dacron swab (like a long Q-tip) is gently inserted into one of the nostrils until resistance is met (about 1 to 2 inches in), then rotated several times and withdrawn. This is not painful, but it may tickle a bit and cause the person’s eyes to tear.