Table 1.

Instructions for saliva collection.

For parents/guardians with infants and children <3 years old: 1. Collect sample right before the baby is going to feed. 2. If the child is a toddler, provide him/her with a chew toy to prevent the child from biting down on the pipette. 3. Squeeze the bulb of the pipette and insert it into the lower part of the front of the mouth, under the tongue where saliva will pool when a child is sitting upright. Alternatively insert the pipette along the cheeks if the baby is on his/her side. 4. Release the bulb to collect saliva once the pipette is in the mouth. 5. Remove the pipette from mouth and squeeze the bulb again to empty the saliva into the tube. 6. Repeat until roughly 0.5-1 mL of saliva is in the tube.

For parents/guardians with children >3 years old: 1. Place the child's favorite food either in front of them or in their hands. We suggest something they cannot easily start eating (for example, an apple, a baby food pouch, or a banana). Alternatively, instruct child to think of his/her favorite food. This will increase saliva production. 2. Allow child about 30 seconds to pool saliva in the mouth. 3. Place conical tube along lower lip and instruct child to spit gently into the tube. 5. Repeat until roughly 0.5-1 mL of saliva is in the tube.

Suggested instructions for saliva collection are divided by age group (<3 years of age and >3 years of age). These strategies are illustrated visually in Supplementary Video 1.