(HealthDay News) -- Whooping cough, also called pertussis, is a bacterial respiratory infection that's often characterized by a "whoop" sound when the person breathes.

There is a vaccine for pertussis, but the infection can still strike very young children who aren't yet immunized. Children age 1 year and younger are most susceptible to pertussis. It's also among this age group that the illness is most dangerous.

If you suspect that your child may have pertussis, call your pediatrician immediately to avoid spreading the infection to others.

Here's a list of ways to recognize pertussis, courtesy of the Nemours Foundation:

• Initial symptoms usually include a runny nose, cough, sneezing, and a mild fever.
• After a week or two, the cough is usually dry, and often turns into violent coughing spells.
• Coughing spells may last a minute or more, and cause your child's face to turn red or purple.
• The child may vomit after excessive coughing.
• "Whooping" sounds when breathing are common.