Whooping cough, also known as pertussis, is a respiratory infection caused by the bacteria  Bordetella pertussis. 

Whooping cough is characterized by severe coughing spells, which sometimes end in a "whooping" sound when the infected person breathes in. 

This disease mainly infects infants who are younger than six months old, because they have not received the adequate immunizations. It also affects children 11 to 18 years old whose immunizations are less effective because they have started to wear off. 

Before a vaccine was available, whooping cough killed between 5,000 and 10,000 people in the United States each year, according to kidshealth.org. The vaccine has greatly reduced the number of deaths from the illness, but in recent years, the incidence of the illness is increasing again. 

Some signs and symptoms of whooping cough include: 

- Runny nose

- Sneezing

- Coughing

- Low-grade fever

After about one or two weeks, the dry, throat-irritating cough often evolves into coughing spells that can last fore more than a minute. During a coughing spell, a child can turn red or purple in the face. At the end of the coughing episode, the child may make the characteristic "whooping" sound or may vomit. 

Pertussis is highly contagious. 

The bacteria spread from person to person through tiny drops of fluid from an infected person's nose or mouth. These may become airborne when the person sneezes, coughs, or laughs. Others then can become infected by inhaling the drops or getting the drops on their hands and then touching their mouths or noses.

Infected people are most contagious during the earliest stages of the illness for up to about 2 weeks after the cough begins. Antibiotics shorten the period of contagiousness to 5 days following the start of antibiotic treatment.

Whooping cough can be prevented with the pertussis vaccine, which is part of the DTaP (diphtheria, tetanus, acellular pertussis) immunization. DTaP immunizations are routinely given in five doses before a child's sixth birthday.