Whooping cough (pertussis) is a highly contagious bacterial
infection (Bordetella pertussis or B. parapertussis bacteria) of
the upper respiratory system, specifically the area where the
nasal passages meet the back of the throat (nasopharynx). The
infection causes irritated airways and severe coughing spells
that often lead to a characteristically loud whooping or crowing
sound as air is Symptoms can occur in three distinct stages that
altogether may last 6 to 10 weeks or longer. The first stage is
symptoms that resemble a cold, including sneezing, runny nose,
and mild coughing. The second stage is a dry, hacking cough that
changes to bursts of uncontrollable, often violent coughing. The
third stage is a cough that sounds worse. Severe coughing spells
may cause vomiting, exhaustion, and a blue tint to the skin and
nail beds. Although whooping cough can occur at any age, it is
of greatest concern in children younger than 4 months and adults
age 60 or older, because their risk of complications is higher
than t