Pertussis usually starts with cold or flu-like symptoms such as runny nose, sneezing, fever and a mild cough. These symptoms can last up to two weeks and are followed by increasingly severe coughing spells. Fever, if present, is usually mild. Symptoms appear between six to twenty-one days (average 7-10) after exposure to the pertussis bacteria.
Among older children and adults, the disease usually results in symptoms that can be mistaken for bronchitis and Upper Respiratory Infections - persistent cough, but no whoop. In infants younger than 6 months, apnea (cessation of breathing) is a common manifestation and whoop may be absent.
It is important to remember that while pertussis is most often considered a young child's disease, it can occur at any age. Pertussis should be considered in older children and adults who have a persistent cough lasting more than 7-14 days, that cannot be attributed to another specific illness. Untreated, these older children and adults can act as a reservoir for pertussis disease and infect younger children.
