Whooping Cough (Pertussis) - Exams and Tests

Exams and Tests

A health professional considers the following when making a preliminary diagnosis of whooping cough (pertussis):

• Symptoms. A health professional may suspect whooping cough when a person has recently had cold symptoms and a dry, hacking cough that progresses to bursts of uncontrollable, often violent coughing that may make it temporarily impossible to breathe. The characteristic whooping noise sometimes occurs when trying to inhale quickly through airways narrowed by inflammation. Babies may have flushed cheeks, a pale or bluish complexion from lack of oxygen, and bulging or watery eyes. A baby may also stick out his or her tongue, push the chest forward, or flail arms and legs in distress. Fever, sore throat, and wheezing are usually absent or very mild with whooping cough; when present, these symptoms can help a health professional distinguish between whooping cough and other conditions with similar symptoms, such as a cold or bronchitis.
• Immunization status. An important consideration when making a preliminary diagnosis of whooping cough (pertussis) is whether a person's immunizations against pertussis are up to date.
  • DTaP. Children start getting their pertussis immunizations at age 2 months. A total of 5 injections are given at different times until age 4 to 6 years. The pertussis vaccine is given along with the vaccines for diphtheria and tetanus in a single injection. For children, age 6 and younger, the vaccine is called DTaP.
  • Tdap. Combination booster vaccines (for pertussis, diphtheria, and tetanus), known as Tdap, are available for people age 7 to 64 . (Until recently, no vaccine was available for pertussis after age 6.) A booster dose of Tdap is recommended for adolescents between 11 and 12.¹ Teenagers who have not had a booster shot should get one between ages 13 and 18.¹ For routine prevention, adults 19 to 64 years of age should have one dose of this booster shot instead of Td (tetanus and diphtheria) vaccine. People who get booster shots for whooping cough get continued protection, which helps prevent the spread of the disease. This is especially important for protecting babies younger than 2 months of age and others who are at high risk for becoming infected and developing complications from the disease.
• Community outbreaks. Whooping cough may be suspected when other cases of whooping cough have recently been reported within the local community.

A diagnosis of whooping cough can be confirmed through lab testing of mucus collected from the nasopharynx region, which is where nasal passages meet the back of the throat. Mucus for culture may be obtained by passing a swab or suction tube deep into the back of the nose. But because the results take 10 to 14 days to obtain, treatment will usually start right away if your health professional strongly suspects whooping cough as a cause of symptoms.

Other tests may also be done to rule out other problems, to monitor the person's condition, or determine whether complications have developed.

• A complete blood count or other blood tests may be done to help rule out other diseases.
• Chest X-rays may occasionally be done, especially in infants. Although X-rays often appear normal in whooping cough, they may be needed to rule out other possible causes of symptoms or to determine whether complications, such as pneumonia, have developed.
• A pulse oximeter may be used to check the blood oxygen levels, which helps a health professional monitor lung function and guide treatment options.