Tell me more about pertussis.
The disease pertussis (also known as whooping cough from the deep intake of breath following a spasm of coughing) is caused by the bacterium Bordetella pertussis. The disease is characterized by paroxysmal coughing, where the patient can find him/herself unable to breathe. These coughing spells are followed by an inspiratory whoop and vomiting. Pertussis is extremely contagious and can infect nine of ten (90%) non-immune contacts. Pertussis is a major source of child mortality around the world, and still causes death in the US. It is preventable by the DTaP vaccine (Diphtheria-Tetanus-acellular Pertussis).
What are the symptoms of pertussis?
Pertussis has three stages that are characterized by different symptoms. Following a 7-10 day incubation period, a person with pertussis disease will move through these stages:
The catarrhal stage is the first stage, which involves the non-specific symptoms of runny nose, sneezing, low-grade fever, and mild cough. This stage lasts 1-2 weeks, and the cough gradually becomes more severe as a person progresses through this stage.
The paroxysmal stage involves numerous, rapid bursts of coughing (called paroxysms), and is when pertussis is first suspected and diagnosed. The bouts of coughing may be so severe that the person will turn blue, and the need for oxygen so extreme that the person will inhale strongly enough to cause an inspiratory whoop. The paroxysms of coughing are most frequent at night, and can occur up to 15 times in a 24 hour time period. The cough gradually increases in frequency and severity for the first week of this stage, remains constant for 2-3 weeks, and then begins a decline.
The convalescent stage involves the gradual cessation of the cough and recovery from pertussis. The cough slowly decreases in frequency and loses the paroxysmal strength. This stage can last from weeks to months.
Adolescents and adults who were vaccinated against pertussis in the past but whose immunity may have waned are likely to have a less severe course of disease.
How is pertussis transmitted?
Pertussis is transmitted either by direct contact with respiratory secretions or by airborne droplets of these secretions. The infected person is most contagious in the catarrhal stage, before a diagnosis of pertussis is usually suspected.
Adolescents and adults are thought to be a reservoir for B. pertussis, and a source of infection for many infants and children who contract the disease.
How is pertussis treated?
Most care for pertussis patients is mainly supportive, providing assistance with breathing and oxygen supply. Antibiotics, if given early in the course of disease, can ease some of the symptoms and alter the course of disease by helping to eliminate the bacteria from the respiratory tract.
Care is also given to prevent some of the complications of pertussis, mainly pneumonia, which occurs in almost one out of five cases of the disease.
How can I prevent pertussis?
A safe, reliable, effective vaccine for pertussis has existed since the 1940s, so the most important thing you can do is to complete the full series of pertussis vaccines. It is administered along with the diphtheria and tetanus vaccines. An adolescent pertussis booster shot has been recommended by the American Council of Immunization Practices in Summer 2005 to prevent teens and older adults from contracting the disease if their immunity begins to decline.
If someone in your household is diagnosed with pertussis, you may be asked to take a prophylactic 14-day course of the antibiotic erythromycin to prevent infection with B. pertussis. A good handwashing routine is also critical.
CDC Info on Pertussis:
More Info on Pertussis: