Whooping cough is a disease caused by the bacteria Bordetella pertussis and is transmitted only from human-to-human contact. It has been called the “100-day cough” because of how long the toxin released by the bacteria can affect the body, how long the contagious phase lasts, and how long it takes for the body to recover from the infection. It can affect any human at any age and is transmitted through airborne droplets, but is most dangerous and deadly in children less than one year old.
Whooping cough has three stages; it starts off very similar to a common cold, with a runny nose, low-grade fever, and cough. This is the catarrhal stage in which the person is most contagious. About two weeks after the cough has begun, the paroxysmal stage starts, in which the cough changes and lasts longer, sounding like the classic whooping noise (made by trying to catch one’s breath during the coughing fit) and is usually followed by vomiting or a moment where the patient stops breathing at the end of the coughing fit. A few weeks later, the convalescent phase begins, indicated by a milder cough. This phase may last several more weeks.
In the United States, we have been fortunate to see a decrease in the incidence of B. pertussis since the introduction of DTap and TDap vaccines in the 1940s. However, over the last several years, we are starting to see a rise in the number of cases of whooping cough across the country.
According to the Center for Disease Control and Prevention (CDC), in 2012 there were 48,277 reported cases of pertussis and 20 deaths from pertussis in the United States. Worldwide, there are still about 16 million cases or pertussis and 195,000 deaths from pertussis each year. Most of the deaths were in infants less than 3 months old in the United States. This is because of the vaccination schedule, a newborn’s immature immune system, and weaker, more susceptible respiratory systems in younger children. In Mobile, 18 cases of pertussis were reported in the first half of June alone, with many more cases being reported since.
The DTap vaccine (which has components to promote immunity against Diptheria, Tetanus, and Pertussis) is given to most children at 2 months, 4 months, and 6 months of age. Because of the time it takes to build-up immunity in response to these vaccines, children are not considered to have enough of an immune response to protect them from pertussis until about 6 months old after the first 3 series of the vaccine has been administered. This is why it is so important for adults and older children to continue to be vaccinated against pertussis. The next DTap vaccine in the series is given between 12-18 months of age and again at 4-6 years old. The TDap vaccine is then given at the 11-12 year old check-up, and is recommended every 10 years afterwards. The reason for this is that immunity has been shown to wear off after about 10 years. It is especially important for expectant mothers and those who will be in close contact with infants to have a TDap vaccine within the last 10 years.
If someone is infected with B. pertussis, they need to be treated with an antibiotic, and all close contacts and family members need to be treated as well, regardless of their immunization history or if they are showing symptoms. People are most contagious during the early phases when they may be asymptomatic, or they may never develop severe symptoms, especially the older they are. There are diagnostic tests a physician can perform to determine if a patient has pertussis, and every confirmed case is reported to the CDC. Contact your physician if you or your children are showing any signs of whooping cough and make sure that your vaccinations are up to date.