By Peter S. Waldstein, M.D., F.A.A.P and Julia A. White, M.D., F.A.A.P
You may have heard about the recent epidemic of whooping cough in the news, and like most parents probably have many questions. Pertussis (also know as “whooping cough”) is a respiratory illness that is characterized by paroxysms of cough. Vaccinations greatly decrease the incidence of the disease, although we do see some cyclical peaks in activity. Now, pertussis has made a come back with this year being on track to have the most cases in almost 50 years. Infants and young children are the most severely affected, and it can be fatal especially in young infants. All of the fatalities from pertussis this year in California have been in children under the age of 3 months.
Whooping cough is a bacterial infection caused by the bacterium Bordatella pertussis. It may also be caused by Bordatella parapertussis, but less commonly. It is spread by contact with respiratory secretions or droplets of an infected person, and is most infectious during the initial catarrhal phase of the illness. A normal incubation period for the illness is about 7 to 10 days, but may be shorter or longer. After this, the symptoms start to appear.
Patients with a pertussis infection may present in different ways, particularly depending on age. The classic case of pertussis goes through 3 stages. The initial phase is called the catarrhal stage, which is characterized by symptoms such as runny nose, congestion, mild cough, and possibly low grade fever like any other upper respiratory illness. The second phase, called the paroxysmal phase, is where the typical whooping cough symptoms appear. Patients experience episodes of coughing many times in a row. After several coughs, the patients may then have a “whoop” when breathing back in against a narrowed airway. Children will often turn red in the face from the multiple episodes of coughing, and may have vomiting after coughing. The final phase, called the convalescent phase, consists of a chronic cough which may last for several weeks. The first 2 phases may each last for 1-2 weeks, making the total duration of the illness very long, frequently up to 2 months or more.
Older infants and young children are the most likely to present with the classic presentation. Younger infants will often have the coughing paroxysms but may not have the “whoop.” Older children, adolescents, and adults will often just have severe chronic cough.
The complications of the illness can make it more dangerous. Infants frequently develop apnea, which is a short period of cessation of breathing. They are also susceptible to wearing out from the illness. This can all lead to low oxygen levels, and need for respiratory support with oxygen or even ventilators if severe. Other complications can include pneumonia and neurological consequences.
If you are exposed to a known case of pertussis, you should speak with your child’s pediatrician who will determine what steps need to be taken. Close contacts of an infected patient should be treated with azithromycin regardless of vaccine status. By receiving the antibiotic ahead of any potential symptoms, it greatly reduces the chances of presenting with the disease.
Prevention of pertussis can be achieved through vaccines. The pertussis vaccine that is given now (as a part of the DTaP vaccine – Diphtheria/Tetanus/Acellular Pertussis) is an acellular version, meaning that only purified proteins are in the vaccine and not the whole cell of the killed bacterium. This vastly reduced side effects, and it is considered a very safe vaccine to give. The initial vaccine was a whole-cellular vaccine which brought on more side effects of high fever, persistent crying, local reactions, and occasional seizures; for this reason, it is no longer given.
Children should receive the pertussis vaccine (as part of the DTaP vaccine) at ages 2 months, 4 months, 6 months, and a 4th at 15-18 months. A booster vaccine is then given at age 4 years. After it was found that immunity to pertussis decreased in adolescence and adulthood, pertussis was added to the tetanus booster which is given at age 11, a vaccine known as “Tdap.” In addition to children getting vaccinated, it is recommended that parents and caregivers of infants receive the Tdap vaccine if they have not already. For recommendations regarding this, you should discuss with your OBGYN or internist.
Dr. Waldstein and Dr. White are both board certified pediatricians who practice in Beverly Hills.