What is pertussis?

Commonly referred to as whooping cough, pertussis is a very contagious disease that can affect people of all ages. It is caused by a bacterium called Bordetella pertussis that’s found in the mouth, nose and throat of infected people. The bacteria are spread through the air when an infected person coughs and sneezes. Pertussis is so contagious that 8 of 10 non-immune people will be infected when exposed to someone with the disease.

Older children and adults commonly transmit pertussis to infants and young children. In infants, the disease can be particularly severe, even deadly;  more than half of infants less than 1 year who get whooping cough end up requiring hospitalization. While the pertussis vaccine is effective, protection against the disease fades over time. You can also get pertussis more than once.

Historically, whooping cough was a major problem and led to thousands of deaths in the 1930s and 1940s. With the advent of the pertussis vaccine, the rate of death has declined dramatically. Unfortunately, pertussis epidemics continue to occur due to waning immunity after vaccination as well as falling vaccination rates.

Currently, pertussis activity has increased throughout the United States. According to the CDC, there have been more than 11,000 cases of pertussis in the U.S. as of August 2024 compared with a total of 3,021 cases in the entirety of 2023. In Pennsylvania, we have had 1,666 cases so far in 2024 compared with a total of 179 cases in 2023. (Source: CDC, August 17, 2024)

Signs and symptoms

The disease usually takes one to three weeks to develop, then progresses through three stages. The following are the most common symptoms of whooping cough, according to each stage. However, each child may experience symptoms differently. Symptoms may include:

• First stage (often lasts one to two weeks):
  • Mild cough
  • Low grade fever
  • Runny nose
• Second stage (may last for several weeks):
  • Cough gets worse and comes in severe fits
  • Cough is dry and harsh
  • Cough ends with a whoop sound on inspiration
  • Newborns and young infants do not have the strength to develop a “whoop” sound and may have a hard time breathing
  • Child may vomit with the coughing and appear to be strangling on the vomit
  • Cough can be started by many factors, including feeding, crying, or playing
• Third stage (usually begins around the fourth week):
  • Vomiting and the whooping cough cease first
  • The cough usually decreases around the sixth week, but may continue on occasion for the next one to 2 months

The symptoms of whooping cough may resemble other medical conditions. Always consult your child's physician for a diagnosis.

Testing and diagnosis

In addition to a complete medical history and physical examination, diagnosis of whooping cough is often confirmed by testing secretions taken from the nose or throat, and/or blood testing for antibodies.

If your child has had a known exposure to someone with pertussis, please let your doctor know. Testing would be indicated if they have symptoms. If they do not have symptoms, they may be eligible for antibiotics to help prevent them from getting pertussis.

Treatment

Specific treatment for whooping cough will be determined by your child's physician based on:

• Your child's age, overall health, and medical history
• Extent of the condition
• Your child's tolerance for specific medications, procedures, or therapies
• Expectations for the course of the condition

In some cases, your child may be hospitalized for supportive care and monitoring. Sometimes, oxygen and intravenous (IV) fluids are needed until the child begins to recover.

Antibiotic treatment (i.e. azithromycin [Zithromax®] or a related antibiotic) may also be ordered by your child's physician. It is important to follow the schedule for giving medications exactly as your physician prescribed. Family members and other people who have been in close contact with your child may also start on antibiotic therapy, regardless of whether they have received the vaccine or not.

Other treatment may include:

• Keeping your child warm
• Eating small, frequent meals to help prevent vomiting
• Using a clean, cool mist vaporizer to help loosen secretions and soothe the cough.
• Drinking plenty of fluids, including water, juices, and soups, and eating fruits to prevent dehydration (lack of fluids)
• Keeping your home free from irritants that can trigger coughing, such as smoke, dust, and chemical fumes

If your child has been diagnosed with pertussis, call your doctor or nurse practitioner if she:

• Has a temperature above 101-102° F (38.9° C) that is not relieved by Tylenol
• Is vomiting often
• Is not eating or drinking fluids
• Is urinating less often or has dry lips or sunken eyes
• Has frequent coughing that gets worse
• Does not seem to be improving

Get medical attention immediately if your child:

• Gets blue lips or skin during a coughing spell
• Has trouble breathing or has periods when breathing slows or stops
• Is restless or cannot sleep or is acting listless and sleeping too much
• Is not acting normally
• Is 3 months old or younger with a rectal temperature of 101º F or higher

Preventing the spread of pertussis

Preventing the spread of whooping cough is important. The best way to prevent whooping cough is by making sure your family is vaccinated. Children who are not vaccinated against the disease are eight times more likely to become infected than those who are vaccinated. There is a vaccine available for both children and adults against whooping cough. While vaccine immunity is not life long, significant immunity is conferred with each booster dose, so being up to date on vaccines is important. The vaccine is less protective the further out from the last dose you are. 

Vaccines are very effective at preventing pertussis in young infants when given to pregnant mothers with each pregnancy. This is important because young infants typically have the most severe disease and high rates of hospitalizations with pertussis infections.  

Protection from pertussis through vaccination is provided by the DTaP vaccine — which stands for diphtheria, tetanus, and pertussis. This vaccine is usually given to infants at 2, 4, 6, and 15 to 18 months of age, with a booster at 4 to 6 years of age. The acellular pertussis vaccine now recommended produces fewer adverse reactions than the older vaccine.

Because immunity from the childhood pertussis vaccination series declines over time, keeping up to date on booster vaccination (called Tdap) is important in adolescents starting at 11-12 years of age, and adults, particularly to reduce exposure to disease in vulnerable infants. More information on the vaccine is available on the CDC website and from the CHOP Vaccine Education Center.

Other ways you can help prevent the spread of pertussis:

• Always practice good hand washing and cough etiquette.
• Keep your child home from school or daycare. If your child has been diagnosed with whooping cough, he or she cannot return to school/daycare until the prescribed medication course has been completed. Once completed, your child will no longer be infectious or capable of spreading the disease. However, your child’s cough may continue for up to 10 weeks or more.