Coughing Up the Facts on Pertussis (Whooping Cough)

California is on pace to have its worst outbreak of pertussis, more commonly known as whooping cough, in 50 years. This bacterial respiratory disease is is highly contagious and most dangerous to infants and young children.

In fact, whooping cough was a leading cause of death and serious illness among infants and young children until the pertussis vaccine was introduced in the 1940s. In the 1920s and 1930s, an average of more than 160,000 cases and 5,000 deaths were reported annually.

Now the disease is preventable through vaccination, and most years there are relatively few cases. But, pertussis is cyclical, and every three to five years there's a large spike in cases nationwide. This year California is experiencing an epidemic of whooping cough.

As of mid-June, the state recorded 910 cases - a four-fold increase from the same period last year. So far, five infants, all of them were under 3 months of age, too young to have completed vaccinations, have died from whooping cough this year. According to the California Department of Public Health, the state's last peak was in 2005, logging 3,182 cases and eight deaths. Outbreaks generally peak during the summer months.

What is Pertussis?
Pertussis is a bacterial respiratory disease caused by Bordetella pertussis. It starts out as what seems like a mild cold or flu lasting about two weeks, and is marked by mild coughing and a runny nose. It then steadily progresses into a more severe cough with the telltale "whoop" While the child is taking in a breath. Many adults may endure a bout of pertussis and never realize it, but for young children - particularly infants - the disease can cause complications requiring hospitalization. The cough can become so severe that it's difficult for babies to eat, drink or breathe.

In addition to the worsening cough, children may vomit with the coughing, the cough is dry and harsh, and can be started by nearly any activity including feeding, crying or playing. About four weeks into the infection, the vomiting and whooping cease, though coughing may persist for several weeks and may continue on occasion for up to two months. In some cases, pertussis could lead to pneumonia.

Pertussis Prevention
Immunizations are the only method of preventing pertussis. One possible reason why we are seeing an upswing in the number of cases may be due to parents withholding the pertussive vaccine from their children based upon the unfounded fear that vaccines cause autism (see my prior blog on vaccine safety). The vaccine called DTaP protects against diphtheria, tetanus and pertussis. The best protection for infants is to be sure they get their DTaP vaccine on time. Typically the vaccine is given in five doses, first at two, four and six months old, and then at 15 to 18 months old. Another dose is given between four and six years of age. Children are not protected until they have received at least three doses of the vaccine, which confers about 80-85% immunity.

Protection from childhood vaccination wanes over time, and infants are most likely to catch whooping cough from adult family members who may not even realize they have it. Hundreds of cases of whooping cough go undiagnosed because the symptoms, for those who have some level of immunity, are so similar to the common cold. But immunity begins to wane by five to 10 years after the last childhood pertussis vaccine dose, which means children should get a combined booster vaccination for tetanus, diphtheria and pertussis called Tdap at age 11 or 12.

Adults up to age 64 who never received a Tdap booster should get one, especially women who plan to become pregnant. New mothers who have not received the vaccine should get it before they leave the hospital with their newborn.

The same goes for fathers, siblings, grandparents and anyone else who might be in contact with an infant. The Centers for Disease Control have recommended Tdap since 2005, but coverage rates are not what they should be. Among adolescents, an estimated 40 percent were vaccinated in 2008. Among adults, the numbers are even lower, with fewer than 6 percent receiving the booster, according to the CDC. The Tdap vaccine can replace one of the usual tetanus and diphtheria (Td rather than Tdap) boosters adults typically receive every decade.

Also keep in mind that if one member of the family catches whooping cough, it's so contagious that the rest of the household is likely to get it. Anyone diagnosed during the first few weeks of the cough should take antibiotics such as clarithromycin or azithromycin to reduce symptoms and spread of the disease. If you live with someone taking antibiotics for whooping cough, you should see a doctor about getting on antibiotics yourself - because you probably have it, also.

But, common sense still applies: Wash your hands with soap and water or with an alcohol-based rub, especially after touching your nose, coughing or sneezing. And, just like our mothers and school teachers constantly told us, cover your nose and mouth when coughing or sneezing. Encourage kids to do the same.

When it comes to whooping cough, the key truly is to vaccinate, vaccinate, vaccinate. Protect infants by making sure they get their shots on time. Remember that unlike some vaccines, the effects of the pertussis vaccines are not lifelong, and a booster shot is necessary. The booster can provide 90 percent renewed immunity against whooping cough. If you are an adult with young children, or a caregiver to children, please be sure you've received a booster. The life of a baby you dearly love could depend on it.