By Chris Woolston, M.S.
Whooping cough (pertussis) is a disease that should be rare by now. We've had an effective vaccine against whooping cough for decades, but the illness continues to thrive. The year 2012 was the worst for whooping cough in five decades, with more than 48,000 cases reported. By 2015 and beyond, more than 20,000 cases were reported yearly in the United States among people of all ages, and many more cases go unreported.
Whooping cough has been on the rise since the 1980s, health officials report. An unusual whooping cough outbreak in California in 2010, for example, sickened more than 6,000 infants and killed 10, state officials reported. It underscores the need for adults to get a pertussis booster shot -- not only for themselves, but to protect infants who haven't finished their full vaccinations and to whom the illness can be life-threatening.
If I was vaccinated against whooping cough as a child, do I need to get more shots?
Whooping cough is usually a disease of the day-care and playground set. But adults can catch it, too: About 28 percent of reported American cases occur in adults, and the actual numbers may even be higher. In fact, adults are often even more susceptible to whooping cough than young children because the vaccinations most children receive eventually wear off -- sometimes as early as high school. (Adults can get booster shots, but few ever do.)
Among adults, an estimated 20 to 30 percent of all lingering coughs (lasting two or more weeks) turn out to be whooping cough. Not only are adults coming down with the disease, they're also spreading it to others. Children too young to be fully immunized are at highest risk because the five-shot DTaP vaccine series for young children isn't finished until age 4 to 6.
What causes whooping cough?
Whooping cough -- also called pertussisis -- is caused by a highly contagious bacterial infection. The disease-causing bacterium, Bordetella pertussis travels through the air in tiny droplets released when a person coughs or sneezes. If whooping cough germs find a home in the windpipe, the bacteria start producing toxins that irritate the surrounding tissues. The body responds by producing lots of mucus that clogs the windpipe and causes a wracking cough.
If you live with someone who has whooping cough -- and if you haven't been vaccinated (or already had the disease) -- there's an 80 percent chance that you'll also get sick. Even if you've been vaccinated in the past, you can still get the disease, though it may be a milder case. Without treatment, whooping cough remains contagious for about three weeks.
Is whooping cough dangerous?
In general, whooping cough isn't especially dangerous for adults, and most can expect a full recovery without complications. Many cases are probably never even diagnosed. Often, the biggest danger of adult whooping cough is the possibility that it can spread to an infant. While most children usually recover, the disease does carry the risk of severe complications, including pneumonia and brain damage.
What are the symptoms of whooping cough?
The name "whooping cough" comes from the characteristic "whoop" or whistling sound that children make as they gasp for air while coughing. Adults usually don't make this sound, and babies may not either.
At first, whooping cough feels a lot like a common cold, complete with sneezing, runny nose, dry cough, and low fever. After a week or two, symptoms may turn worse, especially the cough. In many adults, the symptoms are similar to bronchitis. In fact, it has been called "the 100-day cough" since it lasts so long.
The coughing tends to come in rapid-fire bursts -- up to 15 coughs in a row -- and may get worse at night. In some cases, the coughing can be violent enough to crack a person's ribs. The coughs are often dry and unproductive, but can sometimes bring up thick phlegm. Some people will even vomit right after a coughing fit. One feature that distinguishes whooping cough from other illnesses is that a person typically feels fine in between coughing spells.
How is whooping cough diagnosed?
Whooping cough can be tricky to diagnose. But if a person has been having fits of violent coughing for two weeks or more, and there's no other known cause, a doctor should suspect whooping cough.
Doctors can run tests to confirm the disease, but don't expect fast results from a culture. Culturing the bacteria -- which involves swabbing the nostrils and sending the sample to a lab -- takes five to 12 days to complete because the bacteria is difficult to grow. Pertussis cultures also have a high rate of false-negatives, meaning they miss a lot of cases, especially late in the course of the disease.
It can be detected much faster through a polymerase chain reaction (PCR) test. A PCR test that looks for telltale DNA of the whooping cough bacteria takes only one or two days to yield results. The Centers for Disease Control and Prevention (CDC) recommends doing both tests at the same time to be certain.
What's the treatment for whooping cough?
Doctors who suspect a case of whooping cough can prescribe an antibiotic such as azithromycin or erythromycin to kill the germ. These are most effective when started early in the infection. The antibiotics won't immediately cure the disease, but they can shorten the length of time you have symptoms. Importantly, you will no longer be contagious after five days of antibiotic treatment.
If you have whooping cough, you can take a few steps to make yourself more comfortable. Namely, drink plenty of liquids and get lots of rest. Warm, moist air can soothe your airways, so consider using a humidifier or taking a lot of warm showers. You should also avoid tobacco smoke or other irritants that can trigger a coughing fit.
How can I prevent whooping cough?
All children should get vaccinated against whooping cough. The CDC recommends a series of five shots of the DTaP vaccine that protects against diptheria, tetanus, and pertussis. Children usually get their first shot at age 2 months, 4 months, 6 months, 15-18 months, and 4-6 years. Older children and teens should also get a booster dose of Tdap for extended protection (for more information, see below).
The CDC recommends that if you are 18 to 64, make sure you are also up to date on your pertussis booster (Tdap). All adults who are in contact with infants or work in healthcare should receive a Tdap vaccine within two years of their last tetanus vaccination, and other adults in the same age range should be offered the vaccine 10 years or more after their last tetanus shot, the agency says.
However, in the event of outbreaks of whooping cough in the community, these adults can be vaccinated even if they got last tetanus shot less than 10 years ago, the agency said.
In addition, in the wake of the pertussis outbreak in California, CDC's Advisory Committee on Immunization Practices, or ACIP, voted to recommend the off-label use of the Tdap vaccine in two specific patient groups. The committee now recommends that children 7 to 9 years old who did not complete the recommended childhood series of shots to protect against diphtheria, tetanus, and pertussis (DTaP) receive a catch-up dose of Tdap; booster shots in some formulations for ages 10 and up are already recommended. It also recommends that adults 65 and older who have close contact with infants receive a dose of Tdap. (If you are in this age group and have not previously received Tdap, you can also receive a dose.)
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