Proactive Pertussis Prevention

By Tracy Denninger

Geriatricians and members of the geriatrics care team should encourage older adults to be vaccinated against pertussis, which can lead to serious complications.

Generally considered a condition manifest largely in the pediatric population, pertussis appears to be affecting a significant number of older adults as well. In fact, a recent report by GlaxoSmithKline researchers indicates that the incidence of pertussis among US adults aged 50 and older may be underrecognized and underreported.

According to the researchers, who examined 48 million cases of cough-related illnesses in the United States between 2006 and 2010, the estimated number of pertussis cases was approximately 520,000 among adults aged 50 to 64 (vs. 8,764 medically attended cases) and approximately 480,000 cases among adults aged 65 and older (vs. 6,359 medically attended cases).

These figures indicate an average incidence rate of 202 pertussis cases per 100,000 US adults aged 50 to 64 and 257 cases per 100,000 among those aged 65 and older. The Centers for Disease Control and Prevention says 48,277 total pertussis cases were reported in the United States in 2012, the largest number in nearly 60 years.

Statistics such as these should encourage geriatricians and related health care professionals to discuss the importance of pertussis vaccination with their older adult patients.

Not Just in Kids
Symptoms of pertussis, a highly contagious disease caused by exposure to the Bordetella pertussis bacteria, generally appear between five and 21 days following exposure. The symptoms initially appear similar to those of the common cold but progress into a stubborn cough characterized by a whooping sound in young children.

However, “Pertussis presents differently in adults than children,” explains Leonard Friedland, MD, vice president and director of scientific affairs and public health for GSK Vaccines who has worked in the pertussis field for the past 10 years. “Adults don’t typically have the ‘whoop’ but a prolonged coughing illness that practitioners and the patients themselves may consider as a cold, bronchitis, or smoking related, for example, and don’t think about it being pertussis.”

“Most commonly, pertussis presents in adults as a persistent dry cough. Adults may only seek medical attention after several weeks of symptoms because pertussis is also low on their radar,” adds Lora Cox-Vance, MD, geriatric fellowship director for UPMC St Margaret Family Medicine in Pittsburgh.

The consequences of failing to diagnose pertussis in older adults can mean “a prolonged cough-related illness that lasts for two or three months, which can be quite debilitating, often disrupts sleep, and possibly causes fractured ribs. Occasionally, it can develop into pneumonia,” Friedland says.

Additionally, Cox-Vance notes that the coughing may cause older adults to avoid their usual activities and can cause dyspnea for some. The cough also may lead older adults to develop or experience worsening stress incontinence because of the increased pressure of the coughing, which can impact a patient’s quality of life.

“Older adults, especially those with multiple underlying chronic medical illnesses, may be more vulnerable to serious effects from pertussis,” Cox-Vance notes. “These serious complications include exacerbation of underlying medical illnesses—for example, COPD or congestive heart failure—as well as cough-related rib fractures and development of secondary pneumonia. Life-threatening illnesses, including intracranial hemorrhage and carotid artery dissection, have been reported in older adults with pertussis. Death as a result of pertussis in older adults also has been reported.”

Especially for older adults who spend time around young children, baby-sitting grandchildren, for example, the bacteria could spread to a population even more vulnerable to their effects. “Pertussis is very contagious, and it can spread to children, who are even more susceptible and can experience severe complications from it. Young infants under the age of 6 months [who have not received their full course of pertussis vaccinations] are especially vulnerable, and that’s where deaths are most common,” Friedland says.

Prevention
“Pertussis is not an infection that is seasonal, so the best time to be vaccinated is any time during the year,” Friedland says.

Cox-Vance notes that one dose of the Tdap vaccine is recommended for all adults aged 65 and older. This vaccine also protects against tetanus and diphtheria.

She says there currently is no recommendation for adults to receive an additional dose of the pertussis vaccine. “Researchers are actively studying how long the pertussis vaccine protects older adults from the illness, and a recommendation for revaccination may emerge in the future,” she says, noting that patients should receive additional doses of the Td vaccine every 10 years.

Friedland says only about 12% of adults receives the pertussis vaccine, and “that number is probably lower in older adults. There’s a lot of opportunity where health care providers can say, ‘Pertussis is something I really need to think about. What can I do to approach this?’ Then they should think of vaccination as one strategy. The best way to prevent pertussis is to vaccinate against it.”

“The general population needs to be dispelled of the idea that pertussis only causes illness in childhood,” Cox-Vance explains. “Older adult patients should be encouraged to seek evaluation for persistent cough, as persistent cough from any cause can negatively impact quality of life. A cough can be the presenting symptom for many conditions, including viral illness, postnasal drip, acid reflux, acute bronchitis, COPD, and pneumonia. Pertussis also must be included on the list of potential causes of cough.”

“Physicians need to think about their role in helping the public health community address preventable communicable diseases such as pertussis,” Friedland adds. “They need to educate themselves and think of themselves as vaccinators, that it’s not just pediatricians’ job to vaccinate against pertussis. I think this will help them become more comfortable talking about the vaccine with their patients.”

He also recommends physicians consult professional societies that offer resources regarding pertussis and older adults, noting that “physicians should be discussing all preventable diseases with vaccines, especially in the elderly population.”

— Tracy Denninger is the senior production editor for Today’s Geriatric Medicine.