Whooping cough makes a comeback
It sounds like something straight out of Dickens, closer to 1804 than 2004 -- a rattling, breath-robbing, rib-cracking cough, symptoms that linger for months, loss of sleep and weight.
The diagnosis -- pertussis, better known as whooping cough. At one time, public-health specialists had figured it was destined for extinction in the United States, just like polio and smallpox. But it's still here, six decades after vaccinations for the bacterial illness became routine -- a testament to the hardiness of infectious diseases.
"The bad news is that this disease is not gone," said Dr. Ken McIntosh, an infectious-disease specialist at Children's Hospital Boston. "I certainly have seen people with it, and they're miserable. And they're making everybody else in their lives miserable, and they're quite contagious. So it's not a nice disease to have."
The Centers for Disease Control and Prevention received reports of 11,647 cases of pertussis last year, compared with 1,707 in 1980 -- when the disease seemed to be dying out.
So, what explains the upsurge? And is it a true increase -- or a reflection of better reporting and testing?
Years ago, when pertussis was pervasive, children were regularly exposed and developed natural immunity.
"When the vaccine was licensed in the late 1940s and early 1950s, we saw a real drop in pertussis," said Dr. Susan Lett, medical director of the immunization program at the state Department of Public Health. "That was because all the adults at that point had had pertussis as kids, and their children were getting vaccinated, and so we saw a steep decrease."
In effect, the bacteria had no easy targets left.
But as the vaccine came into wider use, an important shortcoming was identified: The shot's effectiveness wanes within five to 10 years.
"What happened was that people at that time were so much in appreciation of the benefits of the vaccine that they did not think about the limitations," said Dr. Trudy Murphy, a medical epidemiologist in the CDC's National Immunization Program.
Doctors considered giving adolescents and adults another round of shots, but it turned out that side effects from the vaccine were amplified in older recipients. So that ceased to be an attractive option.
The result: Even though millions of US children have been immunized against whooping cough, the eroding effectiveness of the shot leaves them vulnerable to infection as they enter adolescence.
And, with the passage of time, there are fewer and fewer living Americans who were exposed to the bacteria when it was commonplace, meaning fewer people have natural immunity. The consequence, Lett said, is a "growing pool of susceptibles" -- more people whom the bacteria can successfully attack.
But McIntosh said the reported increase more likely reflects doctors being diligent about alerting health authorities to outbreaks, as well as improvements in laboratory tests used to confirm the disease.
"People are recognizing it more," McIntosh said, "and that's a good thing."
Nowhere is it recognized more than in Massachusetts. The state recorded about 1,700 cases of whooping cough last year -- one of every seven cases reported in the nation.
That doesn't necessarily mean we have more cases here. It's more likely proof of the state's aggressive testing for the disease, which began in the 1980s.
When pertussis kills, which is rare (19 Americans died in 2003), its victims are almost always infants.
Babies start getting immunized against pertussis when they are 2 months old, with another shot at the age of 4 months, and a final inoculation at 6 months.
"So what we really worry about is the 16-year-old who has pertussis, and it's unrecognized, and then the teenager baby-sits an infant younger than 6 months," said Dr. Alfred DeMaria, the state's director of communicable disease control.
Infants are especially susceptible -- and can become far sicker -- because their capacity to battle disease has yet to mature.
In anyone, whooping cough can cause significant discomfort, with dramatic bouts of coughing interfering with sleep and producing fits of vomiting.
And the effects are persistent: Studies have shown that 62 percent of adults with pertussis are still coughing three months after symptoms first appear.
Two drug companies --
The new formulations are less potent than the shots given to infants, and drug company trials suggest they don't deliver the side effects that doomed earlier boosters.
"It is so important to express to people the importance of vaccination," said Lisa Rae, whose son, Kyle, contracted pertussis as an infant in suburban Philadelphia. "I remember stories my Mom told us about whooping cough. This wasn't anything we ever expected."
Stephen Smith can be reached at stsmith@globe.com.
