Occurring cyclically, whooping cough cases have soared 488 percent, compared with the average of the last five years. There has been one confirmed case each in Carroll and Guthrie counties and two cases in Shelby County.
Occurring cyclically, whooping cough cases have soared 488 percent, compared with the average of the last five years. There has been one confirmed case each in Carroll and Guthrie counties and two cases in Shelby County.
Monday, July 30, 2012

Carroll County’s first case of whooping cough this year was reported last week as an epidemic sweeps across Iowa at its fastest rate since 2004 and threatens the largest national outbreak in more than 50 years.

More than 800 cases of whooping cough — formerly known as pertussis — have been reported in Iowa this year, a 484-percent increase compared with Iowa’s average of the past five years, according to the Iowa Department of Public Health. But no whooping cough-related deaths have been reported to state officials this year.

Health officials say the spike in cases is due to less-effective vaccines and a decline in parental support of vaccination.

No details about Carroll’s first confirmed case have been released due to medical privacy laws, said Robyn Klocke-Sullivan, clinical coordinator of Carroll’s Public Health Services.

Linn and Cerro Gordo counties have the most reported infections with 127 and 101, respectively. Scott, Dubuque and Polk counties trail close behind with upwards of 60 cases each.

Whooping cough is a highly contagious respiratory infection that causes violent coughing fits and can lead to vomiting or difficulty breathing. Infants are most at-risk for whooping cough-induced complications, which include death, but children between the ages of 10 and 15 are the most-infected group. The bacterial infection is typically treated with a five-day antibiotic.

Carroll’s first diagnosis adds to the mounting statewide anxiety that, with five months to go, whooping cough infections this year will surpass Iowa’s last all-time high of 1,000 cases in 2004, said Klocke-Sullivan. She receives a weekly update from the state health officials each Friday with infection breakdowns by county, age and week.

“It’s not overwhelming, but it is very concerning,” she said. “That’s why everyone in the state is taking precautions.”

To protect against whooping cough, Iowa requires all children entering elementary school to receive a vaccine against the disease. The shots are administered in a series — the first at the ages of 2, 4 and 6 months, then between 15 and 18 months, and a final dose between 4 and 6 years of age.

Danger is heightened for infants, who cannot be vaccinated until they are 2 months old. If infected, their small bodies are vulnerable to pneumonia, seizures and death — and a host of other conditions caused by whooping cough. Of the 27 deaths reported nationwide this year, 25 were children younger than 1.

By nature, whooping cough comes in waves, experts say, spurring an epidemic every three to five years. Those cycles aren’t precisely fixed — the last was in 2010 — but a surge in infections shouldn’t cause panic, said Mikala Landon, an infection preventionist at St. Anthony Regional Hospital in Carroll.

Landon monitors the spread of infections throughout the hospital’s staff and patients. She said she has never seen a case of whooping cough within hospital doors.

“It’s just a cyclical event that happens every three to four years,” she said. “And it’s just going to run its course.”

But the sheer velocity of infections may point to inefficient vaccination efforts, where both medical and cultural forces are at play.

The first whooping cough vaccine was introduced in the 1940s and instigated a significant drop in cases, which initially numbered in the hundred thousands. For the next 25 years, fewer than 5,000 cases were reported annually in the United States, but the vaccine appeared to induce other side effects including rash and fever.  

In the 1990s, doctors swapped out the old vaccine for a safer alternative, but with it came a jump in cases — more than 25,000 in 2004 and 2005. There is increasing speculation that the updated vaccine can wear off as soon as five years after the initial dose, Klocke-Sullivan said.

To maintain immunity, medical experts recommend a booster shot beginning at age 10. Some states are beginning to require adolescents to get the extra protection before entering middle school.

But these days, parents are more reluctant to vaccinate their children than they were several decades ago, Klocke-Sullivan said. And those efforts dwindle as kids get older. About 84 percent of 3-year-olds have gotten the recommended number of shots, but that percentage dips to fewer than 70 percent for all adolescents.

Nationally, 18,000 cases of whooping cough have been counted so far, a rate that could make this the worst year for whooping cough since 1959 when there were 40,000 diagnoses.

Iowa fares better than other parts of the country. The biggest outbreaks have slammed Washington and Wisconsin with more than 3,000 cases each. To keep conditions under control here, Klocke-Sullivan stresses vaccination first and then basic hand hygiene.

Immunization clinics held in Carroll twice a week offer the vaccine for free to people who are uninsured or whose insurance doesn’t cover vaccines and Medicaid patients. Out of pocket, the vaccination costs about $65. Clinics are also held in Coon Rapids and Manning, alternating locations every other week.

In the meantime, simple measures can go a long way.

“Covering your cough and your sneeze, washing you hands and staying away from people who have a severe cough,” Klocke-Sullivan said.