EDUCATION

Whooping cough cases are up in South Dakota: What you need to know

Katie Nelson
Argus Leader

Pertussis cases are increasing in South Dakota, with the state already seeing 27 cases early in 2019. In particular, the Sioux Falls School District has seen 10 cases in 11 different schools since December.

We spoke with Dr. Joshua Clayton, the state epidemiologist for the South Dakota Department of Health, to find out what you need to know.

What is pertussis and how common is it?

According to the Centers for Disease Control and Prevention, pertussis, or whooping cough, is a contagious respiratory disease that can cause uncontrollable and violent coughing. Nationwide, there are between 10,000 and 40,000 cases of pertussis per year on average. It can be fatal, especially for infants.

Out of the 27 cases in South Dakota so far in 2019, 18 of them have been in children under 5 years old, Clayton said.

Why is South Dakota seeing more pertussis cases?

Pertussis outbreaks tend to be cyclical, with spikes occurring every three to five years in general, Clayton said. In 2014, there were 109 cases, but that number dropped to as low as nine in 2017 before skyrocketing to 162 cases in 2018.

"Every three to five years we do see an increase," Clayton said. "Part of that is due to waning immunity."

Unlike some vaccines, pertussis vaccines are only 85 percent effective, Clayton said, meaning there is a chance people who have been vaccinated will still get sick. Immunity typically only lasts about two years before beginning to decline.

Molly Satter, the health services coordinator for the Sioux Falls School District, said nine out of the 10 cases seen in the district this winter were up to date on their shots. Of the more than 23,000 students enrolled in the district, upward of 98 percent are fully vaccinated, she said.

"The vaccine is not 100 percent effective," Satter said. 

Should I still get vaccinated?

Despite the vaccine not being entirely foolproof, Clayton said it is still important for both children and adults to be up to date on vaccines and boosters, partly to protect more vulnerable populations.

"We see a lot more risk in children less than one year of age," Clayton said, adding that pregnant women who could pass pertussis on to their babies and people who have a weakened immune system are also at higher risk for developing the disease.

In addition, the CDC says getting the pertussis vaccine can help prevent infection and lessen the severity of symptoms, even if you do get the disease. Before the pertussis vaccine was introduced in the 1940s, about 200,000 children contracted pertussis and 9,000 died each year from it. Now, out of the 10,000 to 40,000 cases seen nationwide each year, only 20 people die each year.

What are the symptoms of pertussis?

Early symptoms of pertussis can look like those of a cold, the CDC says, including:

  • Runny nose
  • Low-grade fever
  • Mild cough
  • Pauses in breathing

But after a week or two, more aggressive symptoms can develop, including high-pitched coughing fits ("whooping") and vomiting and exhaustion due to coughing fits. Coughing fits can last for as long as 10 weeks.

How much school will my child miss if they get pertussis?

Once a child is diagnosed and is put on a course of antibiotics, they may return to school five days after starting the antibiotics, Clayton said. Prior to that time is when people with the disease are most contagious.

If someone in your child's class gets pertussis, Clayton said you should monitor your own child for symptoms and seek medical care right away if you see any. But if you are in your third trimester of pregnancy or have a young infant at home, antibiotics may be prescribed as a measure of caution, Clayton said.

How can I prevent pertussis?

Clayton offered several tips on how to protect you and your loved ones from pertussis:

  • Ensure children are fully vaccinated and adults get booster shots
  • Avoid contact with people who are sick
  • Cover your mouth with your upper sleeve when you cough or sneeze
  • Wash your hands thoroughly with soap and water

Pertussis is primarily spread through bacteria being transmitted from person to person, similar to many other respiratory diseases. 

While the number of cases in South Dakota is high right now, Clayton said it will likely not stay that way.

"There's a good chance we'll see our numbers increase in the short term, decrease in the long term," he said.