Whooping cough infections rising in Iowa and the US. What you should know:

Whooping cough cases are on the rise in Iowa, state public health officials say.

There have been 72 cases of whooping cough identified so far this year, the highest case count recorded since 2019, according to the Iowa Department of Health and Human Services.

Whooping cough, or pertussis, is a highly contagious respiratory tract infection. It causes lengthy and repeated bouts of coughing, which can sometimes lead to infected individuals making a signature "whoop" sound .

Case counts in Iowa have been increasing since May. Infections of whooping cough have been identified across the state, predominantly among Iowans younger than 20 years, said Alex Murphy, spokesperson for Iowa HHS.

Polk County has detected 14 cases from June 1 to Aug. 27, said Addie Olson, public health communications officer for the Polk County Health Department. The current case count is higher than local public health officials would typically see in a year, she added.

Blank Children's Hospital in Des Moines confirmed the hospital had one pediatric admission in recent days for whopping cough.

MercyOne Medical Center saw at least two cases in June, including one hospitalization, said Dr. Aneesa Afroze, infectious disease specialist and director of infection prevention, hospital epidemiology and antimicrobial stewardship.

“Even when we see two or three cases, that's a lot for us,” Afroze said.

Johnson County also confirmed it has detected at least three cases in the past two weeks, said Sam Jarvis, community health manager for Johnson County Public Health.

Whooping cough case counts returning to prepandemic levels in Iowa, nationwide

The recent rise in case counts indicates the infection is returning to levels seen before the pandemic, state and federal health officials say.

Whooping cough normally circulates at low levels throughout the world, but infections had dropped significantly during the COVID-19 pandemic, when social isolation and other coronavirus-related mitigation strategies caused a lull in case counts.

"People were not gathering, people were staying home and working from home, they were masking," Afroze said. "All of those things, I think, protected us from respiratory illnesses. Once those (mitigation efforts) died down, we started seeing a little more influenza, a little more rhinovirus and pertussis.”

However, cases identified statewide each year since 2020 were still lower than in years before the pandemic, Murphy said. From 2015-2019, from 163 to 276 pertussis cases were recorded each year in Iowa.

The U.S. Centers for Disease Control and Prevention says preliminary data shows "more than four times as many cases" have been reported nationwide so far this year compared with the same time frame in 2023.

As of Aug. 17, the most recent data available, about 11,500 cases of pertussis were reported so far this year. There were a little more than 3,000 cases in that same time period in 2023, per the CDC .

How does whooping cough spread?

Whooping cough, which is caused by a bacteria, is spread through droplets in the air left by an infected person coughing or sneezing. Olson said the infection is most contagious early on, making early detection and prevention critical to prevent spread.

Afroze said because early symptoms of whooping cough are the same as the common cold or allergies, it can be easy for some individuals to spread the infection to others.

“It's a very contagious disease if somebody has it, so we have to be vigilant about it,” Afroze said.

Without treatment, individuals with whooping cough are infectious as long as 21 days after they start coughing. Infected individuals are not infectious once they complete the recommended round of antibiotic treatment.

What are the symptoms of whooping cough?

According to the CDC, it usually takes 5 to 10 days after exposure for symptoms to appear.

Early symptoms of whooping cough can appear similar to a common cold, and include stuffed or runny nose, mild cough and low-grade fever.

About one to two weeks after symptoms start, individuals may develop violent coughing fits, occurring over a period that can last anywhere from one to 10 weeks. These coughs are followed by a high-pitched whoop when the infected person breathes in after a coughing fit.

The cough usually gets worse as the illness continues, according to the CDC. In some cases, coughing fits may cause people to have difficulty sleeping, struggle to breathe or even fracture a rib.

Individuals who have been vaccinated can still get whooping cough, but the illness is generally milder, per the CDC.

Who is most at-risk from an infection?

Whooping cough can cause serious complications in babies and young children, especially for those children who haven't had all the recommended vaccines. Babies develop serious complications such as apnea, or life-threatening pauses in breathing, and pneumonia.

Because they are at greatest risk for complications, babies and infants with whooping cough are more likely to be hospitalized. The CDC estimates that among U.S. babies younger than one year who get whooping cough, one in three will need hospital care.

Adults can also develop complications, but those are usually less severe.

Those with symptoms, such as a prolonged cough, should talk with their health care provider.

“If it starts as a common cold and you think it’s allergies or just a cold, at least mask and stay away from people who are elderly or people who are immunocompromised,” Afroze said. “If it doesn’t get better in a couple of days, seek medical attention and get tested because early detection is the best way to prevent the spread of any disease.”

How do I stay healthy against whooping cough?

Vaccination is a critical step to protect yourself against a pertussis infection, local and state public health officials say.

The CDC recommends routine childhood immunizations include the DTaP vaccine, or the vaccine against diphtheria, tetanus and pertussis. This five-dose vaccine should be given to babies at 2 months old, 4 months old, 6 months old, 15-18 months old and at 4-6 years old.

Pregnant woman should get a booster shot during their pregnancy, according to the CDC.

A booster dose of the vaccine is also recommended every 10 years. Afroze said parents, grandparents and other family members of newborns in particular should get a booster vaccine to help protect their young family member before they're old enough to be immunized.

Health officials also recommend individuals stay home when they are feeling sick, regularly wash your hands and cover your mouth and nose when coughing or sneezing.

Michaela Ramm covers health care for the Des Moines Register. She can be reached at mramm@registermedia.com , at (319) 339-7354 or on Twitter at @Michaela_Ramm .

This article originally appeared on Des Moines Register: Whooping cough infections rising in Iowa and the US. What you should know: