AUSTIN, Texas — State and local health officials are warning of a surging number of cases of pertussis, or whooping cough, in Texas and across the nation.
According to the Texas Department of State Health Services (DSHS), the state has seen three times as many cases as during the same period in 2023. The trend aligns with preliminary data nationwide, which show a fivefold increase in cases across the U.S.
Pertussis is a highly contagious illness caused by the bacteria Bordetella pertussis. It often spreads through small particles of the virus expelled when infected people cough or sneeze.
"It spreads through droplets, so if someone is coughing a lot, those droplets are released into the air," Dr. Varun Shetty, the chief state epidemiologist for the DSHS, said. "If someone were to get in contact with that, it could spread that way."
The early symptoms are similar to a common cold, but after a week or two, they can worsen and progress to coughing fits that could cause people to vomit or make a characteristic "whoop" sound when breathing in. Generally, the cough lasts more than three weeks.
Since the initial symptoms look like any other type of respiratory illness, Shetty said it makes diagnosing it difficult for doctors.
"It'll be things like a cough, runny nose, maybe a mild fever that can last for a week or two, and then you start seeing these more hallmark symptoms of pertussis, this really bad cough that starts all of a sudden and goes on and on," Shetty said. "It can cause a lot of discomfort, and then it could cause this classic whooping sound when someone tries to breathe in while they're coughing. It can be difficult to watch."
The symptoms can be different in infants. Instead of the coughing fits, their symptoms could include things like gagging, gasping, vomiting or difficulty breathing.
"Younger children may not eat as well and may have a fever or trouble breathing," said Dr. Desmar Walkes, the Austin/Travis County Health Authority and Medical Director for Austin Public Health. "If it gets bad and severe enough, people may require hospitalization."
According to the DSHS, infants and young children, particularly younger than 1, are especially vulnerable to severe complications.
Shetty said that about one-third of kids under 1 year old who get the illness need to go to the hospital for treatment.
"The youngest kids, their immune systems are still developing, and so getting an illness like this can be really difficult for their bodies to react and respond to," Shetty said. "We also know that there are a lot of complications that happen in these young kids. They can have trouble breathing. They could develop things like pneumonia, in severe cases, even seizures, and very rarely, even death."
Cases in the Austin area
In the Austin area, Walkes said there have been cases among people who need hospitalization, primarily among people who are older and are immunocompromised or have chronic conditions that would complicate their recovery and young children.
Last year, Walkes said the county public health department saw 11 cases of whooping cough, but so far this year, it has already had 49.
"It's a big jump," Walkes said. "We know that there are a lot of people who may have missed out on getting their children vaccinated in the last couple of years as we were dealing with the pandemic and recovery and getting up to date on all of our preventative measures, so we're trying to get people back in to get their vaccines."
Public health experts say getting vaccinated is the best way to protect against whooping cough. However, Shetty said it is still possible for vaccinated people to get the disease because immunity wanes over time.
"It is highly effective at preventing whooping cough infections, but it is possible to get whooping cough even if you have the vaccine," Shetty said. "If you did get vaccinated, there is evidence to show that your illness may be milder because of it."
The vaccine for young children is called DTaP. It is a several vaccine dose series, starting at 2, 4 and 6 months old, then again a little bit after a child's first birthday between 15 and 18 months. The last one is sometime between 4 and 6 years old.
Shetty said DTaP protects 98% of children within the year following the last dose in that series.
There is also a Tdap vaccine, which is available to pre-teen children around 11 and 12 years old, adults at any time and pregnant women. Pregnant women are encouraged to get the Tdap vaccine during their pregnancy to help protect their vulnerable newborns.
"We want to make sure that mothers are protected so they're not getting sick and passing whooping cough on to their newborn babies," Shetty said. "That's important for all caregivers who are going to be around small children, and it's highly effective at protecting both the mothers and the babies in those situations."
Treating whooping cough
Shetty said early treatment – such as antibiotics like azithromycin, erythromycin and clarithromycin – is crucial to reduce the severity of the illness and decrease the risk of it being spread to others.
"It could reduce the chances of becoming very sick," Shetty said. "It could lower the number of days that you're sick."
Shetty said people who have or suspect they have whooping cough should stay away from others and contact their health care provider to get testing, medical help and treatment as soon as possible.
Because it's so highly contagious, the DSHS advises people to stay home from work, school and public places until they undergo five days of antibiotics.
"The guidance is to treat close contacts, so for children in school, others that are close to them in school who may have been around them when they were coughing or sneezing, and to also treat household contacts so that we can decrease the spread of whooping cough," Walkes said.
According to Shetty, the surge in cases this year is part of a return to pre-pandemic trends in a rebound from relatively low numbers of cases during the pandemic.
"The actions that we were taking as communities to protect ourselves against COVID-19 also protected us against other diseases like pertussis," Shetty said. "In 2021 and 2022, we saw abnormally low levels of whooping cough. 2023 saw an increase, and now we're starting to see even more of an increase."
It is still less than the average number of 1,400 cases reported in Texas each year prior to the pandemic, but Shetty said it is headed toward getting back to that.
The surge in cases is coming at the start of the respiratory season, but it is not a typical wintertime disease like the flu. Prior to the pandemic, cases of whooping cough peaked in springtime or summertime. Doctors are concerned that the disease is rising now, when they expect traditional winter diseases like flu and RSV to pick up in the coming weeks, which could burden health care systems.
"Now is the time to go and get your vaccinations," Walkes said. "We're coming up on several celebrations and holiday gatherings. Having the shots that you need will help us have safe holiday seasons and allow us to protect ourselves and our community."
Walkes and Shetty encouraged people to take routine preventative measures like covering coughs and sneezes, staying home if they're sick and frequently washing their hands to help limit the spread of whooping cough and protect vulnerable populations.