Whooping cough cases surge in Florida and across US: Key symptoms to know

It’s not just the flu that Americans need to worry about this fall season. In recent months, public health officials have sounded the alarm as cases of whooping cough (also known as pertussis) have risen sharply in Florida and across many parts of the United States. Once considered largely under control due to vaccines, pertussis is now experiencing a strong resurgence. In Florida alone, 488 cases were recorded early in 2025 — a striking jump from just 96 during the same period in 2024. Preliminary 2025 data show more than 8,000 cases reported through April. This resurgence comes amid concerns over waning vaccine immunity and declining vaccination rates.

But what really is whooping cough? It’s not just a persistent cough; it can be life-threatening, especially in infants and vulnerable populations. It starts like a common cold but then escalates into severe, unpredictable coughing fits that “whoop” as patients struggle to gasp for air. The bacteria attack the airways, causing prolonged coughing fits and damage to the lungs. It’s especially dangerous for babies, for whom the disease can be life-threatening.

As cases rise, being aware of key symptoms, understanding risk factors, and knowing prevention tips becomes crucial for everyone — especially parents, caretakers, and health workers.

Whooping cough is caused by the bacterium Bordetella pertussis. The bacteria attach to the lining of the airways, release toxins that irritate and damage cilia (tiny hairs that move mucus), and produce inflammation in the respiratory tract. The disease spreads easily via airborne droplets when an infected person coughs or sneezes. People are contagious from the early, mild cold-like stage and remain contagious for up to three weeks after coughing begins, unless treated.

During the COVID-19 pandemic, many respiratory infections, including pertussis, declined (due to masking, distancing, etc.). But as those mitigation measures relax, pertussis is returning, even surpassing pre-pandemic levels. Some estimates suggest the US could hit 70,000 cases by year’s end if the trend continues.

One challenge is that early pertussis symptoms often mimic a mild respiratory infection – runny nose, sneezing, low fever, and occasional cough. After 1 to 2 weeks, the disease often enters the paroxysmal (coughing-fit) stage, which is more alarming. Typical signs include:

Intense, rapid coughing fits (paroxysms) that can last for 1 to 6 weeks or more.

A high-pitched “whoop” sound when inhaling after a bout of coughing (not everyone develops this).

Vomiting after coughing fits.

Exhaustion, fatigue, and difficulty sleeping.

In infants, the “whoop” might not appear; what is seen instead may be apnea (pauses in breathing), cyanosis (turning blue), feeding problems, or choking episodes.

In older children and adults, sometimes the only symptom is a prolonged hacking cough without the whoop.

Because the early phase is so mild, many cases go undiagnosed until the cough becomes severe.

Infants under one year, who are too young to complete the full vaccination series and vulnerable to life-threatening complications, are at the highest risk.

Unvaccinated or under-vaccinated individuals, including preschoolers, school children, and adults. Because vaccine protection wanes over time, booster doses are critical.

Pregnant women and newborns, as immunizing mothers in the third trimester pass protective antibodies to babies.

Older adults, especially those with weakened immunity or chronic respiratory illnesses.

Health care workers, caregivers, and people close to infants, because they may transmit infection unknowingly.

Several factors are contributing:

Waning immunity: The current acellular pertussis vaccines are less durable over time, so protection fades.

Declining vaccination coverage: Kindergarten immunization rates dipped to 92.3% in 2023-2024 (from ~94.9% before the pandemic).

Vaccine hesitancy and misinformation: Some parents delay or refuse vaccines, eroding herd immunity.

Post-COVID shifts: Mitigation measures (masks, distancing) reduced transmission during the pandemic. As those are relaxed, respiratory diseases like pertussis rebound.

Natural cyclic peaks: Pertussis is known to surge in 3-5 year cycles, so a major wave was anticipated.

Improved reporting and detection: Enhanced surveillance may capture more cases that previously went unnoticed.

Vaccination: Your first line of defense

The DTaP vaccine is given to infants and young children in a scheduled series. Older children, adolescents, and adults can get Tdap boosters. Pregnant women should receive a Tdap vaccine in each pregnancy (ideally in the early third trimester) to transfer protection to the newborn. Health care workers and caregivers around infants should also stay up to date.

Antibiotic treatment and post-exposure prophylaxis (PEP)

If you or someone is diagnosed early, antibiotics (e.g., azithromycin, clarithromycin, erythromycin) can reduce severity and contagiousness. Close contacts may be offered prophylactic antibiotics in certain cases to prevent spread.

Early recognition and prompt medical care

If a persistent severe cough develops – especially with “whoop,” vomiting, or breathing trouble – seek medical attention early. Early diagnosis is key to limiting complications.

Respiratory etiquette and hygiene

Cover your mouth when coughing, use tissues, wash your hands frequently, and avoid close contact with vulnerable people when sick.

Embrace the “cocooning” strategy

Protect infants by ensuring those around them – parents, siblings, and caregivers – are vaccinated. This creates a protective “cocoon” around the baby.

Public health surveillance and boost immunization coverage

Sustaining high vaccine coverage, timely boosters, and strong disease surveillance are essential to prevent outbreaks.