Whooping cough (pertussis) is a bacterial infection of the respiratory tract. It's highly contagious and spreads easily from person to person through droplets when an infected person coughs, sneezes, or talks. With whooping cough, thick mucus forms deep inside the airways. This leads to severe coughing spells that make a “whooping” sound (sharp intake of breath). Most infants and children in the U.S. get a series of vaccines to prevent whooping cough. But infants too young to be fully immunized are vulnerable to infection. Sometimes, whooping cough can occur in children who have had the full series of vaccines. Protection from the vaccine or the disease will also wear off over time. This can leave older children, teens, and adults at risk.

• At first, whooping cough seems like a common cold. Symptoms include a runny nose, sneezing, mild fever, and a slight cough.
• One to 2 weeks later, the cough becomes severe. It often comes in spells that last a minute or more and end with a high-pitched whoop. The intense coughing can cause a child to break a rib, vomit, turn blue, or even pass out. This stage can last 1 to 6 weeks or longer.
• In time, the cough improves. But it may linger in a less severe form for months.

Whooping cough can cause other problems including:

• Ear infections
• Pneumonia
• Slowed or stopped breathing
• Fluid loss (dehydration)
• Seizures

Babies and children younger than 2 years old are more at risk for serious problems and even death.

Children who have all of the vaccines are usually protected from whooping cough. But others are at risk, including:

• Babies 6 months and younger who haven't had at least 3 doses of whooping cough vaccine
• Children and teens age 11 to 18 who haven't had a booster shot of the vaccine
• Anyone who hasn't been vaccinated or who hasn't had a booster shot of the vaccine

Your child's doctor will ask about your child's health history and do a physical exam. A small sample of material may be taken from your child's nose or throat. The sample is sent to a lab and tested for the bacteria that cause whooping cough. Your child may also have blood tests or chest X-rays.

Older children and teens are often treated at home with self-care to keep them comfortable until the symptoms pass. Infants and toddlers are more likely to have complications. So they are often treated in the hospital. During a hospital stay, children with whooping cough may:

• Be given medicines to ease inflamed airways.
• Have their breathing carefully watched.
• Have their airways suctioned to remove mucus.
• Be given antibiotics through an I.V. (intravenous) line into a vein in the arm.

A child can spread the infection for about 2 weeks after the cough starts. This may be shorter with antibiotics.

Antibiotics may shorten the illness, but only if given early. They won't cure whooping cough in most cases. But they may still be prescribed to help make your child less contagious. In that case:

• Make sure your child takes all the medicine, even if they feel better. If not, the infection may come back.
• Be sure your child takes the medicine as directed. For example, some antibiotics should be taken with food.
• Ask your child's doctor or pharmacist what side effects the medicine may cause and what to do about them.

Your child should stay home from school until they have completed at least 5 days of antibiotic treatment. If appropriate antibiotic treatment is not used, they should wait 3 weeks or 21 days after the start of the cough.

To help your child recover fully from whooping cough:

• Give plenty of fluids, such as water, juice, or warm soup. Fluids help loosen mucus, so your child can breathe more easily. They also help prevent dehydration.
• Offer smaller meals. Small amounts of food are easier to eat when coughing is severe.
• Make sure your child gets enough rest. Ask your child's doctor about the best sleeping position to improve breathing.
• Run a humidifier in your child's bedroom to ease coughing and loosen mucus in the airways. Be sure to clean the humidifier regularly to prevent growth of mold and bacteria.
• Keep your house free of irritants that can trigger coughing spells. These include tobacco smoke and fumes from fireplaces.
• Don't give your child over-the-counter cough syrups. They won't ease your child's cough and may be harmful.
• Don't take your child with whooping cough to school or daycare until the doctor says it's okay.
• Ask your child's doctor if others in your home should get a booster shot to help keep them from getting sick.

Call 911 right away if your child:

• Has trouble breathing.
• Stops breathing even for an instant.
• Has skin or lips that look blue, purple, or gray.
• Has a seizure.
• Shows a sudden lack of energy or can't move.
• Is unconscious or does not respond.
• Has a fever (see "Fever and children" below).
• Has signs of dehydration, such as sunken eyes, dry mouth, extreme tiredness (lethargy), dark or strong-smelling urine, or no urine output in 6 to 8 hours.

Contact your child's doctor if your child has any of these:

• A whooping sound between or after coughing
• Exhaustion after coughing spells
• Loss of appetite and eating poorly
• Vomiting after coughing spells
• Is weak and looking sick

Use a digital thermometer to check your child's temperature. Don't use a mercury thermometer. There are different kinds and uses of digital thermometers. They include:

• Rectal. For children younger than 3 years, a rectal temperature is the most accurate.
• Forehead (temporal). This works for children age 3 months and older. If a child under 3 months old has signs of illness, this can be used for a first pass. The doctor may want to confirm with a rectal temperature.
• Ear (tympanic). Ear temperatures are accurate after 6 months of age, but not before.
• Armpit (axillary). This is the least reliable but may be used for a first pass to check a child of any age with signs of illness. The doctor may want to confirm with a rectal temperature.
• Mouth (oral). Don't use a thermometer in your child's mouth until they are at least 4 years old.

Use the rectal thermometer with care. Follow the product maker's directions for correct use. Insert it gently. Label it and make sure it's not used in the mouth. It may pass on germs from the stool. If you don't feel okay using a rectal thermometer, ask the doctor what type to use instead. When you talk with any doctor about your child's fever, tell them which type you used.

Below are guidelines to know if your young child has a fever. Your child's doctor may give you different numbers for your child. Follow your doctor's specific instructions.

Fever readings for a baby under 3 months old:

• First, ask your child's doctor how you should take the temperature.
• Rectal or forehead: 100.4°F (38°C) or higher
• Armpit: 99°F (37.2°C) or higher

Fever readings for a child age 3 months to 36 months (3 years):

• Rectal, forehead, or ear: 102°F (38.9°C) or higher
• Armpit: 101°F (38.3°C) or higher

Contact the doctor in these cases:

• Repeated temperature of 104°F (40°C) or higher in a child of any age
• Fever of 100.4° F (38° C) or higher in baby younger than 3 months
• Fever that lasts more than 24 hours in a child under age 2
• Fever that lasts for 3 days in a child age 2 or older

Most children get a vaccine against whooping cough starting at 2 months old. It's often combined with vaccines for 2 other diseases, diphtheria and tetanus. The combination vaccine (called DTaP) is given in a series of 5 shots at these ages:

• 2 months
• 4 months
• 6 months
• 15 to 18 months
• 4 to 6 years, just before starting school

Make sure your child has the full series of whooping cough vaccines. If your child misses a shot, talk with your child's doctor about a makeup schedule. The vaccine's effects may start to fade by age 11. Make sure to stay away from adults or children with symptoms of whooping cough.

The American Academy of Pediatrics and CDC recommend single dose whooping cough vaccine (called Tdap) for:

• Preteens between the ages of 11 to 12
• Pregnant people during weeks 27 to 36 of each pregnancy
• Adults over age 18 who have never been vaccinated followed by a booster every 10 years