Introduction

What is pertussis?

Pertussis is a highly contagious bacterial infection that affects the respiratory system. It is caused by the bacterium Bordetella pertussis.¹ The infection is known for causing severe coughing fits that can make it hard to breathe. The coughing can be so intense that it leads to a "whooping" sound when the person tries to take a breath. This is where it gets its other name from– whooping cough. Pertussis can affect people of all ages, but it is especially dangerous for infants and children under the age of one, who can experience serious complications.¹

Overview of complications in infants with pertussis

Infants with pertussis, or whooping cough, can face several serious complications. Since their immune systems are still developing in their tiny bodies, they are more vulnerable to the severe effects of the infection. Common complications include breathing problems, brain issues, heart problems and other complications. Below you can find a detailed discussion of these common complications specific to infants.²

Respiratory complications

Respiratory complications or complications of the lungs are some of the most serious problems that infants with pertussis can face. Some of them are as follows:

• Pneumonia: This is an infection in the lungs. Infants with pertussis can develop pneumonia because their lungs are weakened by the severe coughing fits. Pneumonia makes it hard for them to breathe and can lead to high fever and chest pain. It often requires hospitalization and treatment with antibiotics.^{2, 3}
• Apnea: Apnea is when a baby stops breathing for a short time. This is especially dangerous for infants because their little bodies are not yet fully developed. During an episode of apnea, the infant might turn blue or very pale. It can be very scary and usually needs immediate medical attention.³
• Respiratory failure: This is a severe condition where the baby can't breathe well enough on their own to get the oxygen their body needs. The intense coughing from pertussis can tire out an infant, making it extremely difficult for them to breathe. Respiratory failure often means the baby needs to be in the hospital, possibly using a machine to help them breathe.³

Neurological complications

Neurological complications are problems that affect the brain and nervous system. In infants with pertussis, these complications can be very serious. 

• Seizures: Seizures are unexpected, unregulated electrical disruptions in the brain. For an infant with pertussis, severe coughing fits can sometimes lead to seizures. During a seizure, a baby might shake uncontrollably, lose consciousness, or have strange movements. Seizures can be very frightening and need immediate medical attention.^{2, 4}
• Encephalopathy: Encephalopathy is an umbrella term for problems occurring in the brain. In infants with pertussis, the lack of oxygen during intense coughing fits can damage the brain.² This can lead to encephalopathy, which might cause the baby to be very sleepy, irritable, or have trouble with feeding and movement. It can have long-lasting effects on a child's development.⁴

Both of these neurological complications are dangerous because they affect how the brain works. Since the brain controls everything the body does, problems here can have widespread effects on a baby's health.

Cardiovascular complications

Cardiovascular complications affect the heart and blood vessels. In infants with pertussis, these complications can be very serious. 

• Pulmonary hypertension: This is when the blood pressure in the lungs' blood vessels is too high. In infants with pertussis, severe coughing and breathing difficulties can strain the heart and lungs, leading to this condition. It is hard for the heart to pump blood through the lungs because of high pressure, causing the baby to have trouble breathing and thus making their heart work much harder than normal.⁵
• Myocarditis: Myocarditis is a term used for inflammation of the heart muscle. In infants with pertussis, the infection can sometimes spread to the heart, causing myocarditis. This inflammation can weaken the heart muscle, making it less effective at pumping blood throughout the body. Symptoms might include fatigue, weakness, and trouble feeding. In severe cases, it can lead to heart failure.⁵

Other complications

In addition to respiratory, neurological, and cardiovascular issues, infants with pertussis can face several other complications. 

• Dehydration: Severe coughing fits can make it hard for babies to drink enough milk or formula. When they don't get enough fluids, they can become dehydrated. Dehydration means the body doesn't have enough water to function properly. Signs of dehydration include fewer wet diapers, dry mouth, and crying without tears. It's important to make sure babies with pertussis stay hydrated.²
• Weight loss: Babies might not get enough nutrition because pertussis makes it hard for them to feed properly. This can lead to weight loss. Infants need to gain weight to grow and be healthy, so losing weight can be a serious issue. It is important to ensure that they get enough to eat, even if it means giving smaller, more frequent feedings.²

Management and prevention

Management

• Medication: Doctors usually prescribe antibiotics to treat pertussis. Antibiotics can help get rid of the bacteria causing the infection and can also make the illness less contagious. It's important to start the medication as soon as possible.^{3, 4, 5}
• Hospital care: Sometimes, babies with severe pertussis need to stay in the hospital. In the hospital, doctors can give them oxygen to help them breathe better and fluids through an IV to keep them hydrated. This care can help manage the serious symptoms and prevent complications.^{4, 5}
• Supportive care: At home, make sure the baby is comfortable. Keep them warm, in a calm and quiet environment to avoid triggering coughing fits. Give them small, frequent feedings to ensure they stay hydrated and get enough nutrition.⁴

Prevention

• Vaccination: The most fool-proof way to prevent pertussis is by vaccination. Babies should get the DTaP vaccine, which protects against diphtheria, tetanus, and pertussis. The vaccine is given in a series of shots starting at 2 months old. It's also important for pregnant people in their third trimester to get the vaccine during pregnancy to protect their newborns.^{4, 3}
• Good hygiene: Maintain good hygiene to stop the spread of germs. Wash your hands frequently with soap and water.
• Avoiding sick people: Keep your baby away from people who are sick, especially if they have a cough. Pertussis is highly contagious, so it's important to minimize the baby's exposure to infection.

FAQs

What are the most common complications of pertussis in infants?

The most common complications include severe breathing problems like pneumonia and apnea, which is when babies stop breathing for short periods. Infants can also develop seizures, brain issues like encephalopathy, heart problems like pulmonary hypertension, and inflammation of the heart (myocarditis).

Why is pneumonia a concern for babies with pertussis?

Pneumonia is a lung infection and a cause for concern because it makes it very hard for babies to breathe. Since their lungs are still developing, any infection can be serious. Pneumonia often requires hospital treatment and antibiotics.

What is apnea, and how does it affect infants with pertussis?

Apnea is when a baby stops breathing for a few seconds. In infants with pertussis, intense coughing fits can trigger these episodes, which can be very dangerous and require immediate medical attention.

How does pertussis lead to seizures in infants?

Severe coughing fits from pertussis can reduce oxygen flow to the brain, which might cause seizures. These seizures are sudden, uncontrolled movements or shaking and can be very scary and harmful.

Can pertussis cause long-term brain issues in infants?

Yes, pertussis can lead to encephalopathy, which is a problem with brain function due to lack of oxygen or infection. This can result in long-term developmental delays or other neurological issues.

How does pertussis affect the heart in infants?

Infants with pertussis might develop pulmonary hypertension (high blood pressure in the lungs) or myocarditis (inflammation of the heart muscle). Both of these put extra strain on the heart and can lead to serious health problems.

How can pertussis affect an infant's overall growth and development?

Pertussis can cause feeding difficulties, leading to dehydration and weight loss. Babies need proper nutrition to grow, so these complications can slow their development and weaken their immune systems.

How can parents help manage and prevent complications from pertussis?

Parents can help by ensuring their baby gets vaccinated on schedule, seeking medical care quickly if pertussis is suspected, keeping their baby hydrated and well-nourished, and practising good hygiene to avoid spreading germs. Frequent visits to your doctor are also important.

Summary

Pertussis, or whooping cough, can cause serious complications in infants. The most common issues include breathing problems like pneumonia and apnea, which can make it hard for babies to breathe. Seizures and brain issues like encephalopathy can also occur due to a lack of oxygen during coughing fits. Some of the other risks are heart problems such as pulmonary hypertension and inflammation of the heart muscle (myocarditis). These complications can affect an infant's growth and development, leading to feeding difficulties, dehydration, and weight loss. 

Parents can help manage and prevent complications by ensuring their baby receives timely vaccinations, seeking medical care promptly if pertussis is suspected, and keeping their baby well-hydrated and nourished. Good hygiene practices like handwashing, can also prevent the spread of germs. Regular check-ups with a doctor are important for monitoring the baby's health and catching any complications early. By taking these steps, parents can help protect their baby from the serious effects of pertussis.