Whooping cough (in a baby): what it is, symptoms, treatment, vaccine

Long nights of a strong cough that leave the child breathing heavily can be very worrying and cause serious problems.

Whooping cough is a disease that is also known as long cough due to the intense and long-lasting cough characteristic of the disease.

It is important that people are vaccinated against the bacteria that causes the infection. Read on to learn about pertussis!


What is pertussis?

Whooping cough or pertussis is a bacterial infection that affects the lungs. It is known as whooping cough or long cough , as its clearest symptom is a persistent cough that makes the person tired and is often accompanied by vomiting.

While for adults it is not an especially dangerous disease, often with no symptoms at all, it poses a great risk for children, especially babies, who have thinner airways and are sensitive to violent coughs and mucus.

Whooping cough immunization is present in the current pentavalent vaccine and is effective in protecting children from infection. It is especially necessary since the disease spreads easily through the air.

During the 1940s, shortly before the vaccine was created, the disease was a major cause of death in the United States.

Symptoms are often mistaken for a cold or flu at first , but whooping cough is very characteristic and lasts for weeks.

The whooping cough code in the ICD-10 is A37 .

What is pertussis in babies?

Whooping cough in babies is the same disease, however, in them, it is extremely dangerous. As children’s airways are narrower, the large amount of phlegm caused by whooping cough can present a serious danger to breathing, especially if the child is less than 1 year old.

In addition, there is a danger of pneumonia , which can easily develop from pertussis in younger children, who have a weaker immune system. Whooping cough in babies is an emergency and the child should be treated by a doctor.

Causes of pertussis disease

Whooping cough is caused by the bacteria Bordetella pertussis , which only affects humans. It adheres to the cells of the bronchi (structures that carry air to the lungs) and causes large production of mucus, in addition to a toxin from the bacteria.

The bacterium has some resistance to macrophages, cells of the immune system that deal with infections. Therefore, the cure time, if there is no treatment, can be extended.

On average, the bacteria are incubated for 5 to 20 days and the cough starts after the end of this period.

This infection causes inflammation of the bronchi and necrosis in some areas, and after two to three weeks, a convulsive cough sets in, which is frequent at night and seeks to expel the exaggerated amount of mucus from the lungs.

The symptom lasts an average of 3 weeks and there may be vomiting because of the intensity. After this phase, it can take a few weeks for the body to recover completely

About ⅓ of adult patients do not even have symptoms, but children are at risk of death, as their airways are smaller and the amount of mucus can cause obstruction.

How is pertussis transmitted?

The long cough is easily transmitted through droplets with the bacteria that escape the infected body through the cough. As the disease is common in children, schools where students are not vaccinated have a high risk of a localized epidemic.

This bacterium can be transmitted throughout the coughing phase, but in the first weeks (catarrhal phase) it is more transmissible, affecting up to 90% of those exposed who are not immunized.

Even in cases of infected adults who have no symptoms, Bordetella pertussis can be spread by droplets in the mouth to other people.

Patients infected with the bacterium should remain in isolation until symptoms pass, to avoid spreading the disease to unvaccinated people, especially children, who are at risk of death if they get pertussis.

On average, 80 to 85% of patients who survive pertussis contamination develop immunity to the disease and are not at risk of being infected again.

Whooping cough stages

Whooping cough can be divided into three stages based on symptoms. Are they:

Catarrhal stage

This is the first stage of the disease and also the one with the greatest transmissibility . During this phase, the symptoms are similar to those of the flu, involving dry cough, sneezing and mild fever .

The phlegm production gradually increases over the course of 1 to 2 weeks and, as a result, also increases the intensity of coughs, which leads to the next stage of the condition.

Paroxysmal phase

The second phase of the disease lasts from 2 to 6 weeks and is marked by a reduction in transmissibility, but an increase in coughs and the appearance of coughing fits, called whooping cough .

They are intense crises, which appear frequently during the night, last from a few seconds to a few minutes and can appear up to 30 times in the course of 24 hours.

This symptom is especially dangerous for children and babies, as their airways are more sensitive and smaller.

The coughs are so intense that they can cause vomiting and prevent breathing while they occur. Often, crises end up leaving the person breathing heavily and producing a noise called a hiss or squeak, which is a forced inhalation from the air.

When the patient is not in crisis, there is no discomfort.

Convalescence phase

In this phase, the coughing episodes gradually reduce until finally they end, and the patient is free of the disease. At this stage, the patient no longer transmits the condition. It can last from a few weeks to months.

Risk factors

Anyone who is not immunized can get pertussis. The bacterium is extremely infectious and initially resistant to the immune system, which means that the strength of the immune cells is not that relevant to the risk of contracting the disease.

Therefore, the only risk factor for pertussis is the lack of vaccination . Of course, if you have not been vaccinated but have contracted the disease once, the chances of having pertussis again are extremely low.

Whooping cough symptoms


The symptoms of pertussis are initially similar to those of a common cold:

  • Sneezing;
  • Discharge;
  • Low fever;
  • Dry cough
  • Sore throat.


However, they quickly evolve and can result in the main symptom of the disease, whooping cough.

Whooping cough

Whooping cough usually begins approximately 2 weeks after the onset of symptoms.

When there is phlegm in the lungs, the body forces coughs to eliminate it. However, in the case of a long cough, the amount of phlegm is large and its production is fast.

Therefore, the result of this amount of pulmonary mucus is strong and severe coughs, with phlegm. They can be so intense that they prevent the patient from breathing or even cause vomiting.

Coughing bouts can be accompanied by strong breaths of air, which cause hisses, a sound that can also be known as “squeak”.

It is an especially dangerous symptom for children as the amount of phlegm can block the respiratory tract.

After a few weeks – approximately 3 – the convalescence phase begins, in which the patient gradually improves over another 3 weeks.

At this stage, coughs may become louder, however they are also less frequent and crises last less time.

How is the diagnosis made?

The diagnosis of long cough is made by an infectious disease physician , clinically and through the technique of bacterial culture.

Bacterial culture

The bacterial culture is made from samples of the lining of the throat, trachea and airways.

This examination places the sample with the bacteria in an environment conducive to their reproduction, which allows them to multiply and be easily identifiable.

The procedure is most effective during the initial stage of the disease, when it is most easily transmitted, but also when it is most confused with other diseases.

After the patient enters the phase in which intense coughing attacks appear, the amount of bacteria in the samples is reduced and their identification becomes more difficult.

Blood test

A blood test can be performed to identify the concentration of antibodies against the bacteria. Although it does not confirm the presence of the bacteria in the body, it can be a strong indication for the aid of diagnosis.

Clinical examination

The clinical examination, during the initial stages of the disease, is not the most effective since pertussis, in the first weeks, has symptoms similar to that of other diseases of the respiratory system.

However, when the condition enters whooping cough, clinical diagnosis is easier for the doctor.

Whooping cough is curable?

-Yeah . Usually pertussis cures on its own and the patient just needs to rest and withstand coughing fits. However, there are drug treatments that can facilitate healing and relieve symptoms.

What is the treatment for pertussis?

Treatment for pertussis is done with antibiotic medications . It is effective when applied during the incubation phase of the bacterium or at the beginning of the symptomatic phase.

During this period, he is able to reduce or even completely eliminate the clinical manifestations.

When whooping cough begins, treatment with antibiotics is not effective and there is no way to prevent the course of the disease, but the same antibiotics can eliminate bacteria present in the respiratory system, reducing transmissibility.


When pertussis affects children, hospitalization and isolation may prove necessary.

As the disease can cause the death of children, especially those under the age of one, hospitalization may be necessary for medical care to be immediate.

The main concerns for children are the possibility of pneumonia developing, in addition to the lack of oxygen caused by difficulty breathing during coughing fits, which is much more dangerous for babies than for adults.

Whooping cough medications

Whooping cough drugs are antibiotics, substances that kill bacteria. They are most effective when used during the incubation phase and the first symptoms. In these phases, medication can greatly reduce clinical manifestations.

However, when the disease reaches the whooping cough stage, antibiotics are not very effective, they only reduce the transmissibility of pertussis.

The main drugs used to treat long cough are:

  • Azithromycin ( Azimed );
  • Clarithromycin ( Klaricid UD );
  • Erythromycin ( Tromaxil ).


Preventive treatment with antibiotics should be carried out in newborns whose mother has had symptoms of pertussis, especially in the last 45 days of pregnancy.


NEVER self-medicate or stop using a medication without first consulting a doctor. Only he will be able to tell which medication, dosage and duration of treatment is the most suitable for his specific case. The information contained in this website is only intended to inform, not in any way intended to replace the guidance of a specialist or serve as a recommendation for any type of treatment. Always follow the instructions on the package insert and, if symptoms persist, seek medical or pharmaceutical advice.

Living together

Whooping cough lasts for weeks and its main symptom is a violent cough. It poses a great risk for children, and it is recommended to take care of it during episodes.

Coughing spells can last for a long time, require a lot of effort and usually happen during the night. Some attitudes can facilitate the process:


During the crisis, it is important that the patient is as comfortable as possible. Coughs are violent and are not easy, but they tend to pass.

Ensuring comfort is ideal for waiting for crises to end. When the patient is a child, the comfort of the parents is important so that he is not too scared. If the child is small – less than a year – he must be taken to the doctor for treatment.


Seizures of long cough can eliminate a lot of water, either through coughing or through vomiting and sweating. Keeping your body hydrated is essential.

Reduce evening meals

As long cough attacks are more common at night, it is recommended to avoid large meals at this time to reduce the chances of vomiting because of coughs.

Avoid smoke near the patient

The smoke caused by cigarettes, incense and the like can cause dryness of mucus in the patient’s lungs. This makes it difficult to cough and makes the attack more intense and painful for the throat and lungs.


In most cases, the disease heals on its own and the patient recovers completely. Despite having some resistance to the immune system, in a short time the bacteria is eliminated from the body.

The symptoms, despite persisting for several weeks, go away and the vast majority of people survive the disease, especially adults.

However, the disease kills between 1% and 2% of infected children under 1 year.

In the case of children, special attention is needed as the disease can be a danger to them, both due to the possibility of other infections caused by the bacteria – such as pneumonia – and due to the intensity of the cough symptoms, which can cause problems.

When treated properly, a long cough is not life threatening, but it can cause great discomfort and pain for a long time, so prevention is important, especially with children.



The complications of pertussis are mostly due to whooping cough, although this is not the norm. Among them are:

Rib fractures

Rarely, coughs can be so violent as to cause fractures in the patient’s ribs.

Coughing fits can last a long time and strain the body a lot. Rib fractures are rare, but they can occur, as well as cracks that do not fully develop into fractures.

Sleep problems

Coughing attacks caused by whooping cough are much more common at night. This can cause serious sleep problems for patients, who are unable to sleep while coughing.

This can disrupt work and school, not only for the patient but for everyone who lives in the house as the coughs are loud and intense.


Due to the effort caused by coughs, in addition to shortness of breath during them, it is possible that the person infected with pertussis will faint.


Hernias happen when an organ or other tissue moves through a muscle opening that shouldn’t have been there. Coughs cause a great deal of effort, which can cause hernias.


Vessels and veins can rupture due to coughing fits, especially the vessels in the eyes and nose, which can be more sensitive.


This symptom is more common in babies with pertussis, but it can also affect adults. Seizures are believed to be caused by neurological effects of the toxin produced by the bacteria in the lungs.


Like seizures, encephalopathy – a brain inflammation – can be caused by the toxin that the bacteria produces. This complication appears in less than 0.5% of cases in children.

Encephalopathy can cause permanent brain damage.


Whooping cough is at risk of dehydration due to the amount of fluid that is lost during coughing and phlegm attacks.


Pneumonia is one of the biggest concerns of pertussis in children, especially those under the age of one, as it is a disease that can lead to death. Whooping cough bacteria can cause pneumonia.

Breathing difficulties

Due to the infection, problems with breathing can occur. Coughs can also cause this complication, and especially when it affects babies, the airways can be blocked by phlegm, which can cause a lack of oxygen.


The otitis is an ear infection. It is a complication of pertussis that affects children especially, when the infection spreads to other parts of the body.


Death is the biggest possible complication caused by whooping cough. The disease is especially dangerous for children and babies and treatment is essential to ensure the patient’s survival.

How to prevent pertussis?

As pertussis is extremely transmissible and even a strong immune system can hardly stop the infection from starting.

On average, 90% of people without immunity who are exposed to the bacteria develop whooping cough and the only effective way of prevention is vaccination .

The vaccine is offered by SUS and is usually given in 3 doses. The first comes in the bacterial pentavalent vaccine , which protects against tetanus, pertussis, hepatitis B , diphtheria and influenza B.

Whooping cough vaccine


The pertussis vaccine was developed in 1926, but began to be used on a large scale a few decades later. There are two different types, the whole cell vaccine and the acellular vaccine .

When it comes to the whole cell vaccine, we are talking about a vaccine that carries the body of dead bacteria. In this way, the immune system can be exposed to the agent that causes the disease without the risk of being infected, which allows the patient to produce adequate antibodies.

With the acellular vaccine, what is in the vaccine is not the dead bacteria, but antigens from other people who have already been immunized by exposure.

The whole cell vaccine has a 78% immunization rate while the acellular vaccine varies between 71% and 85%, due to variations in the immune system.

Although high, the immunization rate still leaves many people out in a single application, so the vaccine for long cough is applied in 3 doses, which increases the effectiveness to approximately 98% to up to 99.7%.

It is important to mention that the effectiveness of the pertussis vaccine decreases over the years from the last dose . Therefore, it can happen to an adult who was vaccinated as a child to contract the disease.

However, the phase in which there is a greater risk with pertussis is precisely childhood, so it is important that, during this phase, it is protected since in adults the disease is not so dangerous.


There are some contraindications for the pertussis vaccine. It is not recommended that people older than 7 years get the vaccine. It should also be avoided if there is a history of allergy to any of its components. Talk to your doctor about other possible contraindications.

It is very important that everyone who can get vaccinated against diseases precisely because of the existence of people who cannot get the vaccine. If all the people around the person who cannot be vaccinated are immunized, the disease cannot reach that person.

Common questions

Whooping cough alone?

Yes , especially in adults. The disease is resistant to the immune system, but not immune to it and over time, it can heal itself.

However, its symptoms can be dangerous, in addition to the high risk of transmission, so it is important to carry out medical treatment for pertussis.

Does pertussis vaccine protect you forever?

No . The pertussis vaccine protects for a long time, but it is not permanent. Despite this, it remains indispensable for children, since the risk of death if a baby contracts the disease is much greater than that of someone older.

Vaccination is effective for approximately 10 years, so the chances of contracting the disease increase after that period.

It is important to remember that after the age of ten, the risk of suffering severe complications from pertussis is very small.

What is the period of transmission of pertussis?

The pertussis transmission period lasts from 5 days after contact with the bacteria to 3 weeks after the start of whooping cough. The first stage of the disease is more contagious and after the start of coughs the transmissibility drops.

How do I get immune to pertussis?

There are two ways to acquire pertussis immunity. This immunity is not permanent, but lasts up to 10 years, long enough to leave childhood, which is the time when the disease poses the greatest danger.

Vaccination makes the patient immune to pertussis, which prevents the disease and can save lives.

It is also possible to be immune from contracting pertussis once, which leaves the immune system ready to stop a possible second infection before the disease develops.

Pregnant women can take the adult vaccine from week 20 of pregnancy, ensuring that they will not contract the disease and transmit it to the baby.