What Is Whooping Cough? What Is Pertussis?

Editor's Choice
Main Category: Infectious Diseases / Bacteria / Viruses
Also Included In: Respiratory / Asthma;  Pediatrics / Children's Health
Article Date: 15 Mar 2013 - 0:00 PDT


Whooping cough, known medically as Pertussis, is an extremely contagious disease caused by the bacterium Bordetella pertussis. Whooping cough is called the 100 days' cough in some countries.

In many patients there is a distinctive hacking cough which is followed by a high-pitched gasp for air that sounds like a "whoop", hence the name.

Before the development of a vaccine, whooping cough was mainly a disease of childhood. Today, it mainly affects children who are too young to have completed the full course of vaccinations, as well as adolescents whose immunity has waned.

Before vaccines, approximately 157 people per 100,000 developed whooping cough in the USA (reported cases). There were peaks every two to five years. In 93% of cases, they were children under 10. Experts say the real incidence at that time was much higher (not all cases were reported. After the introduction of mass vaccinations in the 1940s, whooping cough rates dropped to less than 1 per 100,000 by 1970. However, since 1980 numbers have started to creep back up slightly.

In developed nations, whooping cough mortality rates are extremely low, and occur almost exclusively among infants. It is vital that pregnant mothers, as well as those who are in close contact with infants (newborns and babies up to 12 months of age), be vaccinated against pertussis.

Whooping cough affects approximately 48.5 million people every year, of whom 295,000 die. According to WHO (World Health Organization), pertussis is one of the leading causes of vaccine-preventable deaths globally. The majority of cases (over 90%) occur in low- and middle-income countries.

Children of parents who will not let them be vaccinated are 23 times more likely to develop whooping cough compared to fully immunized kids, researchers reported in the journal Pediatrics.

According to Medilexicon's medical dictionary, Pertussis is:

"An acute infectious inflammation of the larynx, trachea, and bronchi caused by Bordetella pertussis; characterized by recurrent bouts of spasmodic coughing that continues until the breath is exhausted, then ending in a noisy inspiratory stridor (the "whoop") caused by laryngeal spasm."

What are the signs and symptoms of whooping cough (pertussis)?

A symptom is something the patient feels and describes to the doctor or those around him/her, while a sign is something the doctor, nurse or others can see/detect. An example of a symptom is pain, while watering eyes could be a sign.

Whooping cough symptoms usually appear between six to twenty days after the Bordetella pertussis bacterium has infected the patient, in other words, pertussis has 6-to-20 day incubation period.

The illness starts off with mild symptoms, which then get much worse before improving.

Initial signs and symptoms of pertussis are similar to those of the common cold:

• Blocked nose
• Dry and irritating cough
• Malaise (general feeling of being unwell)
• Mild fever
• Runny nose
• Sore throat
• Watery eyes

The above signs and symptoms are typical during the first week, after which they become more severe.

Paroxysmal symptoms (more severe, suddenly intensifying symptoms)

During this second "paroxysmal stage", there are extremely intense episodes of coughing, often called "paroxysms of coughing". Symptoms include:

• Severe bouts of coughing - a bout can last a couple of minutes. Sometimes, each bout comes so soon after the last that the patient and those around him/her witness cluster bouts that last for tens of minutes. There are typically ten to 15 bouts each day.


• Coughing with phlegm


• During a bout of coughing, the patient eventually gasps for air between coughs and also immediately after the bout is over, producing a "whoop" sound. This is less common in very young children and babies - they may gag or gasp, or even stop breathing temporarily.
  
  During a coughing bout young children may become blue in the face (cyanosis). Although frightening for parents, it is virtually never as bad as it looks and breathing soon resumes.
  
  (This video contains scenes that some viewers may find distressing)
  


• Coughing bouts followed by vomiting (more frequent among young children and babies)


• Exhaustion and a red face after an episode of coughing

In adults and teenagers, whooping cough paroxysmal symptoms are less severe than in babies and young kids - they are usually similar to the symptoms found in bronchitis.

In very rare cases, whooping cough can cause sudden unexpected death in babies.

Whooping cough - Recovery stage

In this stage the patient starts showing signs of recovery. There are fewer bouts of coughing, which are also less intense. The recovery stage can take three or more months. Even in this stage, the patient can experience bouts of intense coughing.

What are the causes of whooping cough?

As mentioned before, whooping cough is a bacterial infection caused by Bordetella pertussis. Infection occurs in the lining of the airways, principally in the trachea (the windpipe) as well as the bronchi (airways that branch off from the trachea to the lungs.


The bacterium Bordetella pertussis mainly infects the lining of the trachea and bronchi

As soon as Bordetella pertussis reaches the lining of the airways it multiplies, causing an accumulation of mucus. As the mucus builds up, the patients tries to expel it by coughing, the coughing becomes more intense because there is so much mucus.

As inflammation of the airways gets worse (they swell up), they become narrower, which makes it harder to breathe and causes the "whoop" when the patient tries to get his/her breath back after a bout of coughing.

How does whooping cough spread?

People who are infected with Bordetella pertussis can transmit the infection to others from 6-20 days after the bacterium entered their body to three weeks after the start of the "whooping" cough.

The bacterium is transported in tiny droplets of water in the air. When the patient coughs and sneezes, hundreds of droplets of moisture are expelled into the air. If people nearby inhale some of it, they are exposed and could become infected.

Why are there more cases of whooping cough today?

• Whooping cough in the UK - according to the Health Protection Agency, there were 1,080 confirmed cases of pertussis for November 2012 in the United Kingdom, down from 1,631 in October, bringing the total for the year up to the end of November to 8,819. Thirteen infants have died since the beginning of the current outbreak which started in the summer of 2011.

Whooping cough in the USA - according to the CDC, the USA had the highest number of reported cases of whooping cough in 2012 since 1959. From January 1st to the end of June 2012, nearly 18,000 cases of pertussis were reported across the USA.

Washington state health authorities declared a state of emergency last year after reported cases of whooping cough rose 1,300% in one year.

Even though vaccinations against whooping cough are administered extensively all over the USA, people ask why incidence is currently the highest in years. Experts say that this is because:

• The effect of the whooping cough vaccine wears off. Researchers at the CDC (Centers for Disease Control and Prevention) confirmed several studies which showed that between the fifth dose (when the child is 4 to 6 years old) and the booster vaccine (when the child is 11 or 12) the vaccine's protective effect wanes considerably.


• Children do not acquire full immunity to pertussis until the third vaccination is administered. This means that infants age up to six months are at risk of infection.


• The vaccines used today have fewer unpleasant side effects. One drawback though, is that they provide slightly less protection than the older, more powerful vaccine.

How is whooping cough diagnosed?

During its early stages misdiagnosis is common, because the signs and symptoms of early stage whooping cough are similar to those found in other respiratory diseases, such as bronchitis, the flu and the common cold.

A good GP (general practitioner, primary care physician), can usually diagnose whooping cough by asking questions regarding symptoms and listening to the cough (the whooping cough sound stands out).

The following diagnostic tests may be ordered:

• A throat or nose culture test - the doctor or nurse takes a swab or suction sample, which is sent to the lab and checked for the presence of the Bordetella pertussis bacterium.


• Blood tests - the doctor may want to know what the white blood cell count is. If it is high it means there is probably some kind of infection. The white cells help the body fight off infections, including whooping cough. The Health Protection Agency, UK, has made available to UK doctors sophisticated methods for analyzing blood samples and confirming the presence of Bordetella pertussis.


• Chest X-ray - the doctor may want to see whether there is any inflammation or fluid in the lungs. One of the possible complications of whooping cough is pneumonia (plus other respiratory infections).

According to WHO:

• Classic whooping cough (severe pertussis) - consists of 21 or more days of cough illness with paroxysms, associated "whoops" or post-tussis vomiting (vomiting after a bout of coughing), plus culture confirmation.


• Mild whooping cough (pertussis) - is any pertussis that is confirmed in the laboratory that does not meet classic pertussis criteria

If whooping cough is suspected in an infant, he/she may need to be diagnosed in hospital.

What are the treatment options for whooping cough (pertussis)?

Infants are usually admitted to hospital for treatment because for that age group pertussis is more likely to lead to complications. Intravenous infusions may be required if the child is unable to keep fluids or food down. The infant will be placed in an isolation ward to make sure the disease does not spread.

Older children, adolescents and adults can usually be treated at home.

Drugs

• Antibiotics are given to kill the bacterium Bordetella pertussis, and to help the patient recover faster. Antibiotics might be prescribed for household members too.
  
  Antibiotics also stop the patient from being infectious within five days of taking them.
  
  If pertussis is not diagnosed until the later stages antibiotics should not be given, because by then the bacteria have gone.


• Corticosteroids - prescribed if the child has severe symptoms, are administered together with antibiotics. Corticosteroids are powerful hormones (steroids) that are very effective at reducing inflammation in the airways, making it easier for the child to breathe.


• Oxygen - may be given through a facemask if additional help with breathing is needed. A bulb syringe may also be used to suction away mucus that has built up in the airways.


• Treatment for cough - OTC (over-the-counter) cough medications are ineffective at relieving the symptoms of whooping cough, and doctors advise against their use. Unfortunately, there is not much that can be done about the cough. Coughing helps bring up phlegm which has accumulated in the airways.

Measures you can take at home

For older children and adults symptoms are usually less severe. The doctor may advise that the patient get:

• Plenty of rest
• Consume plenty of fluids to prevent dehydration
• Try to keep excess mucus and vomit cleared from the airways and the back of the throat to prevent choking
• Tylenol (acetimophen, paracetamol) or ibuprofen to relieve sore throat and reduce a fever. Do not give aspirin to children aged under 16 years

What are the complications of whooping cough (pertussis)?

Older children and adults - the majority of patients recover from pertussis with no complications or problems. In most cases, complications are caused by the strain of coughing so much and so intensely, and may include:

• A swollen face
• Abdominal hernias
• Broken blood vessels in the sclera (whites of the eyes)
• Cracked or bruised ribs
• Mouth and tongue ulcers
• Nosebleeds
• Otitis media (middle-ear infection)

Infants and young children - are much more susceptible to serious complications from whooping cough, including:

• Pneumonia
• Severe dehydration
• Fits (seizures)
• Hypotension (low blood pressure)
• Kidney failure
• Temporary pause in breathing. If breathing difficulties are severe, there is a risk of brain damage due to oxygen deprivation (extremely rare)
• Weight loss if they vomit excessively

The following groups of people, including older children and adults are also at risk of whooping cough complications:

• Pregnant mothers - usually done at the 20th week of pregnancy. Vaccination also provides the newborn with some protection.


• People with weakened immune systems, such as those undergoing chemotherapy, organ transplant recipients who are on immunosuppressant medications, and people with HIV


• Diabetics and patients with some chronic (long-term) illnesses or conditions, such as asthma or heart failure.

Prevention of whooping cough (pertussis)

This video is from JAMA (Journal of the American Medical Association)


The pertussis vaccine - USA

The most effective way to prevent whooping cough is by vaccinating your child. In the USA doctors usually administer a triple vaccine which protects from tetanus, diphtheria and pertussis. In the USA, the CDC recommends a series of five injections which should be given at the following ages:

• 2 months
• 4 months
• 6 months
• 15 to 18 months
• 4 to 6 years

A booster vaccine should be given when the child is 11 or 12 years old. Adults should also consider booster shots and should discuss with their doctor - some types of tetanus shots which are given every ten years also include protection against pertussis. After twenty weeks of gestation, pregnant women should have a pertussis vaccine.

Side effects may include high fever, seizures (shock or coma) and persistent crying which may last a few hours.

The 5-in-1 vaccine - UK

According to the National Health Service, in the United Kingdom the whooping cough vaccine is administered as part of the 5-in-1 vaccine (DTaP/IPV/Hib). This vaccine protects against diphtheria, tetanus, whooping cough (pertussis), polio, and Hib (Haemophilus influenzae type b).

Babies are given the 5-in1 vaccine at the following ages:

• 2 months
• 3 months
• 4 months
• Between 3 and 4 years of age a booster vaccine (DTap/IPV) is administered before they start school

5-in-1 vaccine available in the USA - The 5-In-1 pediatric vaccine combination was licenced by the US Food and Drug Administration in June 2008.

Written by Christian Nordqvist
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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