Pertussis (Whooping Cough)

Causes

Pertussis is caused by a bacterium called Bordetella Pertussis.

Pertussis is a highly contagious bacterial infection of the lungs and airways.

Mode of transmission of the disease

People with pertussis are infectious from 6 days after exposure to the bacterium to three weeks after the 'whooping' cough begins.

The Bordetella pertussis bacterium is carried in droplets in moisture in the air. When someone with whooping cough sneezes or coughs, they propel hundreds of infected droplets in the air. If the droplets are breathed in by someone else, the bacterium will infect their airways.

The disease is passed from person to person through droplets in the air from coughing and sneezing. 

The symptoms of pertussis usually take between 6 and 20 days to appear after infection with the Bordetella pertussis bacterium. This delay is known as the incubation period.

The bacterium infects the lining of the airways, mainly the trachea and the two airways that branch off from it to the lungs (the bronchi).

When the bacterium comes into contact with the lining of these airways, it multiplies and causes a build-up of thick mucus. It is the mucus that causes the intense bouts of coughing as yur body tries to expel it.

It also causes the airways to swell up, making them narrower than usual. As a result, breathing is difficult, which causes the 'whoop' as you gasp for breath after a bout of coughing.

The condition begins with a persistent dry and irritating cough that progresses to intense bouts of coughing. Other symptoms include a runny nose, raised temperature and vomiting after coughing.

The coughing can last for around three months. Pertussis tnds to develop in stages, with mild symptoms coming first, followed by a period of more severe symptoms, before improvement begins.

• Runny or blocked nose
• Sneezing
• Watering eyes
• Dry, irritating cough
• Sore throat

The second stage of pertussis is often called the paroxysmal stage and is characterised by intense bouts of coughing. The bouts are sometimes referred to as 'paroxysms' of coughing.

Paroxysmal symptoms include:

• Intense bouts of oughing, bringing up thick phlegm.
• A 'whoop' sound with each sharp intake of breath after coughing
• Vomiting after coughing, especially in infants and young children
• Tiredness and redness in the face from the effort of coughing.

Boughts of coughing last between one and two minutes, but several bouts may occur in quick sucession and last several minutes. The number of coughing bouts experienced each day varies, but is usually between 12 and 15.

The paroxysmal symptoms of pertussis usually last at least two weeks, but can last longer, after treatment. This is because the cough continues even after the Bordetella pertussis bacterium has been cleared from your body. 

Infants younger than 6 months may not make the 'whoop' sound after coughing, but they may start gagging or gasping, and may temporarily stop breating. 

Though rare, it is possible for pertussis to cause sudden unexpected death in infants.

Young children may also seem to choke or become blue in the face (cyanosis) when they have a bout of coughing. This looks worse than it is, and breathing will quickly start again.

Eventually, the symptoms of whooping cough gradually start to improve, with fewer and less extreme bouts of coughing occuring. This period of recovery can last up to three months or more. However, intense bouts of coughing may still occur during this period.

Severe complications:

• Pneumonia
• Temporary pauses in breathing
• Weight loss due to excessive vomitting
• Seizures

Less serious complications:

• Nose bleeds and burst blood vessles in the whites of the eyes
• Bruised ribs 
• A hernia
• A swollen face

This is vaccinated with the 5-in-1 vaccine.