Whooping cough can affect anyone of any age. The main symptom is bouts of intense coughing. In between bouts of coughing you can be perfectly well. Sometimes hours go by between bouts of coughing. Whooping cough can be a distressing illness which usually lasts several weeks. Full recovery is usual but serious complications occur in some cases. Whooping cough is uncommon in children in the UK, mainly due to immunisation. However, some adults and older children get whooping cough because the effect of whooping cough immunisation can wane over time in some people.
The number of people infected with whooping cough, including babies, greatly increased in 2011 and 2012. Because of the increasing number of babies infected with whooping cough and the risk of severe illness in babies, a programme to offer whooping cough vaccination to pregnant women was started in October 2012. Whooping cough vaccination has been shown to be safe for pregnant women and effective in helping to reduce the risk of the baby becoming infected with whooping cough.
What is whooping cough?
Whooping cough is an infection caused by a germ (bacterium) called Bordetella pertussis. Whooping cough is also known as 'pertussis'. The bacterium is spread to others through contaminated droplets in the air, produced during coughing. It can also be spread by close contact with an affected person. The bacterium attaches to cells which line the airways. It then multiplies and causes the symptoms.
Bordetella pertussis bacteria affect the lining of the airways in some way to cause the cough to continue for a long time after the bacteria have gone.
What are the symptoms of whooping cough?
The illness typically follows a pattern.
Early stage (catarrhal phase)
At first there is often a sore throat. Within a day or so a mild, dry, ordinary cough develops. At this stage you may feel mildly unwell and have a slightly high temperature (fever). You may also have a runny nose. Over a few days the cough may become more productive with some phlegm (sputum) - but at first it still seems to be an ordinary cough.
Main coughing stage (paroxysmal phase)
After several days, usually 7-14 days from the start of the illness, the cough worsens and becomes paroxysmal. This means there are bouts (paroxysms) of intense coughing. They are sometimes called choking coughs.
- During a bout of coughing, you repeatedly cough over and over again. The face often goes red and the body becomes tense. Eventually, there is a desperate attempt to breathe in, which may cause a whooping sound. Note: the whooping sound at the end of a bout of coughing only happens in about half of cases.
- Some children may stop breathing at the end of a bout of coughing and go blue for a short time. This looks worse than it actually is, as breathing usually quickly resumes.
- Each bout of coughing typically lasts 1-2 minutes.
- Several bouts of coughing may occur together and last several minutes in total.
- It is common to be sick (vomit) at the end of a bout of coughing.
- The number of coughing bouts per day varies from case to case. You may only have a few bouts each day but some people have up to 100 bouts per day. The average is about 12-15 bouts per day.
Between the bouts of coughing you are likely to be well (unless you develop a complication, which is not common). The symptoms of fever, runny nose and other symptoms of illness have usually gone by this main coughing stage. However, each bout of coughing can be distressing.
This main coughing stage of the illness usually lasts at least two weeks and often longer.
Easing stage (convalescent phase)
The bouts of coughing then ease gradually over a period which can last up to three months or more. (In some countries whooping cough is known as the cough of a hundred days.) As things seem to be easing, you may still have the odd bout of severe coughing.
Whooping cough can be very miserable, as the bouts of coughing can be distressing. However, in some cases the symptoms are milder than described above. There may be just intermittent bouts of coughing which are not too bad without any whooping or vomiting.
Who gets whooping cough?
Anybody of any age can get whooping cough. It is usually a more serious illness in young babies under 6 months of age.
In countries with no immunisation, most children develop whooping cough at some stage. In the UK before immunisation was available there was an epidemic every 3-4 years. About 8 in 10 children had whooping cough by the time they were 5 years old.
After immunisation was introduced in the UK in the 1950s, the number of cases fell greatly. There was a slump in immunisation after a scare in the 1970s when there was concern about side-effects from the vaccine. This led to two further epidemics. Each epidemic affected an estimated 400,000 children. Immunisation rates then went up again and most children are now immunised. Whooping cough is now uncommon in UK children but remains a major cause of illness in children in countries with poor rates of immunisation.
Adults and older children
Whooping cough is not just a childhood illness. Adults can get whooping cough. Indeed, because of immunisation, most cases in the UK now occur in older children and in adults. This is because some adults have not been immunised. Also, the protection from whooping cough immunisation may wane over the years in some people. So, even if you were immunised as a young child, you may still get whooping cough as an older child or adult.
It is hard to prove the diagnosis of whooping cough definitely from tests (see below). Whooping cough is probably a common cause of many 'mystery coughs' which last for several weeks.
How infectious is whooping cough?
It is very infectious in the early stage of the illness, ie for the first three weeks. You will normally pass on the infection to most household members who are not immunised (or who have not previously had whooping cough). Symptoms develop 7-20 days after being infected.
If you have whooping cough you should stay away from others either:
- Until you have finished a five-day course of antibiotics (see below).
- Or, if you do not have antibiotics, for three weeks after symptoms start. After this, although you will probably still have bouts of coughing, you are not likely to be infectious.
Government advice is that children should stay off nursery and school for this period of time (five days if on antibiotics, three weeks if not). Adults who work in healthcare or with young babies should also stay off work. Others whose work does not bring them into contact with vulnerable people do not necessarily need to stay off work.
How is whooping cough diagnosed?
Whooping cough is often diagnosed by the typical symptoms. If it is suspected, you may have a test to confirm the diagnosis. However, results can take some time, so you will normally be treated without waiting for a result if your symptoms are typical.
In the early stages, there is a test that can identify the germ (bacterium) to confirm the diagnosis. This involves taking a swab from the very back of the nose to send to the laboratory for testing. A swab is much like a cotton bud on a long stick or wire. This is passed right through your nostrils to the back of the nose and is rather uncomfortable. However, in many cases of 'cough for several weeks', the bacterium that causes whooping cough will have gone but the cough usually continues for several further weeks. Therefore, a negative test, with no bacteria found, does not rule out the diagnosis of whooping cough in someone who has been coughing for several weeks.
A blood test may also be used, especially in adults. This test detects the protective proteins your immune system produces (antibodies) in response to the whooping cough bacterium. These antibodies can also be detected in a sample of fluid from the mouth and this may also be tested. These tests for antibodies are done in people who have had symptoms for more than two weeks.
What are the possible complications?
Most people fully recover but some develop complications. Complications most commonly develop in babies under the age of 6 months. Possible complications include:
- Lung infection (pneumonia). Other germs (bacteria) can infect the lungs more easily if you have whooping cough. So, pneumonia caused by other germs (secondary infections) sometimes occurs. Pneumonia is suspected in a baby or child if they become more ill, have a high temperature (fever), breathe fast, or have difficulty breathing between bouts of coughing.
- Pressure effects of the severe coughing can, rarely, lead to some complications. For example, it can cause blood vessels to burst, resulting in nosebleeds, blood in the eyes (subconjunctival haemorrhage), or skin bruises. Also rarely, the increased pressure can cause ribs to break (fracture) or a hole in the lung (pneumothorax). The increase of pressure in the tummy (abdomen) during bouts of coughing may cause a split in the muscle wall, called a hernia. It can also cause incontinence of urine.
- Rarely, brain infection or damage occurs.
Complications such as severe pneumonia or brain damage can sometimes cause death.
What is the treatment for whooping cough?
The germ (bacterium) which causes whooping cough can be killed by antibiotics. However, once the bouts of coughing have started, treatment with antibiotics makes little impact on the course of the illness. In effect, the bacteria will have done what they need to do to the airways to set off the bouts of coughing for the next few weeks.
However, a course of antibiotics is still usually given if the disease is diagnosed in the first three weeks of the illness. This is because after five days of antibiotics you are no longer infectious. Without antibiotics, you can remain infectious for about three weeks after the bouts of coughing start.
- General comforting.
- Clearing away any mucus and sick (vomit) during bouts of coughing to prevent them from being inhaled by the child.
- Looking out for complications such as pneumonia which may be more serious.
- Making sure an ill child is getting enough food and drink.
Can whooping cough be prevented?
A course of antibiotics may be given to non-immunised people who have come into close contact with a person with whooping cough. This may prevent the illness from developing. This is particularly used for young babies, as they are most at risk of a more serious form of the illness. It may also be used for people who are likely to come into contact with small babies.
Also the antibiotics given to people who have whooping cough are really for prevention rather than cure. They make that person less infectious to others. This also means the child or person with whooping cough can go back to school or work more quickly.
In the UK, immunisation against whooping cough is routinely offered to all children. It is part of the triple vaccine. Three doses are usually given at ages 2, 3 and 4 months and then a preschool booster at ages 3-5 years. Immunisation is good but not 100% effective. This is why some immunised children still get whooping cough. Also, as mentioned above, the effect of the immunisation may wane over the years. This is the reason why some older children and adults who were immunised as a young child develop whooping cough.
In order to help protect young babies from becoming infected with whooping cough, a programme to offer whooping cough vaccination to pregnant women was started in 2012. The vaccine helps the pregnant woman develop antibodies and these are passed on to the baby in the womb. In this way, the newborn baby has some protection against whooping cough to protect him or her until he or she is old enough for routine immunisations.
What is the outlook (prognosis)?
Most people who develop whooping cough make a full recovery. However, it can be a miserable illness, as the relentless bouts of coughing can be distressing. The total length of the full illness is commonly 6-8 weeks but often lasts three months or more. Severe complications and death are uncommon but occur mostly in babies under 6 months of age. Serious illness is less common in older children and adults. Once recovered, you are usually then immune to whooping cough and so are very unlikely to get it again.
Further help & information
Dr Tim Kenny
Dr Mary Harding
Dr Helen Huins