The medical name for whooping cough is pertussis (per-TUS-is). In some children whooping cough can cause serious illness. Children and adults who have whooping cough spread the illness by coughing and sneezing contaminated droplets which are highly infectious. These infected droplets are breathed in by those people who may be in close contact.
Once inside the airways the pertussis bacteria produce chemical toxins that interfere with the respiratory tract’s normal ability to eliminate bacteria. These bacteria also produce chemicals, causing inflammation, which damage the lining of the airways of the lungs.
Pertussis was once considered to be an old-fashioned illness, only dangerous to children. Now, however, it seems to be making a comeback, not only in young children, but also in older children and adults who had been vaccinated previously, which was thought to last a lifetime. It appears that the vaccination starts to lose its effectiveness between the ages five and 10, leaving older children and adults susceptible to the illness.
In Australia, for instance, the number of people diagnosed with whooping cough is the highest it’s been in 20 years and in 2012 the states of Queensland, New South Wales and Victoria recorded the highest infection rates at 7,526, 5,808 and 4,409 respectively. The country had a record 38,500 cases of whooping cough diagnosed in 2011, and in 2010 there were four people diagnosed with whooping cough every hour.
Pertussis often goes undiagnosed or misdiagnosed in both children and adults, and the cough may be misdiagnosed as bronchitis or asthma. Before the pertussis vaccine was developed in the 1940s, whooping cough killed close to 10 000 people in the USA each year. Today, the annual number of fatalities in the US has dropped to around 20, with more than half of those being babies less than one year old.
During the late 1970’s and in the 1980’s there were many severe epidemics of whooping cough when fewer babies were immunised against pertussis as their parents chose not to vaccinate their children. Also the level of protection offered by the vaccine declines steadily during childhood and booster vaccinations are required to offer continued protection against this illness.
Although whooping cough is caused by bordetella pertussis bacteria, similar bacteria, known as bordetella parapertussis, causes ‘parapertussis’, which is usually a milder and less often fatal form of whooping cough, although the symptoms are very similar to pertussis itself.
Who’s at risk?
- Worldwide it still causes an estimated 300,000 deaths per year, and in non-vaccinated populations it remains a major health risk for children.
- If anyone in a household contracts pertussis, there is a 90 percent likelihood of non-immune family members contracting it too.
- Infected teenagers and adults, who may not be diagnosed as having the disease at first, are regarded as the major source for spreading pertussis to infants and children.
- Pertussis cases mainly occur in unvaccinated or incompletely vaccinated infants.
- Many cases, however, are adolescents and adults who were previously vaccinated, but where protection from the pertussis vaccine has decreased over time.
Symptoms and signs
Whooping cough may last from 10 to 12 weeks and there are three distinct stages of this illness:
This stage resembles a cold and usually lasts two to three days starting off with sneezing, tearing of the eyes, a runny nose and red watery eyes. Loss of appetite, listlessness and a dry cough, first at night then also during the day are early symptoms. There is usually no fever. This stage is the most contagious part of the illness.
The cough becomes severe after three to four days with bouts of distressing coughing spasms, followed by the characteristic whoop at the end of the coughing spell. They are often worse at night and may result in vomiting. Children may go red or blue in the face and stringy white mucus often flows from the nose and mouth. Nose bleeds and small bleeds in the whites of the eye may occur due to the severity of the coughing spells. In infants it is more common to have choking spells than whooping. Again there is no fever.
This usually begins at any time between six and 12 weeks after the onset of the typical cough and symptoms start to decrease in severity. There are less frequent and severe coughing spells, especially during the day, also less vomiting, and the child starts to look healthier. Although the symptoms gradually become progressively less severe, coughing at night may continue for up to six months in some children.
When see your doctor
It is important to see your doctor immediately if you suspect your child has pertussis. Also, call your doctor if your child has been exposed to someone with pertussis, even if your child has already received all of the scheduled immunizations.
The doctor can confirm the diagnosis of pertussis by taking special swabs from your child’s nose and sending them to a laboratory where Bordetella pertussis bacteria are identified. Blood tests are also helpful in confirming the diagnosis, especially if a considerably increased white blood cell count is found.
Older children who have whooping cough do not necessarily need bed rest if their symptoms are mild. Because the child may have many vomiting spells, it is essential to see that he or she remains hydrated. Giving frequent small meals helps reduce the chance of vomiting and will keep nutrients in the child’s body. Water, fruit juices and clear soups help prevent dehydration. Steam inhalation can also prove beneficial for clearing the airways and facilitating breathing.
Antibiotics will eradicate the bordetella pertussis bacteria that cause whooping cough. Antibiotic treatment also reduces the spread of the disease to the rest of the family. Some doctors recommend giving preventive antibiotics to help stop the spread of the pertussis bacteria within the household, and also giving vaccine boosters to family members.
Infants with whooping cough usually require hospitalisation. Expert care is important during the critical stages of the disease and almost all infants who are less than six months old will need hospital treatment for their illness. About 40 percent of older babies with pertussis will also be hospitalised. Many of these children may develop pneumonia associated with this infection. While in hospital, an infant or child with pertussis will need suctioning of the thick respiratory mucus, and additional oxygen is often required.
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