Whooping Cough Pertussis

Pertussis (also known as whooping cough) is a bacterial infection of the respiratory tract caused by the bacterium Bordetella pertussis.  It is commonly found in many countries and is common in children everywhere, regardless of ethnicity, climate, or geographic location. Pertussis is among the most lethal diseases of infants and young children in non-immunised populations.

Parapertussis is a similar but milder disease caused by Bordetella parapertussis.

Pertussis occurs worldwide. Outbreaks of pertussis occur every 3 or 4 years, primarily in the developing world where vaccination coverage is low. There has been a significant decline in incidence and mortality rates over the past 40 years, mainly in communities with active immunization programs and where good nutrition and medical care are available. In countries with high vaccination coverage, the incidence rate of pertussis in children under 15 is less than 1 per 100,000. The majority of deaths caused by pertussis occur in Africa, where vaccine coverage is lowest.

Anyone who is not immunised for pertussis is susceptible. The highest number of cases of pertussis occur among children less than 5 years of age, except where infant vaccination programs have been implemented. In these areas, adolescent cases of pertussis are becoming increasingly more frequent in those who have not had booster immunizations.

Females are more likely to acquire infection and die from pertussis than males.

When a person has recovered from pertussis, they acquire prolonged immunity, but subsequent re-infections can occur.

The first stage of pertussis usually lasts from one to two weeks and is called the catarrhal stage. Symptoms include runny nose, sneezing, and a mild cough that gradually becomes more severe.

The second stage usually lasts from one to six weeks but may persist for up to 10 weeks and is called the paroxysmal stage. Symptoms include bursts of violent, rapid coughing due to difficulty expelling thick mucus from the lungs. Coughing episodes occur more frequently at night, with an average of 15 to 24 attacks over 24 hours. Coughs are followed by a noisy, high-pitched, “whooping” indrawn breath.  Vomiting and exhaustion typically follow coughing episodes.

During the third stage of pertussis, known as the convalescent stage, the patient gradually recovers. The cough becomes less severe and usually disappears over two to three weeks. Paroxysmal coughing can recur with subsequent respiratory infections for many months.

Complications of pertussis can include: pneumonia; atelectasis (partial or total collapse of a lung or segment of a lung); seizures; encephalopathy (disease, damage, or malfunction of the brain); weight loss; hernias; death.

When given early in the course of the disease, antibiotics (erythromycin, clarithromycin, and azithromycin) decrease the duration of infectiousness and help prevent spread of pertussis. Antibiotics that are given later in the course of the illness will not alter the symptoms. Effective treatments of the cough associated with this illness have not yet been developed.

Pertussis occurs worldwide. Outbreaks of pertussis occur every 3 or 4 years, primarily in the developing world where vaccination coverage is low. Over the past 40 years, there has been a significant decline in the number of cases and deaths due to pertussis, mainly in communities with active immunization programs and where good nutrition and medical care are available.