Whooping cough, or pertussis, is a contagious disease. Unlike some other diseases, a new born baby has no immunity to this disease, and can contract it at any time after birth. It commonly affects infants during the first year of life although many cases occur in children up to 5 years of age. Pertussis is primarily spread from person to person by direct contact with mucus or droplets from the nose and throat of infected individuals. Frequently, older siblings who may be harboring the bacteria in their nose and throat can bring the disease home and infect an infant in the household.The disease may cause serious trouble in the lungs.
This highly infectious disease is caused by bacteria. It spreads rapidly from one person to another by droplet-infection. This is especially true during the early catarrh stage, but once the typical spasmodic bout starts, the infectivity becomes negligible. This disease has a prolonged course of 8 to 10 weeks.
Persons with pertussis are most infectious during the catarrhal period and during the first two weeks after onset of the cough (approximately 21 days), or in most cases until 5 days after the start of appropriate antimicrobial treatment.
The disease has a catarrhal and a spasmodic stage. For the first week, the cough is like an ordinary upper respiratory catarrh. At the end of a week, it becomes spasmodic and comes in bouts - initially more often during the night, but later during the day as well. When a child suffers from whooping cough, his face becomes red and suffused, the tongue protrudes and the eyes begin to water. At the end of the bout, the child takes a deep breath, and there is a prolonged croaking sound which is called a whoop, hence the name of the condition. The sound is produced by the air entering through a partially closed glottis, the entrance to the larynx. There can be a sticky secretion from the nose and mouth and vomiting usually follows. At the end of the bout, the child lies back exhausted. Gradually, the duration of the coughing bouts decreases and disappears altogether about 8 to 10 weeks from the onset.
Due to the severity of the coughing bouts, bleeding can occur into the eyes, from the nose, the lung, and in rare cases, into the brain, resulting in convulsions. In many young children, lung complications are common because of the thick sticky nature of the secretions blocking the passage of air to the lung. Secondary infection may result in pneumonia. They may be convulsions, and in rare cases, inflammation of the brain.
Whooping cough is caused by micro-organisms, or bacteria, called Bordetella pertussis and Bordetella para pertussis. Bordetella pertussis is the more severe. These bacteria attach to the cilia (tiny, hair-like extensions) that line part of the upper respiratory system and release toxins that lead to inflammation and swelling. Whooping cough is also associated with various adenoviruses, parainfluenza and respiratory viruses.