Pertussis In Humans

Pertussis is a very contagious disease of the mucous membranes that line the air passages. It is also called whooping cough. Pertussis is caused by Bordetella pertussis, a bacterium. Pertussis occurs worldwide. Pertussis bacteria live in the mouth, nose, and throat of an infected person. Pertussis spreads easily from person to person. People get pertussis by breathing in droplets expelled from the nose or throat of an infected person during coughing or sneezing. It is also spread by direct contact with discharges from the nose or throat of an infected person. Pertussis begins as a mild upper respiratory infection. The first symptoms are like those of a cold, including sneezing, runny nose, low-grade fever, and a mild cough. Within 2 weeks, the cough becomes much worse. Children with pertussis often have episodes of rapid, spasmodic coughing followed by a characteristic intake of breath that sounds like a "whoop." The violent coughing spells are worse at night and can last for as long as 1 to 2 months. The spells can make it hard for a child to eat, drink, or even breathe. Infants under age 6 months, adolescents, and adults generally have milder symptoms without the typical whoop. Symptoms usually appear in 5 to 10 days but can take as long as 21 days.Pertussis can usually be diagnosed by symptoms. The disease can be missed in persons who do not have the characteristic "whoop." Anyone can get pertussis, but children, especially unvaccinated or incompletely vaccinated infants under age 1 year, are most at risk. Pertussis can result in serious complications, including middle ear infections, pneumonia, convulsions (seizures), disorders of the brain, and brief episodes of stopped breathing. Pertussis causes about 9 deaths per year in the United States.