Whooping Cough

Whooping Cough Overview

Whooping cough is an infectious bacterial illness that affects the respiratory passages. First described in the 1640s, whooping cough is so named because spasms of coughing are punctuated by a characteristic "whoop" when the person inhales.

• Whooping cough is the most common vaccine-preventable disease among children younger than 5 in the United States. It is also known as pertussis -- the "P" in the DTaP combination vaccine routinely given to children and the "p" in Tdap given to adolescents and adults.
• Despite the widespread use of vaccines, whooping cough has made a comeback in recent years. According to the CDC, prior to the introduction of the pertussis vaccine there was an average of 175,000 cases of whooping cough each year.  This dropped off to fewer than 3,000 cases per year in the 1980s; however, 25,827 cases of pertussis were reported in 2004.  This was a huge increase compared with the 8,296 cases reported in 2002.
  
• The World Health Organization estimates there were more than 17.6 million cases of whooping cough and 297,000 deaths worldwide in 2003, making this easy-to-prevent disease one of the leading causes of illness and death. The WHO estimates that global vaccination prevented about 38.3 million cases and 607,000 deaths.

Whooping Cough Causes

Whooping cough is caused by the bacteria Bordetella pertussis. Humans are the only known reservoir of these bacteria.

• Whooping cough is spread by contact with droplets coughed out by someone with the disease or by contact with recently contaminated hard surfaces upon which the droplets landed. The bacteria thrive in the respiratory passages where they produce toxins that damage the tiny hairs (cilia) that are needed to remove particulate matter and cellular debris that are normally introduced into the airways with each breath.  This results in an increased inflammation of the respiratory passages and the cough, which is the hallmark of the infection. Whooping cough is contagious from seven days after exposure to the bacteria to up to three weeks after the onset of coughing spasms. The most contagious time is during the first stage of the illness.
• Initially thought to be a disease of childhood, recent studies have shown that adults are susceptible to whooping cough and account for up to 25% of cases. The disease, however, tends to be milder in adults and adolescents -- a persistent cough much like an upper respiratory infection or cold. Because of this fine distinction, the diagnosis of whooping cough is frequently missed in that population and thus allows the bacteria to spread to more susceptible infants and children.
• Whooping cough is highly contagious. Between 75% and 100% of unimmunized household contacts of a person with pertussis will develop the disease. Even among fully immunized and naturally immunized people living in the same household, there have been reports of undetectable infection following extreme exposure.