1) It was initially thought that only children can get the disease. However, whooping cough can affect teens and adults who either didn't get vaccinated, or their immunity has faded. The disease affects infants the most severely because death is possible. This is why vaccines are encouraged for anyone coming into contact with the baby, either the pregnant woman herself or any caregiver/relative/etc.
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2) The disease is spread through the air. Any cough erupts particles of the bacteria into the air for anyone close by to breathe in. It is important to cover up the cough as much as possible, or to keep away from other people. Any surfaces in which the cough particles may have landed on must also be cleaned. For example, if a person coughs into their hand and uses the door knob, then the bacteria most likely will spread to clean hands who also use the door. The bacteria is only known to reside inside humans, as there are no current documented cases of it originating from animals.
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3) The condition mainly takes place in the airways or respiratory tract (often known as a respiratory tract infection). The bacteria Bordetella pertussis basically binds itself to the lungs, and that prevents the lungs from cleaning itself, triggering the coughing fit (more specifically the bacteria produces a cytotoxin that causes a chemical reaction to lead to the coughing). Symptoms include: Fever, cough, runny nose, red/watery eyes, nasal congestion, and thick mucus buildup in the airways. Perhaps the most known symptom is the characteristic loud hacking cough, followed by a high pitched inhalation of breath. The cough sounds like a "whoop" which is where the condition gets its name from. Other symptoms may include having a red or blue face, extreme fatigue, and vomiting. Easily the scariest symptom in infants isn't a cough at all, but rather they struggle to breathe or may not breathe at all.
Answers:
(1). Most children and infants, that is why it was previously called childhood disease before the development of the vaccine.
(2).Whooping cough is caused by a type of bacteria called Bordetella pertussis. When an infected person coughs or sneezes, tiny germ-laden droplets are sprayed into the air and breathed into the lungs of anyone who happens to be nearby.
(3).Bordetella pertussis causes the disease, and is not found in any animal or environmental reservoirs, but resides in the mouth, nose, and throat of humans.
