Pertussis, known by its common name whooping cough, is a highly contagious disease that affects an estimated 48.5 million people worldwide each year, and results in almost 300,000 deaths.

These numbers seem extremely high, and it is partially due to the subtlety of the disease. Symptoms are typically confused with the common cold and are worse at night, making whooping cough hard to diagnose.

Whooping cough symptoms usually start off very mild and develop into severe coughing fits later on. These coughing fits culminate in the distinct "whoop" sound upon inhalation, giving the cough its name. The coughing stage can last six to eight weeks before getting better. For healthy adults, the cough is mostly just a nuisance. Conversely, for infants this cough can be deadly.

About one-fifth of children seen by their doctors for persistent coughs may actually have whooping cough, according to a study published in the British Medical Journal. Whooping cough is preventable with the vaccine, but it is still kills as many people as it does because the vaccine is not used everywhere – especially in developing countries. However even in the U.S., where the vaccine is widely used, there have been several outbreaks in the last few years.

In 2010, health authorities declared an epidemic in California with 9,120 cases and ten infant deaths. In April and May 2012, there was an epidemic in Washington, reaching 3,308 cases by December. Later that same year, there were pertussis epidemics in Vermont and Wisconsin as well. Most recently, there has been a whooping cough epidemic in California with more than 800 cases reported in the first two weeks of June.

Because of the extremely long duration of the disease, prevention through vaccination is the primary defense against the bacterial infection. Whooping cough is also exceedingly infectious. It is estimated that one person who contracts the cough will infect an average of 12 other people.

Prevention is most important in young children, as the cough can be deadly for them. It is imperative to immunize young infants globally as to prevent further transmission of the disease, and make sure whooping cough epidemics do not become more common.

If you are suffering from whooping cough, unfortunately the disease must run its course and your body will fight it off on its own. Many doctors will recommend antibiotics in order to shorten the duration of infectiousness, and prevent it from spreading to others.

In addition to early prevention through vaccination, there are also booster shots of the vaccine. These are typically given to U.S. adolescents at ages 11 or 12 to “boost” their original vaccination. The vaccine given to infants only provides protection for four to 12 years.

So if you or someone you know is suffering from a persistent cough which lasts weeks, it is advisable to see your physician and make sure it is not whooping cough.