Yellow fever was once a feared disease and remains an ongoing cause of illness and death. It was commonly called Yellow Jack because a yellow flag (a jack) was often raised to warn people when the fever had been detected. As the disease could spread rapidly, the flag was seen as a warning that illness and death awaited travellers to an infected area. In the seventeenth century, yellow fever was often carried by members of the crews of sailing ships. This may have inspired the legend of the Flying Dutchman, a ship that inhabited by the ghosts of sailors who had died from the infection. It was doomed to roam the seas for eternity because no port would allow entry to a vessel infested with this deadly disease. Other terms for yellow fever include black vomit and black blood, symptoms of a severe form of the disease. The disease caused fear because outbreaks often began without warning, rampaging through towns and cities for weeks or months, killing up to 10% of the population. Then it would disappear as quickly as it started, only to reappear several years later. This fear was made worse because no one knew how yellow was spread [1, 2].