By Kim Smiley

Few people think of the plague as a present-day problem, but a teen boy died of the plague on June 8, 2015 in Colorado.  Officials believe he was bitten by a flea carrying the disease on his family’s farm although the exact source of exposure isn’t known. According to the Centers for Disease Control and Prevention, there are an average of seven cases of plague in the United States a year and a small percentage of these cases result in death.

A Cause Map, a visual root cause analysis, can be built to analyze this case and better understand how a patient died of the plague.  The first step in building a Cause Map is to fill in an Outline with the basic background information to define the issue.  The Outline includes a place to list the impacts to the goals resulting from an issue to help define the scope of the problem.  Focusing on the safety goal for this example, a death would be an obvious impact.  Next, “why” questions are used to build the Cause Map.

So why did the teen die from the plague?  There are two causes that contributed to his death; first, he was infected with the plague and second, he wasn’t treated for the plague.  When there are two causes that both contribute to an issue, both are listed vertically on the Cause Map and separated by an “and”.  So why was the patient exposed to the plague?  Officials believe that he was bitten by an infected flea.  The bacteria that causes plague lives in rodents and their fleas.  Investigators haven’t been able to identify which species of rodent was the culprit.

The teen wasn’t treated for plague because it wasn’t identified that he had the plague until it was too late.  All forms of plague can be successfully treated with antibiotics, but the window for treating the illness before it becomes life-threatening can be relatively short and plague can be difficult to identify.  It is suspected that this patient had septicemic plague which occurs when the plague bacteria enter the bloodstream directly.  Septicemic plague is caused by the same bacteria as the more common Bubonic plague, but the symptoms are different and more difficult to identify.  Rather than the telltale presence of swollen, discolored lymph nodes (also known as buboes) caused by the Bubonic plague, the main symptoms of the septicemic plague are fever, chills and abdominal pain which are very similar to the flu and other common illnesses.  In this heart-breaking case, the family of the teen understandably believed he had the flu and he wasn’t treated for the plague in time to prevent his death.

As alarming as this case is, it is important to note that plague cases in the United States are very rare and occur primarily in two regions – northern New Mexico, northern Arizona, and southern Colorado and California, southern Oregon and far western Nevada. If you are planning to enjoy the outdoors in one of these areas, just remember that the best way to prevent plague is to prevent flea bites.

Click on “Download PDF” above to see a Cause Map and Outline for this example.