Now, back to our Mongolian Mystery.
- Click on Diagnosis tab under Infectious Diseases. In country list, choose Mongolia. Note that many countries have alternate names – such as Democratic Republic of Congo for Zaire. You can access the alternate country list by pressing the icon to the right of the ‘Disease acquired in’ list, and scroll to any unfamiliar designation to access its official name in GIDEON.
- If you wish, you can add the dates on which disease began; and when exposure began and ended. In the present case, it might be useful to know when the patient entered (or left) Mongolia; when he was in contact with rats, etc. These details can be entered by clicking the small ‘Calendar’ icons below the country name – or by entering the data manually. Such details will help to narrow the differential diagnosis by factoring in the element of incubation period. So, lets say that the patient entered Mongolia on January 1 and became ill on January 20.
- In the Clinical Presentation screen, you may indicate the presence or absence of any number or combination of clinical and laboratory findings. Place the cursor on the desired sign and click once (yes) displays , or twice (no) displays . Note that major categories are subdivided (ie, hemoptysis is a subheading in ‘Pulmonary, thoracic or cardiac). Subheadings can be accessed by clicking the small + sign to the left of the desired category. In some cases, there are sub-sub categories (ie, Neutrophilia is a category under Hematological, which is in turn under Laboratory tests). Also note that as your cursor passes through the names of signs and symptoms, text boxes appear with relevant images, followed by a definition of each finding.
After you have entered this patient’s clinical picture, the screen should look something like this:
Now you can see the Diagnosis results in the box below. GIDEON will list a ranked differential diagnosis list for this patient as follows:
At this point, you have a number of interesting options – appearing as buttons on the top right. You may E-mail or Print the case; or ask GIDEON why a given disease did not appear among the diagnoses by clicking on the Why Not button. For example, you may have felt that this patient is suffering from Lassa Fever. Press ‘Why Not’ and scroll to Lassa Fever. Read the attached box to see why this is not possible:
You may have noted that we only entered a few symptoms and signs. What additional information would help GIDEON sharpen the diagnosis in this case. The Compare option allows you to access further discriminative findings which would distinguish among the listed diseases (2-or-more at a time; or all together). Simply mark the diseases in question using the mouse, and press the button at the bottom left corner of Diagnosis results box.
In this case, I have chosen to compare the top 5 disease results:
Note from the resulting list that GIDEON considers an Ingestion history and Cough to be key discriminative findings in this case (ie, listed first in this screen). Also note that additional clues for each disease are listed at the bottom of the chart.
Do you remember the rats which entered our patient’s tent? Go back to the Diagnosis screen and scroll down to ‘Exposure’. and click +, then + for ‘Animal’ and Check for ‘Rodent’. It should look as follows:
Now you can see the new Diagnosis results displayed, as shown in the screen below:
In essence, you have ‘told’ GIDEON to limit diagnoses to those associated with rodents. Similarly, you might have changed the country name – i.e., what diseases should we consider if a patient returns from Romania with identical signs and symptoms?
At this point you have several options:
- Click on the disease names listed in blue. The resulting screens allow you to explore the clinical features and epidemiology of diseases listed in the differential diagnosis. For example, the General note tells us the following about plague:
- Specific worldwide distribution information can be found by clicking the Distribution tab. Additionally, the presence of a blue ‘globe’ icon next to a disease name indicates that specific country information is available. Upon clicking the globe icon, a note for plague in Mongolia appears as follows:
- You can also see images and clinical information by choosing the associated tab:
If you wish, you can also use the Diagnosis module to simulate diseases. For example, how many different diseases are associated with diarrhea, worldwide? … or in your country?