A. Some diseases are covered as a group, for example, “Arthropod-borne viral arthritis and rash” and “Viral encephalitides, mosquito-borne.” Specific diseases within the group are listed in the synonyms and diseases index.
B. Not covered in IDdx are congenital and neonatal infections.
*CCDM = Control of Communicable Diseases Manual
The aim is to list all common findings for each infectious disease (except for findings of congenital and neonatal infections).
A. The general symptoms (prefixed with the > symbol) are usually present as initial symptoms.
B. The complications (prefixed with the * symbol) may be extremely rare for the disease, but they are still important to describe because of their impact on individual and public health. For example, only about 1 per 100,000 patients with measles develop subacute sclerosing panencephalitis.
When building a differential diagnosis list, think “zoom-intersection” rather than a laundry list of every symptom.
A. General symptoms like fever and fatigue are not very useful in narrowing down the list.
B. An effective query will combine one or more findings with one or more epidemiological factors.
C. The opening search screen also provides five additional ways to narrow the list: Category (including “Exclude Localized Infections”), Endemic, Acuity, Incubation Period, Occupation, Immunocompromised at Risk, and Only Bioterrorism Diseases.
You may limit the results by selecting a category of Acuity.
A. Be aware that these categories overlap, and that diseases can present in different ways.
B. For example, while tuberculosis is classified as subacute/chronic, it may sometimes present as either acute-severe (emergency admission), or acute-moderate (recent onset of symptoms treated in a clinic).