Making a List and Checking it Twice

Serologic tests are often used to establish the diagnosis of leptospirosis and ehrlichiosis. Establishing a diagnosis of leptospirosis is challenging and requires a high index of suspicion. Clinicians should be aware of the limitations of the diagnostic accuracy of the serologic assays for leptospirosis because they are frequently negative in the first week after symptom onset. The classic finding of conjunctival suffusion is helpful in differentiating leptospirosis from human ehrlichiosis (HE). The case study discussed in the chapter highlights the importance of the clinical practice of making a list of suspected diagnoses, remaining open to these possibilities, and checking serologic tests again in convalescence to confirm the diagnosis.