Anecdote

The doctor who diagnosed typhoid really well.
Lewis Thomas, a doctor in NY in 19th century described the following case. A doctor had very high sensitivity and specificity in diagnosing typhoid fever and he did it simply by physical examination. Every time this doctor said that it was typhoid, in the most cases, it was indeed typhoid fever.

But...... he made the diagnosis by palpating the tongue of the patients..... without gloves..... in a ward where thypoid was endemic.