4.2 The perfect rapid diagnostic test

The perfect diagnostic test for bacterial infection should answer four questions:

• Is the infection bacterial or viral?
• If the infection is bacterial, what type of bacteria is causing the infection?
• Are the bacteria resistant to a particular drug?
• Which drugs are the bacteria susceptible to?

Traditional diagnostic tests – such as those shown in Video 4 – can answer all four questions but not quickly. The challenge for rapid diagnostics is to answer these questions within minutes so that doctors and other healthcare professionals can decide which antibiotics are needed.