Lack of diagnostic tests

Antibiotics aren’t effective against viral infections. Similarly, an antibiotic won’t be effective against a bacterium that is already resistant to it.

Rapid diagnostic tests that tell us this basic information are few and far between, so healthcare practitioners often have to treat empirically until the results from slower diagnostic tests are available. This is essentially a “best guess”, based on the presentation of symptoms and information on the known infectious diseases common to the area at the time. The treatment is often correct, but not always, and this can lead to the inappropriate use of antibiotics. This results in the patient being sicker for longer, and greater opportunity for bacteria to evolve resistance.

Making a test which is rapid, cheap and can accurately diagnose many different types of bacteria and resistance types is challenging, which is why there are so few of them. Below are the questions an ideal test would answer (adapted from amr-review.org).

Criteria for a good diagnostic test (Click image to expand) © Josie Bryant 2017

Whole genome sequencing has the ability to provide answers to all the above questions, however there are practical and cost barriers that prevent it from being used routinely.