Landmark Developments in Infectious Diseases

A 20-Year Look-Back: Two Steps Forward, One Step Back

Ingrid G. Hein


October 20, 2015

In This Article

Diagnosis and Treatment of Infectious Diseases

Over the past 20 years, molecular biology has drastically changed the way in which we diagnose, prevent, and treat infectious disease. Molecular tools have enhanced the capacity to track transmission of new threats and find new ways to prevent and treat them. Had AIDS emerged 100 years ago, when laboratory-based diagnostic methods were in their infancy, the disease might have remained a mysterious syndrome for many decades.

"Genomes and molecular methods for sequencing have changed everything in the past 20-30 years," says Dr Lance Peterson, director of microbiology and infectious diseases research at NorthShore University HealthSystem in Evanston, Illinois. "We have laid the groundwork for a more personalized approach in medicine."

He says that by understanding both the virus and the individual, we will soon be able to administer more targeted treatment of infections, and have the potential to better understand resistant bacteria.

The cost and time involved in the diagnosis and treatment of infectious diseases have been drastically reduced. "When we started in 1990, it cost $1000 to do a complete bacterial genome. Now it can be done for about $1. Tests to find out whether a patient has methicillin-resistant Staphylococcus aureus (MRSA) now take 2 or 3 hours instead of 3 days," says Peterson.

Peterson talks about the increasing importance of diagnosis, for better antibiotic stewardship. "The difficulty is that a lot of bacteria might be present, but may not be causing infection. So you might get group A streptococcus out of the throat, but you don't really know whether it's causing an infection."

"We have been working on tests to let us know whether the host is responding to the infection—whether treatment is necessary," Peterson says. "For example, in many cities, 10% of the population has C difficile in their stool, but only 4%-5% have the infection. You want to treat infection, not just colonization."


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