In July 2004, the Infectious Diseases Society of America (IDSA) released a report called "Bad Bugs, No Drugs." This report identified several species of antibiotic-resistant bacteria that were expected to play a lead role in the next global health crisis to come. The authors cited a high prevalence of drug-resistant infections--362,000 in the US in 2002--and lack of new antibiotics in development as warning signs. Twelve years have passed since the report published, and according to the CDC, >2 million people become infected and >23,000 die from drug-resistant infections every year. A 2009 paper by Boucher et al implicated six actors from their pathology, persistence, and presence in US hospitals: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter, Pseudomonas aeruginosa and Enterobacter. They termed them "ESKAPE" pathogens.
Examining search terms on Google sheds light on how the public perceives this threat. But is exposure from reports and other publications sufficient to elicit greater public awareness?
First, let's quickly go over our methodology. Some ESKAPE pathogens are represented by their species and others are represented by their genus alone. To see if search interest would vary significantly between genus and species we did a Google Trends search for Staphylococcus aureus, a gram positive bacterium most commonly known for its nosocomial, and deadly, MRSA outbreaks:
The chart above reveals a change in search intensity between genus vs genus+species, and no big difference between genus vs species. As a result, we chose to use genus+species in future searches. Not to get off track, but it is interesting to note that 1) there was a peak in search interest in October 2007 and 2) an overall slight decline in interest in Staphylococcus since 2004. You might be wondering what caused this spike? It turns out the CDC released a report titled "Invasive Methicillin-Resistant Staphylococcus aureus Infections in the United States" on October 17th. A quick search for "MRSA" confirms this, overlapping with one of the first peaks of 'superbug'.
Five killer pathogens...
Second, by using our insight on genus+species we compared the search interest of the five most represented ESKAPE pathogen species, plotted over time since July 2004:
Despite no significant long-term trend, we are immediately drawn to the spike in interest for Pseudomonas aeruginosa, a gram negative pathogen and frequent culprit in respiratory illnesses like ventilator-associated pneumonia and cycstic fibrosis. Two possibilities come to mind: 1) an association with another report or publication or 2) an outbreak that was picked up by the news. Next, we compared this peak with 'cyctic fibrosis' and 'superbug' to see if any overlap existed:
Alas, no clear association was found in these search terms as the impact of Pseudomonas aeruginosa seems unrelated to several uncovered January publications on cystic fibrosis and Pseudomonas. And, as seen above, the public also does yet not associate 'superbug' with Pseudomonas aeruginosa, even if it is multi-drug resistant. So what is causing this peak in Google search terms?
...and a Brazilian supermodel?
We focused in on the peak to pinpoint its maximum as if we were examining a LC/MS readout. Comparing the peak on January 24th 2009 to the term 'outbreak' we found no association between the two:
We did, however, find something unexpected. We searched Pseudomonas aeruginosa on the peak date of January 24th and came across news articles on 20-year old Brazilian model Mariana Bridi da Costa, a Miss World 2008 finalist who was battling septic shock from this "little known" disease. What started out as a urinary tract infection got progressively worse, to the point where both her feet and hands had to be amputated from tissue necrosis caused by sepsis. After a short battle, Miss Da Costa passed away on the 24th. The world knew about it.
What does it all mean?
Although search terms for Pseudomonas aeruginosa eventually decreased over time, awareness was elevated for several months after the story was published. The public was searching more for this pathogen on one day than all ESKAPE pathogens combined, even more so than on March 8th, 2012 when the IDSA released its report promoting antimicrobial stewardship before the House Committee on Energy and Commerce Subcommittee on Health.
Understandably, technical searches such as genus+species are more difficult search terms than 'superbug' or 'MRSA.' However, we don't know which search terms will become popular until the story gets picked up. Government and policy-minded agencies can multiply the impact of news events by promoting simple search terms in conjunction with peak search terms from their counterparts. ESKAPE was an attempt to do this, but unfortunately its awareness is still limited. It is important for policy makers to use the same keywords to promote a unified message to the public. This, in turn, will directly impact how the public perceives the threat to come.
For more information on drug-resistant bacteria please visit: http://www.idsociety.org/Index.aspx
Find your own trends on Google Trends: https://www.google.com/trends/explore