Monitoring a toxicological outbreak using Internet search query data

A novel group of drugs of abuse colloquially known as "bath salts" had a dramatic rise in exposures recently noted in Europe and the United States. Internet search query data have been shown to be correlated with office visits for influenza-like illnesses. The purpose of this study was to determine whether internet search query data could have been used as a surveillance method for this outbreak.

This was a retrospective database review of the National Poison Database System and internet search query data provided by Google Insights for Search (GIS) comparing exposures reported to "bath salts" with internet searches for "bath salts".

1072 cases of exposures to "bath salts" were reported to US poison centers from 7/1/10 to 2/28/11. GIS data for the search term "bath salts" had a correlation of 0.84 with exposures to bath salts reported to US poison centers over the study period. Poison center exposures and GIS data did not differ significantly in detecting a change from the baseline (p = 0.85). When comparing exposures by state to search volumes by state for "bath salts", the correlation was 0.79. Symptoms and treatments were typical of an exposure to a sympathomimetic drug.

Internet search data correlated very well with exposures reported to US poison centers for a novel drug of abuse. In this particular outbreak, it is possible that using internet search data may have provided a means for public health officials to monitor the rise in usage on a national and regional basis.