JMIR Publications

ABSTRACT

Background:

The coronavirus disease 2019 (COVID-19) is a novel viral illness that has rapidly spread worldwide. While the disease primarily presents as a respiratory illness, gastrointestinal symptoms such as diarrhea have been reported in up to a third of confirmed cases.

Objective:

This study examined whether internet searches in the United States for gastrointestinal symptoms associated with COVID-19 increased prior to the rise of confirmed cases.

Methods:

The search terms chosen for analysis in this study include common gastrointestinal symptoms such as diarrhea, nausea, vomiting, and abdominal pain. Furthermore, fever and cough were used as positive controls and constipation as a negative control. Daily query shares for the selected symptoms were obtained from Google Trends for the first 3 months of 2020 from the 25 most populous U.S. states. These shares were divided into two time periods: pre-COVID-19 (prior to March 1) and post-COVID-19 (March 1-March 31). Confirmed COVID-19 case number was obtained from the Johns Hopkins University Center for Systems Science and Engineering data repository. Moving averages of the daily query shares (normalized to baseline) were then analyzed against the confirmed disease case count to establish a temporal relationship.

Results:

While the search count of many symptoms including nausea, vomiting, abdominal pain, and constipation remained near or below baseline throughout the time period studied, there was a notable increase in searches for the positive controls, “fever” (ratio 1.69, P <.001), and “cough” (ratio 1.49, P <.001), as well as for “diarrhea” (ratio 1.25, P <.001). This increase in daily search queries for fever, cough, and diarrhea preceded the rapid rise in case number by about 10-14 days.

Conclusions:

Google searches for symptoms may precede the actual rise in cases and hospitalizations during pandemics. During the current COVID-19 pandemic, this study demonstrates that internet search queries for “fever”, “cough”, and “diarrhea” increase prior to confirmed case count by available testing. Internet query search data may be a useful tool at a population level to identify areas of active disease transmission.