Analysis of Google Trends queries in Russia during the coronavirus infection pandemic as a tool for epidemiological surveillance

Online queries as a criterion for evaluating epidemiological status and effectiveness of COVID-19 control measures in Russia: results from Yandex.Wordstat analysis

“…Our study demonstrated a strong correlation (r>0.7) between the number of smell-related queries in Yandex and new COVID-19 cases in 59 regions and 85 large cities of Russia (70%). The obtained results are consistent with our previous data that revealed a strong correlation between smell queries and new infection cases (r=0.81) in Russia using Google Trends 18. Higgins et al 22 also pointed out that worldwide search queries related to shortness of breath, anosmia, dysgeusia and ageusia, headache, chest pain, and sneezing had a strong correlation (r>0.60; p<0.001) both with daily new confirmed cases and with the number of deaths caused by COVID-19.…”

“…The obtained results are consistent with our previous data that revealed a strong correlation between smell queries and new infection cases (r=0.81) in Russia using Google Trends. 18 Higgins et al 22 also pointed out that worldwide search queries related to shortness of breath, anosmia, dysgeusia and ageusia, headache, chest pain, and sneezing had a strong correlation (r>0.60; p<0.001) both with daily new confirmed cases and with the number of deaths caused by COVID-19. Similar results were obtained by Walker et al 19 who found a strong correlation between daily RSV associated with loss of smell, the daily increase in COVID-19 cases, and deaths ranging from 0.633 to 0.952 (p<0.05) in several countries.…”

“…During the second peak of the coronavirus infection incidence in Russia, the increase in the number of smell-related queries outpaced the increase in new infection cases by 1-2 weeks in 36 regions of Russia, including Moscow. In 14 regions, the increase in queries Table 1 The gap in weeks between an increase in the number of online smell-related queries and an increase in the number of new cases of COVID-19 over two periods (13)(14)(15)(16)(17)(18)(19)(20)(21)(22) Open access outpaced the increase in new infection cases by more than 2 weeks. A previous study also showed the time interval between the onset of COVID-19-associated symptoms and their actual detection.…”

“…In a previous study, we demonstrated a strong correlation between the relative search volume (RSV) in Russia when using Google Trends to assess ‘smell’ queries and actual infection cases (r=0.81). 18 The interest in the above queries increased along with the number of new cases from 16 March 2020 to 11 May 2020 and 27 August 2020 to 1 October 2020 (r=0.93 and 0.87, respectively). From 2 April 2020 to 12 April 2020, the increase in queries outpaced the increase in actual COVID-19 cases by 2–5 days.…”