2.3 Search Term Analysis
Walker et al were unique in their approach and used Google Trends to
track search terms related to loss of smell. They demonstrate
statistically significant association of the Google search terms and the
incidence COVID-19 cases and deaths. The previous figures for the same
time period in 2019 and the H1N1 pandemic were used as controls. This
correlation was present across numerous countries including Italy,
Spain, the United Kingdom (UK), the United States of America (USA),
Germany, France, Iran and the Netherlands. They propose that this data
could be used to track disease hot spots internationally where targeted
control measures could then be implemented. For this to be effective
there needs to be clear data on the positive predictive value of new
onset anosmia and COVID-19 positivity .