We suggest that careful enquiry observes a higher prevalence of migraine by capturing milder cases (ie, by better case ascertainment), and that, although both of these explanations may contribute in part, migraine is indeed more prevalent than past estimates have suggested.
This explained the second disproportionate enquiry peak observed during the followed winter seasonal wave of influenza.
The seasonal Google enquiry peak, observed during the winter of 2005-06, was much higher than that observed in the preceding and following seasons.
Another major peak of enquiries was observed during the late summer at the start of the academic year.
Indeed, in 2005 when the novel A/H5N1 avian Influenza virus which was potentially highly pathogenic for humans, emerged [16], [17], the first big Google enquiry peak was observed.
During the current pandemic, a major enquiry peak was observed when the World Health Organization announced the emergence of A/H1N1 [18], although it had been featured on the news media for some time.
The first peak of enquiries (P1, figure 5) was observed in late April 2009, when the World Health Organization officially announced the emergence of the novel A/H1N1 virus [18], reflecting the anxiety of the population following news media reports that A/H1N1 was causing epidemics in the Americas, and as previously observed when A/H5N1 avian influenza was widely reported in the news media.
For the latter, even if he himself observed a particular battle, he made as thorough an enquiry as he could for he realized that eyewitnesses, either from faulty memory or from bias, were not always reliable.
This pattern is very similar to the ethnic differences in maternal death rates observed in the most recent reports from the Confidential Enquiry into Maternal and Child Health.
Based on the information obtained from GIFS, enquiries concerning RSV in France correlated closely with the incidence data observed in the Marseille Virology laboratory (figure 4A).
