History of dental caries in Inuit populations: genetic implications and 'distance effect'.

Dental caries is considered the third most important scourge in the world. In North America, Inuit populations are the population the most severely affected by dental caries. It is often assumed that this situation can be explained by a combination of factors classical for Indigenous populations: remoteness (geographical distance), low economic status and low health literacy (cultural distance). Using a bibliographic approach, we tested this hypothesis of the "distance effect" by exploring the caries prevalence in other Indigenous populations living in high-income countries. Next, we tested whether the high prevalence of caries is due to population-specific characteristics by tracking caries prevalence over the past few centuries. In result, we showed that while other Indigenous populations are more impacted by caries than the general populations, the Inuit populations present the highest prevalence. Paradoxically, we showed also that past Inuit populations were almost immune to caries before 1950. These two elements suggest that the prevalence of caries observed presently is a recent maladaptation and that beyond the effect of cultural and geographical distance, specific biocultural factors have to be investigated.

Smell and taste changes are early indicators of the COVID-19 pandemic and political decision effectiveness.

In response to the COVID-19 pandemic, many governments have taken drastic measures to avoid an overflow of intensive care units. Accurate metrics of disease spread are critical for the reopening strategies. Here, we show that self-reports of smell/taste changes are more closely associated with hospital overload and are earlier markers of the spread of infection of SARS-CoV-2 than current governmental indicators. We also report a decrease in self-reports of new onset smell/taste changes as early as 5 days after lockdown enforcement. Cross-country comparisons demonstrate that countries that adopted the most stringent lockdown measures had faster declines in new reports of smell/taste changes following lockdown than a country that adopted less stringent lockdown measures. We propose that an increase in the incidence of sudden smell and taste change in the general population may be used as an indicator of COVID-19 spread in the population.