Using photo-epidemiology, we found extreme variation in COVID-19 related face covering use in Phnom Penh, Cambodia (97%); Lima, Peru (86%); Kerala, India (41%); Cuernavaca, Mexico (25%); Atlanta, USA (21%); and Kinshasa, DRC (4%) probably attributable to differences in population experience with face coverings and variations in timing and implementation of relevant advisories.
Photo-epidemiology to estimate face covering use in select areas in Asia versus the Americas and Africa during the COVID-19 pandemic