Can age and sex explain the variation in COPD rates across large urban cities?
Age and sex differences account for most of the heterogeneity in COPD estimates across large cities within the same country. Adjustments for age and sex are essential in comparing COPD rates across the country.
This study suggests that O-antigen variation was introduced to the classical bordetellae via HGT through recombination. Additionally, genetic variation may be maintained within the O-antigen locus because it can provide escape from immunity to different O-antigen types, potentially allowing for the circulation of different Bordetella strains within the same host population.