Respiratory virus infections in decedents in a large, urban medical examiner's office.

OBJECTIVE: Most respiratory virus surveillance relies on medically attended respiratory illness, but an understanding of the true patterns of infection independent of care-seeking behaviour would enhance clinical and public health responses to respiratory virus outbreaks. We evaluated the potential of decedent surveillance by estimating the burden of respiratory virus infection in decedents in a large, urban medical examiner's office. STUDY DESIGN: Observational. METHODS: In 2020-2022, we tested nasopharyngeal swabs from 4121 decedents in Detroit, Michigan for 15 respiratory viruses, including SARS-CoV-2, respiratory syncytial virus, and influenza virus A and B. We analysed infection prevalence over time and by age, sex, race/ethnicity, and manner of death. RESULTS: Of 4113 valid tests, 30.2% were positive for at least one virus, and 6.1% were positive for multiple viruses. All viruses were detected except for influenza A/H1N1 and influenza B. The most prevalent viruses were SARS-CoV-2 (15.7%), rhinovirus (11.2%), and adenovirus (4.9%), which were detected in all months. Most viruses exhibited decreasing prevalence with age, higher prevalence among Black and Hispanic than among White decedents and lower prevalence among deaths from natural causes; SARS-CoV-2 was a notable exception to the patterns by age and manner of death, instead reflecting community trends in catchment counties. CONCLUSIONS: There was high prevalence and diversity of respiratory viruses in decedents entering a large, urban medical examiner's office. Decedent surveillance could offer a clearer picture of the true underlying burden of infection, motivating public health priorities for intervention and vaccine development, and augmenting data for real-time response to respiratory virus outbreaks.

Racial inequality in the annual risk of Tuberculosis infection in the United States, 1910-1933.

Tuberculosis (TB) mortality rates in the USA fell rapidly from 1910 to 1933. However, during this period, racial disparities in TB mortality in the nation's expanding cities grew. Because of long delays between infection and disease, TB mortality is a poor indicator of short-term changes in transmission. We estimated the annual risk of TB infection (ARTI) in 11 large US cities to understand whether rising inequality in mortality reflected rising inequality in ARTI using city-level TB mortality data compiled by the US Department of Commerce from 1910 to 1933. We estimated ARTI for African-Americans and whites using pediatric extrapulmonary TB mortality data for African-Americans and whites in our panel of cities. We also estimated age-adjusted pulmonary TB mortality rates for these cities. We find that the ratio of ARTI for African-Americans vs. whites increased from 2·1 (95% CI = 1·7, 2·4) in 1910 to 4·2 (95% CI = 3·4, 5·2) in 1933. This change mirrored the increasing inequality in age-adjusted pulmonary TB mortality during this period. These findings may reflect the combined effects of migration, inequality in access to care, increasing population density, and racial residential segregation in northern cities during this period.

Heterogeneity in norovirus shedding duration affects community risk.

Norovirus is a common cause of gastroenteritis in all ages. Typical infections cause viral shedding periods of days to weeks, but some individuals can shed for months or years. Most norovirus risk models do not include these long-shedding individuals, and may therefore underestimate risk. We reviewed the literature for norovirus-shedding duration data and stratified these data into two distributions: regular shedding (mean 14-16 days) and long shedding (mean 105-136 days). These distributions were used to inform a norovirus transmission model that predicts the impact of long shedders. Our transmission model predicts that this subpopulation increases the outbreak potential (measured by the reproductive number) by 50-80%, the probability of an outbreak by 33%, the severity of transmission (measured by the attack rate) by 20%, and transmission duration by 100%. Characterizing and understanding shedding duration heterogeneity can provide insights into community transmission that can be useful in mitigating norovirus risk.