Comparative hospitalization risk for SARS-CoV-2 Omicron and Delta variant infections, by variant predominance periods and patient-level sequencing results, New York City, August 2021-January 2022.

BACKGROUND: Comparing disease severity between SARS-CoV-2 variants among populations with varied vaccination and infection histories can help characterize emerging variants and support healthcare system preparedness. METHODS: We compared COVID-19 hospitalization risk among New York City residents with positive laboratory-based SARS-CoV-2 tests when ≥98% of sequencing results were Delta (August-November 2021) or Omicron (BA.1 and sublineages, January 2022). A secondary analysis defined variant exposure using patient-level sequencing results during July 2021-January 2022, comprising 1-18% of weekly confirmed cases. RESULTS: Hospitalization risk was lower among patients testing positive when Omicron (16,025/488,053, 3.3%) than when Delta predominated (8268/158,799, 5.2%). In multivariable analysis adjusting for demographic characteristics and prior diagnosis and vaccination status, patients testing positive when Omicron predominated, compared with Delta, had 0.72 (95% CI: 0.63, 0.82) times the hospitalization risk. In a secondary analysis of patients with sequencing results, hospitalization risk was similar among patients infected with Omicron (2042/29,866, 6.8%), compared with Delta (1780/25,272, 7.0%), and higher among the subset who received two mRNA vaccine doses (adjusted relative risk 1.64; 95% CI: 1.44, 1.87). CONCLUSIONS: Hospitalization risk was lower among patients testing positive when Omicron predominated, compared with Delta. This finding persisted after adjusting for prior diagnosis and vaccination status, suggesting intrinsic virologic properties, not population-based immunity, explained the lower severity. Secondary analyses demonstrated collider bias from the sequencing sampling frame changing over time in ways associated with disease severity. Representative data collection is necessary to avoid bias when comparing disease severity between previously dominant and newly emerging variants.

Synergy between low BMI and hyperglycemia at baseline increases tuberculosis incidence among people living with HIV.

OBJECTIVES: Low BMI and hyperglycemia are each important risk factors for tuberculosis (TB). However, the contribution of synergy between low BMI and hyperglycemia to risk of TB among people living with HIV (PWH) is unexplored. We compared TB incidence among PWH with different exposure profiles to low BMI (BMI < 18.5 kg/m2) and hyperglycemia (random blood glucose ≥140 mg/dl). DESIGN AND METHODS: We conducted a cohort study using data of PWH (≥15 years) who enrolled in Myanmar's Integrated HIV Care Program between 2011 and 2017. We used their follow-up data until 2018 to determine TB incidence. RESULTS: Among 20 865 PWH included in this study, 7610 (36%) had low BMI only, 1324 (6%) had hyperglycemia only, and 465 (2%) patients had concurrent low BMI and hyperglycemia (joint exposure) at baseline. During a median follow-up of 2.2 years (interquartile range: 0.5, 4.2), 3628 (17%) developed TB [6.7, 95% confidence interval (CI): 6.5,7.0 cases per 100 person-years (PY)]. TB incidence among PWH with joint exposure was 21.0 (95% CI: 18.0, 24.7), with low BMI only was 10.9 (95% CI: 10.4, 11.4), with hyperglycemia only was 5.2 (95% CI: 4.4, 6.3) and with no exposure was 4.6 (95% CI: 4.4, 4.9) cases per 100 PY. The attributable proportion of incident TB due to synergy between low BMI and hyperglycemia was 0.23 (95% CI: 0.06, 0.36). CONCLUSION: Synergy between low BMI and hyperglycemia was associated with increased excess TB incidence in PWH. TB preventive treatment, nutritional support, and hyperglycemia management should be evaluated as interventions to reduce TB risk in PWH with joint exposure.