Association between SARS-CoV-2 infections during pregnancy and preterm live birth.

We examined associations between mild or asymptomatic prenatal SARS-CoV-2 infection and preterm live birth in a prospective cohort study. During August 2020-October 2021, pregnant persons were followed with systematic surveillance for RT-PCR or serologically confirmed SARS-CoV-2 infection until pregnancy end. The association between prenatal SARS-CoV-2 infection and preterm birth was assessed using Cox proportional-hazards regression. Among 954 pregnant persons with a live birth, 185 (19%) had prenatal SARS-CoV-2 infection and 123 (13%) had preterm birth. The adjusted hazard ratio for the association between SARS-CoV-2 infection and preterm birth was 1.28 (95% confidence interval 0.82-1.99, p = 0.28), although results did not reach statistical significance.

Household Transmission of Influenza A Viruses in 2021-2022.

Importance: Influenza virus infections declined globally during the COVID-19 pandemic. Loss of natural immunity from lower rates of influenza infection and documented antigenic changes in circulating viruses may have resulted in increased susceptibility to influenza virus infection during the 2021-2022 influenza season. Objective: To compare the risk of influenza virus infection among household contacts of patients with influenza during the 2021-2022 influenza season with risk of influenza virus infection among household contacts during influenza seasons before the COVID-19 pandemic in the US. Design, Setting, and Participants: This prospective study of influenza transmission enrolled households in 2 states before the COVID-19 pandemic (2017-2020) and in 4 US states during the 2021-2022 influenza season. Primary cases were individuals with the earliest laboratory-confirmed influenza A(H3N2) virus infection in a household. Household contacts were people living with the primary cases who self-collected nasal swabs daily for influenza molecular testing and completed symptom diaries daily for 5 to 10 days after enrollment. Exposures: Household contacts living with a primary case. Main Outcomes and Measures: Relative risk of laboratory-confirmed influenza A(H3N2) virus infection in household contacts during the 2021-2022 season compared with prepandemic seasons. Risk estimates were adjusted for age, vaccination status, frequency of interaction with the primary case, and household density. Subgroup analyses by age, vaccination status, and frequency of interaction with the primary case were also conducted. Results: During the prepandemic seasons, 152 primary cases (median age, 13 years; 3.9% Black; 52.0% female) and 353 household contacts (median age, 33 years; 2.8% Black; 54.1% female) were included and during the 2021-2022 influenza season, 84 primary cases (median age, 10 years; 13.1% Black; 52.4% female) and 186 household contacts (median age, 28.5 years; 14.0% Black; 63.4% female) were included in the analysis. During the prepandemic influenza seasons, 20.1% (71/353) of household contacts were infected with influenza A(H3N2) viruses compared with 50.0% (93/186) of household contacts in 2021-2022. The adjusted relative risk of A(H3N2) virus infection in 2021-2022 was 2.31 (95% CI, 1.86-2.86) compared with prepandemic seasons. Conclusions and Relevance: Among cohorts in 5 US states, there was a significantly increased risk of household transmission of influenza A(H3N2) in 2021-2022 compared with prepandemic seasons. Additional research is needed to understand reasons for this association.

Severe Clinical Outcomes Among Adults Hospitalized With Respiratory Syncytial Virus Infections, New York City, 2017-2019.

OBJECTIVES: Respiratory syncytial virus (RSV) causes substantial morbidity and mortality in older adults. We assessed severe clinical outcomes among hospitalized adults that were associated with RSV infections. METHODS: We performed a nested retrospective study in 3 New York City hospitals during 2 respiratory viral seasons, October 2017-April 2018 and October 2018-April 2019, to determine the proportion of patients with laboratory-confirmed RSV infection who experienced severe outcomes defined as intensive care unit (ICU) admission, mechanical ventilation, and/or death. We assessed factors associated with these severe outcomes and explored the effect of RSV-associated hospitalizations on changes in the living situations of surviving patients. RESULTS: Of the 403 patients studied (median age, 69 years), 119 (29.5%) were aged ≥80. Severe outcomes occurred in 19.1% of patients, including ICU admissions (16.4%), mechanical ventilation (12.4%), and/or death (6.7%). Patients admitted from residential living facilities had a 4.43 times higher likelihood of severe RSV infection compared with patients who were living in the community with or without assistance from family or home health aides. At discharge, 56 (15.1%) patients required a higher level of care than at admission. CONCLUSIONS: RSV infection was associated with severe outcomes in adults. Living in a residential facility at admission was a risk factor for severe outcomes and could be a proxy for frailty rather than an independent risk factor. Our data support the development of prevention strategies for RSV infection in older populations, especially older adults living in residential living facilities.