Breast Cancer Screening During the COVID-19 Pandemic in the United States: Results From Real-World Health Records Data.

PURPOSE: The COVID-19 pandemic abruptly interrupted breast cancer screening, an essential preventive service in primary care. We aimed to evaluate the pandemic's impact on overall and follow-up breast cancer screening using real-world health records data. METHODS: We retrospectively analyzed a cohort of women eligible for breast cancer screening through the study period from January 1, 2017 to February 28, 2022 using TriNetX Research Network data. We examined the temporal trend of monthly screening volume throughout the study period and compared the rate of adherence to follow-up screening within 24 months after the previous screening when the follow-up screening was due in the pre-COVID period vs the COVID period. To account for multiple screenings in the longitudinal data, we applied a logistic regression model using generalized estimating equations with adjustment for individual-level covariates. RESULTS: Among 1,186,669 screening-eligible women, the monthly screening volume temporarily decreased by 80.6% from February to April 2020 and then rebounded to close to pre-COVID levels by June 2020. Yet, the follow-up screening rate decreased from 78.9% (95% CI, 78.8%-79.0%) in the pre-COVID period to 77.7% (95% CI, 77.6%-77.8%) in the COVID period. Multivariate regression analysis also showed a lower adherence to follow-up screening during the COVID period (odds ratio = 0.86; 0.86-0.87) and a greater pandemic impact among women aged 65 years and older and women of non-Hispanic "other" race (Asian, American Indian or Alaska Native, and Native Hawaiian or Other Pacific Islander). CONCLUSIONS: The COVID-19 pandemic had a transient negative effect on breast cancer screening overall and a prolonged negative effect on follow-up screening. It also exacerbated gaps in adherence to follow-up screening, especially among certain vulnerable groups, requiring innovative strategies to address potential health disparities in primary care.

Intracellular Diversity of WNV within Circulating Avian Peripheral Blood Mononuclear Cells Reveals Host-Dependent Patterns of Polyinfection.

Arthropod-borne virus (arbovirus) populations exist as mutant swarms that are maintained between arthropods and vertebrates. West Nile virus (WNV) population dynamics are host-dependent. In American crows, purifying selection is weak and population diversity is high compared to American robins, which have 100- to 1000-fold lower viremia. WNV passed in robins leads to fitness gains, whereas that passed in crows does not. Therefore, we tested the hypothesis that high crow viremia allows for higher genetic diversity within individual avian peripheral blood mononuclear cells (PBMCs), reasoning that this could have produced the previously observed host-specific differences in genetic diversity and fitness. Specifically, we infected cells and birds with a molecularly barcoded WNV and sequenced viral RNA from single cells to quantify the number of WNV barcodes in each. Our results demonstrate that the richness of WNV populations within crows far exceeds that in robins. Similarly, rare WNV variants were maintained by crows more frequently than by robins. Our results suggest that increased viremia in crows relative to robins leads to the maintenance of defective genomes and less prevalent variants, presumably through complementation. Our findings further suggest that weaker purifying selection in highly susceptible crows is attributable to this higher viremia, polyinfections and complementation.

Intracellular diversity of WNV within circulating avian peripheral blood mononuclear cells reveals host-dependent patterns of polyinfection.

Error-prone replication of RNA viruses generates the genetic diversity required for adaptation within rapidly changing environments. Thus, arthropod-borne virus (arbovirus) populations exist in nature as mutant swarms that are maintained between arthropods and vertebrates. Previous studies have demonstrated that West Nile virus (WNV) population dynamics are host dependent: In American crows, which experience extremely high viremia, purifying selection is weak and population diversity is high compared to American robins, which have 100 to 1000-fold lower viremia. WNV passed in robins experiences fitness gains, whereas that passed in crows does not. Therefore, we tested the hypothesis that high crow viremia allows higher genetic diversity within individual avian peripheral-blood mononuclear cells (PBMCs), reasoning that this could have produced the previously observed host-specific differences in genetic diversity and fitness. Specifically, we infected cells and birds with a novel, barcoded version of WNV and sequenced viral RNA from single cells to quantify the number of WNV barcodes that each contained. Our results demonstrate that the richness of WNV populations within crows far exceeds that in robins. Similarly, rare WNV variants were maintained by crows more frequently than by robins. Our results suggest that increased viremia in crows relative to robins leads to maintenance of defective genomes and less prevalent variants, presumably through complementation. Our findings further suggest that weaker purifying selection in highly susceptible crows is attributable to this higher viremia, polyinfections and complementation. These studies further document the role of particular, ecologically relevant hosts in shaping virus population structure. Author Summary: WNV mutational diversity in vertebrates is species-dependent. In crows, low frequency variants are common, and viral populations are more diverse. In robins, fewer mutations become permanent fixtures of the overall viral population. We infected crows, robins and a chicken cell line with a genetically marked (barcoded) WNV. Higher levels of virus led to multiple unique WNV genomes infecting individual cells, even when a genotype was present at low levels in the input viral stock. Our findings suggest that higher levels of circulating virus in natural hosts allow less fit viruses to survive in RNA virus populations through complementation by more fit viruses. This is significant as it allows less represented and less fit viruses to be maintained at low levels until they potentially emerge when virus environments change. Overall our data reveal new insights on the relationships between host susceptibility to high viremia and virus evolution.

American alligators are capable of West Nile virus amplification, mosquito infection and transmission.

West Nile virus (WNV) overwintering is poorly understood and likely multifactorial. Interest in alligators as a potential amplifying host arose when it was shown that they develop viremias theoretically sufficient to infect mosquitoes. We examined potential ways in which alligators may contribute to the natural ecology of WNV. We experimentally demonstrated that alligators are capable of WNV amplification with subsequent mosquito infection and transmission capability, that WNV-infected mosquitoes readily infect alligators and that water can serve as a source of infection for alligators but does not easily serve as in intermediate means for transmission between birds and alligators. These findings indicate potential mechanisms for maintenance of WNV outside of the primary bird-mosquito transmission cycle.

Adverse Effects of Common Drugs: General Concepts.

Adverse drug reactions (ADRs) contribute to substantial morbidity and mortality and add to rising health care costs. Many ADRs are preventable with appropriate prescribing and monitoring because they often occur as an extension of a drug's mechanism of action or known drug interactions. Patients at higher risk of ADRs include those at the extremes of age, those with multiple comorbidities, those taking multiple drugs, and patients admitted to intensive care units or experiencing transitions of care. Because the risk of ADRs becomes greater as the number of drugs and dietary supplements taken increases, it is imperative that prescribers be vigilant about the prescribing cascade and take steps to discontinue drugs that are likely to be more harmful than helpful. Pharmacists serve as important partners in clinical care environments by conducting comprehensive drug reviews, aiding in drug/dosage selection, and developing therapeutic monitoring plans. Although the potential exists for clinicians to use electronic health record systems to aid in clinical decision making through drug safety decision support tools, computer systems should never replace clinical judgment. Clinicians also are encouraged to report ADRs to the Food and Drug Administration Adverse Event Reporting System.

Adverse Effects of Common Drugs: Children and Adolescents.

Drug use and harms are increasingly common among newborns, infants, children, and adolescents during ambulatory practice, emergency department, and in-hospital treatment, including treatment in pediatric intensive care units. The pharmacokinetic and pharmacodynamic parameters of drugs often are different for children compared with adults and must be considered before prescribing. Drug exposure and the potential for harms also should be considered for fetuses and breastfeeding infants. As with adult patients, a thorough drug and allergy history (including nonprescription drugs and herbal and dietary supplements) should be obtained and reviewed at each medical visit. Children and adolescents are increasingly at risk of drug harm/overdose through accidental or intentional ingestion of nonprescription and prescription drugs (eg, cough and cold preparations, candy-appearing vitamins, stimulants, narcotics). Parents and caregivers should receive training in the proper use, storage, and administration of all drugs. Prescribing clinicians should be vigilant in withholding unnecessary drugs, such as antibiotics for viral infections. When prescribing, clinicians should be aware of common drugs frequently associated with adverse reactions, including stimulants, antipsychotics, analgesics, asthma therapies, acne therapies, and tumor necrosis factor inhibitors. Scientifically based prescribing practices should be used and consultation with evidence-based resources and pharmacists sought as needed.

Adverse Effects of Common Drugs: Dietary Supplements.

Dietary supplement-induced adverse effects often resolve quickly after discontinuation of the offending product, especially in younger patients. The potential for unwanted outcomes can be amplified in elderly patients or those taking multiple prescription drugs, especially where interactions exist with drugs metabolized by cytochrome P450 enzymes. Attributing injury or illness to a specific supplement can be challenging, especially in light of multi-ingredient products, product variability, and variability in reporting, as well as the vast underreporting of adverse drug reactions. Clinicians prescribing a new drug or evaluating a patient with a new symptom complex should inquire about use of herbal and dietary supplements as part of a comprehensive evaluation. Clinicians should report suspected supplement-related adverse effects to the local or state health department, as well as the Food and Drug Administration's MedWatch program (available at https://www.safetyreporting.hhs.gov). Clinicians should consider discussing suspected adverse effects involving drugs, herbal products, or dietary supplements with their community- and hospital-based pharmacists, and explore patient management options with medical or clinical toxicology subspecialists.

Adverse Effects of Common Drugs: Adults.

Although drugs can be an essential and lifesaving component of the care of adult patients, their use frequently is accompanied by adverse effects and life-threatening adverse drug reactions that can result in significant disability and mortality. The potential for drug-related severe morbidity and mortality is compounded during periods of hospitalization, when high-risk drugs such as anticoagulants or insulin are used, and when care in an intensive care unit is required. Patient factors in adults that can increase the risk of drug harms include immunosuppression, cognitive impairment, depression, alcoholism and other substance abuse disorders, chronic kidney disease, hepatic dysfunction, coagulopathies, limited English proficiency, institutional/nursing home care, and underinsurance or lack of insurance. Physician factors that can increase the risk of drug harms include inappropriate prescribing of drugs (including to pregnant and breastfeeding women), failure to appropriately discontinue/deprescribe drugs, insufficient drug reconciliation, failure to coordinate care among multiple prescribing clinicians, and failure to elicit and incorporate into health histories and clinical decision-making the widespread use of nonprescription drugs, herbal products, and dietary supplements.

PATHOGENESIS AND IMMUNE RESPONSES OF FRANCISELLA TULARENSIS STRAINS IN WILD-CAUGHT COTTONTAIL RABBITS (SYLVILAGUS SPP.).

Francisella tularensis is a highly virulent, zoonotic bacterium that causes significant natural disease and is of concern as an organism for bioterrorism. Serologic testing of wildlife is frequently used to monitor spatial patterns of infection and to quantify exposure. Cottontail rabbits (Sylvilagus spp.) are a natural reservoir for F. tularensis in the US, although very little work has been done experimentally to determine how these animals respond to infection; thus, information gathered from field samples can be difficult to interpret. We characterized clinical disease, bacteremia, pathology, and antibody kinetics of North American cottontail rabbits experimentally infected with five strains of F. tularensis. Rabbits were infected with four field strains, including MA00-2987 (type A1b), WY96-3418 (type A2), KY99-3387, and OR96-0246 (type B), and with SchuS4 (type A1a), a widely used, virulent laboratory strain. Infection with the different strains of the bacterium resulted in varied patterns of clinical disease, gross pathology, and histopathology. Each of the type A strains were highly virulent, with rabbits succumbing to infection 3-13 d after infection. At necropsy, numerous microabscesses were observed in the livers and spleens of most rabbits, associated with high bacterial organ burdens. In contrast, most rabbits infected with type B strains developed mild fever and became lethargic, but the disease was infrequently lethal. Those rabbits infected with type B strains that survived past 14 d developed a robust humoral immune response, and F. tularensis was not isolated from liver, spleen, or lung of those animals. Understanding F. tularensis infection in a natural reservoir species can guide serosurveillance and generate new insights into environmental maintenance of this pathogen.

Experimental evolution of an RNA virus in wild birds: evidence for host-dependent impacts on population structure and competitive fitness.

Within hosts, RNA viruses form populations that are genetically and phenotypically complex. Heterogeneity in RNA virus genomes arises due to error-prone replication and is reduced by stochastic and selective mechanisms that are incompletely understood. Defining how natural selection shapes RNA virus populations is critical because it can inform treatment paradigms and enhance control efforts. We allowed West Nile virus (WNV) to replicate in wild-caught American crows, house sparrows and American robins to assess how natural selection shapes RNA virus populations in ecologically relevant hosts that differ in susceptibility to virus-induced mortality. After five sequential passages in each bird species, we examined the phenotype and population diversity of WNV through fitness competition assays and next generation sequencing. We demonstrate that fitness gains occur in a species-specific manner, with the greatest replicative fitness gains in robin-passaged WNV and the least in WNV passaged in crows. Sequencing data revealed that intrahost WNV populations were strongly influenced by purifying selection and the overall complexity of the viral populations was similar among passaged hosts. However, the selective pressures that control WNV populations seem to be bird species-dependent. Specifically, crow-passaged WNV populations contained the most unique mutations (~1.7× more than sparrows, ~3.4× more than robins) and defective genomes (~1.4× greater than sparrows, ~2.7× greater than robins), but the lowest average mutation frequency (about equal to sparrows, ~2.6× lower than robins). Therefore, our data suggest that WNV replication in the most disease-susceptible bird species is positively associated with virus mutational tolerance, likely via complementation, and negatively associated with the strength of selection. These differences in genetic composition most likely have distinct phenotypic consequences for the virus populations. Taken together, these results reveal important insights into how different hosts may contribute to the emergence of RNA viruses.

Evidence for co-evolution of West Nile Virus and house sparrows in North America.

West Nile virus (WNV) has been maintained in North America in enzootic cycles between mosquitoes and birds since it was first described in North America in 1999. House sparrows (HOSPs; Passer domesticus) are a highly competent host for WNV that have contributed to the rapid spread of WNV across the U.S.; however, their competence has been evaluated primarily using an early WNV strain (NY99) that is no longer circulating. Herein, we report that the competence of wild HOSPs for the NY99 strain has decreased significantly over time, suggesting that HOSPs may have developed resistance to this early WNV strain. Moreover, recently isolated WNV strains generate higher peak viremias and mortality in contemporary HOSPs compared to NY99. These data indicate that opposing selective pressures in both the virus and avian host have resulted in a net increase in the level of host competence of North American HOSPs for currently circulating WNV strains.