The high transmissibility of SARS-CoV-2 before and shortly after the onset of symptoms suggests that only diagnosing and isolating symptomatic patients may not be sufficient to interrupt the spread of infection; therefore, public health measures such as personal distancing are also necessary. Additionally, it will be important to detect the newly infected individuals who remain asymptomatic, which may account for 50% or more of the cases. Molecular techniques are the “gold standard” for the diagnosis of SARS-CoV-2 infection. However, the massive use of these techniques has generated some problems. On the one hand, the scarcity of resources (analyzers, fungibles and reagents), and on the other the delay in the notification of results. These two facts translate into a lag in the application of isolation measures among cases and contacts, which favors the spread of the infection. Antigen detection tests are also direct diagnostic methods, with the advantage of obtaining the result in a few minutes and at the very “pointof-care”. Furthermore, the simplicity and low cost of these tests allow them to be repeated on successive days in certain clinical settings. The sensitivity of antigen tests is generally lower than that of nucleic acid tests, although their specificity is comparable. Antigenic tests have been shown to be more valid in the days around the onset of symptoms, when the viral load in the nasopharynx is higher. Having a rapid and real-time viral detection assay such as the antigen test has been shown to be more useful to control the spread of the infection than more sensitive tests, but with greater cost and response time, such as in case of molecular tests. The main health institutions such as the WHO, the CDC and the Ministry of Health of the Government of Spain propose the use of antigenic tests in a wide variety of strategies to respond to the pandemic. This document aims to support physicians involved in the care of patients with suspected SC2 infection, in the context of a growing incidence in Spain since September 2020, which already represents the second pandemic wave of COVID-19.

Background: Nursing homes for older adults have concentrated large numbers of severe cases and deaths for COVID-19. Methods: Point seroprevalence study of nursing homes to describe the demography and characteristic of SARS-CoV-2 IgG-positive residents and staff. Results: Clinical information and blood samples were available for 9,332 residents (mean age 86.7 ± 8.1 years, 76.4% women) and 10,614 staff (mean age 45.6 ± 11.5, 86.2% women). Up to 84.4% of residents had frailty, 84.9% co-morbidity and 69.3% cognitive impairment; 65.2% of workers were health-aides. COVID-19 seroprevalence was 55.4% (95% CI, 54.4–56.4) for older adults and 31.5% (30.6–32.4) for staff. In multivariable analysis frailty of residents was related with seropositivity (OR: 1.19, p = 0.02). In the case of staff, age > 50 years (2.10, p < 0.001), obesity (1.19, p = 0.01), being a health-aide (1.94, p < 0.001), working in a center with high seroprevalence in residents (3.49, p < 0.001), and contact with external cases of COVID-19 (1.52, p < 0.001) were factors associated with seropositivity. Past symptoms of COVID-19 were good predictors of seropositivity for residents (5.41, p < 0.001) and staff (2.52, p < 0.001). Conclusions: Level of dependency influences risk of COVID-19 among residents. Individual and work factors, and contacts outside the nursing home are associated with COVID-19 exposure in staff members. It is key to strengthen control measures to prevent the introduction of COVID-19 into care facilities from the community.

Background: Assessment of T-cell responses to SARS-CoV-2 antigens may be of value to determine long-lasting protection to breakthrough infections or reinfections. Interferon-gamma release assay is a validated method to test cellular immunity in mycobacterial infections and has been proposed for patients with SARS-CoV-2 infection or vaccination. Methods: Quantitative IgG to spike and qualitative IgG to nucleocapsid antigens were determined by chemiluminescence microparticle immunoassay using the Architect® platform (Abbott®), and interferon-gamma release assay against two Qiagen® proprietary mixes of SARS-CoV-2 spike protein (antigen-1 and antigen-2) were performed for a selected group of subjects. Results: A total of 121 subjects in a cloistered institution after a COVID-19 outbreak were studied. IgG-spike levels and interferon-gamma concentration were highest among subjects after two doses of vaccine, followed by patients with a longer history of past COVID-19 and no vaccination. Best cut-off for interferon-gamma assay was 25 IU/μL for all subgroups of individuals and the two sets of SARS-CoV-2 antigens studied. Conclusions: Testing T-cell response may be of clinical utility to determine immunity after exposure to SARS-CoV-2 antigens, with the interferon-gamma concentration of 25 IU/μL as the best cut-off either after infection or vaccination.

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BackgroundThe aim of the present study is to analyze the incidence of hip fracture as a complication of admissions to internal medicine units in Spain.MethodsWe analyzed the clinical data of 2,134,363 adults who had been admitted to internal medicine wards. The main outcome was a diagnosis of hip fracture during hospitalization.Outcome measures included rates of in-hospital fractures, length of stay and cost.ResultsA total of 1127 (0.057%) admittances were coded with an in-hospital hip fracture. In hospital mortality rate was 27.9% vs 9.4%; p < 0.001, and the mean length of stay was significantly longer for patients with a hip fracture (20.7 days vs 9.8 days; p < 0.001). Cost were higher in hip-fracture patients (6927€ per hospitalization vs 3730€ in non fracture patients). Risk factors related to fracture were: increasing age by 10 years increments (OR 2.32 95% CI 2.11-2.56), female gender (OR 1.22 95% CI 1.08-1.37), admission from nursing home (OR 1.65 95% CI 1.27-2.12), dementia (1.55 OR 95% CI1.30-1.84), malnutrition (OR 2.50 95% CI 1.88-3.32), delirium (OR 1.57 95% CI 1.16-2.14), and anemia (OR 1.30 95%CI 1.12-1.49).ConclusionsIn-hospital hip fracture notably increased mortality during hospitalization, doubling the mean length of stay and mean cost of admission. These are reasons enough to stress the importance of designing and applying multidisciplinary plans focused on reducing the incidence of hip fractures in hospitalized patients.