Abstract: medRxiv preprint doi: https://doi.org/10.1101/2021.07.30.21261220; this version posted July 31, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license . COVID-19 in hospitalized patients in 4 hospitals in San Isidro, Buenos Aires, Argentina Authors: María Ana Barra1, Nelson Adolfo Carlos Medinacelli1, Camilo Andres Meza Padilla1, Lucrecia Di Rocco1, Ramiro Manuel Larrea1, Giuliano Gaudenzi2, Verónica Vanesa Mastrovincenzo3, Elisa Raña3, Inés Moreno3, Dagmar Ana Sörvik4, Andrea Sarlingo4, Florencia Dadomo5, Miguel Torrilla5 1 Internal Medicine. Hospital Central San Isidro, Acassuso C.P. 1640. Argentina 2 Critical Care Hospital Central San Isidro, Acassuso, C.P. 1640, Argentina 3 Internal Medicine. Sanatorio San Lucas, San Isidro, C.P. 1640, Argentina 4 Internal Medicine. Sanatorio Las Lomas. San Isidro, C.P. 1640, Argentina 5 Internal Medicine. Sanatorio Trinidad San Isidro. San Isidro. C.P. 1640, Argentina Corresponding: Internal Medicine. Hospital Central San Isidro. María Ana Barra. Moreno 2571Victoria. 1644. Argentina abarrabarra@gmail.com Abstract: In December 2019, a novel illness called coronavirus disease 2019 (COVID-19) was described in China and became pandemic in a few months. The first case was detected in Argentina on March 3, 2020. A multicentre prospective observational cohort study on hospitalized patients with COVID- 19 was conducted in 4 hospitals in San Isidro district from March 1, 2020 to October 31. Data was obtained by the attendant physician. 668 patients were included, the median age was 54 years, and 42.7% were female. Male sex and older age were associated with COVID-19 disease and more strongly with severity. Most frequent symptoms were fever and cough followed by dyspnoea, myalgia, odynophagia, headache, anosmia, and diarrhoea. Non-severe patients had more upper respiratory symptoms while severe patients had mainly lower respiratory symptoms on admission. Most common comorbidities were arterial hypertension, diabetes, and cardiovascular disease. A great proportion of patients had normal thorax X-ray and ground-glass opacity in tomography. In severe patients, radiography and tomography had a predominant ground – glass pattern, but normal radiography and tomography on presentation were present in 22% and 5.9%, respectively. The absence of fever and normal radiology on admission neither excluded the disease nor further severity. PCR elevation was related with COVID-19 disease and with severity, while lymphopenia was more related with the disease and leukocytosis and thrombocytopenia with severity. 8, 4% of patients were health care workers. The mortality rate was 12.4%, 32.7% in severe patients and 61.2% in ventilated patients. Mortality was higher in the public hospital, probably associated with patients with older age and more comorbidities. All these observations can contribute to the knowledge of this disease in terms of diagnosis and prognosis. Key words: COVID-19, epidemiology, clinical, laboratory, outcome, treatment, critical illness 1 NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice. medRxiv preprint doi: https://doi.org/10.1101/2021.07.30.21261220; this version posted July 31, 2021. The copyright holder for this..