Abstract INTRODUCTION COVID-19 sequelae, or the short-, medium-, and long-term manifestations of the disease are under continuous study. There are currently few reports on the evolution of hematological variables following a demonstrated absence of SARS-CoV-2 after infection. OBJECTIVE Identify hematological alterations in Cuban adults recovered from SARS-CoV-2 infection, and their relation with disease severity. METHODS We selected 348 persons recovered from COVID-19 residing in Havana, Cuba with an RT-PCR study negative for SARS-CoV-2 performed two weeks after hospital discharge; a structured survey was administered to obtain clinical–epidemiological data. Three groups were established according to COVID-19 clinical criteria: asymptomatic, mild/moderately symptomatic, and severely symptomatic, which, in turn, were divided according to hospital discharge date and blood sample collection date. We performed hemograms with differential leukocyte counts and compared results among groups. We then measured the associations between hematological variables, personal medical history, and relevant lifestyle habits (smoking). RESULTS All hematological variables were within normal reference limits, although men from the group of severely ill patients had increased total leukocytes, neutrophils and lymphocytes, and decreased hemoglobin and eosinophils, which was also evident in those with a recovery time of 31–90 days. CONCLUSIONS The relation between hematological variables and degree of clinical severity offers evidence as to persistence of systemic alterations (possibly inflammatory) associated with viral infection. Their identification and characterization can facilitate personalized patient followup and rehabilitation.

ABSTRACT Introduction: Havana city was the most complex territory at the national level facingthe first outbreak of COVID-19. Its condition of capital, the population density, the limited geographical delimitation between its municipalities, the high inter-municipal and inter-provincial flow of people, added to the fact that it is the province that receives the largest number of travelers from abroad, conferred particularities on this territory. Objective: To determine the main clinical-epidemiological characteristics of patients affected by COVID-19 living in Havana. Methods: An observational, analytical, cross-sectional study was carried out. The sample contained 431 patients, older than one year, with epidemiological discharge from the SARS-CoV-2 infection. To collect information, a questionnaire was applied through an interview. Results: The average age of the sample was 45 years. More than half of the cases evolved in a symptomatic way (not serious or serious). Fever was the most frequent clinical manifestation. The individuals included in the sample, with blood group O or with a background of asthma, showed less risk of presenting symptomatic forms of the disease. Conclusions: The results suggest that age is the main risk factor for developing symptomatic forms (not severe or severe) of COVID-19. On the contrary, blood group O and a history of asthma are protective factors for these forms of clinical evolution.

RESUMEN Introducción: La Habana fue el territorio más complejo a nivel nacional en el enfrentamiento al primer brote de la COVID-19. Su condición de capital, la densidad poblacional, la escasa delimitación geográfica entre sus municipios, el elevado flujo intermunicipal e interprovincial de personas, sumado a que es la provincia que mayor número de viajeros recibe procedentes del extranjero, confirieron a este territorio particularidades en el enfrentamiento a la pandemia. Objetivo: Determinar las principales características clínico-epidemiológicas de pacientes cubanos residentes en La Habana afectados por la COVID-19. Métodos: Se realizó un estudio observacional, analítico, de corte transversal. La muestra quedó formada por 431 pacientes, mayores de un año, de alta epidemiológica de la infección por SARS-CoV-2. Para la recolección de información se aplicó un cuestionario a través de una entrevista. Resultados: La edad promedio de la muestra fue de 45 años. Más de la mitad de los casos evolucionaron de modo sintomático (no grave o grave). La fiebre fue la manifestación clínica más frecuente. Los individuos incluidos en la muestra, con grupo sanguíneo O, o con antecedentes de asma, mostraron menos riesgo de presentar formas sintomáticas de la enfermedad. Conclusiones: Los resultados sugieren que la edad constituye el principal factor de riesgo para desarrollar formas sintomáticas (no graves o graves) de la COVID-19. De modo contrario, el grupo sanguíneo O y el antecedente de asma son factores de protección para estas formas de evolución clínica.

ABSTRACT Introduction: Until June 11, 2020, 10.4% of the total positive cases of SARS-CoV-2 in Cuba corresponded to patients under 18 years of age. Clinical manifestations in children affected by SARS-CoV-2 are usually mild and few deaths occur compared to other age groups. Objective: Characterize from the clinical, epidemiological and immunological point of view the Cuban pediatric patients infected by SARS-CoV-2 until June 11, 2020. Methods: Observational, cross-sectional study in 137 pediatric patients infected with COVID-19, who were epidemiologically discharged. Results: 56.9 % of the patients presented asymptomatic form of the disease. Havana was the most affected province and the average age was 11.3 years. The most frequent symptoms were: fever, cough and diarrhea and occurred more frequently in patients with black skin (Odd Ratio = 3.40). Antibody concentrations for tetanus and Haemophilus influenzae type b provided protection in 92.7% to 100% of children, while for diphtheria 24.8% had no reliable protection. Of the symptomatic patients, 62.5% developed specific total antibodies against SARS-CoV-2. Conclusions: Patients in pediatric ages can contribute significantly to the transmission dynamics. Reliable protection for specific vaccines, the development of total antibodies to SAR-Cov-2, and general favorable prognosis without complications require continued research to identify biological and immunological differences between children and other age groups.

RESUMEN Introducción: Las manifestaciones clínicas en niños afectados por el SARS-CoV-2 suelen ser más leves, un número reducido evoluciona hacia la gravedad y se producen pocas muertes en comparación con otros grupos de edad. Objetivo: Caracterizar desde el punto de vista clínico, epidemiológico e inmunológico a los pacientes pediátricos en Cuba infectados por SARS-CoV-2 a partir del 11 de marzo de 2020 y que se encontraban de alta epidemiológica el 11 de junio del mismo año. Métodos: Estudio observacional, de corte transversal en 137 pacientes en edad pediátrica infectados por la COVID-19, que se encontraban de alta epidemiológica. Resultados: Presentaron forma asintomática de la enfermedad 56,9 %. La Habana fue la provincia más afectada y la edad promedio de 11,3 años. Los síntomas más frecuentes fueron: fiebre, tos y diarreas y se presentaron con mayor frecuencia en pacientes de color de piel negra (Odd Ratio= 3,40). Las concentraciones de anticuerpos para tétano y Haemophilus influenzae tipo b proporcionaron protección entre 92,7 y 100 % de los niños, mientras que para la difteria 24,8 % no tuvo protección confiable. De los sintomáticos, 62,5 % desarrollaron anticuerpos totales específicos frente al SARS-CoV-2. Conclusiones: Los pacientes en edades pediátricas pueden contribuir de manera importante a la dinámica de la transmisión. La protección confiable para vacunas específicas, el desarrollo de anticuerpos totales frente a SAR-Cov-2 y el pronóstico general favorable sin complicaciones, obliga a continuar las investigaciones para identificar las diferencias biológicas e inmunológicas entre niños y otros grupos de edad.