Abstract INTRODUCTION The percentage of asymptomatic COVID-19 cases worldwide is estimated at 18–50%; 53% in Cuba specifically, and 58% in Havana, the Cuban capital and the 2020 epicenter of the country’s COVID-19 epidemic. These figures, however, do not represent the transmission capacity or behavior of asymptomatic cases. Understanding asymptomatic transmission’s contribution to SARS-CoV-2 spread is of great importance to disease control and prevention. OBJECTIVE Identify the epidemiological implications of asymptomatic SARS-CoV-2 infection in Havana, Cuba, during the first wave of the epidemic in 2020. METHODS We carried out a cross-sectional study of all confirmed COVID-19 cases diagnosed in Havana, Cuba, from March 16 through June 30, 2020. The information was obtained through review of the standardized form for investigation of suspected and confirmed cases. Examined variables included age, sex, occupation, case type and source of infection. Cases were divided into asymptomatic and symptomatic groups, and transmission was characterized through the creation of a contact matrix. Analysis was carried out in Epidat and R. RESULTS We studied 1287 confirmed cases, of which 57.7% (743) were asymptomatic, and 42.3% (544) were symptomatic. Symptomatic presentation was the most common for both imported and introduced cases, while asymptomatic presentation was more common in autochthonic cases and infections from an undetermined source. Asymptomatic infection was more common in groups aged <20 and 20–59 years, while symptomatic infection was more common in those aged >60 years. In the contact matrix, 34.6% of cases (445/1287) were not tied to other cases, and 65.4% (842/1287) were infectious–infected dyads, with symptomatic–symptomatic being the most common combination. The majority of primary cases (78.5%; 1002/1276) did not generate secondary cases, and 85.6% (658/743) of asymptomatic cases did not lead to other cases (although one asymptomatic superspreader led to 90 cases in a single event). However, 63.2% (344/544) of symptomatic primary cases generated secondary cases, and 11 symptomatic superspreaders spawned 100 secondary cases in different events. CONCLUSIONS Asymptomatic SARS-CoV-2 infection was the most common form of COVID-19 in Havana during the study period, but its capacity for contagion was lower than that of symptomatic individuals. Superspreader events under specific conditions played an important role in sustaining the epidemic.

ABSTRACT Introduction: The high transmission of COVID-19 has resulted in healthcare workers becoming infected while caring for patients and spreading the disease to other hospital patients or coworkers. Objective: To describe an in-hospital COVID-19 outbreak. Methods: A cross-sectional descriptive study conducted in March 2020 at the “General Calixto García Íñiguez” Clinical-Surgical University Hospital, Havana. The study included 545 individuals among patients and healthcare workers. The data was collected from the clinical-epidemiological profiles and the medical records. Each case was described using the following criteria: type of health worker, service provided, sex, signs, symptoms, and comorbidities. To determine the outbreak intensity, a contact matrix was created and the reproductive number and the dispersion value were calculated. Results: Of the 545 studied individuals, 30% were patients and 70% workers of seven services, 30 tested positive for SARS-CoV-2. Outbreak control actions were aimed at identifying, reporting and isolating sick individuals. The average age was 45 years. The clinical pictures was characterized by cough, dyspnea and asthenia. The most common comorbidities (60%) were hypertension, ischemic cardiopathology, and diabetes mellitus; 53.3% were asymptomatic and three people died. The attack rate was 5.5%. Conclusions: During the outbreak, medical doctors and nurses were the most affected. The timeliness of outbreak control actions and the quality of the epidemiological investigation are essential to ensure effective control.

RESUMEN Introducción: La alta transmisión de la COVID-19 propicia que el personal de salud contraiga la infección durante la atención a los pacientes con la probabilidad de propagarla a otros pacientes hospitalizados y compañeros de trabajo. Objetivo: Describir un brote intrahospitalario de COVID-19. Métodos: Estudio descriptivo, transversal realizado en el Hospital Universiario Clínico Quirúrgico “ General Calixto García” , La Habana en marzo de 2020. Se estudiaron 545 personas entre pacientes y trabajadores. Los datos se recolectaron mediante fichas clínico-epidemiológicas e historias clínicas. Los casos se describieron según: tipo de personal de salud, servicios que atienden, sexo, síntomas, signos y comorbilidades. Se realizó una matriz de contactos y para evaluar la intensidad del brote se calculó el número reproductivo y el valor de dispersion. Resultados: De los 545 estudiados, 30 % fueron pacientes y 70 % trabajadores de siete servicios, 30 tuvieron el diagnóstico confirmado de SARS-CoV-2. Las acciones de control de foco se dirigieron a la identificacion, notificacion y aislamiento de los enfermos. La edad promedio fue de 45 años, el cuadro clínico caracterizado por tos, disnea y astenia. Las comorbilidades más frecuentes (60 %) fueron hipertensión arterial, cardiopatia isquémica y diabetes mellitus, asintomaticos 53,3 % y tres fallecidos. La tasa de ataque fue de 5,5 %. Conclusiones: Los trabajadores más afectados son los médicos y las enfermeras. La oportunidad en las acciones del control de foco y la calidad en la investigacion epidemiológica son esenciales para lograr un control efectivo.

ABSTRACT Introduction: Deficient handwashing is still a problem in hospitals. The compliance of the international recommendations on this matter provides security in the care. Objective: To identify the level of knowledge, attitudes and practices in the technique of handwashing in a pediatric hospital in Havana. Methodology: Descriptive study applied to 145 workers (31.7% doctors, 35.2% nurses, 22.8% residents, and 10.3% students) of 13 services. Emergencies, Respiratory, Surgery, Neurosurgery and Caumatology were the services with more participation. The study was conducted in three stages: 1. Direct observation of the technique of handwashing. 2. Quality observation of the handwashing using fluorescent lamp. 3. Extent of knowledge on handwashing and attitudes through survey. Results: In the first stage, the 51.7% the handwashing was assessed as inappropriate, in the second stage the 64.8% was also evaluated as inadequate, and in the surveys, the 52.4% had an incorrect knowledge; the attitude towards this activity was described as inappropriate in the 53.1%, with a better percentage in the nursing staff. Conclusions: The knowledge, attitudes and practices on handwashing were poor, so it must be designed a training program at all levels, whether undergraduate, graduate or continuing training, where individual responsibility of each healthcare professional exists, and should be highlithed.

RESUMEN Introducción: El lavado de manos deficiente, sigue siendo un problema hospitalario. Cumplir con las recomendaciones internacionales ofrece seguridad en el cuidado. Objetivo: Identificar el nivel de conocimiento, actitudes y prácticas en la técnica del lavado de manos en personal de salud en un hospital pediátrico de La Habana. Metodología: Estudio descriptivo a 145 trabajadores (31,7 % médicos, 35,2 % enfermeros, 22,8 % médicos residentes y 10,3 % estudiantes). De 13 servicios el cuerpo de guardia, sala de respiratorio, cirugía, neurocirugía y quemados, fueron los que más participación tuvieron. El estudio se realizó en tres etapas: 1. Observación directa de la técnica del lavado de manos. 2. Observación de la calidad del lavado de manos mediante lámpara fluorescente. 3. Medida del conocimiento acerca del lavado de manos y actitud mediante encuesta. Resultados: En la primera etapa, el 51,7 % calificó de inadecuado, en la segunda etapa el 64,8 % también tuvo una evaluación inadecuada y en las encuestas, el conocimiento alcanzó solo 52,4 %, considerado inapropiado. La actitud ante esta actividad fue calificada de inadecuado en el 53,1 %, con un mejor porcentaje en el personal de enfermería. Conclusiones: Los conocimientos, actitudes y prácticas sobre el lavado de manos es deficiente, por lo que debe diseñarse un programa de capacitación en todos los niveles, sea pregrado, posgrado o formación continua, donde exista responsabilidad individual de cada profesional sanitario, y se insista en ello.

The bacterial neurologic syndromes are a worldwide health problem and surveillance is an important pillar for its prevention and control. The surveillance subsystem of bacterial meningoencephalitis was evaluated in two hospital of La Habana in 2006. For that reason the qualitative attributes of system were selected including its simplicity, acceptability and flexibility and also quantitative attributes including sensitivity, the positive predictive value and the chance, all above mentioned attributes were selected by expert's consultation, criteria, indicators and standards. Authors used the qualitative and quantitative techniques to obtain information including documentary review, interviews and survey. The main qualitative results were a good acceptation, flexibility and simplicity. The quantitative attributes not detected the patients really diseased, particularly the direct information system and the obligatory declaration of death system, qualified as inappropriate because of the figures under the established standard. At study here were some deficiencies in some of the evaluated attributes, thus, it is necessary to consider its solution and improvement.

Los síndromes neurológicos bacterianos son un problema de salud mundial, y la vigilancia constituye un pilar importante para su prevención y control. Se evaluó el subsistema de vigilancia de las meningoencefalitis bacterianas en dos hospitales de La Habana en el año 2006. Para esto se seleccionaron atributos cualitativos del sistema, como la simplicidad, la aceptabilidad y la flexibilidad, y atributos cuantitativos como la sensibilidad, el valor predictivo positivo y la oportunidad. Los atributos fueron seleccionados mediante consulta de expertos, criterios, indicadores y estándares. Se emplearon técnicas cualitativas y cuantitativas de obtención de información, tales como la revisión documental, la entrevista y la encuesta. Los principales resultados cualitativos fueron buena aceptabilidad, flexibilidad y simplicidad. Los atributos cuantitativos no detectaron los casos verdaderamente enfermos, particularmente el sistema de información directa y el sistema de enfermedades de declaración obligatoria, que fueron evaluados de inadecuados por presentar cifras por debajo del estándar establecido. Al momento del estudio existían deficiencias en algunos de los atributos evaluados, por lo que debe considerarse su solución y perfeccionamiento.

Bacterial neurological syndromes are a world health problem and surveillance is important pillar for its prevention and control. The surveillance subsystem of bacterial meningocephalitis was assessed in two hospital of Ciudad de La Habana in 2006. Thus, qualitative attributes of system were selected including simplicity, acceptability and flexibility and the quantitative ones included the positive predictive value and the chance. To collect information qualitative and quantitative techniques were used including the documentary review, interview and survey. The main results were a good acceptability, flexibility and simplicity but neither corresponding in the same measure to quantitative attributes, which were able to detect really ills nor the alarming difficulty in the opportunity for the Direct Information System (DIS) and the obligatory statement diseases system (OSD) assessed as inappropriate since there were figures below the established standard. Finally, at moment of study there were deficiencies in some the assessed attributes, thus, it is necessary to take them into account for its solution and improvement.

Los síndromes neurológicos bacterianos constituyen un problema de salud mundial, y es la vigilancia un pilar importante para su prevención y control. Se evaluó el subsistema de vigilancia de la meningoencefalitis bacteriana en dos hospitales de Ciudad de La Habana en el año 2006. Para esto se seleccionaron atributos cualitativos del sistema, como la simplicidad, la aceptabilidad y la flexibilidad; y los cuantitativos, como la sensibilidad, el valor predictivo positivo y la oportunidad. Se crearon mediante consulta de expertos criterios, indicadores y estándares. Se emplearon técnicas cualitativas y cuantitativas de obtención de información, tales como la revisión documental, la entrevista y la encuesta. Los principales resultados fueron una buena aceptabilidad, flexibilidad y simplicidad; pero no correspondieron en igual medida a los atributos cuantitativos, que fueron poco capaces de detectar los casos verdaderamente enfermos, ni la alarmante dificultad en la oportunidad para el sistema de información directa (SID) y el sistema de enfermedades de declaración obligatoria (EDO), los que fueron evaluados de inadecuados, ya que se identificaron cifras por debajo del estándar establecido. Finalmente, se consideró que al momento del estudio existían deficiencias en algunos de los atributos evaluados, por lo que deben tenerse en cuenta para su solución y perfeccionamiento.