Mr. Director:

SARS-CoV-2 severe acute respiratory syndrome began in Wuhan, China, in late 2019 and has spread rapidly around the world. Due to this, the global scientific community has expressed itself in favor of the implementation of preventive measures in view of the risk of contagion of the population ¹.

Over the past few decades, the potential of primary health care (PHC) in improving the health of individuals and the community has been recognized internationally. In Cuba, PHC is in constant progress, aiming at more effective care through the medical offices present in each community.

Research as a useful way to detect diseases is not a new measure in Cuba; it is part of the routine activities of undergraduate students in the medical sciences and many of their professionals. Cuba incorporates the application of the active research method in a permanent and systematic way for the identification and timely solution of the population's health problems, as a State responsibility ².

The Cuban authorities define active research, also called screening, as the "systematic and periodic clinical examination of the population" to detect diseases early ². Although this strategy has been applied for years to certain risk groups, it has been the coronavirus pandemic that has triggered its generalization.

The Commander in Chief Fidel Castro Ruz, in his speech for the celebration of July 26th in the province of Granma in 2006, where he refers to the active investigation and defines it as: "The true diagnosis of the state of health of a population and the greatest advance that can be conceived to raise the life perspectives of the human being at present" ³.

The ultimate goal of a survey program is to decrease the disease-specific mortality subject to screening by identifying the greatest number of individuals who can be offered the possibility of timely and effective treatment to improve the quality of life of each patient during the disease stage ¹.

Guilarte-Rojas et al. ³, highlighted the role in this contest of the young students; remembering that the future is full of tasks, of struggles that require conscience, courage, revolutionary spirit and knowledge. Fulfilling this precept, every morning, homes all over the country, whether in the western province of Pinar del Río, Havana, or Santiago de Cuba and no matter how intricate their location; receive the visit of the young students of the medical sciences.

Every morning, students collect data regarding the presence of symptoms, carry out health promotion actions, by explaining the measures and adjustments in daily behavior. In addition, they identify the care needs of the elderly and the disabled. All these actions are carried out from an ethical and disinterested point of view and in compliance with protection standards.

Another of the tools designed to make this prevention effective is the applications launched for self-selection. Up to 29 April 2020, the application was used by more than 11,000 people, 65 of whom said they had had contact with infected people and 1,801 declared they had some symptom.

Thanks to active and continuous research and the application of other measures such as the mandatory use of masks, social distancing and hand washing, Cuba shows positive results in containing the coronavirus. The epidemiological situation does not admit any doubt in the way of acting of students and health professionals, so they must act accordingly and this means fulfilling their duty: active investigation. It is therefore necessary to carry it out with the responsibility and dedication that the moment demands.