The great concern stemming from the current COVID-19 pandemic has been a challenge for governments and international organizations around the world. Likewise, the diagnosis has played an important role in the prioritization processes, in particular, for the identification and follow-up of cases. In this context, PCR and serological tests have become the international standard; however, some limitations, as well as the scope of these techniques, must be understood in terms of population numbers. This comment seeks to clarify the interpretation of the results of these tests from a public health perspective.