I only heard the medical background of the second case, diagnosed a week ago. That patient contracted a different strain of COVID-19 than his first occurrence (there are something like 30 different strains, each with different symptoms)

I did not hear the background of the first diagnosed patient.

A couple months ago there was a report of a positive COVID test in a patient who had also tested positive months earlier for the presence of the COVID antibodies. Considering the possibility of a false positive for antibodies, medical sources were hesitant to consider that a second contraction of the disease.