This is a complicated question. There are confirmed cases presented by doctors where someone tested positive in March, had weak or no symptoms, they went away, and now they’ve tested positive again in July with far stronger symptoms. There are several possibilities:
1. The first test was a false positive, their early symptoms were some other illness, and they only just now got it.
2. The virus somehow went dormant in the people for a few months then flared back up. There are viruses that can do that.
3. The person had it, and because of the weak symptoms they did not develop a strong immune response, allowing them to be reinfected soon after.
Any of those could fit Soto, and it is also possible that the most recent test was just dead/remnant virus in his system from an earlier infection. Right now it is unknown whether the virus can really do any of those things above, and it will be a while to know if any of those are possible.