Likelihood of severe stomach issues coming from swimming in SF bay?

I recently came down with the most intense vomiting I have ever experienced, then coming out of both ends, then loss of temperature regulation followed by nearly a week of nausea.

This came the next day after I was swimming in SF Bay. Initially I thought it was food poisoning due to a rapid development of the symptoms, but now I'm wondering if the sewage dumped in the Bay could be the cause.

About 5 days after I got it, my girlfriend got it as well. Would not wish this on anyone