It wasn't clear from the article if there were only 10 cases during this time, or if they only looked at 10 cases, but there were more during this period. Kind of an important detail!
Yeah, I think this was just a sample. There’s no mention of naegleria fowleri[0], which will definitely kill you even if you’re healthy. Wikipedia cites nasal irrigation as the source for about 9% of infections. Still not super high risk, but still a risk that I’ll happily avoid.
[0]https://en.m.wikipedia.org/wiki/Naegleria_fowleri