This seems dubious to me. I can't imagine it would aerosolize, and even droplets would need to be close to a human to infect them.
Is there a citation for this?
The study only looked at houseflies and as long as you're two meters away from the zapper, the danger is very low. You probably don't want the zapper on your patio but if it's in a part of the yard where people aren't close by, it's probably ok.
They have so many hyperlinks in the article that I don't want to check if any go to other studies. Certainly a lot of the links are to statements by professors and organizations rather than papers. But this passage seemed at least noteworthy:
"""We found similar statements from the Harvard Medical School (“Don’t buy a bug zapper”), Iowa State University (“Bug Zappers are Harmful, not Helpful”), the Texas Tech University Infant Risk Center (“Don’t use bug zappers”), and the US Department of Agriculture (PDF) """
[0] https://www.nytimes.com/wirecutter/blog/do-bug-zappers-work/
[1] https://link.springer.com/article/10.1007/s002840010132
[2] https://archive.org/stream/cbarchive_110397_densityanddivers...
[0] https://archive.org/stream/cbarchive_110397_densityanddivers...