Hi, and thank you for your question.
Hand jobs are generally regarded as low risk for getting an STI. Infections such as HIV, chlamydia, and gonorrhea are not passed this way. Infections that are spread through skin to skin contact such as HPV, herpes, and syphilis are not commonly passed through hand jobs and would be possible only if the person touched an infected area on themselves before they touched you.
From what you have described about the encounter, the chances of getting any infection would be very low. If you have any symptoms or other concerns I would recommend visiting your healthcare provider. And of course we always recommend regular STI testing for sexually active individuals
For more information about how STIs are spread, visit: (hyperlink know your chances)
Let us know if this does not answer your question or if you have any more questions or concerns.
Health Nurse